Cellular and Molecular Life Sciences最新文献

Although androgen receptor (AR) inhibitors such as enzalutamide are initially effective in castration resistant prostate cancer through suppression of AR signaling pathway, acquired resistance invariably develops, presenting a significant therapeutic challenge. Understanding the mechanisms of enzalutamide resistance (ENZR) is essential for developing improved therapeutic strategies. Here, we demonstrated that ZNF711 was significantly overexpressed in ENZR, and high ZNF711 levels correlated with poor clinical outcomes. Functionally, ZNF711 promoted ENZR progression both in vitro and in vivo. Mechanistically, ZNF711 directly bound to the AR promoter, transcriptionally upregulating AR expression. ZNF711 knockdown markedly reduced AR chromatin occupancy at target loci. Additionally, ZNF711 formed a complex with BMI1 and AR, enhancing AR signaling pathway by suppressing CpG methylation at the promoter of AR and its downstream target genes (e.g., KLK3, TMPRSS2), thereby potentiating AR transcriptional activity. Notably, targeting ZNF711 with antagonistic chimeric siRNA restored enzalutamide sensitivity in vivo. Collectively, our findings establish ZNF711 as a critical regulator of ENZR that promotes resistance by dually modulating the AR signaling pathway via transcriptional activation and epigenetic demethylation. Targeting the ZNF711-AR axis represents a novel therapeutic strategy to overcome ENZR in prostate cancer.

The IQGAP protein family-comprising IQGAP1, IQGAP2, and IQGAP3-exhibits structural similarity but fulfils distinct cellular functions. We previously demonstrated that IQGAP1 is recruited to Marburg virus (MARV)-induced inclusion bodies (IBs) and associates with motile nucleocapsids. To further elucidate the roles of IQGAP proteins in the MARV life cycle, we generated Huh-7 cell lines with single, combined, or triple knockouts (KOs) of IQGAP isoforms. Loss of IQGAP proteins consistently reduced cellular permissiveness to MARV infection and impaired multiple key viral processes: (i) transcription and replication efficiency was diminished predominantly by IQGAP3 KO; (ii) virus release was most notably reduced in IQGAP3 KO cells, whereas cell-to-cell spread was more strongly impaired in IQGAP1 KO cells; and (iii) although actin tails continued to form at nucleocapsids in triple KO cells, long distance nucleocapsid transport was altered, with reduced spatial displacement efficiency observed in both IQGAP1 KO and IQGAP3 KO cells. The expression of individual IQGAPs in triple KO cells demonstrated their functionality and ability to partially restore the phenotype of wild-type cells. These findings identify IQGAPs as critical host factors that support MARV transcription/replication, nucleocapsid transport, and viral spread, likely through modulation of actin dynamics.

Mitochondrial function and its regulation within the placenta are critical for maintaining a healthy pregnancy. This study investigated the role of G-protein signaling 12 (RGS12) in placental mitochondrial function and pregnancy outcomes. RGS12 was found to be localized within the mitochondria of placental trophoblast cells. RGS12 knockdown in human placental cells resulted in decreased mitochondrial abundance, impaired oxidative phosphorylation, and reduced antioxidant capacity. Mechanistically, RGS12 enhanced the function of ATP5B, a key mitochondrial enzyme, by promoting its tyrosine phosphorylation. In a mouse model, placental RGS12 deficiency led to reduced tolerance to preterm birth (PTB) challenge, decreased fetal weight, and trophoblast cell death. These adverse effects were associated with diminished ATP synthase activity and activation of the p38MAPK signaling pathway, while restoring RGS12 expression improved the phenotype of mitochondrial dysfunction in placental trophoblast cells. Furthermore, reduced RGS12 expression and impaired mitochondrial function were observed in placentas from cases experiencing PTB. Collectively, these findings provide hitherto undocumented evidence of a specific molecular mechanism by which placental mitochondrial dysfunction contributes to adverse pregnancy outcomes. Our study suggests that RGS12 may represent a novel therapeutic target for improving pregnancy outcomes through its role in regulating placental mitochondrial function.

