Promoting effect and immunologic role of secretogranin II on bladder cancer progression via regulating MAPK and NF-κB pathways.

Bladder cancer (BLCA) is ranked among the top ten most prevalent cancers worldwide and is the second most common malignant tumor within the field of urology. The limited effectiveness of immune targeted therapy in treating BLCA, due to its high metastasis and recurrence rates, necessitates the identification of new therapeutic targets. Secretogranin II (SCG2), a member of the chromaffin granin/secreted granin family, plays a crucial role in the regulated release of peptides and hormones. The role of SCG2 in the tumor microenvironment (TME) of lung adenocarcinoma and colon cancer has been established, but its functional significance in BLCA remains uncertain. This study aimed to investigate SCG2 expression in 15 bladder cancer tissue samples and their corresponding adjacent control tissues. The potential involvement of SCG2 in BLCA progression was assessed using various techniques, including analysis of public databases, immunohistochemistry, Western Blotting, immunofluorescence, wound-healing assay, Transwell assay, and xenograft tumor formation experiments in nude mice. This study provided novel evidence indicating that SCG2 plays a pivotal role in facilitating the proliferation, migration, and invasion of BLCA by activating the MEK/Erk and MEK/IKK/NF-κB signaling pathways, as well as by promoting M2 macrophage polarization. These findings propose the potential of SCG2 as a molecular target for immunotherapy in human BLCA.

[High expression of secretogranin II increases oxaliplatin resistance of colorectal cancer cells].

OBJECTIVE: To investigate the expression of secretogranin II (SCG2) in colorectal cancer (CRC) tissues and its impact on oxaliplatin resistance of CRC cells. METHODS: We performed immunohistochemistry to detect the expression level of SCG2 on a tissue microarray containing 96 CRC and 84 adjacent tissues and analyzed the association of SCG2 expression with the clinical features of the CRC patients. SCG2 expression was also measured in DLD1 cells treated with oxaliplatin using immunoblotting and RT-qPCR analyses. The effects of SCG2 expression on oxaliplatin sensitivity and cell viability were evaluated in a DLD1 cell model of SCG2 knockout established using CRISPR-cas9 technique, and the expressions of apoptosis-related proteins were detected using Western blotting and RT-qPCR. We further examined SCG2 expression levels in an oxaliplatin-resistant DLD1 cell line and its parental DLD1 cells. RESULTS: SCG2 expression was significantly increased in CRC tissues as compared with the adjacent tissues (1.932±0.816 vs 1), and the tumor tissues in advanced stages showed higher SCG2 expression levels. In DLD1 cells, treatment with oxaliplatin significantly increased SCG2 expression, and SCG2 knockout obviously increased oxaliplatin sensitivity of the cells and enhanced the expressions of apoptosis-related proteins. Compared with the parental cells, oxaliplatin-resistant DLD1 cells showed a significant increase of SCG2 expression by 3.901±0.471 folds. CONCLUSION: SCG2 may serve as a risk gene in CRC, and its high expression increases oxaliplatin resistance of CRC cells.

Bone marrow-derived mesenchymal stem cells accelerate angiogenesis in pregnant experimentally induced deep venous thrombosis rat model via up-regulation of pro-angiogenic secretogranin II.

The present study investigated whether bone marrow-derived mesenchymal stem cells (BMMSCs) facilitate angiogenesis and improve outcomes of pregnancy with obstetric deep venous thrombosis (DVT) and explored the underlying mechanism. A pregnant DVT rat model was established using a "stenosis" method on the lower segment of the inferior vena cava (IVC). The extent of vascularization in thrombosed IVC was examined by immunohistochemistry. In addition, the effect of BMMSCs on DVT pregnancy outcomes was evaluated. We also characterized the effect of BMMSC-derived conditioned medium (BM-CM) on the impaired human umbilical vein endothelial cells (HUVECs). Thereafter, transcriptome sequencing was employed to identify the differentially expressed genes in thrombosed IVC tissues of DVT and DVT plus BMMSCs (thrice) groups. Lastly, the candidate gene's role in the promotion of angiogenesis was demonstrated in vitro and in vivo. The DVT model was successfully established using IVC stenosis. The injection of three consecutive BMMSC doses into pregnant SD rats with DVT was demonstrated to be the most effective treatment, which significantly reduced the length and weight of the thrombus, induced the highest level of angiogenesis, and ameliorated the embryo absorption rate. In vitro, BM-CM efficiently increased the abilities of impaired endothelial cells to proliferate, migrate, invade, and form vessel-like tubes, while inhibiting their apoptosis. Transcriptome sequencing revealed that BMMSCs induced a prominent upregulation of a variety of pro-angiogenic genes, including secretogranin II (SCG2). When SCG2 expression was knocked down by lentivirus, the BMMSCs' and BM-CM-induced pro-angiogenic effects on pregnant DVT rats and HUVECs were markedly attenuated. In conclusion, the study results suggest that BMMSCs enhance angiogenesis via up-regulation of SCG2, providing an effective alternative regenerative agent and novel target for the therapy of obstetric DVT.

