Diabetic peripheral neuropathy (DPN), a severe complication of Type 2 diabetes (T2D), is marked by progressive distal-to-proximal axonal degeneration. Although animal models have advanced our understanding of DPN pathogenesis, preclinical successes rarely translate into effective therapies, underscoring the need for models that more faithfully mirror human disease. In this study, we characterized two polygenic mouse strains, NONcNZO10/LtJ (RCS10) and TALLYHO/JngJ (TH), and found that both models developed obesity, hyperglycemia, dyslipidemia, and DPN by 24 weeks of age. However, hyperinsulinemia was observed only in RCS10 mice. Compared to monogenic and high-fat diet-induced models, the metabolic and neuropathic phenotypes of RCS10 and TH more closely resembled those of human DPN. In the second phase of the study, RCS10 mice were subjected to a calorie-restricted diet (60% of standard intake) for 8 weeks, which improved metabolic health and restored large fiber function, although intraepidermal nerve fiber density remained unchanged. Together, these findings identify RCS10 and TH mice as clinically relevant polygenic models for studying DPN pathogenesis and evaluating targeted therapeutic strategies.
In contrast to mammals, adult zebrafish (Danio rerio) undergo neuronal regeneration following spinal cord injury (SCI), thereby allowing successful functional recovery. The adaptive regenerative response to SCI in zebrafish includes injury-induced proliferation of ependymal radial glial cells (ERGs) and neurogenesis. The molecular mechanisms underlying injury-induced neurogenesis in "regenerative" species, such as zebrafish, have not been fully elucidated and are an area of great interest. In mammals, the purinergic receptor P2Y2 has been shown to mediate NSC proliferation and neurogenesis, but its potential role following SCI or in zebrafish is unknown. Here, we found that P2Y2 is dysregulated following SCI in adult zebrafish, and pharmacological inhibition decreased swim capacity 2 weeks after injury. While P2Y2 was expressed on actively proliferating ERGs, antagonism of this receptor did not affect their proliferation levels. However, P2Y2 inhibition did attenuate SCI-induced neurogenesis and is strongly expressed by immature and mature neurons in adult zebrafish. Overall, P2Y2 serves as a pro-neurogenic factor during injury-induced neurogenesis and contributes to the recovery of swimming behavior in adult zebrafish.
IgA nephropathy (IgAN) is a progressive glomerular disease marked by mesangial IgA deposition, inflammation, podocyte injury, and fibrogenesis. Although understanding of its pathophysiology has advanced, effective disease-modifying therapies are still limited. Sarsasapogenin (SAR), a natural steroidal sapogenin, demonstrates anti-inflammatory, antioxidant, and antifibrotic properties by modulating signaling pathways such as NF-κB and TGF-β. The present study investigated the renoprotective effects of SAR in an experimental model of IgAN. IgAN was induced in Sprague-Dawley rats using bovine serum albumin (BSA), carbon tetrachloride (CCl4), and lipopolysaccharide (LPS). SAR was administered at 60 mg/kg/day from week 7 through week 12. Renal function, histopathological changes (Oxford MEST-C classification), and immunohistochemical, ultrastructural, and molecular alterations were assessed. Induction of IgAN resulted in significant proteinuria, renal dysfunction, mesangial IgA deposition, and podocyte alterations, accompanied by increased expression of IL-6, TGF-β1, SMAD3, fibronectin, and α-SMA. Masson's trichrome staining did not reveal excessive collagen deposition, indicating early fibrogenic activity rather than established fibrosis. SAR treatment significantly reduced proteinuria and improved renal function, accompanied by decreased IL-6-mediated inflammation and reduced activation of the TGF-β1/SMAD3 pathway. SAR also preserved podocyte-associated proteins, including nephrin and podocin, and lowered pre-fibrotic markers. Ultrastructural analysis confirmed preservation of podocyte architecture, with reduced foot process fusion and mesangial matrix expansion. Overall, sarsasapogenin modulated multiple targets in experimental IgAN by reducing inflammation and early fibrogenesis while supporting podocyte integrity. These findings indicate that SAR is a promising therapeutic candidate for early IgAN, although further mechanistic and long-term studies are warranted.
