Endoplasmic reticulum stress impedes regulated secretion by governing key exocytotic and granulogenic molecular switches.

Dense core vesicles (DCVs) and synaptic vesicles are specialised secretory vesicles in neurons and neuroendocrine cells, and abnormal release of their cargo is associated with various pathophysiologies. Endoplasmic reticulum (ER) stress and inter-organellar communication are also associated with disease biology. To investigate the functional status of regulated exocytosis arising from the crosstalk of a stressed ER and DCVs, ER stress was modelled in PC12 neuroendocrine cells using thapsigargin. DCV exocytosis was severely compromised in ER-stressed PC12 cells and was reversed to varying magnitudes by ER stress attenuators. Experiments with tunicamycin, an independent ER stressor, yielded similar results. Concurrently, ER stress also caused impaired DCV exocytosis in insulin-secreting INS-1 cells. Molecular analysis revealed blunted SNAP25 expression, potentially attributed to augmented levels of ATF4, an inhibitor of CREB that binds to the CREB-binding site. The effects of loss of function of ATF4 in ER-stressed cells substantiated this attribution. Our studies revealed severe defects in DCV exocytosis in ER-stressed cells for the first time, mediated by reduced levels of key exocytotic and granulogenic switches regulated via the eIF2α (EIF2A)-ATF4 axis.

Putative regulation of macrophage-mediated inflammation by catestatin.

Catestatin (CST) is a bioactive cleavage product of the neuroendocrine prohormone chromogranin A (CgA). Recent findings show that CST can exert anti-inflammatory and antiadrenergic effects by suppressing the inflammatory actions of mammalian macrophages. However, recent findings also suggest that macrophages themselves are major CST producers. Here, we hypothesize that macrophages produce CST in an inflammation-dependent manner and thereby might self-regulate inflammation in an autocrine fashion. CST is associated with pathological conditions hallmarked by chronic inflammation, including autoimmune, cardiovascular, and metabolic disorders. Since intraperitoneal injection of CST in mouse models of diabetes and inflammatory bowel disease has been reported to be beneficial for mitigating disease, we posit that CST should be further investigated as a candidate target for treating certain inflammatory diseases.

Hybrid insulin peptide isomers spontaneously form in pancreatic beta-cells from an aspartic anhydride intermediate.

Hybrid insulin peptides (HIPs) form in beta-cells when insulin fragments link to other peptides through a peptide bond. HIPs contain nongenomic amino acid sequences and have been identified as targets for autoreactive T cells in type 1 diabetes. A subgroup of HIPs, in which N-terminal amine groups of various peptides are linked to aspartic acid residues of insulin C-peptide, was detected through mass spectrometry in pancreatic islets. Here, we investigate a novel mechanism that leads to the formation of these HIPs in human and murine islets. Our research herein shows that these HIPs form spontaneously in beta-cells through a mechanism involving an aspartic anhydride intermediate. This mechanism leads to the formation of a regular HIP containing a standard peptide bond as well as a HIP-isomer containing an isopeptide bond by linkage to the carboxylic acid side chain of the aspartic acid residue. We used mass spectrometric analyses to confirm the presence of both HIP isomers in islets, thereby validating the occurrence of this novel reaction mechanism in beta-cells. The spontaneous formation of new peptide bonds within cells may lead to the development of neoepitopes that contribute to the pathogenesis of type 1 diabetes as well as other autoimmune diseases.

Chromogranin A and its derived peptides: potential regulators of cholesterol homeostasis.

Chromogranin A (CHGA), a member of the granin family of proteins, has been an attractive therapeutic target and candidate biomarker for several cardiovascular, neurological, and inflammatory disorders. The prominence of CHGA stems from the pleiotropic roles of several bioactive peptides (e.g., catestatin, pancreastatin, vasostatins) generated by its proteolytic cleavage and by their wide anatomical distribution. These peptides are emerging as novel modulators of cardiometabolic diseases that are often linked to high blood cholesterol levels. However, their impact on cholesterol homeostasis is poorly understood. The dynamic nature of cholesterol and its multitudinous roles in almost every aspect of normal body function makes it an integral component of metabolic physiology. A tightly regulated coordination of cholesterol homeostasis is imperative for proper functioning of cellular and metabolic processes. The deregulation of cholesterol levels can result in several pathophysiological states. Although studies till date suggest regulatory roles for CHGA and its derived peptides on cholesterol levels, the mechanisms by which this is achieved still remain unclear. This review aims to aggregate and consolidate the available evidence linking CHGA with cholesterol homeostasis in health and disease. In addition, we also look at common molecular regulatory factors (viz., transcription factors and microRNAs) which could govern the expression of CHGA and genes involved in cholesterol homeostasis under basal and pathological conditions. In order to gain further insights into the pathways mediating cholesterol regulation by CHGA/its derived peptides, a few prospective signaling pathways are explored, which could act as primers for future studies.