SCG2: A Prognostic Marker That Pinpoints Chemotherapy and Immunotherapy in Colorectal Cancer.

Background: Fluorouracil (FU)-based chemotherapy regimens are indispensable in the comprehensive treatment of colorectal cancer (CRC). However, the heterogeneity of treated individuals and the severe adverse effects of chemotherapy results in limited overall benefit. Methods: Firstly, Weighted gene co-expression network analysis (WGCNA) identified modules tightly associated with chemotherapy response. Then, the in-house cohort and prognostic cohorts from TCGA and GEO were subjected to Cox proportional hazards model and survival analysis to ascertain the predictable function of SCG2 on the prognosis of CRC patients. Finally, we performed In vitro experiments, functional analysis, somatic mutation, and copy number variation research to explore the biological characteristics of SCG2. Results: We identified red and green as the modules most associated with chemotherapy response, in which SCG2 was considered a risky factor with higher expression predicting poorer prognosis. SCG2 expression in the APC non-mutation group was remarkably higher than in the mutation group. The mutation frequencies of amplified genes differed significantly between different SCG2 expression subgroups. Besides, CRC cell lines with SCG2 knockdown have reduced invasive, proliferative, and proliferative capacity. We discovered that the SCG2 high expression subgroup was the immune hot type and considered more suitable for immunotherapy. Conclusion: This study demonstrates the clinical significance and biological characteristics of SCG2, which could serve as a promising biomarker to identify patients who may benefit from chemotherapy and immunotherapy.

Differential Expression of Secretogranins II and III in Canine Adrenal Chromaffin Cells and Pheochromocytomas.

Secretogranin II (SgII) and III (SgIII) function within peptide hormone-producing cells and are involved in secretory granule formation. However, their function in active amine-producing cells is not fully understood. In this study, we analyzed the expression profiles of SgII and SgIII in canine adrenal medulla and pheochromocytomas by immunohistochemical staining. In normal adrenal tissues, the intensity of coexpression of these two secretogranins (Sgs) differed from each chromaffin cell, although a complete match was not observed. The coexpression of vesicular monoamine transporter 2 (VMAT2) with SgIII was similar to that with chromogranin A, but there was a subpopulation of VMAT2-expressing cells that were negative or hardly detectable for SgII. These results are the first to indicate that there are distinct expression patterns for SgII and SgIII in adrenal chromaffin cells. Furthermore, the expression of these two Sgs varied in intensity among pheochromocytomas and did not necessarily correlate with clinical plasma catecholamine levels in patients. However, compared with SgIII, the expression of SgII was shown to be strong at the single-cell level in some tumor tissues. These findings provide a fundamental understanding of the expression differences between SgII and SgIII in normal adrenal chromaffin cells and pheochromocytomas.

AGTR1, PLTP, and SCG2 associated with immune genes and immune cell infiltration in calcific aortic valve stenosis: analysis from integrated bioinformatics and machine learning.