Intracranial aneurysms (IAs) represent a significant and potentially life-threatening category of disease, and there is currently a lack of effective treatment options aimed at preventing the progression of the disease. Accordingly, this study is dedicated to exploring and identifying effective drug targets that can help in the prevention of both the formation and rupture of IAs, along with a detailed examination of the underlying potential mechanisms involved in these processes. The data related to IAs for this research was obtained from the ISGC Biobank and UK Biobank. Then, we investigated the possible biological functions and unintended consequences of targeting the specific genes that were highlighted in IAs by using mediation analysis, virtual knockout experiments, and PW-MR studies. A total of 5 unique potential drug targets for IAs (FKTN, MAP3K1, PSMA4, SLC22A4, ADAM17), 4 unique potential drug targets for SAH (PSMA4, ADAM17, GPR160, SLC22A4), and 2 unique potential drug targets for UIA (SLC22A4, PRCP) were identified across brain or blood samples. Among the various candidates identified, SLC22A4 has emerged as a promising potential drug target, showing significant expression levels in both blood and brain tissues. Additionally, phenome-wide MR of SLC22A4 across 32 selected phenotypes did not identify statistically significant adverse associations after FDR correction. Virtual knockout (KO) experiments on SLC22A4 revealed that SLC22A4 KO disrupted 81 genes, all of which are involved in IAs-related pathways. Besides, we recognized BRD-K85337334 as potential candidates for targeting SLC22A4. This research indicates that an increase in SLC22A4 gene expression within the blood or brain is directly linked to a heightened risk of IAs rupture, which will aid in prioritizing the development of drugs for IAs.
African swine fever (ASF) is an acute, febrile, and highly contagious infectious disease of swine with the etiological agent of African swine fever virus (ASFV). The mortality rate of virulent strains is as high as 100%. Strengthening biosafety is so far the most effective way to prevent and control ASF. Therefore, it is urgent to develop a safe and effective vaccine. In this study, a Genotype II live-attenuated ASF vaccine bearing 24 genes deletion in 3 independent regions was constructed based on the highly virulent Eurasian strain ASFV CN/GS 2018 backbone. The resulting mutant ASFV-Δ24 is characterized by complete deletion of 24 genes distributed in 3 genomic positions of 852 to 11 468, 19 732 to 22 929, and 179 519 to 180 617, among which MGF100 and whole MGF300 families are pioneeringly removed. The ASFV-Δ24 displayed a delayed and reduced replication kinetics as well as aberrant icosahedral empty particles devoid of a nucleoid when compared to the parental virus. Animal experiments showed that ASFV-Δ24 was completely attenuated in animals as evidenced by stable body temperature and no ASF-compatible clinical signs in vaccinated pigs. The ASFV-Δ24 could provide complete homologous protection against lethal challenge, as vaccinated pigs demonstrated boosted antibody response, transient but low levels of viremia in blood and virus titers in organs as well as almost undetectable viral shedding. Gene deletions in multiple regions are helpful for prevention of virulence reversion. These results indicate that ASFV-Δ24 can be used as an effective and promising candidate vaccine to control the spread of ASFV.
