Synergistic antitumoral efficacy of a novel replicative adenovirus SG611-PDCD5 and daunorubicin in human leukemic cells

Programmed cell death protein 5 inhibits hepatocellular carcinoma progression by inducing pyroptosis through regulation of TGF-β/Smad2/3/Snail pathway

BACKGROUND

Programmed cell death protein 5 (PDCD5) is involved in apoptosis and is regarded as a tumor suppressor in various tumors. However, its role and underlying molecular mechanisms in hepatocellular carcinoma (HCC) remain unclear.

METHODS

PDCD5-overexpressing cell and xenograft tumor models were developed. Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine, wound healing, Transwell, flow cytometry, immunohistochemistry, and hematoxylin-eosin staining were employed to explore the effects of PDCD5 on HCC cell behaviors and tumor growth. The enzyme-linked immunosorbent assay and western blot were used to detect pyroptosis-related marker levels. The molecular mechanisms underlying PDCD5's role in HCC were investigated through transcriptome sequencing and coimmunoprecipitation. SRI-011381, a TGF-β signaling activator, was applied to evaluate the impact of PDCD5 in modulating the TGF-β/Smad2/3/Snail pathway.

RESULTS

PDCD5 expression was reduced in HCC cells. Overexpression of PDCD5 inhibited HCC cell proliferation, migration, invasion, and xenograft tumor growth. Additionally, PDCD5 overexpression promoted apoptosis and pyroptosis, with corresponding increases in inflammatory factors and Caspase-1, GSDMD, and NLRP3 protein levels. Mechanistically, PDCD5 bound to receptor-regulated Smads (Smad2/3), inhibiting the TGF-β pathway. Treatment with the TGF-β pathway activator SRI-011381 significantly counteracted the inhibitory effects of PDCD5 overexpression on HCC progression.

CONCLUSION

Our findings suggest that PDCD5 impedes the progression of HCC by promoting pyroptosis via regulation of TGF-β/Smad2/3/Snail pathway, which could be a possible therapeutic target for HCC.

The role and mechanisms of PD-L1 in immune evasion during Talaromyces marneffei infection

Talaromycosis, caused by Talaromyces marneffei (T. marneffei), is a systemic fungal disease that involves dissemination throughout the body. The ability of T. marneffei to evade the immune system is considered a crucial factor in its persistent infection, although the specific mechanisms are not yet fully understood. This study aims to investigate the molecular mechanisms underlying the occurrence of latent T. marneffei infection and immune evasion. The gene expression profile analysis in T. marneffei-infected mouse revealed that Pd-l1 exhibited the highest correlation strength with other hub genes, with a median of 0.60 (IQR: 0.50-0.69). T. marneffei infection upregulated the expression of PD-1 and PD-L1 in PBMCs from HIV patients, which was also observed in the T. marneffei-infected mouse and macrophage models. Treatment with a PD-L1 inhibitor significantly reduced fungal burden in the liver and spleen tissues of infected mice and in the kupffer-CTLL-2 co-culture system. PD-L1 inhibitor treatment increased CTLL-2 cell proliferation and downregulated the expression of PD-1, SHP-2, and p-SHP-2, indicating the activation of T cell viability and T cell receptor signaling pathway. Additionally, treatment with a PI3K inhibitor downregulated PD-L1 in T. marneffei-infected kupffer cells. Similar results were observed with treatment using the T. marneffei cell wall virulence factor β-glucan. Overall, T. marneffei infection upregulated PD-L1 expression in HIV / T. marneffei patients, mice, and kupffer cells. Treatment with a PD-L1 inhibitor significantly reduced fungal burden, while activating T cell activity and proliferation, thereby promoting fungal clearance. Furthermore, the PI3K signaling pathway may be involved in the regulation of PD-L1 by T. marneffei.

Simple Isolation of Cordycepin from Cordyceps militaris by Dual-Normal Phase Column Chromatography and Its Potential for Making Kombucha Functional Products

Cordycepin (3′-deoxyadenosine) is a potent bioactive metabolite of the medicinal fungus Cordyceps militaris, which has been increasingly exploited to treat various chronic diseases in humans. However, the current synthesis and purification procedures of cordycepin are principally laborious and complicated. This study provides a simple protocol approach to isolate and purify cordycepin from C. militaris by normal phase column chromatography at room temperature. Besides, this is the first to investigate the potential of cordycepin and cordycepin-included extracts from C. militaris for making Kombucha functional products. By a repeated column chromatography, an amount of 1.16 g of cordycepin is isolated from 2.8 kg of fruiting bodies of C. militaris, which obtained an efficiency of 83.26% compared to that estimated by high-performance liquid chromatography (HPLC). The purity of cordycepin is confirmed by thin-layer chromatography (TLC), HPLC, and proton nuclear magnetic resonance (1H NMR). In addition, kombucha-fermented extracts from cordycepin and cordycepin-included fractions show potential biological activities in terms of antioxidant, anti-diabetes via α-glucosidase inhibitory assay, and cytotoxicity via MTT assay on Meg-01 and HL-60 cell lines. Further studies on optimization of extraction protocol and verification of health benefits of kombucha products from cordycepin should be conducted prior to the official mass production.

The Molecular Evolution and Functional Divergence of Lamprey Programmed Cell Death Genes

The programmed cell death (PDCD) family plays a significant role in the regulation of cell survival and apoptotic cell death. However, the evolution, distribution and role of the PDCD family in lampreys have not been revealed. Thus, we identified the PDCD gene family in the lamprey genome and classified the genes into five subfamilies based on orthologs of the genes, conserved synteny, functional domains, phylogenetic tree, and conserved motifs. The distribution of the lamprey PDCD family and the immune response of the PDCD family in lampreys stimulated by different pathogens were also demonstrated. In addition, we investigated the molecular function of lamprey PDCD2, PDCD5, and PDCD10. Our studies showed that the recombinant lamprey PDCD5 protein and transfection of the L-PDCD5 gene induced cell apoptosis, upregulated the expression of the associated X protein (BAX) and TP53 and downregulated the expression of B cell lymphoma 2 (BCL-2) independent of Caspase 3. In contrast, lamprey PDCD10 suppressed apoptosis in response to cis-diaminedichloro-platinum (II) stimuli. Our phylogenetic and functional data not only provide a better understanding of the evolution of lamprey PDCD genes but also reveal the conservation of PDCD genes in apoptosis. Overall, our results provide a novel perspective on lamprey immune regulation mediated by the PDCD family.