Background: Calcific aortic valve stenosis (CAVS) is a crucial cardiovascular disease facing aging societies. Our research attempts to identify immune-related genes through bioinformatics and machine learning analysis. Two machine learning strategies include Least Absolute Shrinkage Selection Operator (LASSO) and Support Vector Machine Recursive Feature Elimination (SVM-RFE). In addition, we deeply explore the role of immune cell infiltration in CAVS, aiming to study the potential therapeutic targets of CAVS and explore possible drugs. Methods: Download three data sets related to CAVS from the Gene Expression Omnibus. Gene set variation analysis (GSVA) looks for potential mechanisms, determines differentially expressed immune-related genes (DEIRGs) by combining the ImmPort database with CAVS differential genes, and explores the functions and pathways of enrichment. Two machine learning methods, LASSO and SVM-RFE, screen key immune signals and validate them in external data sets. Single-sample GSEA (ssGSEA) and CIBERSORT analyze the subtypes of immune infiltrating cells and integrate the analysis with DEIRGs and key immune signals. Finally, the possible targeted drugs are analyzed through the Connectivity Map (CMap). Results: GSVA analysis of the gene set suggests that it is highly correlated with multiple immune pathways. 266 differential genes (DEGs) integrate with immune genes to obtain 71 DEIRGs. Enrichment analysis found that DEIRGs are related to oxidative stress, synaptic membrane components, receptor activity, and a variety of cardiovascular diseases and immune pathways. Angiotensin II Receptor Type 1(AGTR1), Phospholipid Transfer Protein (PLTP), Secretogranin II (SCG2) are identified as key immune signals of CAVS by machine learning. Immune infiltration found that B cells naï ve and Macrophages M2 are less in CAVS, while Macrophages M0 is more in CAVS. Simultaneously, AGTR1, PLTP, SCG2 are highly correlated with a variety of immune cell subtypes. CMap analysis found that isoliquiritigenin, parthenolide, and pyrrolidine-dithiocarbamate are the top three targeted drugs related to CAVS immunity. Conclusion: The key immune signals, immune infiltration and potential drugs obtained from the research play a vital role in the pathophysiological progress of CAVS.

Secretogranin II impairs tumor growth and angiogenesis by promoting degradation of hypoxia-inducible factor-1α in colorectal cancer.

Distant metastasis is a major cause of death in patients with colorectal cancer (CRC) but the management of advanced and metastatic CRC still remains problematic due to the distinct molecular alterations during tumor progression. Tumor angiogenesis is a key step in tumor growth, invasion and metastasis. However, the signaling pathways involved in angiogenesis are poorly understood. The results of the present study showed that secretogranin II (SCG2) was significantly downregulated in malignant CRC tissues, and higher expression of SCG2 was correlated with longer disease-free survival and overall survival of CRC patients. The results of an animal study showed that ectopic expression of SCG2 significantly inhibited CRC tumor growth by disrupting angiogenesis. Furthermore, the inhibition of expression of vascular endothelial growth factor (VEGF) by SCG2 and rescue of VEGF effectively blocked SCG2-induced inhibition of angiogenesis. Investigations into the underlying mechanism suggested that SCG2 promoted degradation of hypoxia-inducible factor (HIF)-1α by interacting with the von Hippel-Lindau tumor suppressor in CRC cells. Blocking of degradation of HIF-1α effectively attenuated the SCG2-mediated decrease in expression of VEGF in CRC cells. Collectively, these results demonstrated that treatment with SCG2 effectively inhibited CRC tumor growth by disrupting the activities of HIF-1α/VEGF, thereby clarifying the anti-tumor and anti-angiogenesis roles of SCG2 in CRC, while providing a novel therapeutic target and a potential prognostic marker of disease progression.

Bidirectional perisomatic inhibitory plasticity of a Fos neuronal network.

Behavioural experiences activate the FOS transcription factor in sparse populations of neurons that are critical for encoding and recalling specific events1-3. However, there is limited understanding of the mechanisms by which experience drives circuit reorganization to establish a network of Fos-activated cells. It is also not known whether FOS is required in this process beyond serving as a marker of recent neural activity and, if so, which of its many gene targets underlie circuit reorganization. Here we demonstrate that when mice engage in spatial exploration of novel environments, perisomatic inhibition of Fos-activated hippocampal CA1 pyramidal neurons by parvalbumin-expressing interneurons is enhanced, whereas perisomatic inhibition by cholecystokinin-expressing interneurons is weakened. This bidirectional modulation of inhibition is abolished when the function of the FOS transcription factor complex is disrupted. Single-cell RNA-sequencing, ribosome-associated mRNA profiling and chromatin analyses, combined with electrophysiology, reveal that FOS activates the transcription of Scg2, a gene that encodes multiple distinct neuropeptides, to coordinate these changes in inhibition. As parvalbumin- and cholecystokinin-expressing interneurons mediate distinct features of pyramidal cell activity4-6, the SCG2-dependent reorganization of inhibitory synaptic input might be predicted to affect network function in vivo. Consistent with this prediction, hippocampal gamma rhythms and pyramidal cell coupling to theta phase are significantly altered in the absence of Scg2. These findings reveal an instructive role for FOS and SCG2 in establishing a network of Fos-activated neurons via the rewiring of local inhibition to form a selectively modulated state. The opposing plasticity mechanisms acting on distinct inhibitory pathways may support the consolidation of memories over time.