Annexin A4 (A4) is a negative modulator of adenylyl cyclase type 5 (AC5) with increased expression in failing human hearts. Here, we investigated whether A4 deficiency contributes to cardiac electrical and structural remodeling induced by chronic stimulation of β-adrenergic receptors (βAR). A4-deficient mice (gene trapped, GT) and wild-type (WT) were infused for 7 days with isoprenaline (ISO) or NaCl as control. Myocytes of ISO-treated GT (GTISO) displayed more hypertrophy, increased action potential duration, reduced K+-current Ito, preserved L-type Ca2+ current ICaL with a negative shift of voltage dependence of activation, in line with increased AC/cAMP/PKA signaling, and increased NCX1 versus WTISO. At the molecular level, mRNA levels for Kcnd3, Kcnip2, Cacna1c decreased at unchanged protein levels of Kv4.2, Kv4.3, KChIP2, α1C, independent of genotype, suggesting posttranslational modifications of the channels underlying Ito and ICaL. Chronic ISO-induced βAR desensitization and redox stress were confirmed by decreased cAMP production and lower mRNA levels of Adrb1, Adcy5/6, and Sod2, and reduced response to acute ISO, with no additional genotype-dependent effects on calcium handling or contractility. Nevertheless, GTISO cardiomyocytes retained a greater cAMP response to acute ISO, in line with AC5 disinhibition and preserved β2AR and Gαs/i, suggesting genotype-dependent differences in β-adrenergic signaling under stress. mRNA levels of Anxa4 were increased in hypertrophied WTISO vs. normal WTNaCl hearts, supporting a protective role for A4. Overall, the advanced remodeling in A4-deficient myocytes detected in response to chronic βAR stimulation proposes using A4 peptide as a therapeutic tool to prevent the progression of cardiac electrical remodeling.
Phenylketonuria (PKU) is a rare metabolic disorder caused by pathogenic mutations in the phenylalanine hydroxylase (PAH) gene, which impair the conversion of phenylalanine to tyrosine, leading to subsequent neurotoxicity. Dietary management, sapropterin dihydrochloride, and pegvaliase are the current therapies; however, their limited efficacy and adverse effects highlight the pressing need for pharmacological treatments that restore PAH activity. Therefore, in this work, we designed and synthesized pyrimidine-triazole derivatives (Pyr-TZ) as candidate pharmacological chaperones targeting the catalytic domain of PAH. Molecular docking disclosed that Pyr-TZ-2O and Pyr-TZ-2S exhibited higher binding energies (-8.5 to -10.3 kcal/mol) for the wild-type (WT) and mutant (R252Q) PAH compared to sapropterin (-7.0 kcal/mol). Molecular Mechanics with Generalized Born and Surface Area solvation (MM-GBSA) was used here as comparative estimates suggested enhanced binding stability of Pyr-TZ compounds, primarily driven by van der Waals and lipophilic interactions. Drug-likeness and ADMET profiling indicated favorable pharmacokinetic properties. Biological validation in R252Q mutant cells demonstrated significant upregulation of PAH and key tetrahydrobiopterin (BH4) pathway genes, including quinonoid dihydropteridine reductase (QDPR), sepiapterin reductase (SPR), and 6-pyruvoyl-tetrahydropterin synthase (PTS), following Pyr-TZ-2O treatment. Consistent with these findings, sandwich ELISA revealed a dose-dependent increase in PAH protein abundance post-Pyr-TZ-2O treatment. Conclusively, Pyr-TZ-2O can be considered a potential pharmacological chaperone capable of stabilizing mutant PAH and enhancing cofactor regeneration, offering a rational therapeutic approach for PKU.
Fractionated low dose ionizing radiation (LDIR) can induce various biological effects, which are key potential triggers for the development of radiation-induced lung injury (RILI). This study aims to investigate the effects of fractionated LDIR on early-stage cellular senescence, as well as on the levels of oxidation-antioxidation and DNA damage repair, in mouse lung tissue. C57BL/6J mice were exposed to fractionated LDIR, and subsequent assays were performed to evaluate the biological effects. Compared with the control group, mice in all dose groups showed the following changes: varying degrees of pathological alterations in lung tissue; elevated SA-β-Gal activity and upregulated expression of senescence-related genes in lung tissue; increased serum levels of urea, blood glucose (BG), and triglycerides (TG), along with reduced high-density lipoprotein cholesterol (HDL-C) levels; increased levels of oxidative damage markers in lung tissue, accompanied by elevated total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity, but decreased reduced glutathione (GSH) levels; upregulated expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream genes; and increased DNA damage markers in lung tissue, as well as elevated mRNA and protein levels of the DNA repair gene O6-methylguanine-DNA methyltransferase (MGMT). The oxidative damage and DNA damage potentially induced by fractionated LDIR exceeded the compensatory capacity of the repair systems, probably leading to a dual dynamic imbalance in both oxidation-antioxidation and DNA damage repair. These may contribute to the progression of cellular senescence in lung tissue and the initiation of early-stage RILI.
