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Advances in Clinical Chemistry 2022The physin family of proteins, synaptophysin (SYP), synaptophysin like 1 (SYPL1), synaptophysin like 2 (SYPL2) and synaptoporin (SYNRP), are tetratransmembrane transport...
The physin family of proteins, synaptophysin (SYP), synaptophysin like 1 (SYPL1), synaptophysin like 2 (SYPL2) and synaptoporin (SYNRP), are tetratransmembrane transport vesicle proteins distributed throughout the digestive system. Of these, SYP is a required marker for histopathologic identification of neuroendocrine neoplasms (NENs), especially in gastroenteropancreatic NENs (GEP-NENs). Recently, bloodstream SYP, i.e., on platelets and circulating tumor cells, has been correlated to clinicopathologic features of GEP-NENs and may have prognostic significance. Serum SYPL1 also represents a promising biomarker for colorectal cancer. This chapter provides an overview of physin structures and potential use as diagnostic, prognostic and therapeutic tools for digestive tract neoplasms.
Topics: Humans; Synaptophysin; Pancreatic Neoplasms; Digestive System Neoplasms; Neuroendocrine Tumors; Prognosis
PubMed: 36427909
DOI: 10.1016/bs.acc.2022.08.002 -
Developmental Psychobiology Mar 2021This study aims at investigating whether early stress interacts with brain injury due to neonatal hypoxia-ischemia (HI). To this end, we examined possible changes in...
This study aims at investigating whether early stress interacts with brain injury due to neonatal hypoxia-ischemia (HI). To this end, we examined possible changes in synaptophysin (SYN) and brain-derived neurotrophic factor (BDNF) expression in the medial prefrontal cortex (mPFC) of maternally separated rats that were subsequently exposed to a HI episode. Rat pups (n = 11) were maternally separated during postnatal days 1 to 6 (3hr/day), while another group was left undisturbed (n = 11). On postnatal day 7, a subgroup (n = 12) from each postnatal manipulation was exposed to HI. Synaptophysin and BDNF expression was estimated in mPFC prelimbic and anterior cingulate subregions of the ipsilateral and contralateral to the occluded common carotid artery hemispheres. Maternally separated rats expressed significantly less BDNF and SYN in both hemispheres. Neonatal HI significantly reduced BDNF and SYN expression in the ipsilateral mPFC only and this reduction was not further altered by early stress. Our findings indicate the enduring negative effect of a short period of maternal separation on the expression of mPFC SYN and BDNF. They, also, reveal that the HI-associated decreases in these markers are limited to the ipsilateral mPFC and are not exacerbated by early stress. These decreases may have important functional implications given the role of prefrontal area in high-order cognition.
Topics: Animals; Animals, Newborn; Brain-Derived Neurotrophic Factor; Hypoxia; Ischemia; Maternal Deprivation; Prefrontal Cortex; Rats; Stress, Psychological; Synaptophysin
PubMed: 32623722
DOI: 10.1002/dev.22011 -
Diagnostic Pathology Nov 2022Synaptophysin is an immunohistochemical marker for neuroendocrine differentiation and is widely used in pathologic diagnosis. Its expression in malignant lymphoma has...
BACKGROUND
Synaptophysin is an immunohistochemical marker for neuroendocrine differentiation and is widely used in pathologic diagnosis. Its expression in malignant lymphoma has not yet been described. However, we experienced an index case of classic Hodgkin lymphoma with synaptophysin expression. This experience prompted us to investigate synaptophysin expression in classic Hodgkin lymphoma.
METHOD
Immunohistochemical staining of synaptophysin was performed in 59 diagnosed cases of classic Hodgkin lymphoma, 10 anaplastic large cell lymphomas, 16 diffuse large B-cell lymphomas, and 5 extranodal marginal zone lymphoma of the mucosa-associated tissue. Synaptophysin-positive cases were stained for both chromogranin and CD56a.
RESULT
Of 59 classic Hodgkin lymphoma cases, 11 (19%) were positive for synaptophysin. None of the anaplastic large cell lymphomas expressed synaptophysin. Synaptophysin showed weak but specific expression in the cytoplasm of the Hodgkin lymphoma tumor cells. Other background inflammatory cells (such as macrophages, B-, and T-lymphocytes) were all negative for synaptophysin expression. Chromogranin and CD56a were not expressed in the synaptophysin-positive classic Hodgkin lymphomas.
