Jie Dou

Mitophagy, the process of removing mitochondria through the autophagy–lysosome pathway, is crucial for maintaining cellular homeostasis. However, its regulatory mechanisms and pathological implications remain poorly understood. In our study, we revealed that decidual protein induced by progesterone (DEPP) plays a significant role in mitophagy through the DEPP–HIF‐1α–BNIP3/NIX axis. Our findings indicate that interaction between DEPP and hypoxia‐inducible factor 1‐alpha (HIF‐1α) enhances HIF‐1α stability, thereby promoting the transcription of HIF‐1 target genes. The enhanced protein stability of HIF‐1α not only activates mitophagy by stimulating the transcription of BCL2‐interacting protein 3 ( BNIP3 ) and BCL2‐interacting protein 3‐like ( BNIP3L ; also known as NIX ) mRNA but also influences cellular metabolic reprogramming by promoting the transcription of glycolysis‐related genes. In conclusion, our findings suggest that DEPP may act as a potential regulator of mitophagy and HIF‐1α, playing an important role in maintaining cellular metabolic and energy homeostasis.

Introduction: Chronic hepatitis B virus (HBV) infection continues to pose a significant global health burden, and current therapies rarely target the viral covalently closed circular DNA reservoir. Kaempferol (KP), a major flavonoid found in various herbs and plants, exhibits diverse bioactivities, but its potential anti-HBV activity remains unclear. This study aims to investigate the anti-HBV potential of KP and to elucidate its underlying mechanisms. Methods: The HBV-infected Huh7D ^hNTCP cell, viral stable transfection cell HepG2.2.15, as well as a hydrodynamic injection-based chronic HBV infection mouse model, were established to evaluate the antiviral effects of KP. The levels of HBV RNAs, DNA and proteins were detected using ELISA, western blot, qPCR, immunofluorescence and immunohistochemistry. To investigate the mechanisms, viral promoter activities were assessed via dual-luciferase reporter assays, and relevant transcription factors were validated through qPCR and western blot analysis. Results: KP dose- and time-dependently reduced the levels of viral antigens, RNA, and DNA in vitro , and also significantly lowered viral markers and attenuated HBV-induced hepatic pro-inflammatory cytokines expression in vivo . Furthermore, KP acted in combination with the nucleoside analog entecavir to suppress HBV replication. Mechanistically, KP strongly inhibited the transcriptional activity of the HBV core promoter (Cp), and enhanced the phosphorylation of both extracellular signal-regulated kinase (ERK) and its downstream target forkhead box protein O1 (FOXO1). Importantly, the ERK-specific inhibitor U0126 completely abolished the antiviral effects of KP, confirming that its antiviral activity depended on the ERK/FOXO1 pathway. Discussion: Collectively, our results indicate that KP activates ERK-dependent FOXO1 phosphorylation, leading to transcriptional repression of the HBV Cp and thereby suppression of viral replication. These findings identify KP as a potential candidate for developing novel therapeutics against chronic HBV infection.

Background: The abnormal expression and overactivation of the epidermal growth factor receptor (EGFR), a typical cancer marker for non-small cell lung cancer (NSCLC), are closely related to the tumorigenesis and progression of NSCLC. However, the endocytosis mechanism of EGFR in lung cancer is not yet known. Epsin3 (EPN3), a member of the endocytic adaptor protein family, is essential for the endocytosis of multiple receptors. In this study, we aimed to investigate the role of EPN3 in modulating EGFR function, its effects on NSCLC progression, and its potential involvement in tyrosine kinase inhibitor (TKI) resistance, which remains a significant hurdle in NSCLC treatment. Results: Our findings revealed that the expression of EPN3 is significantly up-regulated in NSCLC patients. Elevated EPN3 expression was proportional to shorter overall survival in patients with NSCLC. Functional analyses revealed that EPN3 directly interacts with EGFR, enhancing its recycling to the plasma membrane and preventing its degradation via the lysosomal pathway. This stabilization of EGFR led to sustained downstream signalling, promoting NSCLC cell proliferation and migration. Notably, mutations in the EGFR tyrosine kinase domain, which typically confer resistance to TKIs, did not alter the regulatory effect of EPN3. Conclusions: EPN3 enhances EGFR signalling by promoting its recycling and stability, contributing to NSCLC progression and TKI resistance. Targeting EPN3 could offer a novel therapeutic strategy to overcome drug resistance in EGFR-driven NSCLC.

