ResearchPad - progress-in-adrenal-cortex-and-medulla-research Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[OR03-04 The Study of Cell Senescence in Cortisol-Producing Adrenocortical Adenomas]]> Introduction Aging is associated with the pathogenesis of many endocrine disorders such as cardiovascular diseases and diabetes. Cell senescence has been reported as one of their mechanisms. In addition, stress responsiveness has been reported to be associated with cell senescence. In addition, some genetic abnormalities such as mitochondrial DNA (mtDNA) damages or telomere shortening, have been detected in some endocrine disorders. Cortisol is a well-known stress-induced hormone and closely associated with aging. We previously reported that cortisol-producing adenoma (CPA) more abundantly expressed cell senescent markers such as p16 and p21 than other hormone-producing adrenocortical adenomas. However, the detailed pathophysiology of cell senescence and its association with histological features in CPAs have remained virtually unknown. Therefore, we analyzed cell senescent markers (telomere length, mtDNA copy number, mtDNA deletion and p16 and p21 immunoreactivity) and analyzed their correlation with clinicopathological factors in CPA patients.

Methods & Materials Forty CPA cases was immunohistochemically evaluated. Twenty CPA, ten adjacent ZF and six non-functional adenoma (NFA) were examined for mtDNA abnormalities. mtDNA deletion was evaluated by nested-PCR and mtDNA copy number and telomere length were measured using real-time PCR.

Results p21 immunoreactivity was significantly higher in CPA than that of adjacent ZF (P=0.0001) and significantly inversely correlated with tumor size (P=0.0004). Telomere length was much longer in CPA than that in adjacent ZF(P=0.0038), and NFA (P=0.0018). mtDNA copy number of NFA was significantly higher than that of CPA and adjacent ZF (P=0.0038). mtDNA copy number of compact cells was significantly higher than that of clear cells (P=0.0432). mtDNA copy number of compact cells was positively correlated with urinary free cortisol (UFC) (P=0.0428) and plasma cortisol (F) (P=0.0609). mtDNA copy number of clear cells were inversely correlated with F (0.0497). 4977 bp mtDNA deletion was more frequently detected in CPA (54%) and in adjacent ZF (50%) than in NFA (17%).

Discussion Results of our present study did reveal that CPA harbored more senescent phenotype as demonstrated by abundant p16 and p21, marked telomere shortening, frequent mtDNA 4977bp deletion and relatively low mtDNA copy number, possibly caused by long-term exposure of excessive cortisol in situ compared to NFA. In addition, clear tumor cells could represent more senescent histological phenotype because of their lower mtDNA copy numbers. This is the first study to demonstrate that compact tumor cells were biologically more active than clear tumor cells and could reflect clinical cortisol biosynthesis, resulting in marked functional intratumoral heterogeneity in CPAs.

<![CDATA[OR03-03 New Insights into the Functional Human Adrenal Cortex Zonation]]>


The zonation of the human adrenal cortex has long been established morphologically and histologically as three distinct layers of cells. The outer zona glomerulosa (ZG) comprises densely packed cells arranged in clusters that produce aldosterone; the zona fasciculata (ZF) is composed of cells with large cytoplasm, containing lipid droplets arranged in radial columns that synthetize cortisol; and the zona reticularis is composed of compact and pigmented cells producing androgens. The main purpose of this work was to study the expression of aldosterone synthase (CYP11B2 which catalyzes the last steps of aldosterone synthesis) and 11β-hydroxylase (CYP11B1 which catalyzes the last step of cortisol synthesis) in normal adrenal glands to address issues regarding the zonation and the fate of the cells constitutive of each zone through the expression of Ki-67 and cleaved Caspase-3. Thirty eight normal human adrenals (16 females, 22 males, ranging in age from 22 to 81 years old with a median age of 52 years old) were obtained from brain-dead organ donors (kindly provided by the Organ Transplant Clinics, University Hospital of Rouen). As early as 22 years old, we found that the histological ZG (h-ZG) does not correspond to the functional ZG (f-ZG) expressing CYP11B2. Moreover, the h-ZG CYP11B2- cells were CYP11B1+ showing that these cells ascribed to the h-ZG are in fact cortisol producing cells. The progressive replacement of CYP11B2+ cells by CYP11B1+ cells in the h-ZG might demonstrate the role of the extracellular matrix in the morphological maintenance of the adrenal cortex. Our analysis also showed that steroidogenic cells were either CYP11B1 or CYP11B2 positive. By immunofluorescence, we observed in many cases isolated or clusters of CYP11B2+ cells located deeply in the h-ZF and sometimes in the vicinity of the central vein. We were able to show that those cells were probably issued from CYP11B2+ cell clusters located in h-ZG which migrated centripetally. Ki-67 immunoreactivity was highly variable and observed throughout the entire cortex. We also found a positive correlation between the steroidogenic and endothelial cells proliferation. It is interesting to note that some Ki-67+ cells located in the h-ZG were CYP11B1+. Cortical cells positive for cleaved Caspase-3 were extremely rare but detected in all zones when present. These findings challenge the classic view of lineage conversion of differentiated ZG cells and show a new pathway where the CYP11B2+ cells migrate without changing their phenotype.