Secretogranin III upregulation is involved in parkinsonian toxin-mediated astroglia activation.

Environmental neurotoxins such as paraquat (PQ), manganese, and 1-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) are associated with a higher risk of Parkinson's disease (PD). These parkinsonian toxins exert certain common toxicological effects on astroglia; however, their role in the regulatory functions of astroglial secretory proteins remains unclear. In a previous study, we observed that secretogranin II (SCG2) and secretogranin III (SCG3), which are important components of the regulated secretory pathway, were elevated in PQ-activated U118 astroglia. In the current study, we used the parkinsonian toxins dopamine (DA), active metabolite of MPTP (MPP+), MnCl2, and lipopolysaccharide (LPS) as inducers, and studied the potential regulation of SCG2 and SCG3. Our results showed that all the parkinsonian toxins except LPS affected astroglial viability but did not cause apoptosis. Exposure to DA, MPP+, and MnCl2 upregulated glial fibrillary acidic protein (GFAP), a marker for astrocyte activation, and stimulated the levels of several astrocytic-derived factors. Further, DA, MPP+, and MnCl2 exposure impeded astroglial cell cycle progression. Moreover, the expression of SCG3 was elevated, while its exosecretion was inhibited in astroglia activated by parkinsonian toxins. The level of SCG2 remained unchanged. In combination with our previous findings, the results of this study indicate that SCG3 may act as a cofactor in astrocyte activation stimulated by various toxins, and the regulation of SCG3 could be involved in the toxicological mechanism by which parkinsonian toxins affect astroglia.

Targeted mutation of secretogranin-2 disrupts sexual behavior and reproduction in zebrafish.

The luteinizing hormone surge is essential for fertility as it triggers ovulation in females and sperm release in males. We previously reported that secretoneurin-a, a neuropeptide derived from the processing of secretogranin-2a (Scg2a), stimulates luteinizing hormone release, suggesting a role in reproduction. Here we provide evidence that mutation of the scg2a and scg2b genes using TALENs in zebrafish reduces sexual behavior, ovulation, oviposition, and fertility. Large-scale spawning within-line crossings (n = 82 to 101) were conducted. Wild-type (WT) males paired with WT females successfully spawned in 62% of the breeding trials. Spawning success was reduced to 37% (P = 0.006), 44% (P = 0.0169), and 6% (P < 0.0001) for scg2a-/- , scg2b-/- , and scg2a-/-;scg2b-/- mutants, respectively. Comprehensive video analysis indicates that scg2a-/-;scg2b-/- mutation reduces all male courtship behaviors. Spawning success was 47% in saline-injected WT controls compared to 11% in saline-injected scg2a-/-;scg2b-/- double mutants. For these mutants, spawning success increased 3-fold following a single intraperitoneal (i.p.) injection of synthetic secretoneurin-a (P = 0.0403) and increased 3.5-fold with injection of human chorionic gonadotropin (hCG). Embryonic survival at 24 h remained on average lower in scg2a-/-;scg2b-/- fish compared to WT injected with secretoneurin-a (P < 0.001). Significant reductions in the expression of gonadotropin-releasing hormone 3 in the hypothalamus, and luteinizing hormone beta and glycoprotein alpha subunits in the pituitary provide evidence for disrupted hypothalamo-pituitary function in scg2a and scg2b mutant fish. Our results indicate that secretogranin-2 is required for optimal reproductive function and support the hypothesis that secretoneurin is a reproductive hormone.

Fasting before or after wound injury accelerates wound healing through the activation of pro-angiogenic SMOC1 and SCG2.

