ResearchPad - inflammation https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Betanin purification from red beetroots and evaluation of its anti-oxidant and anti-inflammatory activity on LPS-activated microglial cells]]> https://www.researchpad.co/article/elastic_article_13861 Microglial activation can release free radicals and various pro-inflammatory cytokines, which implicates the progress of a neurodegenerative disease. Therefore suppression of microglial activation can be an appropriate strategy for combating neurodegenerative diseases. Betanin is a red food dye that acts as free radical scavenger and can be a promising candidate for this purpose. In this study, purification of betanin from red beetroots was carried out by normal phase colum chromatography, yielding 500 mg of betanin from 100 g of red beetroot. The purified betanin was evaluated by TLC, UV-visible, HPLC, ESI-MASS, FT-IR spectroscopy. Investigation on the inhibitory effect of betanin on activated microglia was performed using primary microglial culture. The results showed that betanin significantly inhibited lipopolysaccharide induced microglial function including the production of nitric oxide free radicals, reactive oxygen species, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1 beta (IL-1β). Moreover, betanin modulated mitochondrial membrane potential, lysosomal membrane permeabilization and adenosine triphosphate. We further investigated the interaction of betanin with TNF-α, IL-6 and Nitric oxide synthase (iNOS or NOS2) using in silico molecular docking analysis. The docking results demonstrated that betanin have significant negative binding energy against active sites of TNF-α, IL-6 and iNOS.

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<![CDATA[Linker histone H1.2 and H1.4 affect the neutrophil lineage determination]]> https://www.researchpad.co/article/elastic_article_12760 Neutrophils are important innate immune cells that tackle invading pathogens with different effector mechanisms. They acquire this antimicrobial potential during their maturation in the bone marrow, where they differentiate from hematopoietic stem cells in a process called granulopoiesis. Mature neutrophils are terminally differentiated and short-lived with a high turnover rate. Here, we show a critical role for linker histone H1 on the differentiation and function of neutrophils using a genome-wide CRISPR/Cas9 screen in the human cell line PLB-985. We systematically disrupted expression of somatic H1 subtypes to show that individual H1 subtypes affect PLB-985 maturation in opposite ways. Loss of H1.2 and H1.4 induced an eosinophil-like transcriptional program, thereby negatively regulating the differentiation into the neutrophil lineage. Importantly, H1 subtypes also affect neutrophil differentiation and the eosinophil-directed bias of murine bone marrow stem cells, demonstrating an unexpected subtype-specific role for H1 in granulopoiesis.

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<![CDATA[SKAP2 is required for defense against <i>K. pneumoniae</i> infection and neutrophil respiratory burst]]> https://www.researchpad.co/article/elastic_article_12711 Klebsiella pneumoniae is a type of bacteria that can cause life-threatening infections – including pneumonia, blood stream infections, and urinary tract infections – in hospitalized patients. These infections can be difficult to treat because some K. pneumoniae are resistant to antibiotics. The bacteria are normally found in the human intestine, and they do not usually cause infections in healthy people. This implies that healthy people’s immune systems are better able to fend off K. pneumoniae infections; learning how could help scientists develop new ways to treat or prevent infections in hospitalized patients.

In healthy people, a type of immune cell called neutrophils are the first line of defense against bacterial infections. Several different proteins are needed to activate neutrophils, including a protein called SKAP2. But the role of this protein in fighting K. pneumoniae infections is not clear.

To find out what role SKAP2 plays in the defense against pneumonia caused by K. pneumoniae, Nguyen et al. compared infections in mice with and without the protein. Mice lacking SKAP2 in their white blood cells had more bacteria in their lungs than normal mice. The experiments showed that neutrophils from mice with SKAP2 produce a burst of chemicals called “reactive oxygen species”, which can kill bacteria. But neutrophils without the protein do not. Without SKAP2, several proteins that help produce reactive oxygen species do not work.

Understanding the role of SKAP2 in fighting infections may help scientists better understand the immune system. This could help clinicians to treat conditions that cause it to be hyperactive or ineffective. More studies are needed to determine if SKAP2 works the same way in human neutrophils and if it works against all types of K. pneumoniae. If it does, then scientists might be able use this information to develop therapies that help the immune system fight infections.

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<![CDATA[Commentary on: The potency of lncRNA MALAT1/miR-155 in altering asthmatic Th1/Th2 balance by modulation of CTLA4]]> https://www.researchpad.co/article/elastic_article_9234 Asthma is a common, allergic respiratory disorder affecting over 350 million people worldwide. One of the key features of asthma is skewing of CD4+ cells toward Th2 responses. This promotes the production of cytokines like IL-4 that induce IgE production resulting in the hypersecretion of mucus and airway smooth muscle contraction. Understanding the factors that favor Th2 expansion in asthma would provide important insights into the underlying pathogenesis of this disorder. Asthma research has focused on signaling pathways that control the transcription of key asthma-related genes. However, increasing evidence shows that post-transcriptional factors also determine CD4+ cell fate and the enhancement of allergic airway responses. A recent paper published by Liang et al. (Bioscience Reports (2020) 40, https://doi.org/10.1042/BSR20190397) highlights a novel role for the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in Th2 development in asthma. MALAT1 modulates several biological processes including alternative splicing, epigenetic modification and gene expression. It is one of the most highly expressed lncRNAs in normal tissues and MALAT1 levels correlate with poor clinical outcomes in cancer. The mechanisms of action of MALAT1 in tumor progression and metastasis remain unclear and even less is known about its effects in inflammatory disease states like asthma. The work of Liang et al. demonstrates heightened MALAT1 expression in asthma and further shows that this lncRNA targets miR-155 to promote Th2 differentiation in this disease. This insight sets the stage for future studies to examine how MALAT1 manipulation could deter allergic immune responses in asthmatic airways.