Previous studies have linked prenatal exposure to carbon black nanoparticles (CBNPs), a key constituent of air pollution and tobacco smoke, to respiratory abnormalities. However, the distinct impacts of particle size on the maternal-fetal lung axis remain poorly understood. This study investigated the maternal-to-fetal lung toxicological effects and metabolic shifts following exposure to 30 nm (CBNP30) and 120 nm (CBNP120) particles using a high-dose mechanistic exposure model. In maternal lungs, histological analysis (H&E and Masson staining) revealed severe inflammatory infiltration and significant fibrotic injury for both sizes, with CBNP120 inducing more pronounced damage. Dark-field hyperspectral imaging confirmed the transplacental transfer and presence of both CBNP sizes within fetal lung tissues. Notably, fetal lungs did not display overt histological injury. However, significant elevations in oxidative stress and inflammatory markers (mRNA and protein) were observed, indicating clear molecular perturbation. Chemical Isotope Labeling LC-MS further identified size-specific metabolic disruption, with CBNP120 eliciting more extensive changes in the fetal metabolome. Specifically, CBNP30 primarily affected histidine metabolism in both maternal and fetal lungs, whereas CBNP120 disrupted butanoate and arachidonic acid pathways. These metabolic shifts, supported by altered enzyme expression, suggest that profound biochemical disturbances may occur in the fetus even in the absence of observable morphological damage. This study clarifies the distinction between maternal structural injury and fetal molecular dysfunction, providing critical insights for interventions against air pollution-related neonatal health risks.
Hepatic glycogen accumulation is a hallmark of glucose intolerance in carnivorous fish, yet the molecular mechanisms governing the partitioning of surplus carbohydrates remain poorly understood. This study integrated physiology and functional assays to elucidate how insulin-dependent mTOR/SREBP1 signaling governs hepatic glucose partitioning and glycogen accumulation. In the present study, we used largemouth bass (poor glucose utilization) and Nile tilapia (efficient glucose utilization) fed diets containing graded carbohydrate levels for 8 weeks. The results revealed that high-carbohydrate (HC) diets suppressed the PI3K/AKT1/mTOR axis in largemouth bass, reducing nuclear SREBP1 and causing massive hepatic glycogen accumulation. Conversely, tilapia efficiently activated this axis to promote lipid synthesis in response to excessive carbohydrates. Meanwhile, srebp1 knockdown in primary hepatocytes of largemouth bass decreased lipogenic gene expression and triglyceride content while increasing glycogen level. Mechanistic validations in largemouth bass demonstrated that insulin treatment restored AKT1/mTOR pathway activity and SREBP1 nuclear translocation, alleviating glycogen overload while promoting lipogenesis. Knockdown of akt1 or s6k1 prevented SREBP1 activation, whereas tsc2 knockdown rescued mTOR phosphorylation. Furthermore, mTOR inhibition by rapamycin abolished insulin-induced SREBP1 transactivation of lipogenic targets, mimicking the HC-induced glycogen-overload phenotype. In summary, this study identifies the insulin-responsive mTOR/SREBP1 signaling axis as the critical pathway governing lipogenesis in largemouth bass. Functional impairment of the insulin-responsive mTOR/SREBP1 signaling axis is associated with a metabolic shift favoring glycogen storage over lipogenesis, providing mechanistic insights relevant to glucose intolerance across vertebrates.