Hepatitis B virus (HBV) infection remains a major global threat to human health worldwide. Recently, the Chinese medicines with antiviral properties and low toxicity have been a concern. In our previous study, Eupolyphaga sinensis Walker polysaccharide (ESPS) has been isolated and characterized, while its antiviral effect on HBV remained unclear. The anti-HBV activity of ESPS and its regulatory pathway were investigated in vitro and in vivo. The results showed that ESPS significantly inhibited the production of HBsAg, HBeAg, and HBV DNA in the supernatants of HepG2.2.15 in a dose-dependent manner; HBV RNA and core protein expression were also decreased by ESPS. The in vivo studies using HBV transgenic mice further revealed that ESPS (20 and 40 mg/kg/2 days) significantly reduced the levels HBsAg, HBeAg, and HBV DNA in the serum, as well as HBV DNA and HBV RNA in mice liver. In addition, ESPS activated the Toll-like receptor 4 (TLR4) pathway; elevated levels of IFN-β, TNF-α, and IL-6 in the serum were observed, indicating that the anti-HBV effect of ESPS was achieved by potentiating innate immunity function. In conclusion, our study shows that ESPS is a potential anti-HBV ingredient and is of great value in the development of new anti-HBV drugs.

The currently available drugs against influenza A virus primarily target neuraminidase (NA) or the matrix protein 2 (M2) ion channel. The emergence of drug-resistant viruses requires the development of new antiviral chemicals. Our study applied a cell-based approach to evaluate the antiviral activity of a series of newly synthesized benzoic acid derivatives, and 4-(2,2-Bis(hydroxymethyl)-5-oxopyrrolidin-l-yl)-3-(5-cyclohexyl-4H-1,2,4-triazol-3-yl)amino). benzoic acid, termed NC-5, was found to possess antiviral activity. NC-5 inhibited influenza A viruses A/FM/1/47 (H1N1), A/Beijing/32/92 (H3N2) and oseltamivir-resistant mutant A/FM/1/47-H275Y (H1N1-H275Y) in a dose-dependent manner. The 50% effective concentrations (EC₅₀) for H1N1 and H1N1-H275Y were 33.6 μM and 32.8 μM, respectively, which showed that NC-5 had a great advantage over oseltamivir in drug-resistant virus infections. The 50% cytotoxic concentration (CC₅₀) of NC-5 was greater than 640 μM. Orally administered NC-5 protected mice infected with H1N1 and H1N1-H275Y, conferring 80% and 60% survival at 100 mg/kg/d, reducing body weight loss, and alleviating virus-induced lung injury. NC-5 could suppress NP and M1 protein expression levels during the late stages of viral biosynthesis and inhibit NA activity, which may influence virus release. Our study proved that NC-5 has potent anti-influenza activity in vivo and in vitro, meaning that it could be regarded as a promising drug candidate to treat infection with influenza viruses, including oseltamivir-resistant viruses.