Evaluating the usefulness of plasma chromogranin A measurement in cyclic ACTH-dependent Cushing's syndrome.

Cushing's syndrome, a clinical condition characterized by hypercortisolemia, exhibits distinct clinical signs and is associated with cyclic cortisol secretion in some patients. The clinical presentation of cyclic Cushing's syndrome can be ambiguous and its diagnosis is often challenging. We experienced a 72-year-old woman with cyclic ACTH-dependent Cushing's syndrome caused by a pulmonary carcinoid tumor. Diagnosis was challenging because of the extended trough periods, and the responsible lesion was initially unidentified. A subsequent follow-up computed tomography revealed a pulmonary lesion, and ectopic ACTH secretion from this lesion was confirmed by pulmonary artery sampling. Despite the short peak secretion period of ACTH (approximately one week), immunostaining of the surgically removed tumor confirmed ACTH positivity. Interestingly, stored plasma chromogranin A levels were elevated during both peak and trough periods. The experience in evaluating this patient prompted us to investigate the potential use of plasma chromogranin A as a diagnostic marker of ACTH-dependent Cushing's syndrome. A retrospective study was conducted to determine the efficacy of plasma chromogranin A in three patients with ectopic ACTH syndrome (EAS), including the present case, and six patients with Cushing's disease (CD) who visited our hospital between 2018 and 2021. Notably, plasma chromogranin A levels were higher in patients with EAS than in those with CD. Additionally, a chromogranin A level in the present case during the trough phase was lower than that in the peak phase, and was similar to those in CD patients. The measurement of plasma chromogranin A levels could aid in differentiating EAS from CD.

Insulinoma-associated protein 1 (INSM1) immunohistochemical expression in normal, hyperplastic, and neoplastic canine neuroendocrine tissues.

Insulinoma-associated protein 1 (INSM1), a recently identified neuroendocrine marker, is a transcriptional regulator with highly conserved INSM1 homologues in various species. This study investigated the immunohistochemical reactivity of the INSM1 antibody in 20 normal canine neuroendocrine tissues from various anatomical locations, 87 hyperplastic or neoplastic tissues of neuroendocrine origin, and 62 non-neuroendocrine neoplasms and compared the results with those of chromogranin A and synaptophysin in neuroendocrine neoplasms. Western blot was performed on fresh canine pituitary glands and canine parathyroid glands to confirm the specificity of the anti-INSM1 antibody. The results showed that the anti-INSM1 antibody could detect nuclear expression in normal canine neuroendocrine tissues, except for the parathyroid glands. INSM1 was detectable in 79/87 (91%) of the hyperplastic and neoplastic neuroendocrine lesions, but all parathyroid carcinomas and parathyroid adenomas (three samples each) were negative for INSM1. In contrast, INSM1 was detected in only one of 62 (2%) non-neuroendocrine neoplasms. The overall percentage of neuroendocrine neoplasms that immunolabeled positively for all three markers was 89%. In addition, the nuclear expression of INSM1 was easier to interpret than that of chromogranin A or synaptophysin. These findings confirm that INSM1 is a useful immunohistochemical marker for diagnosing canine neuroendocrine neoplasms, except for parathyroid neoplasms, and should be considered as part of immunohistochemistry panels to improve diagnostic capability.

Impact of grade on workup of rectal neuroendocrine tumors: a retrospective cohort study : Grade impact on workup of rectal NETs.

