Cellular and Molecular Life Sciences最新文献

Chronic inflammatory diseases are a significant global burden and are associated with dysregulated resolution of inflammation. Therefore, promoting the process of resolution is a promising therapeutic approach. This study presents the potent anti-inflammatory and pro-resolving effects of a natural product-derived compound called C81. Administration of C81 in a therapeutic window resolved inflammation in the murine imiquimod-induced psoriasis model, and reduced microglial infiltration in a laser-induced choroidal neovascularisation model. Investigations into the underlying mechanisms of C81 identified the DYRK1B/STAT3 axis as a new regulator of inflammatory processes in leukocytes. The inhibition of DYRK1B by C81 resulted in attenuated STAT3 phosphorylation. The depletion of STAT3-regulated gene expression led to the inhibition of leukocyte adhesion and migration due to reduced integrin activation, and in addition to the inhibition of the release of pro-inflammatory mediators such as cytokines and eicosanoids. Importantly, the pro-resolving effects of C81 included the cell type-specific induction of apoptosis in neutrophils and a subsequent increase in efferocytosis. In conclusion, we report the DYRK1B/STAT3 axis as a novel and promising therapeutic target for activating the resolution of inflammation.

Traumatic brain injury (TBI) is a significant global health issue, characterized by high rates of morbidity and mortality, along with substantial economic strains on healthcare systems. This study explores the potential of Aminophylline (AMP), a medication traditionally used for cardiovascular conditions and bronchiectasis, to enhance TBI outcomes by protecting against neuronal damage. Our findings indicate that AMP treatment significantly reduces neuronal ferroptosis in the cortex, leading to less tissue damage and notable improvements in cognitive and motor functions in mice subjected to controlled cortical impact (CCI). Additionally, we found that TBI resulted in decreased expression of miR-128-3p, a reduction that was further strengthened by AMP treatment. Gain-of-function experiments showed that overexpressing miR-128-3p increases neuronal ferroptosis by targeting Slc7a11, indicating how AMP mitigates cognitive and motor impairments in CCI mice. This study highlights the potential of AMP in treating TBI through the miR-128-3p/Slc7a11 pathway, marking the first report of its protective effects against ferroptosis in TBI.

The intracellular pathogen has evolved sophisticated mechanisms to evade host immune defenses by secreting different virulence factors. In our previous study, the eukaryotic factor STPKLRR was identified from the intracellular pathogen Vibrio splendidus AJ01 and shown to facilitate promote AJ01 internalization by mediating actin-dependent coelomocytes phagocytosis. However, the molecular mechanisms underlying AJ01'escaped from the phagosome remained largely unclear. In this study, a novel eukaryotic-like factor was identified, containing both the Serine/Threonine/Tyrosine (STYKc) domain and protein phosphatase 2 C (PP2C) domain (denoted as Sppsk1), which was essential for AJ01 phagosome escape. Deletion of Sppsk1 significantly increased phagolysosome maturation and reduced the intracellular AJ01 levels compared to the wild AJ01. Mechanistic analysis showed that the STYKc domain of Sppsk1 directly phosphorylated phagosome H⁺ transport complex subunit ATP6V1C at Serine-356, resulting in the inhibition of phagosome acidification in coelomocytes and promoting AJ01 phagosome survival. Moreover, the PP2C domain of Sppsk1 dephosphorylated phosphatidylinositol-3-bisphosphate [PtdIns(3)P], converting it to PtdIns(3)P to phosphatidylinositol (PtdIns). Reduction of PtdIns(3)P on phagosomes hindered early endosome antigen 1 (EEA1) recruitment, thereby inhibiting phagosome maturation. These findings demonstrated that Sppsk1 in AJ01 could achieve phagosome escape by two strategies including inhibiting host coelomocytes' phagosome acidification and maturation, which advanced our knowledge of the general biology of pathogen-host interactions.

Coenzyme A (CoA) is a crucial metabolite involved in various biological processes, encompassing lipid metabolism, regulation of mitochondrial function, and membrane modeling. CoA deficiency is associated with severe human diseases, such as Pantothenate Kinase-Associated Neurodegeneration (PKAN) and CoASY protein-associated neurodegeneration (CoPAN), which are linked to genetic mutations in Pantothenate Kinase 2 (PANK2) and CoA Synthase (CoASY). Although the association between CoA deficiency and mitochondrial dysfunction has been established, the underlying molecular alterations and mechanisms remain largely elusive. In this study, we investigated the detailed changes resulting from the functional decline of CoASY using the Drosophila model. Our findings revealed that a reduction of CoASY in muscle and brain led to degenerative phenotypes and apoptosis, accompanied by impaired mitochondrial integrity. The release of mitochondrial DNA was notably augmented, while the assembly and activity of mitochondrial electron transport chain (ETC) complexes, particularly complex I and III, were diminished. Consequently, this resulted in decreased ATP generation, rendering the fly more susceptible to energy insufficiency. Our findings suggest that compromised mitochondrial integrity and energy supply play a crucial role in the pathogenesis associated with CoA deficiency, thereby implying that enhancing mitochondrial integrity can be considered a potential therapeutic strategy in future interventions.