Ischemia-reperfusion (IR) injury induces a pro-inflammatory cascade that disrupts inflammation resolution and exacerbates skeletal muscle fibrosis, leading to impaired regeneration through fibrosis and compromised myofiber regeneration. This study aimed to: (1) Demonstrate IR-induced dysregulation of muscle regeneration following acute injury; (2) Elucidating how TGF-β1 signaling within the FAP-associated inflammatory niche mediates fibrosis and impairs myofiber repair; and (3) Evaluating anti-TGF-β neutralization as a mechanism-based strategy to preserve regenerative capacity. Male C57BL6 mice (8 weeks) received CTX injections into the tibialis anterior (TA) to induce skeletal muscle injury. Transient clamping of femoral artery and vein was induced at 3 days post-injury to induce IR. Mice were stratified into CTX group and CTX-IR group depending on the induction of IR injury. TGF-β neutralizing antibody (TGF-β NAb) was administered in vivo to evaluate therapeutic potential. HE and Sirius red staining was used to assess cross-sectional area (CSA) of myofibers and percentage of fibrotic tissue. Western blotting was used to assess the expression of Collagen I, Collagen III and TGF-β. Flow cytometry was used to assess the number of fibro-adipogenic progenitors (FAPs). Collagen I and CD90 were assessed using immunostaining of TA cryosections and FAPs isolated from muscle tissues. The result shows that CTX-IR mice showed smaller myofiber cross-sectional area and more fibrotic tissue than CTX mice. Western blots revealed higher levels of Collagen I, Collagen III and TGF-β1 in CTX-IR samples. TGF-β1 stimulated the expression of collagen I in FAPs. TGF-β NAb application ameliorated the fibrosis of skeletal muscle and improved myofiber regeneration after IR. In conclusion, IR impairs muscle regeneration through TGF-β-associated FAP activation and collagen deposition. Inhibition of TGF-β attenuates fibrosis and increases the CSA of myofibers, demonstrating it as a potential target for promoting structural recovery and regenerative architecture in co-existing muscle injuries during orthopedic trauma.
Pulmonary fibrosis (PF) is a chronic, progressive interstitial lung disease characterized by recurrent alveolar epithelial injury, aberrant repair, fibroblast activation, excessive extracellular matrix deposition, and irreversible loss of lung function. Although traditionally considered a lung-restricted disorder, increasing evidence suggests that systemic alterations contribute to disease progression and heterogeneity. Complex communication networks between the lung and distant organs, including the gut, liver, thyroid, brain, kidney, cardiovascular system, and oral microbiota, influence fibrosis through immune, metabolic, endocrine, neural, vascular, and microbial pathways. This review systematically summarizes the roles of the gut-lung, liver-lung, thyroid-lung, and brain-lung axes in PF and outlines emerging evidence involving the kidney-lung, cardiopulmonary, and oral-lung microbial axes. This review aims to provide a theoretical basis for a deeper understanding of the systemic pathological mechanisms underlying PF and to offer insights into the development of potential therapeutic targets and novel intervention strategies.
Exosomes, a subset of nanosized extracellular vesicles, are key mediators of intracellular communication that show growing therapeutic potential in skeletal muscle regeneration. By shuttling bioactive cargoes between cells, they modulate recipient cell behavior, influencing proliferation, differentiation, and tissue remodeling. Previous studies demonstrated that different tensile load regimes can modulate both the production and regenerative capacity of myoblast-derived exosomes, positioning mechanically induced vesicle release as a potential driver of morpho-functional adaptations required for myoblast differentiation and myotube formation. Within this framework, shockwave (SW) therapy is gaining increasing attention as a non-invasive mechanical stimulus in regenerative medicine; however, the precise cellular mechanisms linking SW stimulation and tissue repair remain poorly understood. Preclinical evidence shows that extracellular vesicles (EVs) derived from SW-treated cardiomyocytes possess pro-angiogenic and regenerative properties, suggesting that SW-induced paracrine signaling may be conserved across tissues. In this study, we investigated whether in vitro SW treatment affects myogenic exosome release, contributing to SW-mediated muscle regeneration. Tunable Resistive Pore Sensing analysis revealed a significant increase in EV concentration at 6 h post-treatment, with no detectable differences between treated cells and controls at 12 h, indicating a rapid and transient secretory response. Importantly, vesicle size distribution remained unchanged across conditions, suggesting that SW primarily modulates EV production dynamics rather than vesicle morphology. Ultrastructural analyses further confirmed this transient activation, showing vesicular trafficking and exosome-like EV secretion in treated myoblasts. Further mechanistic insights into SW-induced exosome release may uncover novel pathways, contributing to SW regenerative effects supporting its translational application to muscle injuries and disorders.
