Biological role of mitochondrial TLR4-mediated NF-κB signaling pathway in central nervous system injury.

Previous studies suggested that central nervous system injury is often accompanied by the activation of Toll-like receptor 4/NF-κB pathway, which leads to the upregulation of proapoptotic gene expression, causes mitochondrial oxidative stress, and further aggravates the inflammatory response to induce cell apoptosis. Subsequent studies have shown that NF-κB and IκBα can directly act on mitochondria. Therefore, elucidation of the specific mechanisms of NF-κB and IκBα in mitochondria may help to discover new therapeutic targets for central nervous system injury. Recent studies have suggested that NF-κB (especially RelA) in mitochondria can inhibit mitochondrial respiration or DNA expression, leading to mitochondrial dysfunction. IκBα silencing will cause reactive oxygen species storm and initiate the mitochondrial apoptosis pathway. Other research results suggest that RelA can regulate mitochondrial respiration and energy metabolism balance by interacting with p53 and STAT3, thus initiating the mitochondrial protection mechanism. IκBα can also inhibit apoptosis in mitochondria by interacting with VDAC1 and other molecules. Regulating the biological role of NF-κB signaling pathway in mitochondria by targeting key proteins such as p53, STAT3, and VDAC1 may help maintain the balance of mitochondrial respiration and energy metabolism, thereby protecting nerve cells and reducing inflammatory storms and death caused by ischemia and hypoxia.

Comparing Outcomes of Thrombectomy Versus Intravenous Thrombolysis Based on Middle Cerebral Artery M2 Occlusion Features.

BACKGROUND: Current evidence provides limited support for the superiority of endovascular thrombectomy (EVT) in patients with M2 segment middle cerebral artery occlusion. We aim to investigate whether imaging features of M2 segment occlusion impact the effectiveness of EVT. METHODS: We conducted a retrospective cohort study from January 2017 to January 2022, drawing data from the CASE II registry (Computer-Based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation), which specifically documented patients with acute ischemic stroke presenting with M2 segment occlusion undergoing reperfusion therapy. Patients were stratified into the intravenous thrombolysis (IVT) group (IVT alone) and EVT group (IVT plus EVT or EVT alone). The primary outcome was a modified Rankin Scale score 0 to 2 at 90 days. Secondary outcomes included additional thresholds and distribution of modified Rankin Scale scores, 24-hour recanalization, early neurological deterioration, and relevant complications during hospitalization. Safety outcomes encompassed intracranial hemorrhagic events at 24 hours and mortality at 90 days. Binary logistic regression analyses with propensity score matching were used. Subgroup analyses were performed based on the anatomic site of occlusion, including right versus left, proximal versus distal, dominant/co-dominant versus nondominant, single versus double/triple branch(es), and anterior versus central/posterior branch. RESULTS: Among 734 patients (43.3% were females; median age, 73 years) with M2 segment occlusion, 342 (46.6%) were in the EVT group. Propensity score matching analysis revealed no statistical difference in the primary outcome (odds ratio, 0.860 [95% CI, 0.611-1.209]; P=0.385) between the EVT group and IVT group. However, EVT was associated with a higher incidence of subarachnoid hemorrhage (odds ratio, 6.655 [95% CI, 1.487-29.788]; P=0.004) and pneumonia (odds ratio, 2.015 [95% CI, 1.364-2.977]; P<0.001). Subgroup analyses indicated that patients in the IVT group achieved better outcomes when presenting with right, distal, or nondominant branch occlusion (Pall interaction<0.05). CONCLUSIONS: Our study showed similar efficiency of EVT versus IVT alone in acute M2 segment middle cerebral artery occlusion. This suggested that only specific patient subpopulations might have a potentially higher benefit of EVT over IVT alone. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT04487340.

High Engraftment and Metastatic Rates in Orthotopic Xenograft Models of Gastric Cancer via Direct Implantation of Tumor Cell Suspensions.

