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Abstract The characteristic neuropathology of Parkinson’s disease (PD) involves the abnormal accumulation of phosphorylated α-synuclein (αSyn), as well as a significant decrease in neuromelanin (NM) levels within dopamine neurons (DaNs). Unlike αSyn aggregates, the relationship between NM levels and PD pathogenesis is not well understood. In this study, we engineered an E. coli MG1655 strain to produce exosomes containing melanin (E.melanin), and investigated its potential neuroprotective effects on DaNs in the context of PD. By employing a combination of cell cultures, biochemical studies, single nuclear RNA sequencing (snRNA seq), and various in vivo validations, we found that administration of E.melanin effectively alleviated DaNs loss and improved motor behavior impairments observed in both pharmacological and transgenic PD mouse models. Mechanistically, snRNA seq data suggested that E.melanin activated the PSAP-GPR37L1 signaling pathway specifically within astrocytes, leading to a reduction in astrocytic engulfment of synapses. Notably, activation of the GPR37L1 receptor using Tx14(A) peptide successfully rescued motor defects as well as protected against DaNs degeneration in mice with PD. Overall, our findings provide novel insights into understanding the molecular mechanisms underlying melanin’s protective effects on DaNs in PD while offering potential strategies for manipulating and treating its pathophysiological progression.

Pancreatic cancer is the 7th leading cause of cancer death worldwide, and its incidence and mortality rate have been on the rise in recent years in Western developed countries. The specificity of the disease and the lack of appropriate treatments have resulted in a 5-year overall survival rate of only 9%. In this study, we conducted a study based on the TCGA database and GEO database and analyzed using the energy metabolism gene set to establish a prognostic model with the least absolute shrinkage and selection operator to identify 7-genes prognostic signature, and the gene expression was verified by Real-time PCR. The model was validated using a risk score calculation, and the OS rates of the 7 genes were analyzed using one-way Cox regression. The prognostic relationship between vesicle-associated membrane protein 2 (VAMP2) and pancreatic cancer patients was analyzed by OS and progression-free survival, and the prognosis was found to be significantly worse in the high-expression group. A Nomogram showed that VAMP2 was an independent prognostic factor in pancreatic cancer. Gene set enrichment analysis showed that VAMP2 upregulation was enriched in pathways associated with immune response and that VAMP2 downregulation was enriched in metabolism-related pathways. The association of VAMP2 with immune cell infiltration was analyzed for the enrichment results, and VAMP2 was found to be positively associated with all 6 immune cells. The results of this study suggest that VAMP2 is an independent prognostic factor associated with energy metabolism in pancreatic cancer and may be involved in the immune response.

BackgroundTetrastigma hemsleyanum (T. hemsleyanum) is widely used as an adjuvant drug for tumor therapy but its antitumor therapeutic targets and molecular mechanisms have remained unclear. The prediction and analysis of natural products has previously used only network pharmacology methods to identify potential target proteins from public databases. In this study, we use comprehensive bioinformatics analysis and experimental verification to determine the antitumor mechanism of T. hemsleyanum.MethodsNetwork pharmacology analysis was used to predict the potential in vivo target proteins of T. hemsleyanum. The expression matrix and clinical data to perform an analysis of hub genes were collected from the TCGA and GTEx databases, specifically the analysis of expression, prognosis, tumor immune cell infiltration analysis, immune checkpoint genes, microsatellite instability, tumor mutational burden, tumor neoantigen, and immune microenvironment, which identify the roles and biological functions of the hub genes in pan-cancer. Finally, gene set enrichment analysis was used to verify the biological processes and signaling pathways involved in the pan-cancer expression profile.ResultsWe found 124 potential in vivo target proteins of T. hemsleyanum through network pharmacological analysis, and five hub genes (AKR1C1, MET, PTK2, PIK3R1, and CDK6) were then screened by protein–protein interaction (PPI) network analysis and molecular complex detection analysis (MCODE). Experimental intervention with an aqueous extract of T. hemsleyanum verified that these hub genes are the target proteins involved in the regulation of T. hemsleyanum in cells. A pan-cancer analysis then confirmed that CDK6 and MET are potential targets upon which T. hemsleyanum may exert antitumor action, especially in ACC, CESC, LGG, and PAAD. The CDK6 protein targeted by T. hemsleyanum is also involved in the immune and mutation process of pan-cancer, especially in the regulation of immune cell infiltration, immune checkpoint gene expression, microsatellite instability, tumor mutation burdens, and tumor neoantigens. Together, these analyses show that T. hemsleyanum affects tumor immune regulation and genomic stability. Finally, a gene set enrichment analysis confirmed that T. hemsleyanum regulates the cell cycle checkpoint.ConclusionsWe found that T. hemsleyanum can behave as an antitumor agent by acting as a potential cell cycle checkpoint inhibitor in CDK6-driven tumors, such as ACC, CESC, LGG, and PAAD, and that it acts as a tyrosine kinase receptor inhibitor that inhibits the expression of the proto-oncogene MET. Combined with an analysis of immune and mutation correlations in pan-cancer, we determined that T. hemsleyanum may function biologically as an immune regulator and interfere with the stability of the tumor genome, which is worthy of further study.

Dynein is a motor protein with multiple transport functions. However, dynein’s role in crustacean testis is still unknown. We cloned the full-length cDNA of cytoplasmic dynein heavy chain (Pt-dhc) gene and its structure was analyzed. Its expression level was highest in testis. We injected the dynein inhibitor sodium orthovanadate (SOV) into the crab. The distribution of Portunus trituberculatus dynein heavy chain (Pt-DHC) in mature sperm was detected by immunofluorescence. The apoptosis of spermatids was detected using a TUNEL kit; gene expression in testis was detected by fluorescence quantitative PCR (qPCR). The expression of immune-related factors in the testis were detected by an enzyme activity kit. The results showed that the distribution of Pt-DHC was abnormal after SOV injection, indicating that the function of dynein was successfully inhibited. Apoptosis-related genes p53 and caspase-3, and antioxidant stress genes HSP70 and NOS were significantly decreased, and anti-apoptosis gene bcl-2 was significantly increased. The activities of superoxide dismutase (SOD) and alkaline phosphatase (AKP) were significantly decreased. The results showed that there was no apoptosis in testicular cells after dynein function was inhibited, but the cell function was disordered. This study laid a theoretical foundation for the further study of apoptosis in testis and the function of dynein in testis and breeding of P. trituberculatus.