<![CDATA[OR03-02 Identification of a Novel Stem/Progenitor Population of the Adrenal Medulla]]> <![CDATA[OR03-01 Effects Of Alpha-emitting Meta-211At-astato-benzylguanidine (211At-MABG) Compared To 131I-meta-iodobenzylguanidine (131I-MIBG) on Tumor Growth Suppression in a Pheochromocytoma Mouse Model]]> <![CDATA[OR03-05 Novel Lipidome Signature in Active Cushing Syndrome Revealed by UHPLC-MS Metabolomics]]> 2-fold decrease). From the altered metabolites, 3 amino acids (AA), 2 acylcarnitines (ACs), 2 ceramides (CER) and 5 glycerophospholipids showed direction of effect independently associated with 24-h urinary free cortisol (MS) levels. A highly discriminant (AUC 96%) metabolome signature (n=59) characterized by lower levels of AA, ACs, polyunsaturated fatty acids (PUFA) and monoglycerophosphocolines (MGPC) together with increased levels of triacyclglycerols (TG), CER, diacylglycerophosphocholines (DGPC) and cholesteryl esters was identified and cross-validated (R2Y= 0.92, Q2Y= 0.68) using PLS-DA VIP scores >1.5. PUFA omega-6, and alanine, aspartate and glutamate metabolism resulted the most impacted canonical pathways (q-stat 19.7, 10.8 (p<0.001). Finally, topological network analysis detected 158 pairwise differential correlations (p <0.005, 10,000-fold permutation) between 141 metabolites due to CS where the acylPC (P-18:1/0:0) resulted a key metabolite in the network (betweenness =0.117 & closeness centrality =0.467). Conclusion: Active Cushing syndrome leads to a global proatherogenic shift in the circulating ceramides, glycerophospholipids and sphingolipids metabolites which are independently associated to the levels of urinary free cortisol being potential biomarkers of patients’ cardiovascular risk. ]]> <![CDATA[OR03-06 NAD+ Availability Modulates 11β-HSD1-Mediated Glucocorticoid Regeneration in Mouse Skeletal Muscle]]> 90%), NADP+ (>50%) and ATP (>30%) without limiting cell viability. 11β-HSD1 reductase activity was decreased to 30% that of untreated cells (152±18 vs. 512±44 pmol/mg protein/h respectively, p<0.005). Employing H6PD knockout myotubes, NADP+-dependent 11β-HSD1 dehydrogenase activity was also impaired following NAMPT inhibition. The NAD+ precursor nicotinamide riboside (NR, 0.5mM), which bypasses NAMPT inhibition through the NR kinase pathway restored NAD+ levels and rapidly rescued 11β-HSD1 reductase activity in wild type and dehydrogenase activity in H6PD knockout myotubes. To assess this in vivo, we examined 11β-HSD1 reductase activity in muscle explants of inducible muscle-specific NAMPT knockout mice in which NAD+ levels are reduced by 90%, and show 40% lower activity compared to wild type explants (114±14 vs. 67±10 pmol/mg protein/h, p=0.04). These data suggest a novel level of redox-regulated 11β-HSD1-mediated glucocorticoid metabolism in skeletal muscle. These data also imply a pathway by which NAD+ status is communicated between the cytosol and the SR, which is contrary to the current belief that the pyridine nucleotide pool in these compartments is separate. NAMPT inhibition is being studied as a potential anti-cancer therapy and these data reveal hitherto unanticipated effects this therapy may have in a range of tissues. ]]>