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<![CDATA[Silencing of LncRNA PVT1 inhibits the proliferation, migration and fibrosis of high glucose-induced mouse mesangial cells via targeting microRNA-93-5p]]> https://www.researchpad.co/article/elastic_article_9222 Objective: The present study aimed to investigate the regulatory role of long non-coding RNA plasmacytoma variant translocation 1 (PVT1) on high glucose (HG)-induced mouse mesangial cells (MMCs).

Methods: PVT1 expression in diabetic nephropathy (DN) mice and HG-induced MMCs was detected by qRT-PCR. EdU and Colony formation, Annexin V-PI staining, Muse cell cycle, Scratch, and Transwell assays were performed to detect the cell proliferation, apoptosis, cell cycle, migration, and invasion, respectively. The contents of fibrosis factors in cell-culture supernatants were detected by enzyme-linked immunosorbent assay (ELISA). Western blot was performed to detect the expression of factors involved in apoptosis, cell cycle, migration and invasion, fibrosis, and PI3K/Akt/mTOR pathway. The targeting relation between miR-93-5p and PVT1 was predicted by StarBase3.0 (an online software for analyzing the targeting relationship) and identified by Dual-luciferase reporter (DLR) assay.

Results: PVT1 was overexpressed in DN kidney tissues and HG-induced MMCs. HG-induced MMCs exhibited significantly increased EdU-positive cells, cell colonies, S and G2/M phase cells, migration and invasion ability, and contents of fibrosis factors, as well as significantly decreased apoptosis rate compared with NG-induced MMCs. HG significantly up-regulated Bcl-2, CyclinD1, CDK4, N-cadherin, vimentin, Col. IV, FN, TGF-β1 and PAI-1, and down-regulated Bax, cleaved caspase-3, cleaved PARP, and E-cadherin in MMCs. Silencing of PVT1 eliminated the effects of HG in MMCs and blocked PI3K/Akt/mTOR pathway. MiR-93-5p was a target of PVT1, which eliminated the effects of PVT1 on HG-induced MMCs.

Conclusions: PVT1 silencing inhibited the proliferation, migration, invasion and fibrosis, promoted the apoptosis, and blocked PI3K/Akt/mTOR pathway in HG-induced MMCs via up-regulating miR-93-5p.

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<![CDATA[SAT-567 Hypertriglyceridem...From Mild to Fatal!... Is Time for Awareness]]> https://www.researchpad.co/article/elastic_article_8800 Hypertriglyceridemia… From mild to fatal! … Is Time for Awareness.

Hypertriglyceridemia can be primary or acquired. High triglycerides are related to complications such as pancreatitis and there is a positive correlation between hypertriglyceridemia and atherosclerotic burden. In this case series we aim to discuss pancreatitis as a hypertriglyceridemia complication and to acknowledge the importance of prevention and management. Is there something we can do to raise awareness and avoid complications as in the cases?

All cases present with chief complaint of epigastric cramp-like abdominal pain, radiating to the back, nausea/vomiting and with highly lipemic blood samples.

38y/o F admitted after been found with lipase 268 U/L (n<60 U/L), amylase 131 U/L (n<100 U/L) and findings of pancreatitis on CT scan. Patient with one-year history of T2DM refers this is the 4th episode of pancreatitis and reports that last time she was told about having triglycerides in 4,000 mg/dL for which she went to her physician that prescribe her Fenofibrate. Patient triglycerides were 7,931 mg/dL (n<199 mg/dL) and found with poorly controlled diabetes with HgbA1c 8.4%. She was properly managed, and triglycerides decrease to 1,309 mg/dL.

31y/o F with elevated lipase (237 U/L, n<60 U/L) and findings of pancreatitis on CT scan was admitted and found with 7,755 mg/dL triglycerides. She refers to have endometriosis for which she uses OCPs for >5years. She develops intractable abdominal pain along with abdominal distension and progress to Acute Respiratory Distress Syndrome (ARDS) requiring mechanical ventilation. She had a prolonged ICU stay and after management triglycerides decrease to 95mg/dL, symptoms resolve, and patient was discharge.

48y/o F with pancreatitis, lipase levels 1,452 U/L, amylase 744 U/L and positive imaging findings. Patient with uncontrolled diabetes (HgbA1c 11.0%) and breast mass s/p lumpectomy for which she used tamoxifen for the last 2 years. Triglycerides 7,444mg/dL on Gemfibrozil started due to previous levels found >4,000 mg/dL on outpatient evaluation. She deteriorates clinically and develops renal failure, abdominal compartment syndrome, respiratory distress and hypotension requiring mechanical ventilation and vasopressors. On repeated abdominal CT pancreas changes were suggestive of fulminant pancreatitis. Patient did not respond to treatment and passed away 48 hours after admission.