Psoriasis is a chronic inflammatory skin disorder in which biologics targeting immune pathways have markedly improved clinical outcomes. Nevertheless, persistent oxidative stress and stromal abnormalities in lesional skin indicate that pathogenic mechanisms beyond canonical immune circuits remain active. Here, we integrated single-cell RNA sequencing, an imiquimod (IMQ)-induced psoriasiform murine model, LC-MS/MS-based metabolomic profiling of fibroblast-conditioned medium, and complementary in vitro studies to define ferroptosis-related alterations in dermal fibroblasts under psoriasis-like inflammatory conditions. Single-cell analysis revealed a marked expansion of an inflammatory fibroblast subset (iFb1) in psoriasiform lesions, together with enrichment of ferroptosis-related pathways. In vivo and in vitro analyses further showed that inflammatory stimulation induced ferroptosis-related injury in dermal fibroblasts, as evidenced by increased lipid peroxidation, impaired antioxidant defenses, and characteristic ultrastructural alterations. Metabolomic profiling of conditioned medium further indicated secretory remodeling characterized by enrichment of lipid mediators and redox-associated metabolites. Lipocalin-2 (LCN2) was significantly upregulated in psoriasis-associated fibroblasts and exacerbated lipid peroxidation and ferroptosis-related injury. Conditioned medium from inflammation-stimulated fibroblasts enhanced keratinocyte proliferation, whereas inhibition of fibroblast ferroptosis or LCN2 knockdown attenuated this effect. Further experiments suggested that 4-hydroxy-2-nonenal (4-HNE) may act as a potential mediator of fibroblast-keratinocyte crosstalk. Topical administration of carnosine, a potent 4-HNE scavenger, alleviated IMQ-induced psoriasiform skin lesions in vivo. Together, these findings support an LCN2-driven fibroblast-keratinocyte crosstalk axis linked to ferroptosis-related injury in psoriasis and highlight stromal lipid peroxidation as a potential therapeutic target.
Hypoxic pulmonary hypertension (HPH) is characterized by excessive proliferation of pulmonary vascular cells, ultimately resulting in right heart failure and death. Although resveratrol, an active component of Polygonum cuspidatum (PC), has shown efficacy against HPH, the mechanism of PC exosome-like nanovesicles (PCELNs) in HPH remains unclear. PC exosome-like nanovesicles (PCELNs) were characterized using transmission electron microscopy, dynamic light scattering, and immunofluorescence (IF). A mouse HPH model was established by chronic hypoxic exposure. Hemodynamic parameters were measured, and pulmonary vascular pathology was assessed via H&E and Masson staining. Protein expression of PCNA, α-SMA, and OPN was analyzed by immunohistochemistry (IHC) and IF. Mouse primary PASMCs were isolated and cultured. Cell proliferation, apoptosis, and migration were evaluated using EdU assay, flow cytometry, and Transwell assay, respectively. Proteins related to phenotypic switching, autophagy, and the MAPK pathway were detected via Western blot. JC-1 staining, Mito-Tracker staining, IF, ATP/SOD assay kits, and flow cytometry were used to assess mitochondrial membrane potential, morphology, mitophagy, energy metabolism, and reactive oxygen species levels, respectively. Network pharmacology screened common targets of resveratrol and pulmonary hypertension, with molecular docking validating binding affinity. PC exosome-like nanovesicles (PCELNs) alleviated HPH, significantly improving pulmonary artery remodeling and hemodynamic indices in mice, inhibiting abnormal PASMC proliferation and migration, promoting apoptosis, and ameliorating mitochondrial function. The mechanism involves stabilizing paraoxonase 1 (PON1) expression, thereby suppressing MAPK pathway activation. PC exosome-like nanovesicles (PCELNs) alleviate HPH by enhancing PASMC phenotypic switching and mitigating mitochondrial dysfunction through the PON1/MAPK axis, providing a novel therapeutic strategy.