Healing of the chronic diabetic ulceration and large burns remains a clinical challenge. Therapeutic fasting has been shown to improve health. Our study tested whether fasting facilitates diabetic and burn wound healing and explored the underlying mechanism. Methods: The effects of fasting on diabetic and burn wound healing were evaluated by analyzing the rates of wound closure, re-epithelialization, scar formation, collagen deposition, skin cell proliferation and neovascularization using histological analyses and immunostaining. In vitro functional assays were conducted to assess fasting and refeeding on the angiogenic activities of endothelial cells. Transcriptome sequencing was employed to identify the differentially expressed genes in endothelial cells after fasting treatment and the role of the candidate genes in the fasting-induced promotion of angiogenesis was demonstrated. Results: Two times of 24-h fasting in a week after but especially before wound injury efficiently induced faster wound closure, better epidermal and dermal regeneration, less scar formation and higher level of angiogenesis in mice with diabetic or burn wounds. In vitro, fasting alone by serum deprivation did not increase, but rather reduced the abilities of endothelial cell to proliferate, migrate and form vessel-like tubes. However, subsequent refeeding did not merely rescue, but further augmented the angiogenic activities of endothelial cells. Transcriptome sequencing revealed that fasting itself, but not the following refeeding, induced a prominent upregulation of a variety of pro-angiogenic genes, including SMOC1 (SPARC related modular calcium binding 1) and SCG2 (secretogranin II). Immunofluorescent staining confirmed the increase of SMOC1 and SCG2 expression in both diabetic and burn wounds after fasting treatment. When the expression of SMOC1 or SCG2 was down-regulated, the fasting/refeeding-induced pro-angiogenic effects were markedly attenuated. Conclusion: This study suggests that fasting combined with refeeding, but not fasting solely, enhance endothelial angiogenesis through the activation of SMOC1 and SCG2, thus facilitating neovascularization and rapid wound healing.

Circulating secretoneurin concentrations in patients with moderate to severe aortic stenosis.

BACKGROUND: Secretoneurin (SN) concentrations provide important prognostic information in patients with myocardial dysfunction. Whether preoperative SN concentrations improve risk assessment in patients with moderate to severe aortic stenosis (AS) is unknown. METHODS: We included 57 patients with moderate to severe AS referred for presurgical evaluation. All patients were examined with comprehensive echocardiography, electrocardiogram (ECG), and biochemical measurements and compared to 10 age- and sex-matched healthy subjects. RESULTS: Median (quartile 1-3) SN concentrations were 141 (121-163) pmol/L in AS patients and 132 (106-148) pmol/L in control subjects (p = .17). Lower estimated creatinine clearance and use of diuretics, but not standard ECG or echocardiographic indices and cardiac biomarkers, were associated with increasing SN concentrations. Fifteen patients (26%) died during 3.5 years median follow-up. SN concentrations were higher in non-survivors than survivors: 156 (133-209) vs. 140 (116-155) pmol/L, p = .007. Higher SN concentrations were associated with increased risk of mortality also after adjustment for established risk indices, biomarkers, and status regarding valvular surgery: hazard ratio per lnSN 15.13 (95% CI 1.05-219.00); p = .046. Receiver operating characteristics area under the curve for SN to predict mortality was 0.74 (95% CI 0.60-0.88) compared to 0.73 (0.59-0.87) for high-sensitivity cardiac troponin T and 0.67 (0.51-0.82) for N-terminal pro-B-type natriuretic peptide. The previously identified cut-off of SN >204 pmol/L in cardiac surgical patients predicted mortality also in this cohort. CONCLUSIONS: SN concentrations improve risk assessment in patients with moderate to severe AS by providing additional prognostic information to established risk indices such as echocardiography, ECG, and established cardiac biomarkers.

Secretoneurin Is an Endogenous Calcium/Calmodulin-Dependent Protein Kinase II Inhibitor That Attenuates Ca2+-Dependent Arrhythmia.