Hypertriglyceridemia complications can be mild or fatal as in these cases. They were evaluated by a primary care physician before complications occur and had secondary causes that predispose them to hypertriglyceridemia, but they were not addressed, reason for which these scenarios raise concern of how much we know? How much we are doing to prevent these outcomes?... Awareness of hypertriglyceridemia management and adverse effects is necessary to avoid complications and fatal outcomes. Is time!

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<![CDATA[SAT-LB92 Sex Hormones Therapy Differentially Modulates HDL Function in Transgender Individuals]]> https://www.researchpad.co/article/elastic_article_8791 Background/aim: The main proposed atheroprotective function of high-density lipoproteins (HDL) lays on their role to promote macrophage cholesterol efflux. An insightful way to learn more about the effects of sex hormones on HDL function is to study changes during hormone therapy. The present study was aimed at evaluating the effects of exogenous sex hormones administration on HDL cholesterol efflux capacity (CEC) within transgender individuals. CEC estimates the ability of HDL to remove cholesterol from cells, i.e. the initial step in reverse cholesterol transport.

Subjects/Methods: Transmen were treated with testosterone gel, a mix of testosterone esters once every three weeks) or testosterone undecanoate once every twelve weeks, whereas transwomen were treated with either oral estradiol valerate or a transdermal application of estradiol (patches). Cyproterone acetate was prescribed as a testosterone-blocking agent to all transwomen. HDL function was evaluated by a radioisotopic technique. Hormone levels, lipids and HDL function were evaluated after one year of follow-up.

Results: In transmen (n= 15), testosterone markedly increased (+ 97%; p < 0.0001), whereas luteinizing hormone (LH) decreased significantly (- 64%; p = 0.049). Total cholesterol and low-density lipoprotein cholesterol (LDL-C) were not affected by testosterone treatment, whilst triglycerides (TG) were raised (+ 11.76%; p = 0.0078) and HDL-C reduced (- 19.6%, p=0.0103). Concerning HDL CEC, only the aqueous diffusion process was lowered (- 9.8%; p = 0.0032), an effect directly correlated with HDL-C changes (r = 0.6242, p = 0.0002). Total-, ATP-binding cassette transporter (ABCA1)-, and ABCG1-mediated CEC were not affected by testosterone treatment. In transwomen (n= 15), estradiol levels were raised (+200%, p=0.013) whereas LH and testosterone significantly reduced, i.e. - 97% for both. Relative to lipids, estradiol supplementation reduced total cholesterol (- 10.7%, p=0.0017), HDL-C (- 14.3%, p = 0.0024) and LDL-C (- 10.9%, p = 0.0058). Total HDL CEC decreased (- 11%, p=0.0001) with a specific decrement in CEC mediated by the ATP-binding cassette transporter (ABCA1) (-24%, p = 0.0003) and aqueous diffusion (-4.7%, p = 0.0014). This last was associated to a reduction in HDL-C (r = 0.4084, p = 0.0251). Conversely, the drop in ABCA1 and total CEC did not associate to reductions in HDL-C levels.

Conclusions: In transmen, testosterone supplementation was associated with a reduction in aqueous diffusion-mediated CEC, an effect potentially dependent to HDL-C changes. In transwomen, estrogen significantly decreased HDL function (CEC), independent of HDL-C levels changes.

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<![CDATA[SAT-573 Eruptive Xanthomas in a Patient with Hypertriglyceredemia and Type 2 Diabetes Mellitus]]> https://www.researchpad.co/article/elastic_article_8647 BACKGROUND: Eruptive xanthomas are rare, asymptomatic, cutaneous lesions and are markers for serious underlying metabolic disorders that demand an early diagnosis to prevent morbidity and mortality.

Clinical Case: A 27 years old obese female presented with generalized, pruritic eruptions. The eruptions had been present for approximately three weeks. Crops of firm yellow-red circumscribed Papules (diameter 1–3 mm) distributed on the extensor surfaces of both the upper and the lower extremities which were few in numbers to begin with but increased in density subsequently spreading to involve her back, abdomen, knees, and posterior thighs. The patient besides being obese had no other significant past medical or family history. Labs: FBS:258 mg/dl (80-100mg/dl), HbA1c:11.7%(<5.6%), Total lipids: 3680 mg/dl (400–1000 mg/dl), Total Cholesterol: 857 mg/dl (120–200 mg/dl), Triglycerides: 5428 mg/dl (70–150 mg/dl), HDL:15mg/dl (45–64 mg/dl), LDL: 371 mg/l(<130 mg/dl),VLDL: 402 mg/dl (<30 md/dl). Results of kidney, liver and thyroid function tests were normal, as well as amylase and lipase. X-ray chest and abdominal ultrasound were unremarkable. Biopsy of the papules was not carried out due to non-affordability on the part of the patient. The patient was managed by an interdisciplinary approach for diabetes mellitus type 2 and hyperlipidaemia. Treatment was started with oral hypoglycaemic along with lipid lowering agents and the required lifestyle modifications including weight control, adopting a low-fat diet, and regular exercise were advised. The papules resolved within six weeks of the treatment and lab reports indicated improvement in her glycemic control and hypertriglyceridemia. It was clinically diagnosed as Eruptive Xanthomas of secondary hypertriglyceridemia due to diabetes mellitus.