CONCLUSIONS
Synaptophysin is an integral glycoprotein present in presynaptic vesicles of neurons and neuroendocrine cells. It is a diagnostic marker for neuroendocrine tumors. Aberrant synaptophysin expression has been reported in non-neuroendocrine tumors but not in lymphoma or leukemia. To the best of our knowledge, synaptophysin positivity has only been reported in a single case of precursor T-lymphoblastic leukemia/lymphoma to date. Our study showed that aberrant synaptophysin expression in classic Hodgkin lymphoma is an unexpectedly frequent finding. The mechanism underlying, and prognostic significance of, such aberrant expression is unclear. Thus, in a small biopsy, aberrant synaptophysin expression could be a diagnostic pitfall and should be carefully avoided.
Topics: Humans; Hodgkin Disease; Synaptophysin; Immunohistochemistry; Chromogranins; Lymphoma, Large-Cell, Anaplastic; Lymphoma, Large B-Cell, Diffuse; Neuroendocrine Tumors
PubMed: 36401284
DOI: 10.1186/s13000-022-01272-x -
Nature Communications Jan 2023Ectopic expression in fibroblasts of synapsin 1 and synaptophysin is sufficient to generate condensates of vesicles highly reminiscent of synaptic vesicle (SV) clusters...
Ectopic expression in fibroblasts of synapsin 1 and synaptophysin is sufficient to generate condensates of vesicles highly reminiscent of synaptic vesicle (SV) clusters and with liquid-like properties. Here we show that unlike synaptophysin, other major integral SV membrane proteins fail to form condensates with synapsin, but co-assemble into the clusters formed by synaptophysin and synapsin in this ectopic expression system. Another vesicle membrane protein, ATG9A, undergoes activity-dependent exo-endocytosis at synapses, raising questions about the relation of ATG9A traffic to the traffic of SVs. We find that both in fibroblasts and in nerve terminals ATG9A does not co-assemble into synaptophysin-positive vesicle condensates but localizes on a distinct class of vesicles that also assembles with synapsin but into a distinct phase. Our findings suggest that ATG9A undergoes differential sorting relative to SV proteins and also point to a dual role of synapsin in controlling clustering at synapses of SVs and ATG9A vesicles.
Topics: Synaptic Vesicles; Synapsins; Synaptophysin; Synapses; Membrane Proteins
PubMed: 36709207
DOI: 10.1038/s41467-023-36081-3 -
BMJ Case Reports Jan 2023Gastric glomus tumours (GGTs) are rare predominantly benign, mesenchymal neoplasms that commonly arise from the muscularis or submucosa of the gastric antrum and account...
Gastric glomus tumours (GGTs) are rare predominantly benign, mesenchymal neoplasms that commonly arise from the muscularis or submucosa of the gastric antrum and account for <1% of gastrointestinal soft-tissue tumours. Historically, GGT has been difficult to diagnose preoperatively due to the lack of unique clinical, endoscopic and CT features. We present a case of an incidentally identified GGT in an asymptomatic man that was initially considered a neuroendocrine tumour (NET) by preoperative fine-needle aspiration biopsy with focal synaptophysin reactivity. An elective robotic distal gastrectomy and regional lymphadenectomy were performed. Postoperative review by pathology confirmed the diagnosis of GGT. GGTs should be considered by morphology as a differential diagnosis of gastric NET on cytology biopsy, especially if there is focal synaptophysin reactivity. Additional staining for SMA and BRAF, if atypical/malignant, can help with this distinction. Providers should be aware of the biological behaviour and treatment of GGTs.
Topics: Male; Humans; Synaptophysin; Glomus Tumor; Stomach Neoplasms; Pyloric Antrum; Biopsy, Fine-Needle
PubMed: 36707101
DOI: 10.1136/bcr-2022-253020 -
Nature Communications Jan 2020Neuroendocrine prostate cancer (NEPC) is an aggressive malignancy with no effective targeted therapies. The oncogenic MUC1-C protein is overexpressed in...
Neuroendocrine prostate cancer (NEPC) is an aggressive malignancy with no effective targeted therapies. The oncogenic MUC1-C protein is overexpressed in castration-resistant prostate cancer (CRPC) and NEPC, but its specific role is unknown. Here, we demonstrate that upregulation of MUC1-C in androgen-dependent PC cells suppresses androgen receptor (AR) axis signaling and induces the neural BRN2 transcription factor. MUC1-C activates a MYC→BRN2 pathway in association with induction of MYCN, EZH2 and NE differentiation markers (ASCL1, AURKA and SYP) linked to NEPC progression. Moreover, MUC1-C suppresses the p53 pathway, induces the Yamanaka pluripotency factors (OCT4, SOX2, KLF4 and MYC) and drives stemness. Targeting MUC1-C decreases PC self-renewal capacity and tumorigenicity, suggesting a potential therapeutic approach for CRPC and NEPC. In PC tissues, MUC1 expression associates with suppression of AR signaling and increases in BRN2 expression and NEPC score. These results highlight MUC1-C as a master effector of lineage plasticity driving progression to NEPC.