Although the implantation of intact tumor fragments is a common practice to generate orthotopic xenografts to study tumor invasion and metastasis, the direct implantation of tumor cell suspensions is necessary when prior manipulations of tumor cells are required. However, the establishment of orthotopic xenografts using tumor cell suspensions is not mature, and a comparative study directly comparing their engraftment and metastatic capabilities is lacking. It is unclear whether tumor fragments are superior to cell suspensions for successful engraftment and metastasis. In this study, we employed three GC cell lines with varying metastatic capacities to stably express firefly luciferase for monitoring tumor progression in real time. We successfully minimized the risk of cell leakage during the orthotopic injection of tumor cell suspensions without Corning Matrigel by systematically optimizing the surgical procedure, injection volume, and needle size options. Comparable high engraftment and metastatic rates between these two methods were demonstrated using MKN-45 cells with a strong metastatic ability. Importantly, our approach can adjust the rate of tumor progression flexibly and cuts the experimental timeline from 10-12 weeks (for tumor fragments) to 4-5 weeks. Collectively, we provided a highly reproducible procedure with a shortened experimental timeline and low cost for establishing orthotopic GC xenografts via the direct implantation of tumor cell suspensions.

Argatroban in Patients With Acute Ischemic Stroke With Early Neurological Deterioration: A Randomized Clinical Trial.

Importance: The effect of argatroban in patients with acute ischemic stroke (AIS) and early neurological deterioration (END) is unknown. Objective: To assess the efficacy of argatroban for END in AIS. Design, Setting, and Participants: This open-label, blinded-end point, randomized clinical trial was conducted from April 4, 2020, through July 31, 2022. The date of final follow-up was October 31, 2022. This was a multicenter trial. Eligible patients were adults with AIS who experienced END, which was defined as an increase of 2 or more points on the National Institutes of Health Stroke Scale within 48 hours from symptom onset. Patients who withdrew consent, experienced duplicate randomization, or were lost to follow-up were excluded from the study. Interventions: Patients were randomly assigned to the argatroban group and control group within 48 hours of symptom onset. Both groups received standard therapy based on guidelines, including oral mono or dual antiplatelet therapy. The argatroban group received intravenous argatroban for 7 days (continuous infusion at a dose of 60 mg per day for 2 days, followed by 20 mg per day for 5 days) in addition to standard therapy. Main Outcome and Measure: The primary end point was good functional outcome at 90 days, defined as a modified Rankin Scale score of 0 to 3. Results: A total of 628 patients (mean [SD] age, 65 [11.9] years; 400 male [63.7%]) were included in this study (argatroban group, 314 [50%] and control group, 314 [50%]). Of these, 18 withdrew consent, 1 had duplicate randomization, and 8 were lost to follow-up. A total of 601 patients with stroke were included in the intention-to-treat analysis. Finally, 564 patients were included in the per-protocol analysis as 6 participants in the argatroban group and 31 participants in the control group did not follow the complete protocol. The number of patients with good functional outcome at 90 days was 240 (80.5%) in the argatroban group and 222 (73.3%) in the control group (risk difference, 7.2%; 95% CI, 0.6%-14.0%; risk ratio, 1.10; 95% CI, 1.01-1.20; P = .04). The proportion of symptomatic intracranial hemorrhage was 3 of 317 (0.9%) in the argatroban group and 2 of 272 (0.7%) in the control group (P = .78). Conclusions and Relevance: Among patients with AIS with END, treatment with argatroban and antiplatelet therapy resulted in a better functional outcome at 90 days. This trial provided evidence to support the use of argatroban in reducing disability for patients with END. Trial Registration: ClinicalTrials.gov Identifier: NCT04275180.

Prediction factors and clinical significance of different types of hemorrhagic transformation after intravenous thrombolysis.