BACKGROUND: Circulating SN (secretoneurin) concentrations are increased in patients with myocardial dysfunction and predict poor outcome. Because SN inhibits CaMKIIδ (Ca2+/calmodulin-dependent protein kinase IIδ) activity, we hypothesized that upregulation of SN in patients protects against cardiomyocyte mechanisms of arrhythmia. METHODS: Circulating levels of SN and other biomarkers were assessed in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT; n=8) and in resuscitated patients after ventricular arrhythmia-induced cardiac arrest (n=155). In vivo effects of SN were investigated in CPVT mice (RyR2 [ryanodine receptor 2]-R2474S) using adeno-associated virus-9-induced overexpression. Interactions between SN and CaMKIIδ were mapped using pull-down experiments, mutagenesis, ELISA, and structural homology modeling. Ex vivo actions were tested in Langendorff hearts and effects on Ca2+ homeostasis examined by fluorescence (fluo-4) and patch-clamp recordings in isolated cardiomyocytes. RESULTS: SN levels were elevated in patients with CPVT and following ventricular arrhythmia-induced cardiac arrest. In contrast to NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-TnT (high-sensitivity troponin T), circulating SN levels declined after resuscitation, as the risk of a new arrhythmia waned. Myocardial pro-SN expression was also increased in CPVT mice, and further adeno-associated virus-9-induced overexpression of SN attenuated arrhythmic induction during stress testing with isoproterenol. Mechanistic studies mapped SN binding to the substrate binding site in the catalytic region of CaMKIIδ. Accordingly, SN attenuated isoproterenol induced autophosphorylation of Thr287-CaMKIIδ in Langendorff hearts and inhibited CaMKIIδ-dependent RyR phosphorylation. In line with CaMKIIδ and RyR inhibition, SN treatment decreased Ca2+ spark frequency and dimensions in cardiomyocytes during isoproterenol challenge, and reduced the incidence of Ca2+ waves, delayed afterdepolarizations, and spontaneous action potentials. SN treatment also lowered the incidence of early afterdepolarizations during isoproterenol; an effect paralleled by reduced magnitude of L-type Ca2+ current. CONCLUSIONS: SN production is upregulated in conditions with cardiomyocyte Ca2+ dysregulation and offers compensatory protection against cardiomyocyte mechanisms of arrhythmia, which may underlie its putative use as a biomarker in at-risk patients.

Circulating Secretoneurin Concentrations After Cardiac Surgery: Data From the FINNish Acute Kidney Injury Heart Study.

OBJECTIVES: Secretoneurin is associated with cardiomyocyte Ca handling and improves risk prediction in patients with acute myocardial dysfunction. Whether secretoneurin improves risk assessment on top of established cardiac biomarkers and European System for Cardiac Operative Risk Evaluation II in patients undergoing cardiac surgery is not known. DESIGN: Prospective, observational, single-center sub-study of a multicenter study. SETTING: Prospective observational study of survival in patients undergoing cardiac surgery. PATIENTS: A total of 619 patients undergoing cardiac surgery. INTERVENTIONS: Patients underwent either isolated coronary artery bypass graft surgery, single noncoronary artery bypass graft surgery, two procedures, or three or more procedures. Procedures other than coronary artery bypass graft were valve surgery, surgery on thoracic aorta, and other cardiac surgery. MEASUREMENTS AND MAIN RESULTS: We measured preoperative and postoperative secretoneurin concentrations and adjusted for European System for Cardiac Operative Risk Evaluation II, N-terminal pro-B-type natriuretic peptide, and cardiac troponin T concentrations in multivariate analyses. During 961 days of follow-up, 59 patients died (9.5%). Secretoneurin concentrations were higher among nonsurvivors compared with survivors, both before (168 pmol/L [quartile 1-3, 147-206 pmol/L] vs 160 pmol/L [131-193 pmol/L]; p = 0.039) and after cardiac surgery (173 pmol/L [129-217 pmol/L] vs 143 pmol/L [111-173 pmol/L]; p < 0.001). Secretoneurin concentrations decreased from preoperative to postoperative measurements in survivors, whereas we observed no significant decrease in secretoneurin concentrations among nonsurvivors. Secretoneurin concentrations were weakly correlated with established risk indices. Patients with the highest postoperative secretoneurin concentrations had worse outcome compared with patients with lower secretoneurin concentrations (p < 0.001 by the log-rank test) and postoperative secretoneurin concentrations were associated with time to death in multivariate Cox regression analysis: hazard ratio lnsecretoneurin 2.96 (95% CI, 1.46-5.99; p = 0.003). Adding postoperative secretoneurin concentrations to European System for Cardiac Operative Risk Evaluation II improved patient risk stratification, as assessed by the integrated discrimination index: 0.023 (95% CI, 0.0043-0.041; p = 0.016). CONCLUSIONS: Circulating postoperative secretoneurin concentrations provide incremental prognostic information to established risk indices in patients undergoing cardiac surgery.