Zinc is an essential trace element that plays a significant role in DNA damage repair (DDR). Cells must maintain zinc homeostasis to effectively respond to DNA damage caused by various stressful stimuli. Members of the Zrt-, Irt-related protein (ZIP) family are recognized as key regulators of intracellular zinc levels. Dysfunction of ZIPs has been associated with numerous diseases, including cancer, cardiovascular diseases, and neurodegenerative disorders. In the present study, human bronchial epithelial BEAS-2B cells were used to investigate the response of ZIPs to bleomycin, a well-known antibiotic that induces DNA damage. Among the ZIPs that exhibited altered expression following bleomycin treatment, ZIP1 showed the most prompt and significant induction. Both knockdown and overexpression experiments demonstrated that ZIP1 plays a crucial role in the cellular response to DNA damage. Mechanistically, we found that the level of TNFα was upregulated in bleomycin-treated cells, and inhibiting this cytokine reduced the induction effect of ZIP1 caused by bleomycin. Additionally, we observed an increase in the accumulation of NF-κB in the cell nuclei, and inhibition of NF-κB also diminished the effect of bleomycin on ZIP1. Two NF-κB binding sites were identified in the upstream sequence of SLC39A1, the gene that encodes ZIP1. The application of bleomycin significantly enhanced the binding of NF-κB to these specific sites. Taken together, our study reveals that bleomycin treatment may activate the TNFα-NF-κB pathway, which in turn upregulates ZIP1, helping cells better cope with the DNA damage induced by this antibiotic.
Zinc finger protein 217 (Zfp217) mediates adipogenesis via an N6-methyladenosine (m6A)-dependent mechanism; however, its role in hepatic lipid metabolism is unexplored. Nonalcoholic fatty liver disease (NAFLD), characterized by hepatic triglyceride (TG) accumulation resulting from disrupted lipid homeostasis, lacks well-defined epigenetic regulatory mechanisms. Here, we report that global Zfp217 heterozygous knockout alleviates high-fat diet (HFD)-induced hepatic steatosis in mice, as evidenced by reduced liver weight, decreased hepatic and serum TG and total cholesterol (T-CHO) levels, and hepatic lipid deposition. Mechanistically, Zfp217 deficiency suppresses hepatic de novo lipogenesis (DNL) by down-regulating sterol regulatory element-binding transcription factor 1 (SREBF1), a master regulator of lipogenic gene expression. Zfp217 physically interacts with methyltransferase-like 3 (METTL3) to repress its expression, thereby reducing m6A modification of SREBF1 mRNA at a specific coding sequence (CDS) site. Loss of Zfp217 enhances METTL3-dependent m6A modification at a specific site of SREBF1 mRNA, which promotes YTH domain-containing family protein 2 (YTHDF2)-mediated degradation of SREBF1 transcripts. Conversely, our findings identify a novel Zfp217-METTL3-m6A-YTHDF2-SREBF1 regulatory axis that controls hepatic DNL and NAFLD progression, establishing Zfp217 as a potential therapeutic target for NAFLD.