BACKGROUND: Rectal neuroendocrine tumors (RNETs) are often discovered on screening colonoscopy. Indications for staging and definitive resection are inconsistent in current guidelines. We evaluated the role of grade in guiding staging and procedural decision-making. METHODS: Patients with biopsy confirmed RNETs between 2004 and 2015 were reviewed. Baseline characteristics, staging investigations (biochemical and imaging), and endoscopic/surgical treatment were recorded. Associations between grade, preoperative staging, interventions, and survival were determined using Fisher-Freeman-Halton Exact, log-rank, and Kaplan-Meier analysis. RESULTS: Amongst 139 patients with RNETs, 9% were aged ≥ 75 years and 44% female. Tumor grade was: 73% grade 1 (G1), 18%, grade 2 (G2) and 9% grade 3 (G3). Staging investigations were performed in 52% of patients. All serum chromogranin A and 97% of 24-hour urine 5-hydroxyindoleacetic acid tests were normal. The large majority of staging computed tomography (CT) scans were negative (76%) with subgroup analysis showing no G1 patients with CT identified distant disease compared with 38% of G2 and 50% of G3 patients (p < 0.001). G1 patients were more likely to achieve R0/R1 resections compared to G2 (95% vs. 50%, p < 0.001) and G1 patients had significantly better 5-year overall survival (G1: 98%, G2: 67%, G3: 10%, p < 0.001). CONCLUSION: Tumor grade is important in preoperative workup and surgical decision-making. Biochemical staging may be omitted but staging CT should be considered for patients with grade ≥ 2 lesions. Anatomic resections should be considered for patients with grade 2 disease.

Chromogranin A as a diagnostic marker of pheochromocytoma and paraganglioma: A systematic review and meta-analysis.

OBJECTIVES: This work aims to assess the diagnostic value of chromogranin A (CgA) in the laboratory diagnosis of neuroendocrine tumors classified as pheochromocytoma and paraganglioma (PPGL). METHODS: A comprehensive search was performed in PubMed, Embase, the Cochrane Library, and Web of Science databases to obtain relevant studies reporting the diagnostic accuracy of CgA in patients with PPGL. The search involved studies written in English between the time of library inception and May 1, 2023. We computed the pooled sensitivity, specificity, and diagnostic odds ratio (DOR). Additionally, the receiver operating characteristic curve and area under the curve (AUC) were determined. The heterogeneity was assessed using the Chi-square test and the I2 test. The subgroup analyses were performed to investigate the origins of heterogeneity. Stata 15.1 statistical software was used in all data analyses. RESULTS: This meta-analysis included 13 studies involving 1470 patients. CgA had a pooled diagnostic sensitivity of 0.86 (95% CI 0.81-0.91), a specificity of 0.90 (95% CI 0.81-0.95), and a DOR of 57 (95% CI 23-142). CgA had an AUC of 0.93. The studies did not reveal any threshold effect (r = -0.165; p > 0.05). The subgroup analyses revealed that the control group category and the detection method caused the overall heterogeneity. CONCLUSIONS: Our study suggests that CgA is a helpful PPGL biomarker. However, relying solely on CgA for diagnosis is not advisable. A comprehensive approach is essential for accurate diagnosis. Future large-scale research is needed to refine CgA's clinical application.

Clinicopathologic features and diagnostic challenges of small cluster pattern appendiceal neuroendocrine tumors.

Appendiceal neuroendocrine neoplasms (NENs) can present with various growth patterns including the traditional triad of histologic patterns-insular, trabecular and tubular. A small cluster pattern was also found in this study and the literature on this specific morphology is limited. In this study, we conducted a comprehensive review of appendiceal NENs from our institution over a ten-year period. Clinical and demographic data were obtained from medical records. Immunohistochemical stains were performed with antibodies specific for synaptophysin, chromogranin, INSM1, CD56, serotonin and peptide YY. The small cluster pattern was found in 29.4 % of all cases evaluated. The tumor cells in these cases were predominantly located at the distal tip of the appendix, associated with fibrous obliteration. These tumors were smaller in size and tended towards less advanced tumor stage, with reduced incidence of lymphovascular and/or perineural invasion. Chromogranin expression was identified in 76 % of these cases. There is a heterogeneous hormone profile with 46.7 % serotonin and 33.3 % peptide YY. In conclusion, the small cluster pattern NENs present with unique histological features and hormone expression profile. Among the various neuroendocrine markers, INSM1 showed superior diagnostic performance, with high sensitivity and minimal non-specific staining.