Background: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common disorder associated with voiding symptoms and pain in the pelvic or perineal area. Macrophages, particularly the pro-inflammatory M1 subtype, are crucial initiating of CP/CPPS. Interferon regulatory factor 7 (Irf7) has been implicated in promoting M1 polarization, contributing to the onset and progression of autoimmunity. However, the role of Irf7 in the etiology and progression of CP/CPPS remains unclear.

Method: We established the experimental autoimmune prostatitis (EAP) mouse model by subcutaneous injection of prostate antigen combined with complete Freund's adjuvant. Six weeks after the first immunization, we analyzed the prostates, spleen, and blood to assess the degree of prostate inflammation, Irf7 expression levels, glycolysis, and M1 polarization to evaluate whether Irf7 could exacerbate the development of EAP by enhancing Hif-1α transcription, thereby increasing glycolysis and M1 polarization. Further investigations included sh-Irf7 intervention, Dimethyloxalylglycine (a Hif-1α agonist), and in vitro M1 polarization experiments. We also employed ChIP assays, dual-luciferase reporter assays, and q-PCR to explore if Irf7 could directly interact with the Hif-1α promoter in macrophages.

Results: In the EAP mouse and cell models, elevated Irf7 expression was observed in inflamed tissues and cells. Reducing Irf7 expression decreased M1 cell glycolysis by inhibiting the nuclear translocation of Hif-1α, thus mitigating M1 cell polarization. Additionally, Irf7 was identified as a transcription factor that regulates Hif-1α transcription by interacting with its promoter in macrophages, confirmed through ChIP and dual-luciferase assays. Co-culturing macrophage cells with 3T3 fibroblasts with reduced Irf7 levels resulted in decreased fibrosis, and a significant reduction in prostate tissue fibrosis was noted in mice with Irf7 knockdown.

Conclusion: Our findings indicate that Irf7 can contribute to the development and progression of CP/CPPS by promoting glycolysis, which can enhance both M1 polarization as well as interstitial fibrosis in the prostate. This process was found to be mediated by the upregulation of Hif-1α transcription, presenting new potential therapeutic targets for managing CP/CPPS.

RNA interference (RNAi) and autophagy are two pivotal biological processes that regulate virus replication. This study explored the complex relationship between autophagy and RNAi in controlling influenza virus replication. Initially, we reported that influenza virus (H9N2) infection increases the viral load and the expression of autophagy markers while inhibiting the RNAi pathway. Subsequent studies employing autophagy enhancer and inhibitor treatments confirmed that avian influenza virus (AIV, H9N2) promotes viral replication by enhancing autophagy pathways. Further analysis revealed that ATG7, an autophagy protein, can interact with dicer to affect its antiviral functions. Finally, we discovered that infection with other avian RNA viruses, including infectious bursal disease virus (IBDV) and infectious bronchitis virus (IBV), induced the upregulation of ATG7, which blocked the RNAi pathway to facilitate virus replication. Our findings suggested that virus infection might trigger the upregulation of autophagy and downregulation of the RNAi pathway, revealing a complex interaction between these two biological processes in the defence against viral replication.

Elevated intraocular pressure (IOP) is the primary risk factor for glaucoma, a leading cause of irreversible blindness worldwide. IOP homeostasis is maintained through a balance between aqueous humor production and its drainage through the trabecular meshwork (TM)/Schlemm's Canal (SC) outflow pathway. Prior studies by our laboratory reported a key role of mechanical forces and primary cilia (PC)-dependent stretch-induced autophagy in IOP homeostasis. However, the precise mechanism regulating this process remains elusive. In this study, we investigated the upstream signaling pathway orchestrating autophagy activation during cyclic mechanical stretch (CMS) in primary cultured human TM cells, using biochemical and cell biological analyses. Our results indicate that TM cells express catalytic subunits of class IA PI3Ks (PIK3CA, B, and D), and that inhibition of class IA isoforms, but not class II and III, significantly prevent CMS-induced autophagy. Importantly, PIK3CA was found to localize in the PC. Furthermore, we identified a coordinated action of Class IA PI3Ks along INPP4A/B, a 4' inositol phosphatase, responsible for the formation of PI(3,4)P₂ and PI(3)P and stretch-induced autophagy in TM cells. These findings contribute to a deeper understanding of the molecular mechanisms underlying IOP homeostasis.