Topics: Animals; Aurora Kinase A; Basic Helix-Loop-Helix Transcription Factors; Carcinogenesis; Carcinoma, Neuroendocrine; Cell Line, Tumor; Disease Progression; Enhancer of Zeste Homolog 2 Protein; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Male; Mice; Mice, Nude; Mucin-1; N-Myc Proto-Oncogene Protein; Neoplastic Stem Cells; Neuronal Plasticity; Octamer Transcription Factor-3; POU Domain Factors; Prostate; Prostatic Neoplasms; Prostatic Neoplasms, Castration-Resistant; Proto-Oncogene Proteins c-myc; SOXB1 Transcription Factors; Signal Transduction; Synaptophysin; Tumor Suppressor Protein p53
PubMed: 31953400
DOI: 10.1038/s41467-019-14219-6 -
Nature Jun 2024Synaptic vesicles are organelles with a precisely defined protein and lipid composition, yet the molecular mechanisms for the biogenesis of synaptic vesicles are mainly...
Synaptic vesicles are organelles with a precisely defined protein and lipid composition, yet the molecular mechanisms for the biogenesis of synaptic vesicles are mainly unknown. Here, we discovered a well-defined interface between the synaptic vesicle V-ATPase and synaptophysin by in situ cryo-electron tomography and single particle cryo-electron microscopy of functional synaptic vesicles isolated from mouse brains. The synaptic vesicle V-ATPase is an ATP-dependent proton pump that establishes the protein gradient across the synaptic vesicle, which in turn drives the uptake of neurotransmitters. Synaptophysin and its paralogs synaptoporin and synaptogyrin belong to a family of abundant synaptic vesicle proteins whose function is still unclear. We performed structural and functional studies of synaptophysin knockout mice, confirming the identity of synaptophysin as an interaction partner with the V-ATPase. Although there is little change in the conformation of the V-ATPase upon interaction with synaptophysin, the presence of synaptophysin in synaptic vesicles profoundly affects the copy number of V-ATPases. This effect on the topography of synaptic vesicles suggests that synaptophysin assists in their biogenesis. In support of this model, we observed that synaptophysin knockout mice exhibit severe seizure susceptibility, suggesting an imbalance of neurotransmitter release as a physiological consequence of the absence of synaptophysin.
PubMed: 38838737
DOI: 10.1038/s41586-024-07610-x -
Pharmacological Reports : PR Dec 2023Mitragynine (MIT), the primary indole alkaloid of kratom (Mitragyna speciosa), has been associated with addictive and cognitive decline potentials. In acute studies, MIT...
BACKGROUND
Mitragynine (MIT), the primary indole alkaloid of kratom (Mitragyna speciosa), has been associated with addictive and cognitive decline potentials. In acute studies, MIT decreases spatial memory and inhibits hippocampal synaptic transmission in long-term potentiation (LTP). This study investigated the impacts of 14-day MIT treatment on hippocampus synaptic transmission and its possible underlying mechanisms.
METHODS
Under urethane anesthesia, field excitatory post-synaptic potentials (fEPSP) of the hippocampal CA1 region were recorded in the Sprague Dawley (SD) rats that received MIT (1, 5, and 10 mg/kg), morphine (MOR) 5 mg/kg, or vehicle (ip). The effects of the treatments on basal synaptic transmission, paired-pulse facilitation (PPF), and LTP were assessed in the CA1 region. Analysis of the brain's protein expression linked to neuroplasticity was then performed using a western blot.
RESULTS
The baseline synaptic transmission's amplitude was drastically decreased by MIT at 5 and 10 mg/kg doses, although the PPF ratio before TBS remained unchanged, the PPF ratio after TBS was significantly reduced by MIT (10 mg/kg). Strong and persistent inhibition of LTP was generated in the CA1 region by MIT (5 and 10 mg/kg) doses; this effect was not seen in MIT (1 mg/kg) treated rats. In contrast to MIT (1 mg/kg), MIT (5 and 10 mg/kg) significantly raised the extracellular glutamate levels. After exposure to MIT, GluR-1 receptor expression remained unaltered. However, NMDAε2 receptor expression was markedly downregulated. The expression of pCaMKII, pERK, pCREB, BDNF, synaptophysin, PSD-95, Delta fosB, and CDK-5 was significantly downregulated in response to MIT (5 and 10 mg/kg) exposure, while MOR (5 mg/kg) significantly raised synaptophysin and Delta fosB expression.