CONCLUSION:

Recognizing eruptive xanthomas and being aware of its association with hypertriglyceridemia and diabetes mellitus can help to decrease any lag between a patient being seen by a physician and treatment for a serious medical conditions such as coronary artery disease and pancreatitis.

REFRENCES: Digby M; Belli R; McGraw T; Lee A (2011). “Eruptive xanthomas as a cutaneous manifestation of hypertriglyceridemia: a case report”. J Clin Aesthet Dermatol. 4: 44–6. PMC 3030216Freely accessible. PMID 21278899.

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<![CDATA[SAT-577 Severe Asymptomatic Hypertriglyceridemia]]> https://www.researchpad.co/article/elastic_article_8609 Background

Case reports of patients with severely elevated serum triglyceride levels (>1000 mg/dL) have been documented where Insulin infusions, heparin and plasmapheresis have demonstrated rapid and successful decrease in serum Triglyceride levels. The benefits of one approach versus the other to prevent major complications such as cardiovascular events or acute pancreatitis has not been well investigated. We present the case of a patient with severely elevated serum triglyceride levels without any manifestations.

Case Description

A 53-year-old male presented from his primary care provider’s office due to elevated Triglycerides levels over 6000 as per outpatient lab work. Inpatient labs were unattainable initially due to hemolysis secondary to the severely high lipid content. Patient was admitted to the medical ICU for closer monitoring and initiated on an insulin drip. Two days after insulin initiation patient’s triglyceride levels returned as 2,887 with a total cholesterol count of 848. His insulin drip was continued until his TAG levels were less than 1000. Upon discharge his levels were less than 600.

Discussion

Most patients with hypertriglyceridemia are asymptomatic. However, in patients with levels above 1000 mg/dL, the risk of pancreatitis or cardiovascular event is of concern. Hypertriglyceridemia may account for 1 to 14 percent of cases of acute pancreatitis. Treatment is largely based upon symptoms and complications. In the event of pancreatitis or other cardiovascular complication, plasmapheresis is usually recommended. If asymptomatic, Insulin may be used. Insulin promotes synthesis of lipoprotein lipase which functions to hydrolyze triglycerides, and has been shown to be an effective lowering agent in the treatment of such individuals. Case reports of Heparin being used as a lipid lowering agent have also been documented, but was not used in our particular patient.

Normal triglyceride plasma levels are defined as less than 150 mg/dL. Mild hypertriglyceridemia typically ranges between 150-499 mg/dL, moderate between 500-866 mg/dL, and severe is defined as levels greater than 886 mg/dL. Plasma triglyceride levels above 1000 mg/dL occur in fewer than 1 in 5000 individuals. It is said that patients with TAG levels above 2000 mg/dL almost always have both a secondary and a genetic form of Hypertriglyceridemia. For this reason it is very important to identify these patients as early as possible to treat appropriately. Our patient was a known alcohol abuser, yet without the presence of some polygenic familial disorder, the likelihood of our patient having TAG levels >6000 mg/dL, is very unlikely.

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<![CDATA[Ligand-dependent downregulation of MR1 cell surface expression]]> https://www.researchpad.co/article/elastic_article_8302 The antigen-presenting molecule MR1 presents riboflavin-based metabolites to Mucosal-Associated Invariant T (MAIT) cells. While MR1 egress to the cell surface is ligand-dependent, the ability of small-molecule ligands to impact on MR1 cellular trafficking remains unknown. Arising from an in silico screen of the MR1 ligand-binding pocket, we identify one ligand, 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoic acid, DB28, as well as an analog, methyl 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoate, NV18.1, that down-regulate MR1 from the cell surface and retain MR1 molecules in the endoplasmic reticulum (ER) in an immature form. DB28 and NV18.1 compete with the known MR1 ligands, 5-OP-RU and acetyl-6-FP, for MR1 binding and inhibit MR1-dependent MAIT cell activation. Crystal structures of the MAIT T cell receptor (TCR) complexed with MR1-DB28 and MR1-NV18.1, show that these two ligands reside within the A′-pocket of MR1. Neither ligand forms a Schiff base with MR1 molecules; both are nevertheless sequestered by a network of hydrophobic and polar contacts. Accordingly, we define a class of compounds that inhibits MR1 cellular trafficking.

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<![CDATA[SAT-578 A Rare Case of Laboratory Hypertriglyceridemia: Glycerol Kinase Deficiency]]> https://www.researchpad.co/article/elastic_article_7175 Background: Hypertriglyceridemia (HTG) is common; however, pseudo-HTG due to high glycerol in glycerol kinase deficiency (GKD, MIM: 307030) is a rare cause of HTG that need to be delineated for appropriate management. GKD is an X-linked recessive disorder characterized by hyperglycerolemia and glyceroluria. Two of three GKD subtypes are known as “isolate” GKD due to a mutation in GK gene alone: (1) symptomatic juvenile form, and (2) benign adult form, associated with an incidental finding of HTG.