BACKGROUND AND PURPOSE: Hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) in acute ischemic stroke seriously affects the prognosis of patients. This study aimed to investigate the risk factors of different types of HT and their correlation with prognosis after IVT. METHODS: Based on the CASE II registry, we included patients with acute ischemic stroke who received IVT within 4.5 h of onset. HT was further divided into hemorrhagic infarction (HI) and parenchymal hemorrhage (PH). Poor outcome was defined as a modified Rankin Scale (mRS) score of 3-6 at 3 months. Multivariate logistic regression analysis was used to determine the independent influencing factors of HT subtypes and clinical outcome. RESULTS: Among 13108 included patients, 541 (4.1%) developed HI and 440 (3.4%) developed PH. In multivariate analysis, age (OR 1.038, 95% CI 1.028 to 1.049, p < 0.001), atrial fibrillation (OR 1.446, 95% CI 1.141 to 1.943, p = 0.002), baseline diastolic pressure (OR 1.012, 95% CI 1.004 to 1.020, p = 0.005), baseline NIHSS score (OR 1.060, 95% CI 1.049 to 1.071, p < 0.001) and onset to treatment time (OR 1.002, 95% CI 1.000 to 1.004, p = 0.020) independently predicted PH after IVT. In the patients with HT, PH (OR 3.611, 95% CI 2.540 to 5.134, p < 0.001) and remote hemorrhage (OR 1.579, 95% CI 1.115 to 2.235, p = 0.010) were independently related to poor outcome. CONCLUSIONS: Different types of HT after IVT had different risk factors and clinical significance. The occurrence of PH and remote hemorrhage independently increased the risk of poor outcome.

Correlation Study of Chronic Renal Insufficiency and Long-Term Prognosis of Patients with Acute Ischemic Cerebral Apoplexy After Intravenous rt-PA Thrombolysis.

Objective: To investigate the correlation between chronic renal insufficiency and the long-term prognosis of patients with acute ischemic cerebral apoplexy after intravenous recombinant tissue plasminogen activator (rt-PA) thrombolysis. Methods: 290 patients (194 males and 96 females) with acute cerebral infarction who received intravenous rt-PA thrombolysis were admitted to Ningbo Medical Center Lihuili Hospital from May 2018 to December 2020. Their clinical baseline data were recorded. According to the estimated glomerular filtration rate (eGFR) level, patients were divided into the control group (252 cases) and the chronic kidney disease (CKD) group (38 cases). The prognosis of patients was evaluated by a modified Rankin Scale (mRS) 90 days after cerebral apoplexy by telephone interview or outpatient following-up (mRS ≤ 2 reflected good prognosis, mRS >2 reflected unfavorable prognosis). Multivariate logistic regression was used to analyze the prognosis risk relationship of acute ischemic cerebral apoplexy patients with intravenous rt-PA thrombolysis with CKD. Results: Acute ischemic cerebral apoplexy patients with intravenous rt-PA thrombolysis with CKD were older ((79.08 ± 8.96) years vs (65.84 ± 13.31) years, P = .00052, 95% CI = 0.00031-0.00072) than who without CKD, and were more likely to be suffering from hypertension (94.7% (36/38) and 66.3% (167/252), P = .00023, 95% CI = 0.00011-0.00033), atrial fibrillation (50.0% (19/38) and 26.6% (67/252), P = .007, 95% CI = 0.001-0.009), high Uric acidemia (68.4% (26/38) and 17.9% (45/252), P = .00044, 95% CI = 0.00027-0.00061), hyperhomocysteinemia (47.4% (18/38) and 13.1% (33/252), P = .00032, 95% CI=0.00022-0.00053), history of malignant tumor (13.2% (5/38) and 4.4% (11/252), P = .044, 95% CI = 0.0023-0.0053), cardiogenic embolism (Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification of cerebral infarction) (47.4% (18/38) and 29.0% (73/252), P = .038, 95% CI = 0.029-0.055). The mortality rate of the CKD group was higher than the control group (13.2% (5/38) and 4.0% (10/252), P = .033, 95% CI = 0.021-0.053), and the good prognosis rate in the CKD group was significantly lower than in the control group (42.1% (16/38) and 73.8% (186/252), P = .00032, 95% CI = 0.00012-0.00043). Multivariate logistic regression analysis showed that CKD was an independent risk factor for acute ischemic cerebral apoplexy patients undergoing intravenous rt-PA thrombolysis (OR = 4.606, 95%CI 1.176~18.041, P = .028, 95% CI = 0.022-0.043). Conclusion: CKD is an independent risk factor for acute ischemic cerebral apoplexy patients with intravenous rt-PA thrombolysis.