The changes on salivary flow rates, buffering capacity and chromogranin A levels in adults after bariatric surgery.

OBJECTIVES: This study aimed to investigate changes in salivary flow rates, buffering capacity, and salivary chromogranin A (CHGA) levels in adults undergoing bariatric surgery (BS) compared with a non-obese control group. MATERIALS AND METHODS: Salivary analyses were performed on 62 participants aged over 50 years, stratified into two groups matched for age and gender-individuals who had undergone bariatric surgery (BS) (n = 31) and a corresponding healthy control group (n = 31). Before saliva collection, participants completed a comprehensive 11-point visual numerical rating scale (NRS 0-10) xerostomia questionnaire, assessing subjective perceptions of two key aspects: dryness of the oral mucosa and resultant impact on oral functional ability. Three distinct saliva measurements were obtained: unstimulated whole saliva (UWS), stimulated whole saliva (SWS), and unstimulated upper labial saliva (ULS). The buffering capacity of unstimulated saliva was assessed using pH indicator strips, and concentrations of salivary Chromogranin A (CHGA) were quantified in stimulated saliva via enzyme-linked immunosorbent assay (ELISA). RESULTS: After BS, more than 40% of BS group patients reported xerostomia, with 16.1% experiencing only mild symptoms without significant functional impact (p = 0.009). The prevalence of xerostomia and tongue dryness was higher in the BS group compared to the control group (p = 0.028 and p = 0.025, respectively). The comparative analysis unveiled no statistically significant differences in flow rates of unstimulated upper labial saliva (ULS), unstimulated whole saliva (UWS), and stimulated whole saliva (SWS) between the control group and patients who underwent bariatric surgery. However, in patients undergone BS with xerostomia, both ULS and UWS flow rates were significantly lower than in controls with xerostomia (p = 0.014 and p = 0.007, respectively). The buffering capacity was significantly lower in patients undergone BS than in controls (p = 0.009). No differences were found between groups regarding CHGA concentration and output values, nevertheless, higher values of CHGA concentrations were significantly correlated to lower flow rates. CONCLUSION: According to the results, this study suggests that individuals undergoing BS may exhibit altered salivary buffering capacity and reduced unstimulated salivary flows in the presence of xerostomia. Additionally, the findings suggest that elevated concentration of salivary CHGA might be associated, in part, with salivary gland hypofunction. CLINICAL RELEVANCE: The clinical significance of this study lies in highlighting the changes in salivary functions after BS. The identified salivary alterations might be attributed to adverse effects of BS such as vomiting, gastroesophageal reflux, and dehydration. Understanding these changes is crucial for healthcare professionals involved in the care of post-BS patients, as it sheds light on potential oral health challenges that may arise as a consequence of the surgical intervention. Monitoring and managing these salivary alterations can contribute to comprehensive patient care and enhance the overall postoperative experience for individuals undergoing BS.

The Role of Catestatin in Preeclampsia.

Preeclampsia (PE) is a unique pregnancy disorder affecting women across the world. It is characterized by the new onset of hypertension with coexisting end-organ damage. Although the disease has been known for centuries, its exact pathophysiology and, most importantly, its prevention remain elusive. The basis of its associated molecular changes has been attributed to the placenta and the hormones regulating its function. One such hormone is chromogranin A (CgA). In the placenta, CgA is cleaved to form a variety of biologically active peptides, including catestatin (CST), known inter alia for its vasodilatory effects. Recent studies indicate that the CST protein level is diminished both in patients with hypertension and those with PE. Therefore, the aim of the present paper is to review the most recent and most relevant in vitro, in vivo, and clinical studies to provide an overview of the proposed impact of CST on the molecular processes of PE and to consider the possibilities for future experiments in this area.

[Diagnosis and management of patients with pheochromocytoma/paraganglioma: Consensus of experts of the Russian Medical Society for Arterial Hypertension and the Multidisciplinary Group for the Diagnosis and Treatment of Neuroendocrine Tumors].