Since most commercial laboratories determine triglyceride (TG) levels by a glycerol measurement, TG-backbone, patients with GKD are mistakenly labelled as having HTG. Glycerol-blanking is required to reveal the actual TG, but it is costly. Since usual TG-lowering medications are ineffective or even harmful, novel methods to screen for individuals with GKD or pseudo-HTG are necessary.

Objective: Through identification of a clinical case of GKD that was diagnosed by glycerol-blanking, we are proposing two potential methods to screen for pseudo-HTG, and presenting their reliability.

Methods: The patient was recruited into an IRB-approved study investigating etiologies of dyslipidemia at the University of Pennsylvania. Patient provided consent for medical record review.

Results: A 49-year-old man was referred for HTG management. His reported TG levels ranged between 490 and 559 mg/dL without any other adverse lipid levels for several years without a history of pancreatitis or diabetes mellitus. Intriguingly, he reported a family history of HTG.

Since TG-lowering medications (fibrates and fish oil) had not reduced his TG levels, specialized lipid analyses were obtained: a non-blanked TG level of 521 mg/dL and a glycerol-blanked TG of 66 mg/dL, consistent with pseudo-HTG or hyperglycerolemia. Repeat glycerol blanked TG levels were 68 and 69 mg/dL, confirming the previous result, and the likely diagnosis of GKD.

With two methods, estimated TG levels were calculated, using some of his laboratory values: (1) modified Friedewald equation to solve for TG with a direct LDL (dLDL) value, and (2) the application of a newly developed formula derived from a collection of 17,545 patient samples, to calculate the absolute TG-gap, using apolipoprotein A and B, estimating TG levels (% deltaTG), and determining whether a TG mesurement might be falsely deviated from the “plausible” TG value.

Although neither methods showed perfect concordance, the calculated TG-valued derived by the two methods were significantly lower than the non-glycerol blanked TG values. The difference was statistically significant (p<0.05).

Conclusion: The patient was clinically diagnosed with GKD, and was taken off of fibrate and the recently added niacin. These two methods can be used quickly to screen for pseudo-HTG or patients with GKD. Currently, it is unknown whether high glycerol levels are associated with high cardiovascular risks.

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<![CDATA[SAT-574 Whole Exome Sequencing Identifies Several Variants Associated with Immune Deficiency, Inflammasomopathy and Non-Ischemic Dilated Cardiomyopathy in a Complex Case of Acquired Generalized Lipodystrophy]]> https://www.researchpad.co/article/elastic_article_6931 Background: Acquired generalized lipodystrophy (AGL) is characterized by near-total fat loss that develops after birth. Although the molecular pathogenesis of AGL is unclear, there is a link to autoimmunity and inflammation. Notably, the panniculitis associated variety of AGL may present with subcutaneous inflammatory nodules that ultimately progress to generalized fat loss. Here, we report on a complex patient with AGL in whom whole-exome sequencing (WES) identified several pathogenic variants and variants of uncertain significance (VUS) that encourage us to think about AGL more broadly. Clinical Case: This is a 38-year-old male who was first diagnosed with juvenile rheumatoid arthritis at age 2, after being evaluated for delayed ability to ambulate. At that time, he was also diagnosed with Weber-Christian disease following a skin biopsy due to the suspicion of panniculitis. Over time, he progressively lost body fat throughout the body and developed hypertriglyceridemia, hypertension, and nephropathy leading to the diagnosis of AGL. At age 10, he was diagnosed with type 1 diabetes mellitus, and at age 14, with autoimmune hepatitis. Due to the tightening of his hands, calf pain, and increased CPK levels, a muscle biopsy was performed, suggesting polymyositis. He had been treated with azathioprine and steroids, which were discontinued at age 26, after a liver biopsy that showed grade 2 fibrosis. Further, he was diagnosed with non-ischemic dilated cardiomyopathy (DCM), evolving with atrial fibrillation with a rapid ventricular response and complicated with left atrial appendage thrombus. Of interest, his mother and two maternal aunts had been diagnosed with atrial fibrillation. One of his maternal uncles presented non-ischemic cardiomyopathy and an early sudden cardiac arrest. His mother also had mitochondrial myopathy, and his father had type 2 diabetes mellitus and IgG deficiency. WES identified three different variants: a maternally inherited pathogenic variant in TTN (c.88473_88477delAGCTT; p.W29493X) associated with DCM, a paternally inherited pathogenic variant in TNFRSF13B (c.310T>C; p.C104R) associated with CVID/IgA deficiency, and a maternally inherited variant of uncertain clinical significance in NLRP3 (c.1469G>A; p.R490K). Although the frequency of this variant was relatively high, several variants in the NLRP3 gene have been previously associated with inflammasomopathy. Conclusion: This case highlights challenging presentations of AGL and the complexity of the disease. As we are yet beginning to understand the molecular mechanisms behind the so-called “acquired fat loss” and its relation to inflammatory and complex immune system diseases, further efforts are critical to better recognize different AGL phenotypes and phenotype-genotype correlations. Additional efforts should be placed on WES for AGL patients and functional validation of identified VUSs.