Identification of a five-gene signature with prognostic value in colorectal cancer.

Colorectal cancer (CRC) ranks as one of the most commonly diagnosed malignancies worldwide. Although mortality rates have been decreasing, the prognosis of CRC patients is still highly dependent on the individual. Therefore, identifying and understanding novel biomarkers for CRC prognosis remains crucial. The gene expression profiles of five-gene expression omnibus (GEO) data sets of CRC were first downloaded. A total of 352 consistent differentially expressed genes (DEGs) were identified for CRC and paired with normal tissues. Functional analysis including gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment revealed that these DEGs were related to metabolic pathways, tight junctions, and the cell cycle. Ten hub DEGs were identified based on the search tool for the retrieval of interacting genes database and protein-protein interaction networks. By using univariate Cox proportional hazard regression analysis, we found 11 survival-related genes among these DEGs. We finally established a five-gene signature (kinesin family member 15, N-acetyltransferase 2, glutathione peroxidase 3, secretogranin II, and chloride channel accessory 1) with prognostic value in CRC by step multivariate Cox regression analysis. Based on this risk scoring system, patients in the high-risk group had significantly poorer survival results compared with those in the low-risk group (log-rank test, p < 0.0001). Finally, we validated our gene signature scoring system in two independent GEO cohorts (GSE17536 and GSE33113). We found all five of the signature genes to be DEGs in The Cancer Genome Atlas database. In conclusion, our findings suggest that our five DEG-based signature can provide a novel biomarker with useful applications in CRC prognosis.

Epitope mapping of an uncertain endogenous antigen implies secretogranin II peptide splicing.

Background: The search for a tissue-mass reducing reproductive hormone involved a bioassay-guided physicochemical fractionation of sheep blood plasma. This brought forth a candidate protein whose apparent mass on gels and in mass spectrometry (MS) was 7-8 kDa, implying a polypeptide of ~70 residues. Four purification runs gave Edman N-terminal sequences relating to 1MKPLTGKVKEFNNI 14. This is bioinformatically obscure and has been resistant to molecular biological investigation. The sequence was synthesized as the peptide EPL001, against which was raised a goat polyclonal antiserum, G530. Used in an antigen capture campaign, G530 pointed to the existence of a novel derivative of secretogranin II (SgII), the neuroendocrine secretory vesicle helper protein and prohormone. The proposed SgII derivative was dubbed SgII-70, yet the sequence commonality between SgII and EPL001 is essentially NNI. Methods: Immunohistochemical (IHC) labelling with G530 is reported within rat, mouse and human cerebrovasculature and in glandular elements of the mouse intestine. Epitope mapping involved IHC peptide preabsorption, allied to deductive bioinformatics and molecular modelling in silico. Results: G530 is deemed monoepitopic in regard to both its synthetic antigen (EPL001) and its putative endogenous antigen (SgII related). The epitope within EPL001 of the anti-EPL001 antibody is inferred to be the contiguous C-terminal 9KEFNNI 14. This is so because the G530 blockade data are consistent with the epitope in the mammalian endogenous antigen being part contiguous, part non-contiguous KE·F·NNI, ex hypothesi. The observed immunostaining is deduced to be due to pre-SgII-70, which has a non-C-terminal NNI, and SgII-70, which has an N-terminal MLKTGEKPV/N and a C-terminal NNI (these two motifs being in the reverse order in the SgII parent protein). Conclusion: The present data are consistent with the hypothesis that the anti-EPL001 antibody binds to an SgII-related epitope. SgII is apparently subject to peptide splicing, as has been reported for the related chromogranin A.

Secretogranin-II plays a critical role in zebrafish neurovascular modeling.