The understanding of the nature of catecholamine-secreting tumors has changed significantly in recent years, affecting terminology and classification. Phaeochromocytoma/paraganglioma (PCC/PG) is a rare neuroendocrine tumor from chromaffin tissue that produces and secretes catecholamines. The incidence of PCC/PG is relatively low, with 2-8 cases per 1 million population per year; among patients with arterial hypertension, their prevalence is 0.2-0.6%. However, delayed diagnosis of PCC/PG is associated with a high risk of cardiovascular complications and a high mortality rate. The consensus presents the clinical manifestations of the disease with an emphasis on the course of arterial hypertension as the most common symptom in PCC/PG; modern ideas about the features of diagnosis, aspects of preoperative preparation, treatment, and follow-up of patients with PCC/PG are considered.

Use of iTRAQ-based quantitative proteomic identification of CHGA and UCHL1 correlated with lymph node metastasis in colorectal carcinoma.

Metastatic dissemination of colorectal cancer (CRC), the third most common cancer type, is responsible for CRC deaths. Understanding the transition of lymph node metastasis (LNM) from Stage II to Stage III is beneficial in the prognosis and intervention of CRC. In this study, a quantitative proteomic survey was conducted to investigate the LNM-associated proteins and evaluate the clinicopathological characteristics of these target proteins in CRC. By using the LC-MS/MS iTRAQ technology, we analysed the proteomic changes between LMN II and LMN III. Fresh tumours from the CRC specimens consisting of 12 node-negative (Stage II) and 12 node-positive (Stage III) cases were analysed by LC-MS/MS iTRAQ proteome analysis. Subsequently, tissue microarray with immunohistochemistry staining was conducted to access the clinicopathological characteristics of these proteins in 116 paraffin-embedded CRC samples, each for non-LNM and LNM CRC. To study the effects of the differentially expressed proteins on the potential mechanism, Boyden chamber assay, flow cytometry and shRNA-based assessments were conducted to examine the role of the epithelial-mesenchymal transition (EMT) and the invasiveness of CRC cells and others in vivo xenograft mouse model experiments. Forty-eight proteins were found differentially expressed between non-LNM and LNM CRC tissues. Protein abundances of chromogranin-A (CHGA) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) were observed in node-positive CRC (p < 0.05). Knockdown of CHGA and UCHL1 significantly regulate cancer behaviours of HCT-116, including inhibition of cell migration, invasiveness, cell cycle G1/S arrest and reactive oxygen species (ROS) generation. Mechanistically, the CHGA and UCHL1 inactivation displayed decreased levels of UCH-L1, chromogranin A, ß-catenin, cyclin E, twist-1/2, vimentin, MMP-9, N-cadherin and PCNA through the activation of the Rho-GTPase/AKT/NFκB pathways. Histone modification of H3K4 trimethylation of CHGA and UCHL1 promoter were increased to activate their transcription through the signalling transduction such as Rho-GTPase, AKT and NFκB pathways. Our results indicated that UCHL1 and chromogranin A are novel regulators in CRC lymph node metastasis to potentially provide new insights into the mechanism of CRC progression and serve as biomarkers for CRC diagnosis at the metastatic stage.

Dynamic assessment of serum chromogranin A and treatment response with abiraterone acetate in metastatic castration-resistant prostate cancer.

OBJECTIVE: Elevated serum chromogranin A (CGA) is associated with intrinsic or treatment-related neuroendocrine differentiation (NED) in men with metastatic castration-resistant prostate cancer (mCRPC). Fluctuations in serum CGA during treatment of mCRPC have had conflicting results. We analyzed the impact of (i) rising serum CGA and (ii) baseline CGA/PSA ratio during treatment to identify associations with abiraterone acetate (AA) therapy. METHODS: Between June 2013 and August 2015, 92 men with mCRPC were enrolled in a prospective trial with uniform serum CGA processing performed before initiating abiraterone acetate/prednisone (AA/P) and serially after 12 weeks of AA/P treatments. Serum CGA was measured using a homogenous automated immunofluorescent assay. Patients receiving proton pump inhibitors or with abnormal renal function were excluded due to possible false elevations of serum CGA (n = 21 excluded), therefore 71 patients were analyzed. All patients underwent a composite response assessment at 12-weeks. Kaplan-Meier estimates and Cox Regression models were used to calculate the association with time-to-treatment failure analyses and overall survival. RESULTS: An increase in chromogranin was associated with a lower risk of treatment failure (hazard ratio [HR]: 0.52, p = 0.0181). The median CGA/PSA ratio was 7.8 (2.6-16.0) and an elevated pretreatment CGA/PSA ratio above the median was associated with a lower risk of treatment failure (HR: 0.54 p value = 0.0185). An increase in CGA was not found to be associated with OS (HR: 0.71, 95% CI: 0.42-1.21, p = 0.207). An elevated baseline CGA/PSA ratio was not associated with OS (HR: 0.62, 95% CI: 0.37-1.03, p = 0.062). An increase in PSA after 12 weeks of treatment was associated with an increased risk of treatment failure (HR: 4.14, CI: 2.21-7.73, p = < 0.0001) and worse OS (HR: 2.93, CI: 1.57-4.45, p = < 0.0001). CONCLUSIONS: We show that an increasing chromogranin on AA/P and an elevated baseline CGA/PSA in patients with mCRPC were associated with a favorable response to AA/P with no changes in survival. There may be limited clinical utility in serum CGA testing to evaluate for lethal NED as AA/P did not induce lethal NED in this cohort. This highlights that not all patients with an increasing CGA have a worse OS.