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<![CDATA[SUN-542 The Effect of Energy Deprivation on Metabolic Hormone Responses to Meals]]> https://www.researchpad.co/article/elastic_article_6797 Background: Intermittent caloric restriction (ICR) has recently gained popularity as a weight-loss strategy; however, fasting metabolic hormones and dynamic meal-related responses, are not well-established in this setting. Methods: We measured metabolic hormone responses to 5-days of neutral or decreased energy availability (NEA, 45 kcal/kg LBM*d vs DEA, 20 kcal/kg LBM*d) in the early follicular phase (EFP) in 19 regularly-cycling, sedentary, women (age 23.36± 2.08 yr; mean±SD). Hunger was assessed using a visual analogue scale on the 5th day of each condition. Scheduled breakfast and lunch were administered according to assigned caloric intake, while an afternoon snack based on NEA was provided on both occasions. Blood was sampled for leptin, insulin, glucose, and GH at 10-min intervals and cortisol was measured at 30-min intervals over eight hours starting at 0800 h, while Orexin A and adiponectin were measured in fasting samples. AUC for each hormone for every meal and diet condition were analyzed using linear mixed models. Insulin and insulin/glucose ratio (I/G) were also adjusted for meal calories. Percentage body fat mass was measured every visit using air displacement plethysmography (BodPod®). Results are presented as least square mean ± sem. Results: There were no differences in body mass index or % fat mass after NEA vs DEA although there was a significant increase in hunger with DEA (p=0.002). Fasting levels of glucose and insulin were unchanged while leptin decreased with DEA (1.27±0.07 and 1.04±0.07 ng/mL, NEA and DEA respectively; p<0.0001), and Orexin A increased (0.55±0.04 and 0.60±0.04 ng/mL; p=0.04). The AUC for glucose was lower with DEA across all meals (p<0.0001). Insulin, I/G and I/G normalized for ingested calories (nI/G) decreased in response to DEA (p<0.005, p<0.05 and p<0.0001). The slope of the increase in leptin across the day was not different between NEA and DEA (p=0.20). Adiponectin, GH and cortisol were unaffected by DEA. Conclusion: These studies indicate that although fasting glucose and insulin are unaffected by short-term caloric restriction, the insulin response to glucose is attenuated even when adjusting for meal-related calories. Orexin A increased and leptin decreased with reduced caloric intake, acting, at least in part, to stimulate appetite. Taken together, these hormonal responses, directed at preserving energy homeostasis, have important implications for understanding the potential efficacy of intermittent caloric restriction.

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<![CDATA[SUN-543 Real World Evidence of Successful Weight Management for the Obese Population: Complete Reversal of Obesity Related Metabolic Co-Morbidities and Weight Loss in Patients Attending a Multidisciplinary Weight Management Clinic in Australia]]> https://www.researchpad.co/article/elastic_article_6724 Over 2.5 billion people worldwide are overweight or obese. Multidisciplinary weight management interventions have evolved to address the complexity of weight loss for those with one or more chronic diseases, and the trend of weight regain. The aim of these interventions is to encourage sustainable lifestyle changes, resulting in weight loss and weight maintenance and improvements in comorbidities. While some prospective clinical trials have demonstrated efficacy, results are often not reported by real life practices.

The aim of this study was to evaluate the effectiveness of a Sydney based multidisciplinary weight management clinic with endocrinology, dietetics, exercise physiology, psychology, and bariatric surgical domains. All patients who attended the clinic for weight loss purposes between March 2017 and April 2019 were included (n=220). A retrospective chart review was conducted. Patient data on weight, BMI, waist circumference, body composition measurements, and selected blood test results and co-morbidities were analysed. All patient therapy included endocrinological input for co-morbidity identification and management, lifestyle intervention (dietetic and exercise physiology input) with optional adjunct pharmacotherapy or psychological counselling. Of the 220 cohort, 20 of the patients had sleeve gastrectomy.

Patient retention in the clinic after the first consultation was 85% (n=186), a high rate within the weight management community. 59% of patients achieved a minimum of 5% total body weight loss, including 18% who achieved greater than 10% total body weight loss. Additionally, 31% of patients lost enough weight to decrease their BMI class by up to 2 or more classes. Of the gastric sleeve cohort average excess body weight loss was 32kg (21-56kg) enhanced by multidisciplinary care in the lead up to surgery. Across the cohort some patients completely reversed co-morbidities; including dyslipidaemia (n=1), hypertension (n=3), NAFLD (n=1), pre-diabetes (n=8) and type 2 diabetes (n=3), OSA (n=1). These results demonstrate that obesity is a chronic condition that can be successfully managed. We have demonstrated significant durable weight loss and improvement in metabolic co-morbidities with holistic coordinated care. Future directions include translating this model of care into standard practice in Australia and other countries where obesity to date not received the same coordinated approach as other chronic conditions.