Ageing is a degenerative process characterised by a decline in physiological functioning of the organism. One of the core regulators of cellular ageing are telomeres, repetitive DNA sequences of TTAGGG that cap the ends of chromosomes and are maintained by the ribonucleoprotein complex, telomerase. Age-dependent progressive loss of the telomere ends eventually induces cell cycle arrest for the induction of either replicative senescence or apoptosis. It was previously established that overexpression of the 37 kDa/ 67 kDa laminin receptor (LRP/LR) increased telomerase activity and telomere length while concomitantly reducing senescence markers in aged normal cells in vitro. Therefore, it was hypothesized that elevating LRP/LR in vivo may increase telomerase activity and hinder the ageing process on an organism scale. To this end, aged C57BL/6J mice were treated/transfected to induce an overexpression of LRP::FLAG. Various physiological tests and histological analyses were performed to assess overall organism fitness as well as to discern the treatments' ability at reducing tissue degeneration and atrophy. It was found that mice overexpressing LRP::FLAG displayed improved physiological characteristics and markedly less tissue degeneration and atrophy when compared to control and non-treated mice. Alongside these improvements, certain organs displayed increased telomerase activity with a corresponding elongation in average telomere length. In addition the overexpression of LRP::FLAG significantly improved various proliferative and anti-ageing associated proteins while causing a concomitant decrease in senescence associated proteins. These findings are therefore indicative of a novel function of LRP/LR delaying the onset of senescence, while also promoting healthier ageing through elevating TERT and telomerase activity.

Rupture of vulnerable carotid atherosclerotic plaque is one of the leading causes of ischemic stroke. However, the mechanisms driving the transition from stable to vulnerable plaques have not yet been elucidated. NR4A1 is an orphan nuclear receptor that functions in various inflammatory diseases. To explore the role of NR4A1 in vulnerable plaque formation, we generated a vulnerable plaque mouse model by combining partial ligation of the left common carotid artery and left renal artery in ApoE^-/- and ApoE^-/-;NR4A1^-/- mice. Our research revealed that NR4A1 deficiency significantly worsened the pathology of vulnerable plaque, increasing intraplaque hemorrhage, rupture with thrombus, and the occurrence of multilayer with discontinuity. Moreover, NR4A1 deficiency exacerbated macrophage infiltration, inflammation, and oxidative stress. Mechanistically, we identified Bcat1 as the target of NR4A1. NR4A1 modulated the integrated stress response (ISR) in macrophages by transcriptionally inhibiting Bcat1, thus influencing the progression of vulnerable plaque. ISR inhibitor GSK2606414 or Bcat1 inhibitor ERG240 significantly ameliorated atherosclerotic plaque formation and increased plaque stability. Notably, supplementation with Celastrol, an herbal extract, stabilized atherosclerotic plaques in mice. These findings suggest that NR4A1 deficiency exacerbates vulnerable plaque by activating ISR via targeting Bcat1. The NR4A1/Bcat1/ISR axis is therefore an important therapeutic target for stabilizing atherosclerotic plaque.

Acute kidney injury (AKI) is a clinical syndrome caused by various etiologies and causes a rapid decline in renal function in a short period of time. The most common internal modification of mRNAs is the N6-methyladenosine (m6A) modification, which is important for controlling gene expressions. However, the role of m6A modification in AKI is largely unknown. Here, we characterized the role of zinc finger CCCH-type containing 13 (ZC3H13), which is a type of m6A methyltransferases, in cisplatin-induced AKI mouse model and a cisplatin-treated human proximal tubular epithelial cell line (HK2 cells). The ZC3H13 knockdown attenuated the G2/M cell cycle arrest and apoptosis in HK2 cells. In the ZC3H13-overexpressed HK2 cells, the opposite was true. In the presence of cisplatin, mice with the AAV9-mediated silencing of ZC3H13 exhibited milder cell cycle arrest, apoptosis, and renal injury. In addition, we identified nucleic acid binding protein 1 (NABP1) as a target of ZC3H13, which was verified by knocking down and overexpressing ZC3H13 in HK2 cells. Moreover, we confirmed that the ZC3H13-mediated m6A modification stabilized NABP1 mRNA and was discriminated by insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1). In conclusion, ZC3H13 promoted the m6A modification of NABP1 and enhanced its mRNA stability through an IGF2BP1-dependent mechanism. The inhibition of ZC3H13 alleviated the G2/M cell cycle arrest, apoptosis and kidney injury by affecting the expression of NABP1. These results show that the ZC3H13/NABP1 axis is a promising AKI treatment target.