Baicalein has efficient antitumor properties and has been reported to promote the apoptosis of several human cancer cell lines. Decidual protein induced by progesterone (DEPP), a transcriptional target of Forkhead Box O, was originally identified from the human endometrial stromal cell cDNA library. However, the expression and physiological functions of DEPP in human colon cancer cells remain to be fully elucidated. In the present study, it was reported that baicalein stimulated apoptosis and morphological changes of HCT116, A549 and Panc‑1 cells in a dose-dependent manner. It also upregulated the mRNA and protein levels of DEPP and growth arrest and DNA damage-inducible 45α (Gadd45a). In addition, the overexpression of DEPP promoted mitogen-activated protein kinase (MAPK) phosphorylation. To further investigate the role of DEPP and Gadd45a in baicalein-induced apoptosis, HCT116 cells were transfected with small interfering RNA against either DEPP or Gadd45a as in vitro models. Through an Annexin V/PI double staining assay, it was observed that baicalein-induced apoptosis was impaired by the inactivation of either DEPP or Gadd45a, which in turn restricted the baicalein-induced activation of caspase‑3 and caspase‑9 and phosphorylation of MAPKs. In addition, the inhibition of c‑Jun N‑terminal kinase (JNK)/p38 activity with SP600125/SB203580 decreased the expression of Gadd45a, whereas the inactivation of extracellular signal-regulated kinase with SCH772984 had no effect on the expression of Gadd45a. Taken together, these results demonstrated that baicalein induced the upregulation of DEPP and Gadd45a, which promoted the activation of MAPKs with a positive feedback loop between Gadd45a and JNK/p38, resulting in a marked apoptotic response in human colon cancer cells. These results indicated that baicalein is a potential antitumor drug for the treatment of colon cancer.

Baicalin was identified as a neuraminidase (NA) inhibitor displaying anti-influenza A virus (IAV) activity. However, its poor solubility in saline has limited its use in the clinic. We generated sodium baicalin and showed that it exhibited greatly increased solubility in saline. Its efficacy against oseltamivir-resistant mutant A/FM/1/47-H275Y (H1N1-H275Y) was evaluated in vitro and in vivo. Results showed that 10 μM of sodium baicalin inhibited A/FM/1/47 (H1N1), A/Beijing/32/92 (H3N2) and H1N1-H275Y in MDCK cells in a dose-dependent manner, with inhibitory rates of 83.9, 75.9 and 47.7%, respectively. Intravenous administration of sodium baicalin at 100 mg/kg/d enabled the survival of 20% of H1N1-H275Y-infected mice. The treatment alleviated body weight loss and lung injury. Moreover, sodium baicalin exerted a clear inhibitory effect on NAs. The IC₅₀ values of sodium baicalin against H1N1-H275Y and cells-expressing A/Anhui/1/2013-R294K (H7N9-R294K) NA protein (N9-R294K) were 214.4 μM and 216.3 μM. Direct interactions between sodium baicalin and NA were observed, and we simulated the interactions of sodium baicalin with N9-R294K and N9 near the active sites of OC-N9-R294K and OC-N9. The residues responsible for the sodium baicalin-N9-R294K and sodium baicalin-N9 interactions were the same, confirming that sodium baicalin exerts effects on wild-type and oseltamivir-resistant viral strains.

Baicalin is a natural flavonoid glycoside which has potent anti-tumor and antioxidant activity in cancer cells. In the present study, we found that baicalin treatment significantly induced senescence in colon cancer cells. Furthermore, baicalin upregulated the expression of decidual protein induced by progesterone (DEPP) in HCT116 colon cancer cells, which accompanied with the activation of Ras/Raf/MEK/ERK and p16^INK4A/Rb signaling pathways. Meanwhile, these phenomena also appeared under the anti-oxidation effect exerted by baicalin. In addition, ectopic expression of DEPP in HCT116 cells significantly induced the activity of senescence-associated β-galactosidase (SA-β-Gal) in tumor cells regulated by Ras/Raf/MEK/ERK signaling pathway. Knockdown of DEPP by RNA interference efficiently counteracted the baicalin-mediated growth inhibition, senescence and cell cycle arrest in cancer cells. Importantly, in a xenograft mouse model of human colon cancer, we further confirmed that baicalin treatment dramatically inhibited tumor growth, which was due to the induction of tumor cellular senescence via the upregulation of DEPP and the activation of Ras/Raf/MEK/ERK signaling in vivo. In addition to baicalin treatment, we found that the hypoxia-response protein DEPP functions as a positive regulator involving the regulations of Ras/Raf/MEK/ERK signaling pathway and inhibition of human colon cancer by other anti-oxidative drugs, such as curcumin and sulforaphane, resulting in tumor cellular senescence. These results collectively suggest that baicalin upregulates the expression of DEPP and activates its downstream Ras/Raf/MEK/ERK and p16^INK4A/Rb pathways by acting as an antioxidant, leading to senescence in colon cancer cells.