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<![CDATA[A delayed fractionated dose RTS,S AS01 vaccine regimen mediates protection via improved T follicular helper and B cell responses]]> https://www.researchpad.co/article/elastic_article_6355 Malaria-071, a controlled human malaria infection trial, demonstrated that administration of three doses of RTS,S/AS01 malaria vaccine given at one-month intervals was inferior to a delayed fractional dose (DFD) schedule (62.5% vs 86.7% protection, respectively). To investigate the underlying immunologic mechanism, we analyzed the B and T peripheral follicular helper cell (pTfh) responses. Here, we show that protection in both study arms was associated with early induction of functional IL-21-secreting circumsporozoite (CSP)-specific pTfh cells, together with induction of CSP-specific memory B cell responses after the second dose that persisted after the third dose. Data integration of key immunologic measures identified a subset of non-protected individuals in the standard (STD) vaccine arm who lost prior protective B cell responses after receiving the third vaccine dose. We conclude that the DFD regimen favors persistence of functional B cells after the third dose.

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<![CDATA[Kallikrein-kinin blockade in patients with COVID-19 to prevent acute respiratory distress syndrome]]> https://www.researchpad.co/article/elastic_article_6336 The COVID-19 pandemic represents an unprecedented threat to global health. Millions of cases have been confirmed around the world, and hundreds of thousands of people have lost their lives. Common symptoms include a fever and persistent cough and COVID-19 patients also often experience an excess of fluid in the lungs, which makes it difficult to breathe. In some cases, this develops into a life-threatening condition whereby the lungs cannot provide the body's vital organs with enough oxygen.

The SARS-CoV-2 virus, which causes COVID-19, enters the lining of the lungs via an enzyme called the ACE2 receptor, which is present on the outer surface of the lungs’ cells. The related coronavirus that was responsible for the SARS outbreak in the early 2000s also needs the ACE2 receptor to enter the cells of the lungs. In SARS, the levels of ACE2 in the lung decline during the infection.

Studies with mice have previously revealed that a shortage of ACE2 leads to increased levels of a hormone called angiotensin II, which regulates blood pressure. As a result, much attention has turned to the potential link between this hormone system in relation to COVID-19. However, other mouse studies have shown that ACE2 protects against a build-up of fluid in the lungs caused by a different molecule made by the body. This molecule, which is actually a small fragment of a protein, lowers blood pressure and causes fluid to leak out of blood vessels. It belongs to a family of molecules known as kinins, and ACE2 is known to inactivate certain kinins.

This led van de Veerdonk et al. to propose that the excess of fluid in the lungs seen in COVID-19 patients may be because kinins are not being neutralized due to the shortage of the ACE2 receptor. This had not been hypothesized before, even though the mechanism could be the same in SARS which has been researched for the past 17 years. If this hypothesis is correct, it would mean that directly inhibiting the receptor for the kinins (or the proteins that they come from) may be the only way to stop fluid leaking into the lungs of COVID-19 patients in the early stage of disease.

This hypothesis is unproven, and more work is needed to see if it is clinically relevant. If that work provides a proof of concept, it means that existing treatments and registered drugs could potentially help patients with COVID-19, by preventing the need for mechanical ventilation and saving many lives.

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<![CDATA[SAT-565 Familial Homozygous Lipoprotein Lipase Defect Presenting with Recurrent Chylomicronemia Syndrome: Making a Case for Elective Plasmapheresis as an Adjuvant Treatment Modality]]> https://www.researchpad.co/article/elastic_article_6019 Background

The chylomicronemia syndrome is a disorder characterized by severe hypertriglyceridemia and fasting chylomicronemia. Type Ia hyperlipoproteinemia is an extremely rare genetic disorder that results from homozygous deficiency in LPL activity. It is characterized by eruptive xanthomas, lipemia retinalis, memory disturbances, hepatosplenomegaly and frequent episodes of pancreatitis. Pharmacologic agents including fibrates, fish oils and statins have been used for treatment. Patients who fail pharmacologic therapy are usually treated with plasmapheresis. This case showed a patient in which joint decision making led to elective plasmapheresis to avoid chylomicronemia syndrome as an adjunct to medical therapy.

Clinical case

A 35-year-old lady without known medical co-morbidity presented with 2 weeks of dull abdominal pain radiating to the back. She developed nausea and vomiting which led to her presentation. There was no history of alcohol use, gall stones, diabetes mellitus or thyroid dysfunction. She was not on any medications. Physical examination was significant for BMI of 18, moderate abdominal tenderness, splenomegaly and an indurated rash in her legs. Laboratory investigation showed elevated lipase and triglyceride level of 3313 (normal 30-50) mg/dL. CT of the abdomen was consistent with acute interstitial pancreatitis. She was managed with insulin drip and fenofibrate and discharged 3 days later on fenofibrate, atorvastatin and long acting insulin. She developed another episode of acute pancreatitis while on medical therapy requiring readmission and initiation of insulin drip 2 months later. However, triglycerides trended upwards when the drip was stopped and symptoms of acute pancreatitis worsened. She subsequently underwent plasmapheresis which led to resolution of symptoms. Despite maximally tolerated pharmacologic therapy, she persistently has triglycerides above 4000s and persistent abdominal discomfort. Genetic testing confirmed homozygous defect in LPL gene. Following an outpatient Endocrinology visit, a decision was made to pursue elective plasmapheresis as an adjunct to therapy. She had on average 2 sessions monthly for 3 months with overall improvement in abdominal discomfort as well as significant improvement in triglyceride levels.