Brucellosis is a zoonotic disease caused by Brucella spp. that poses a significant threat to human health. Copper resistance is a key determinant of the virulence of many intracellular pathogens, including those expressing the multicopper oxidase CueO. However, the role of CueO in Brucella remains poorly understood. In this study, bioinformatics tools were used to perform sequence homology comparison and conserved domain analysis of the CueO protein. Unmarked cueO deletion mutant and complemented strain of Brucella were constructed using homologous recombination technology. Subsequently, multiple experiments were carried out, including in vitro copper tolerance tests, RAW264.7 macrophage intracellular survival assays, in vivo virulence detection in mice, antibiotic susceptibility tests (AST), and so on. We found that CueO contains highly conserved domains across bacteria (motifs 1-10). Notably, the Brucella homolog contains only motifs 2, 3, 5, 6, and 10; it remains highly conserved within the genus. Despite this reduced domain composition, CueO is important for Brucella to resist copper toxicity. Notably, CueO contributes to intracellular survival in RAW264.7 macrophages and to the maintenance of copper homeostasis in Brucella. Deletion of cueO attenuated bacterial virulence in a mouse model. In addition, CueO influences bacterial susceptibility to doxycycline and levofloxacin. Overall, our results indicate that, despite lacking several typical domains, CueO retains critical functionality and links copper detoxification to intracellular survival, virulence, and antibiotic resistance. These findings enhance our understanding of CueO function and provide new insights into the pathogenesis of Brucella.
Intracellular membrane fusion typically involves two distinct classes of GTPases. Dynamin-like GTPases mediate homotypic fusion between organelles, such as mitochondria and the endoplasmic reticulum (ER), while Rab GTPases facilitate fusion of transport vesicles with target membranes through vesicle tethering. Notably, these two classes of GTPases have not previously been implicated in the same fusion event. In this study, we demonstrate that Rab10 promotes ER membrane fusion driven by the dynamin-like GTPase atlastin (ATL). Rab10 interacted physically with ATL2, a human ATL predominantly expressed in non-neuronal cells, and co-localized with ATL2 throughout the ER, including at three-way junctions where fusion occurs. Fusion between ER microsomes isolated from HEK293T cells, in which ATL2 is the primary ATL isoform, was inhibited by affinity-purified anti-Rab10 antibodies, and was reduced in microsomes derived from Rab10 knockout cells. Moreover, co-reconstitution of Rab10 markedly enhanced fusion of ATL2-containing liposomes. Our findings reveal crosstalk between dynamin-like and Rab GTPases during ATL-mediated ER membrane fusion, uncovering a novel regulatory mechanism for organelle dynamics.
Autophagy has been implicated in tissue remodeling, but its role in scleral remodeling during myopia development and in atropine-mediated myopia control remains unclear. We investigated this issue using complementary in vitro and in vivo models. Human scleral fibroblasts (HSFs) were exposed to hypoxia and treated with rapamycin (RAPA) or 3-methyladenine (3-MA). Beclin-1 knockdown and bafilomycin A1 (BafA1)-based LC3B II accumulation assays were used to assess the functional contribution of autophagy and autophagic flux. In vivo, form-deprivation myopia (FDM) was induced in guinea pigs, followed by atropine, RAPA, or 3-MA intervention. Refractive error, axial length, scleral histology, extracellular matrix remodeling, autophagy-related markers, and AMPK/mTOR/P70S6K signaling were evaluated. Hypoxia induced a remodeling phenotype in HSFs, characterized by decreased COL1A1 and increased MMP2/α-SMA, accompanied by increased autophagy. 3-MA attenuated these changes, whereas RAPA aggravated them. Beclin-1 knockdown similarly suppressed hypoxia and RAPA-associated remodeling changes and reduced autophagic flux, supporting a functional role of autophagy in hypoxia-induced scleral fibroblast remodeling. In FDM guinea pigs, scleral tissue showed increased HIF-1α expression, autophagy activation, and extracellular matrix remodeling. Both 0.05% and 1% atropine slowed myopia progression and axial elongation, improved scleral structural abnormalities, and suppressed autophagy-related changes, with no significant difference between the two concentrations. Subconjunctival RAPA exacerbated, whereas 3-MA alleviated, myopia progression and scleral remodeling. These findings suggest that excessive scleral autophagy links hypoxic stress to scleral extracellular matrix remodeling in experimental myopia. This process may also contribute to the anti-myopic action of atropine.