Secretoneurin (SN) is a neuropeptide derived from specific proteolytic processing of the precursor secretogranin II (SgII). In zebrafish and other teleosts, there are two paralogs named sgIIa and sgIIb. Our results showed that neurons expressing sgIIb were aligned with central arteries in the hindbrain, demonstrating a close neurovascular association. Both sgIIb-/- and sgIIa-/-/sgIIb-/- mutant embryos were defective in hindbrain central artery development due to impairment of migration and proliferation of central artery cells. Further study revealed that sgIIb is non-cell autonomous and required for central artery development. Hindbrain arterial and venous network identities were not affected in sgIIb-/- mutant embryos, and the mRNA levels of Notch and VEGF pathway-related genes were not altered. However, the activation of MAPK and PI3K/AKT pathways was inhibited in sgIIb-/- mutant embryos. Reactivation of MAPK or PI3K/AKT in endothelial cells could partially rescue the central artery developmental defects in the sgIIb mutants. This study provides the first in vivo evidence that sgIIb plays a critical role in neurovascular modeling of the hindbrain. Targeting the SgII system may, therefore, represent a new avenue for the treatment of vascular defects in the central nervous system.

Knockout of the Gnrh genes in zebrafish: effects on reproduction and potential compensation by reproductive and feeding-related neuropeptides.

Gonadotropin-releasing hormone (GNRH) is known as a pivotal upstream regulator of reproduction in vertebrates. However, reproduction is not compromised in the hypophysiotropic Gnrh3 knockout line in zebrafish (gnrh3-/-). In order to determine if Gnrh2, the only other Gnrh isoform in zebrafish brains, is compensating for the loss of Gnrh3, we generated a double Gnrh knockout zebrafish line. Surprisingly, the loss of both Gnrh isoforms resulted in no major impact on reproduction, indicating that a compensatory response, outside of the Gnrh system, was evoked. A plethora of factors acting along the reproductive hypothalamus-pituitary axis were evaluated as possible compensators based on neuroanatomical and differential gene expression studies. In addition, we also examined the involvement of feeding factors in the brain as potential compensators for Gnrh2, which has known anorexigenic effects. We found that the double knockout fish exhibited upregulation of several genes in the brain, specifically gonadotropin-inhibitory hormone (gnih), secretogranin 2 (scg2), tachykinin 3a (tac3a), and pituitary adenylate cyclase-activating peptide 1 (pacap1), and downregulation of agouti-related peptide 1 (agrp1), indicating the compensation occurs outside of Gnrh cells and therefore is a noncell autonomous response to the loss of Gnrh. While the differential expression of gnih and agrp1 in the double knockout line was confined to the periventricular nucleus and hypothalamus, respectively, the upregulation of scg2 corresponded with a broader neuronal redistribution in the lateral hypothalamus and hindbrain. In conclusion, our results demonstrate the existence of a redundant reproductive regulatory system that comes into play when Gnrh2 and Gnrh3 are lost.

Effects of PQ's cytotoxicity on secretory vesicles in astroglia: Expression alternation of secretogranin II and its potential interaction with intracellular factors.

It has been extensively characterized that paraquat (PQ) selectively targets to the substantia nigra and exerts neurotoxic actions on dopaminergic neurons. However, a little knowledge is available about astroglia in PQ exposure, especially its complex secretory machinery. To explore this point, we built up a PQ-induced model in cultural U118 astrocyte. Since the granin family is considered as a master regulator of cargo sorting and large dense core vesicles (LDCVs) biogenesis in the regulated secretory pathway of nervous and neuroendocrine cells, the current study focused on one member, secretogranin II (SCG2) and investigated its alternation and potential relationship with other astrocyte-derived factors under PQ insult. We found that PQ upregulated SCG2 expression on both RNA and protein levels and stimulated the mRNA expression of neurotrophic factors, cytokines and glutamine synthetase (GS) simultaneously. RNAi knockdown of SCG2 did not rescue the cell cycle arrest induced by PQ but affected expressions of IL-6 and GS on mRNA and protein levels. Further studies on subcellular location showed that SCG2-positive secretory granules were partially colocalized with IL-6 but not GS in PQ exposure astrocyte. Taken together, our findings indicate that the expression alternation of SCG2 under astroglial activation by PQ may be necessary compensation for cargo sorting and LDCV biogenesis. The involvement of the IL-6 and GS suggests that the SCG2 may potentially regulate inflammatory factors and excitatory neurotransmitter to the cytotoxicity of PQ on astroglia.