Chromogranin A-derived peptides pancreastatin and catestatin: emerging therapeutic target for diabetes.

Chromogranin A (ChgA) is an acidic pro-protein found in neuroendocrine organs, pheochromocytoma chromaffin granules, and tumor cells. Proteolytic processing of ChgA gives rise to an array of biologically active peptides such as pancreastatin (PST), vasostatin, WE14, catestatin (CST), and serpinin, which have diverse roles in regulating cardiovascular functions and metabolism, as well as inflammation. Intricate tissue-specific role of ChgA-derived peptide activity in preclinical rodent models of metabolic syndrome reveals complex effects on carbohydrate and lipid metabolism. Indeed, ChgA-derived peptides, PST and CST, play a pivotal role in metabolic syndrome such as obesity, insulin resistance, and diabetes mellitus. Additionally, supplementation of specific peptide in ChgA-KO mice have an opposing effect on physiological functions, such as PST supplementation reduces insulin sensitivity and enhances inflammatory response. In contrast, CST supplementation enhances insulin sensitivity and reduces inflammatory response. In this review, we focus on the tissue-specific role of PST and CST as therapeutic targets in regulating carbohydrate and lipid metabolism, along with the associated risk factors.

Chromogranin A: a useful biomarker in castration-resistant prostate cancer.

PURPOSE: The natural history of prostate cancer (PC) almost always evolves to castration-resistant prostate cancer (CRPC) status, sometimes comprising pure or mixed neuroendocrine prostate cancers (NEPC) differentiation. In CRPC, monitoring using only prostate-specific antigen (PSA) is not optimal since neuroendocrine differentiated cells do not secrete PSA. Thus, monitoring with PSA and chromogranin A (CgA) may be useful. This review aims to evaluate evidence for the usefulness of CgA assessments during the monitoring of prostate cancer. METHOD: This review was based on three recent meta-analysis concerning CgA and prostate cancer. Further data were obtained from PubMed and Embase databases by searches using keywords, including chromogranin A and prostate cancer. RESULTS: CgA levels remain largely unchanged during the early PC evolution. The development of NEPC is characterised by lower PSA secretion and increased CgA secretion. Data supporting the prognostic value of high CgA baseline levels for survival are contrasting and scarce. However, increasing CgA levels early during treatment of metastatic (m)CRPC suggests resistance to treatment and predicts shorter survival, particularly in men with high baseline levels of CgA levels. In men with mCRPC, the first-line chemotherapy may be more appropriate than other agents when baseline CgA levels are high. Also, increasing CgA levels during treatment may indicate disease progression and may warrant a change of therapy. CONCLUSION: CgA monitoring at baseline and regularly during mCRPC management may be useful for monitoring disease evolution. An increased CgA baseline levels and increasing CgA levels may assist physicians with choosing and modifying therapy.

Chromogranin A: An Endocrine Factor of Pregnancy.

Pregnancy is a state of physiological and hormonal changes. One of the endocrine factors involved in these processes is chromogranin A, an acidic protein produced, among others, by the placenta. Although it has been previously linked to pregnancy, no existing articles have ever managed to clarify the role of this protein regarding this subject. Therefore, the aim of the present study is to gather knowledge of chromogranin A's function with reference to gestation and parturition, clarify elusive information, and, most importantly, to formulate hypotheses for the future studies to verify.