Anti-apoptotic protein BCL-XL as a therapeutic vulnerability in gastric cancer.

BACKGROUND: New therapeutic targets are needed to improve the outcomes for gastric cancer (GC) patients with advanced disease. Evasion of programmed cell death (apoptosis) is a hallmark of cancer cells and direct induction of apoptosis by targeting the pro-survival BCL2 family proteins represents a promising therapeutic strategy for cancer treatment. Therefore, understanding the molecular mechanisms underpinning cancer cell survival could provide a molecular basis for potential therapeutic interventions. METHOD: Here we explored the role of BCL2L1 and the encoded anti-apoptotic BCL-XL in GC. Using Droplet Digital PCR (ddPCR) technology to investigate the DNA amplification of BCL2L1 in GC samples and GC cell lines, the sensitivity of GC cell lines to selective BCL-XL inhibitors A1155463 and A1331852, pan-inhibitor ABT-263, and VHL-based PROTAC-BCL-XL was analyzed using (CellTiter-Glo) CTG assay in vitro. Western Blot (WB) was used to detect the protein expression of BCL2 family members in GC cell lines and the manner in which PROTAC-BCL-XL kills GC cells. Co-immunoprecipitation (Co-IP) was used to investigate the mechanism of A1331852 and ABT-263 kills GC cell lines. DDPCR, WB, and real-time PCR (RTPCR) were used to investigate the correlation between DNA, RNA, protein levels, and drug activity. RESULTS: The functional assay showed that a subset of GC cell lines relies on BCL-XL for survival. In gastric cancer cell lines, BCL-XL inhibitors A1155463 and A1331852 are more sensitive than the pan BCL2 family inhibitor ABT-263, indicating that ABT-263 is not an optimal inhibitor of BCL-XL. VHL-based PROTAC-BCL-XL DT2216 appears to be active in GC cells. DT2216 induces apoptosis of gastric cancer cells in a time- and dose-dependent manner through the proteasome pathway. Statistical analysis showed that the BCL-XL protein level predicts the response of GC cells to BCL-XL targeting therapy and BCL2L1 gene CNVs do not reliably predict BCL-XL expression. CONCLUSION: We identified BCL-XL as a promising therapeutic target in a subset of GC cases with high levels of BCL-XL protein expression. Functionally, we demonstrated that both selective BCL-XL inhibitors and VHL-based PROTAC BCL-XL can potently kill GC cells that are reliant on BCL-XL for survival. However, we found that BCL2L1 copy number variations (CNVs) cannot reliably predict BCL-XL expression, but the BCL-XL protein level serves as a useful biomarker for predicting the sensitivity of GC cells to BCL-XL-targeting compounds. Taken together, our study pinpointed BCL-XL as potential druggable target for specific subsets of GC.

Myeloid peroxisome proliferator-activated receptor α deficiency accelerates liver regeneration via IL-6/STAT3 pathway after 2/3 partial hepatectomy in mice.