Conclusion

Familial chylomicronemia syndromes often require multimodal therapeutic approaches to prevent morbidity and complications. These include diet and pharmacologic therapy. Although plasmapheresis is often used during hospitalizations for hypertriglyceridemia induced pancreatitis refractory to diet and pharmacologic therapy, it was used in our patient electively and efficaciously to control hypertriglyceridemia and improve symptoms of chylomicronemia syndrome.

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<![CDATA[The tumor microenvironment as a metabolic barrier to effector T cells and immunotherapy]]> https://www.researchpad.co/article/N0a351c1f-39d5-481a-9e94-df671572819a Breakthroughs in anti-tumor immunity have led to unprecedented advances in immunotherapy, yet it is now clear that the tumor microenvironment (TME) restrains immunity. T cells must substantially increase nutrient uptake to mount a proper immune response and failure to obtain sufficient nutrients or engage the appropriate metabolic pathways can alter or prevent effector T cell differentiation and function. The TME, however, can be metabolically hostile due to insufficient vascular exchange and cancer cell metabolism that leads to hypoxia, depletion of nutrients, and accumulation of waste products. Further, inhibitory receptors present in the TME can inhibit T cell metabolism and alter T cell signaling both directly and through release of extracellular vesicles such as exosomes. This review will discuss the metabolic changes that drive T cells into different stages of their development and how the TME imposes barriers to the metabolism and activity of tumor infiltrating lymphocytes.

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<![CDATA[The antibiotic bedaquiline activates host macrophage innate immune resistance to bacterial infection]]> https://www.researchpad.co/article/Na65247c6-547f-43ed-8b5c-75d754c4f79a The discovery of antibiotic drugs, which treat diseases caused by bacteria, has been a hugely valuable advance in modern medicine. They work by targeting specific cellular processes in bacteria, ultimately stopping them from multiplying or killing them outright. Antibiotics sometimes also affect their human hosts and can cause side-effects, such as gut problems or skin reactions.

Recent evidence suggests that antibiotics also have an impact on the human immune system. This may happen either indirectly, by affecting ‘friendly’ bacteria normally present in the body, or through direct effects on immune cells. In turn, this could change the effectiveness of drug treatments. For example, if an antibiotic weakens immune cells, the body could have difficulty fighting off the existing infection – or become more vulnerable to new ones.

However, even though new drugs are being introduced to combat the worldwide rise of antibiotic-resistant bacteria, their effects on immunity are still not well understood. For example, bedaquiline is an antibiotic recently developed to treat tuberculosis infections that are resistant to several drugs. Giraud-Gatineau et al. wanted to determine if bedaquiline altered the human immune response to bacterial infection independently from its direct anti-microbial effects.

Macrophages engulf foreign particles like bacteria and break them down using enzymes stored within small internal compartments, or ‘lysosomes’. Initial experiments using human macrophages, grown both with and without bedaquiline, showed that the drug did not harm the cells and that they grew normally. A combination of microscope imaging and genetic analysis revealed that exposure to bedaquiline not only increased the number of lysosomes within macrophage cells, but also the activity of genes and proteins that increase lysosomes’ ability to break down foreign particles.

These results suggested that bedaquiline treatment might make macrophages better at fighting infection, even if the drug itself had no direct effect on bacterial cells. Further studies, where macrophages were first treated with bedaquiline and then exposed to different types of bacteria known to be resistant to the drug, confirmed this hypothesis: in every case, the treated macrophages became efficient bacterial killers. In contrast, older anti-tuberculosis drugs did not have any such potentiating effect on the macrophages.

This work sheds new light on our how antibiotic drugs can interact with the cells of the human immune system, and can sometimes even boost our innate defences. Such immune-boosting effects could one day be exploited to make more effective treatments against bacterial infections.

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<![CDATA[Yolk-sac-derived macrophages progressively expand in the mouse kidney with age]]> https://www.researchpad.co/article/Nc9607a8e-23e2-4158-a373-7089f452b98a Older people are more likely to develop kidney disease, which increases their risk of having other conditions such as a heart attack or stroke and, in some cases, can lead to their death. Older kidneys are less able to repair themselves after an injury, which may help explain why aging contributes to kidney disease. Another possibility is that older kidneys are more susceptible to excessive inflammation. Learning more about the processes that lead to kidney inflammation in older people might lead to better ways to prevent or treat their kidney disease.

Immune cells called macrophages help protect the body from injury and disease. They do this by triggering inflammation, which aides healing. Too much inflammation can be harmful though, making macrophages a prime suspect in age-related kidney harm. Studying these immune cells in the kidney and how they change over the lifespan could help scientists to better understand age-related kidney disease.

Now, Ide, Yahara et al. show that one type of macrophage is better at multiplying in older kidneys. In the experiments, mice were genetically engineered to make a fluorescent red protein in one kind of macrophage. This allowed Ide, Yahara et al. to track these immune cells as the mice aged. The experiments showed that this subgroup of cells is first produced when the mice are embryos. They stay in the mouse kidneys into adulthood, and are so prolific that, over time, they eventually become the most common macrophage in older kidneys.

The fact that one type of embryonically derived macrophage takes over with age may explain the increased inflammation and reduced repair capacity seen in aging kidneys. More studies will help scientists to understand how these particular cells contribute to age-related changes in susceptibility to kidney disease.

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