Oxidative stress plays an important role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Baicalin has been shown to exert protective effects in various liver diseases. The mechanism of baicalin’s antioxidative effect in NAFLD is currently unclear. The aim of this study was to investigate the effects and mechanisms of baicalin on oxidative stress in a new tissue-engineered liver model of NAFLD. The 3D model of NAFLD was induced by a fat-supplemented medium (fatty acids, FFA group) for 8 days and baicalin was administered on the 5th day. CCK-8 assay showed that baicalin at concentrations below 100 μM had no obvious cytotoxicity. Baicalin inhibited apoptosis and lactate dehydrogenase release in the FFA group. Baicalin reduced the levels of reactive oxygen species and malondialdehyde induced by FFA, and increased superoxide dismutase and glutathione amounts. However, it did not upregulate nuclear erythroid 2-related factor 2 compared with the FFA group. Mitochondrial morphology was partially restored after baicalin treatment, and ATP5A expression and mitochondrial membrane potential were increased. The superoxide anion scavenging ability of baicalin was enhanced in a dose-dependent manner. In summary, baicalin reduces oxidative stress and protects the mitochondria to inhibit apoptosis in the 3D NAFLD model via its own antioxidant activity.

Introduction: This study aimed to investigate the effect of electro‐nape‐acupuncture (ENA) on the differentiation of microglia and the secondary brain injury in rats with acute‐phase intracerebral hemorrhage (ICH) through the programmed cell death protein‐1/ligand‐1 (PD‐1/PD‐L1) pathway.Methods: A total of 27 male Sprague‐Dawley rats were randomly divided into three groups: sham group, ICH group, and ENA group. The autologous blood infusion intracerebral hemorrhage model was used to study the effects of ENA by administering electroacupuncture at GB20 (Fengchi) and Jiaji (EX‐B2) acupoints on 24 h after the modeling, once per day for 3 days. The neurological function damage, hematoma lesion, and inflammatory cell infiltration were measured by the beam walking test and hematoxylin‐eosin staining. The expression of PD‐1, PD‐L1, CD86, CD206, and related cytokines around the hematoma was measured by western blot, quantitative reverse transcription polymerase chain reaction, and immunofluorescence.Results: The ICH group had significant neurological deficits (p < .001), hematoma lesions, and inflammatory cell infiltration. The levels of CD86 protein, inflammatory factors tumor necrosis factors (TNF)‐α, interleukin (IL)‐1β, and IL‐6 were increased (p < .001), while CD206 protein was reduced (p < .01), and the number of CD86⁺/CD11b⁺ cells was also increased (p < .001) compared to the sham group. However, after ENA intervention, there was a significant reduction in neurological function damage (p < .05), infiltration of inflammatory cells, and the expression levels of CD86⁺/CD11b⁺ cells (p < .05), resulting in the increased expression of PD‐1 protein and differentiation of M2 phenotype significantly (p < .001).Conclusion: The study concludes that ENA could reduce neurological function damage, inhibit the expression of pro‐inflammatory cytokines, and improve the infiltration of inflammatory cells to improve secondary brain injury in acute‐phase intracerebral hemorrhage rats. These effects could be related to the increased expression of PD‐1 around the lesion, promoting the differentiation of microglia from M1 to M2 phenotype.

The rapid clearance of hepatitis C virus induced by direct-acting antivirals (DAAs) affects natural killer (NK) cells, but the reported results are not consistent, and the relative mechanism was unclear. This study focused on the dynamic changes of NK cells during and after DAA treatment and analyzed the reasons.