Background: Liver regeneration is a fundamental process for sustained body homeostasis and liver function recovery after injury. Emerging evidence demonstrates that myeloid cells play a critical role in liver regeneration by secreting cytokines and growth factors. Peroxisome proliferator-activated receptor α (PPARα), the target of clinical lipid-lowering fibrate drugs, regulates cell metabolism, proliferation, and survival. However, the role of myeloid PPARα in partial hepatectomy (PHx)-induced liver regeneration remains unknown. Methods: Myeloid-specific PPARa-deficient (Ppara Mye-/-) mice and the littermate controls (Ppara fl/fl) were subjected to sham or 2/3 PHx to induce liver regeneration. Hepatocyte proliferation and mitosis were assessed by immunohistochemical (IHC) staining for 5-bromo-2'-deoxyuridine (BrdU) and Ki67 as well as hematoxylin and eosin (H&E) staining. Macrophage and neutrophil infiltration into livers were reflected by IHC staining for galectin-3 and myeloperoxidase (MPO) as well as flow cytometry analysis. Macrophage migration ability was evaluated by transwell assay. The mRNA levels for cell cycle or inflammation-related genes were measured by quantitative real-time RT-PCR (qPCR). The protein levels of cell proliferation related protein and phosphorylated signal transducer and activator of transcription 3 (STAT3) were detected by Western blotting. Results: Ppara Mye-/- mice showed enhanced hepatocyte proliferation and mitosis at 32 h after PHx compared with Ppara fl/fl mice, which was consistent with increased proliferating cell nuclear antigen (Pcna) mRNA and cyclinD1 (CYCD1) protein levels in Ppara Mye-/- mice at 32 h after PHx, indicating an accelerated liver regeneration in Ppara Mye-/- mice. IHC staining showed that macrophages and neutrophils were increased in Ppara Mye-/- liver at 32 h after PHx. Livers of Ppara Mye-/- mice also showed an enhanced infiltration of M1 macrophages at 32 h after PHx. In vitro, Ppara-deficient bone marrow-derived macrophages (BMDMs) exhibited markedly enhanced migratory capacity and upregulated M1 genes Il6 and Tnfa but downregulated M2 gene Arg1 expressions. Furthermore, the phosphorylation of STAT3, a key transcript factor mediating IL6-promoted hepatocyte survival and proliferation, was reinforced in the liver of Ppara Mye-/- mice after PHx. Conclusions: This study provides evidence that myeloid PPARα deficiency accelerates PHx-induced liver regeneration via macrophage polarization and consequent IL-6/STAT3 activation, thus providing a potential target for manipulating liver regeneration.

The role of hypoxia-inducible factors in cardiovascular diseases.

Cardiovascular diseases are the leading cause of death worldwide. During the development of cardiovascular diseases, hypoxia plays a crucial role. Hypoxia-inducible factors (HIFs) are the key transcription factors for adaptive hypoxic responses, which orchestrate the transcription of numerous genes involved in angiogenesis, erythropoiesis, glycolytic metabolism, inflammation, and so on. Recent studies have dissected the precise role of cell-specific HIFs in the pathogenesis of hypertension, atherosclerosis, aortic aneurysms, pulmonary arterial hypertension, and heart failure using tissue-specific HIF-knockout or -overexpressing animal models. More importantly, several compounds developed as HIF inhibitors or activators have been in clinical trials for the treatment of renal cancer or anemia; however, little is known on the therapeutic potential of these inhibitors for cardiovascular diseases. The purpose of this review is to summarize the recent advances on HIFs in the pathogenesis and pathophysiology of cardiovascular diseases and to provide evidence of potential clinical therapeutic targets.

Cardiomyocyte peroxisome proliferator-activated receptor α is essential for energy metabolism and extracellular matrix homeostasis during pressure overload-induced cardiac remodeling.