Objectives: Clarify the role of progranulin (PGRN) in renal fibrosis and its regulatory mechanism on macrophage efferocytosis.

Methods: To investigate the effect of PGRN on renal fibrosis, construct PGRN-deficient (PGRN^-/-) mice and establish a renal fibrosis model induced by unilateral ureteral obstruction (UUO). The degree of kidney injury and fibrosis was evaluated through histological examination, immunohistochemical detection, enzyme-linked immunosorbent assay, and TUNEL assay. To evaluate the effect of PGRN on the efferocytosis ability, BMDMs extracted from PGRN^-/- mice were co-cultured with apoptotic HK-2 cells. Efferocytosis activity was evaluated by flow cytometry and immunofluorescence. To analyze the molecular mechanism, conduct a transcriptomics analysis. The protein binding relationship was verified through co-immunoprecipitation and molecular docking. The changes in PGRN after interfering with signaling pathways were detected by qRT-PCR and Western blotting.

Results: The deficiency of PGRN significantly alleviated the renal tubular damage and tubular apoptosis induced by UUO. Additionally, it was observed that the infiltration of Mertk^{^+}CD68^{^+} macrophages increased, indicating that PGRN knockout enhanced phagocytosis. In vitro experiments showed that PGRN knockout BMDMs had enhanced phagocytosis of apoptotic HK2. Sequencing results revealed significant differences in the JAK-STAT pathway. Further studies found that the functional effect of this pathway was mainly mediated by STAT1/2, and overexpression of STAT1/2 reversed the enhanced phagocytosis induced by PGRN deficiency, rather than JAK. Mechanistically, PGRN directly binds to PPAR-δ, and its absence upregulates PPAR-δ, inhibiting the downstream expression of STAT1/2, thereby enhancing phagocytosis. However, knocking down or mutating PPAR-δ eliminates this effect.

Conclusion: PGRN inhibits macrophage efferocytosis during renal fibrosis by binding and inhibiting PPAR-δ, thereby activating the STAT1/2 signaling pathway and impairing the clearance of apoptotic cells.

This study aims to elucidate the synergistic protective mechanism of the AMPK agonist 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) in ischemia-reperfusion injury -associated acute kidney injury (IRI-AKI). By establishing a hypoxia/reoxygenation (H/R) injury model using human proximal tubule cells (HK-2) and IRI-AKI rat model, and employing molecular techniques including qRT-PCR, western blotting, serum biochemical assays, renal tissue hematoxylin and eosin staining, immunofluorescence, and transmission electron microscopy (TEM), we demonstrated that AICAR activates AMPK, leading to the significant downregulation of TXNIP and NLRP3, blocks Caspase-1-dependent release of IL-1β and IL-18, and ultimately suppresses pyroptosis, thereby alleviating renal inflammatory injury. Furthermore, AICAR restored mitochondrial membrane potential and ATP levels in H/R-treated HK-2 cells, reduced reactive oxygen species production in renal tissues of IRI-AKI rats, and elevated levels of antioxidant enzymes. Concurrently, utilizing targeted metabolomics technology, we discovered that AICAR effectively restores the levels of multiple metabolites associated with glycolysis, the TCA cycle, the urea cycle, and tryptophan metabolism and alleviates lipid deposition in IRI-AKI. This confirms that AICAR alleviates IRI-AKI by activating AMPK to restore impaired cellular energy metabolism, improve mitochondrial function, and ameliorate oxidative stress. Notably, this study is the first to reveal that AICAR, via AMPK activation, synchronously regulates dual protective pathways: "pyroptosis inhibition" and "energy metabolism remodeling." This synergistic protective mechanism may represent the core advantage distinguishing AICAR from other potential therapeutic strategies, highlighting its substantial translational potential as a multi-mechanism synergistic therapeutic agent. Our findings provide an innovative dual-regulatory ("pyroptosis-energy metabolism") therapeutic strategy for the clinical prevention and treatment of IRI-AKI.