To investigate whether GLT25D2 gene regulates autophagy in acetaminophen (APAP)-induced hepatotoxicity injury. GLT25D2+/+ wild-type C57BL/6J mice and GLT25D2-/- C57BL/6J mice were selected as subjects. (1) In vivo experiment: 20 for wild-type mice and 20 for GLT25D2-/- mice were respectively divided into phosphate buffer (PBS) control group and APAP intervention group according to random number table, with 10 mice in each group. The hepatotoxicity injury model of mice was reproduced by intraperitoneal injection of 25 g/L APAP solution 500 mg/kg. The PBS control group was intraperitoneally injected with the same amount of PBS. The mice were sacrificed immediately after model reproduction, and the liver tissues were harvested. Western Blot was used to detect the expressions of autophagy-related proteins ATG5, ATG7, microtubule-associated protein 1 light chain 3 (LC3) and P62. The ultrastructural changes in liver tissue were observed under electron microscope to observe the level of autophagy. (2) In vitro experiment: primary hepatocytes extracted by two-step collagen perfusion from one GLT25D2+/+ wild-type mouse and one GLT25D2-/- mouse were divided into two parts respectively. One part was treated with 5 mmol/L APAP solution. The cells were harvested at 0, 8, and 12 hours, and the expressions of autophagy-related proteins ATG5, ATG7, LC3, and P62 were determined by Western Blot. The other part was transfected with the green fluorescent protein-LC3 plasmid (GFP-LC3) for 24 hours. The cells were cultured with PBS (PBS control group) or 5 mmol/L APAP (APAP intervention group) for 12 hours, and the positive expression of GFP-LC3 was observed under the fluorescence microscope, thereby reflecting the expression of autophagosomes. (1) In vivo experiment: compared with the corresponding PBS control group, the expressions of the positive-associated proteins ATG5, ATG7 and LC3-II in liver tissue of the APAP intervention group were down-regulated in the wild-type and GLT25D2-/- mice, while the expression of the negative correlation protein P62 was up-regulated, indicating that the overall level of autophagy decreased after treatment with APAP. Compared with wild-type mice, the expressions of autophagy positive correlation proteins ATG5 and ATG7 were up-regulated in GLT25D2-/- mice (ATG5/β-actin: 1.21±0.29 vs. 0.84±0.19, ATG7/β-actin: 1.29±0.14 vs. 1.54±0.40, both P > 0.05), LC3-II expression was slightly down-regulated (LC3-II/β-actin: 0.52±0.06 vs. 0.58±0.06, P > 0.05), while negative correlation protein P62 was down-regulated (P62/β-actin: 1.13±0.94 vs. 1.54±0.40, P > 0.05), indicating that the expression of autophagy in GLT25D2-/- mice was higher than that in wild-type mice. Ultrastructural observation under electron microscope showed that the number of autophagosomes in the liver tissue of wild-type mice did not change significantly after APAP intervention as compared with that in PBS control group, but the number of autophagosomes in GLT25D2-/- mice was increased. (2) In vitro experiment: with the prolongation of APAP intervention, the expressions of ATG5 and ATG7 in the primary hepatocytes of wild-type and GLT25D2-/- mice were up-regulated, LC3 was slightly fluctuated, and the expression of negative-related protein P62 was gradually down-regulated. The peak value or the trough value reached at 12 hours. It was indicated that the expression of autophagy in APAP-stimulated cells was enhanced with a time-dependent manner. Compared with wild-type mice, the expressions of autophagy correlation proteins ATG5, ATG7, LC3-II and P62 were up-regulated in GLT25D2-/- mice at 12 hours (ATG5/β-actin: 0.93±0.09 vs. 0.74±0.06, ATG7/β-actin: 0.80±0.09 vs. 0.65±0.10, LC3-II/β-actin: 1.35±0.30 vs. 1.15±0.20, P62/β-actin: 0.36±0.02 vs. 0.31±0.03, all P > 0.05), indicating that the expression of autophagy was enhanced after gene knockout. Fluorescence microscopy showed that GFP-LC3 positive cells in both wild-type and GLT25D2-/- mice hepatocytes were significantly increased after APAP intervention as compared with those of PBS control group, and the proportion of GFP-LC3 positive cells in GLT25D2-/- mice was significantly higher than that in wild-type mice (0.64±0.08 vs. 0.36±0.05, P > 0.05). GLT25D2 is a negative regulator of autophagy. Knockout of GLT25D2 gene can enhance the autophagy level of APAP-induced hepatotoxicity injury in mice.

Background: The cyclic guanosine monophosphate-adenylate synthase (cGAS)-stimulator of interferon genes (STING) pathway is a critical innate immune signaling pathway that recognizes and transmits cytoplasmic DNA signals, triggering interferon and inflammatory responses. Immune cells enriched in the liver participate in the development of various liver diseases through the STING pathway; however, the precise regulatory mechanisms of this pathway within the immune cells remain poorly integrated. Elucidating these mechanisms holds promise for developing novel therapeutic strategies to address related clinical challenges. Main body: This review systematically elucidates the mechanisms by which immune cells from both innate and adaptive immune systems influence liver diseases via the STING pathway, viewed through the lens of immune cell classification. Considering the differential expression of STING across immune cell types and their cross-regulatory interactions, the review categorizes STING’s impact on liver diseases into two patterns: direct regulation by endogenous STING (intracellular STING) and indirect regulation by exogenous STING (STING originating from other cells). The diseases discussed encompass common liver disorders, such as viral hepatitis, metabolic dysfunction-associated steatotic liver disease(MASLD), hepatocellular carcinoma(HCC), and autoimmune hepatitis (AIH),among others.Integrating the latest preclinical research findings, the review thoroughly explores the potential feasibility and research progress of targeting the STING pathway to modulate the progression of liver diseases, including traditional STING agonist/antagonist, and novel approaches such as targeted delivery systems and microbiotherapy in STING drug development, along with their therapeutic potential in liver diseases. Conclusions: The cGAS-STING pathway serves as a pivotal signaling axis linking innate and adaptive immunity, playing a crucial role in the immune regulation of liver diseases. In-depth investigation of this pathway provides theoretical and translational foundations for elucidating the mechanisms underlying immune-metabolic dysregulation in the liver and developing precision immunotherapy strategies, thereby facilitating its transition from basic research to clinical treatment.