CONCLUSION
Findings from this work reveal that a smaller dose of MIT (1 mg/kg) poses no risk to hippocampal synaptic transmission. Alteration in neuroplasticity-associated proteins may be a molecular mechanism for MIT (5 and 10 mg/kg)-induced LTP disruption and cognitive impairments. Data from this work posit that MIT acted differently from MOR on neuroplasticity and its underlying mechanisms.
Topics: Rats; Animals; Synaptophysin; Rats, Sprague-Dawley; Hippocampus; Neuronal Plasticity; Long-Term Potentiation; Synaptic Transmission
PubMed: 37924443
DOI: 10.1007/s43440-023-00541-w -
Molecular and Cellular Endocrinology Sep 2022The expression of the neuroendocrine markers synaptophysin and chromogranin A was analyzed by immunohistochemistry in 14,584 samples from 103 different tumor types and...
The expression of the neuroendocrine markers synaptophysin and chromogranin A was analyzed by immunohistochemistry in 14,584 samples from 103 different tumor types and subtypes in a tissue microarray format. At least one of these markers was found to be positive in 96.7% of tumors from various subtypes of neuroendocrine neoplasms. In non-neuroendocrine tumors, synaptophysin and/or chromogranin A staining was seen in 6.3% (n = 584), specifically in 41 of 88 non-neuroendocrine tumor entities. Basal cell carcinomas of the skin (50% positive for chromogranin A alone) and adrenocortical carcinomas (91.7% positive for synaptophysin alone) stood out due to a frequent expression of only one specific marker. A subdivision of non-neuroendocrine neoplasms revealed "neuroendocrine differentiation" most commonly in adenocarcinomas from the female genital tract (18.9%), from pancreatico-/hepato-/biliary tract (15.8%) and the prostate (14.9%) while it was rare in urothelial (1.0%) and squamous cell carcinomas (0.6%). A comparison with clinico-pathological parameters of tumor aggressiveness did not suggest a clinical significance of neuroendocrine marker expression in 204 endometrium cancers, 249 pancreatic adenocarcinomas, 233 gastric adenocarcinomas and 1,182 colorectal adenocarcinomas. Within a cohort of 1,073 breast cancers of no special type, synaptophysin positivity was seen in 4.9% of cases and it was significantly linked to advanced tumor stage (p = 0.0427), high tumor grade (p = 0.0319) and loss of estrogen receptor expression (p = 0.0061) but unrelated to patient outcome. In conclusion, "neuroendocrine differentiation" can be observed in many different tumor types with non-neuroendocrine morphology. Evidence for a statistically significant association (p < 0.0001) between such a "neuroendocrine differentiation" and tumor aggressiveness could not be found.
Topics: Adenocarcinoma; Biomarkers, Tumor; Carcinoma, Neuroendocrine; Chromogranin A; Female; Humans; Immunohistochemistry; Male; Neuroendocrine Tumors; Synaptophysin
PubMed: 35921917
DOI: 10.1016/j.mce.2022.111726 -
Der Pathologe Dec 2019To classify as breast cancer with neuroendocrine differentiation a growth pattern as encountered in well differentiated (G1, G2) neuroendocrine tumors (NET) of the... (Review)
Review
To classify as breast cancer with neuroendocrine differentiation a growth pattern as encountered in well differentiated (G1, G2) neuroendocrine tumors (NET) of the gastrointestinal tract and the lung must be present in addition to the immunohistochemical expression of neuroendocrine markers (chromogranin, synaptophysin). The majority of breast cancers fulfilling these criteria show hormone receptor positivity and with regard to prognosis resemble luminal type of breast cancer from which they are not fundamentally different. Despite lacking clinical relevance the up-coming WHO classification of breast cancer will nevertheless introduce the new category of NET luminal type. Immunohistochemical detection of neuroendocrine marker alone cannot be considered as sufficient for classification because it can frequently be encountered in other types of breast cancer (e.g. mucinous, solid papillary). From low grade NET with good differentiation those with poor differentiation and most frequently small cell appearance have to be differentiated. Poorly differentiated NET can primarily originate in the breast, which may be indicated by intraductal growth and co-expression of GATA3 but in these cases metastasis of extra mammary cancers has to be considered and correlation with the clinical findings is required for correct classification.
Topics: Biomarkers, Tumor; Breast Neoplasms; Cell Differentiation; Female; Humans; Male; Neuroendocrine Tumors; Prognosis; Synaptophysin
PubMed: 31781853
DOI: 10.1007/s00292-019-00691-w