Reduction in CgA-Derived CST Protein Level in HTR-8/SVneo and BeWo Trophoblastic Cell Lines Caused by the Preeclamptic Environment.

One of the most dangerous complications of pregnancy is preeclampsia (PE), a disease associated with a high risk of maternal and fetal mortality and morbidity. Although its etiology remains unknown, the placenta is believed to be at the center of ongoing changes. One of the hormones produced by the placenta is chromogranin A (CgA). Thus far, its role in pregnancy and pregnancy-related disorders is enigmatic, yet it is known that both CgA and its derived peptide catestatin (CST) are involved in the majority of the processes that are disturbed in PE, such as blood pressure regulation or apoptosis. Therefore, in this study, the influence of the preeclamptic environment on the production of CgA using two cell lines, HTR-8/SVneo and BeWo, was investigated. Furthermore, the capacity of trophoblastic cells to secrete CST to the environment was tested, as well as the correlation between CST and apoptosis. This study provided the first evidence that CgA and CST proteins are produced by trophoblastic cell lines and that the PE environment has an impact on CST protein production. Furthermore, a strong negative correlation between CST protein level and apoptosis induction was found. Hence, both CgA and its derived peptide CST may play roles in the complex process of PE pathogenesis.

In-depth analysis of proteomic and genomic fluctuations during the time course of human embryonic stem cells directed differentiation into beta cells.

Pluripotent stem cells (PSC) endocrine differentiation at a large scale allows sampling of transcriptome and proteome with phosphoproteome (proteoform) at specific time points. We describe the dynamic time course of changes in cells undergoing directed beta-cell differentiation and show target proteins or previously unknown phosphorylation of critical proteins in pancreas development, NKX6-1, and Chromogranin A (CHGA). We describe fluctuations in the correlation between gene expression, protein abundance, and phosphorylation, following differentiation protocol perturbations at all stages to identify proteoform profiles. Our modeling recognizes outliers on a phenomic landscape of endocrine differentiation, and we describe new biological pathways involved. We have validated our proteomic data by analyzing independent single-cell RNAseq datasets for in-vitro pancreatic islet production and corroborated our findings for several proteins suggestive as targets for future research. The single-cell analysis combined with proteoform data places new protein targets within the specific time point and at the specific pancreatic lineage of differentiating stem cells. We suggest that non-correlating proteins abundances or new phosphorylation motifs of NKX6.1 and CHGA point to new signaling pathways that may play an essential role in beta-cell development. We present our findings for the research community's use to improve endocrine differentiation protocols and developmental studies.

Serum levels of chromogranin are not predictive of poorly differentiated prostate cancer: Results from a multicenter radical prostatectomy cohort.

BACKGROUND: Recently a possible link between elevated Chromogranin A (CgA) levels and poorly differentiated prostate cancer has been proposed. The aim of our study was to explore the association of CgA levels and the risk of poorly differentiated prostate cancer (PCa) in men undergoing radical retropubic prostatectomy (RRP). MATERIALS AND METHODS: From 2012 onwards, 335 consecutive men undergoing RRP for PCa at three centers in Italy were enrolled into a prospective database. Body mass index (BMI) was calculated before RRP. Blood samples were collected and tested for total prostate-specific antigen (PSA) levels and chromogranin A (CgA). We evaluated the association between serum levels of CgA and upstaging and upgrading using logistic regression analyses. RESULTS: Median age and preoperative PSA levels were 65 years (interquartile range [IQR]: 60-69) and 7.2 ng/ml (IQR: 5.3-10.4), respectively. Median BMI was 26.1 kg/m2 (IQR: 24-29) with 56 (16%) obese (BMI ≥ 30 kg/m2 ). Median CgA levels were 51 (39/71). Overall, 129/335 (38,5%) presented an upstaging, and 99/335 (30%) presented an upgrading. CgA was not a predictor of upstaging or upgrading on RP. CONCLUSIONS: In our multicenter cohort of patients, CgA is not a predictor of poorly differentiated PCa on radical prostatectomy. According to our experience, CgA should not be considered a reliable marker to predict poorly differentiated or advanced prostate cancer.