Peroxisome proliferator-activated receptor α (PPARα), a ligand-activated nuclear receptor critical for systemic lipid homeostasis, has been shown closely related to cardiac remodeling. However, the roles of cardiomyocyte PPARα in pressure overload-induced cardiac remodeling remains unclear because of lacking a cardiomyocyte-specific Ppara-deficient (PparaΔCM) mouse model. This study aimed to determine the specific role of cardiomyocyte PPARα in transverse aortic constriction (TAC)-induced cardiac remodeling using an inducible PparaΔCM mouse model. PparaΔCM and Pparafl/fl mice were randomly subjected to sham or TAC for 2 weeks. Cardiomyocyte PPARα deficiency accelerated TAC-induced cardiac hypertrophy and fibrosis. Transcriptome analysis showed that genes related to fatty acid metabolism were dramatically downregulated, but genes critical for glycolysis were markedly upregulated in PparaΔCM hearts. Moreover, the hypertrophy-related genes, including genes involved in extracellular matrix (ECM) remodeling, cell adhesion, and cell migration, were upregulated in hypertrophic PparaΔCM hearts. Western blot analyses demonstrated an increased HIF1α protein level in hypertrophic PparaΔCM hearts. PET/CT analyses showed an enhanced glucose uptake in hypertrophic PparaΔCM hearts. Bioenergetic analyses further revealed that both basal and maximal oxygen consumption rates and ATP production were significantly increased in hypertrophic Pparafl/fl hearts; however, these increases were markedly blunted in PparaΔCM hearts. In contrast, hypertrophic PparaΔCM hearts exhibited enhanced extracellular acidification rate (ECAR) capacity, as reflected by increased basal ECAR and glycolysis but decreased glycolytic reserve. These results suggest that cardiomyocyte PPARα is crucial for the homeostasis of both energy metabolism and ECM during TAC-induced cardiac remodeling, thus providing new insights into potential therapeutics of cardiac remodeling-related diseases.

YAP-TEAD mediates PPAR α-induced hepatomegaly and liver regeneration in mice.

BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor α (PPARα, NR1C1) is a ligand-activated nuclear receptor involved in the regulation of lipid catabolism and energy homeostasis. PPARα activation induces hepatomegaly and plays an important role in liver regeneration, but the underlying mechanisms remain unclear. APPROACH AND RESULTS: In this study, the effect of PPARα activation on liver enlargement and regeneration was investigated in several strains of genetically modified mice. PPARα activation by the specific agonist WY-14643 significantly induced hepatomegaly and accelerated liver regeneration after 70% partial hepatectomy (PHx) in wild-type mice and Pparafl/fl mice, while these effects were abolished in hepatocyte-specific Ppara-deficient (PparaΔHep ) mice. Moreover, PPARα activation promoted hepatocyte hypertrophy around the central vein area and hepatocyte proliferation around the portal vein area. Mechanistically, PPARα activation regulated expression of yes-associated protein (YAP) and its downstream targets (connective tissue growth factor, cysteine-rich angiogenic inducer 61, and ankyrin repeat domain 1) as well as proliferation-related proteins (cyclins A1, D1, and E1). Binding of YAP with the PPARα E domain was critical for the interaction between YAP and PPARα. PPARα activation further induced nuclear translocation of YAP. Disruption of the YAP-transcriptional enhancer factor domain family member (TEAD) association significantly suppressed PPARα-induced hepatomegaly and hepatocyte enlargement and proliferation. In addition, PPARα failed to induce hepatomegaly in adeno-associated virus-Yap short hairpin RNA-treated mice and liver-specific Yap-deficient mice. Blockade of YAP signaling abolished PPARα-induced hepatocyte hypertrophy around the central vein area and hepatocyte proliferation around the portal vein area. CONCLUSIONS: This study revealed a function of PPARα in regulating liver size and liver regeneration through activation of the YAP-TEAD signaling pathway. These findings have implications for understanding the physiological functions of PPARα and suggest its potential for manipulation of liver size and liver regeneration.

Increased systemic immune-inflammation index can predict respiratory failure in patients with Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome (GBS) is a common peripheral neuropathy with relatively heterogenous clinical manifestations. In severe cases, it can result in disabling neuromuscular symptoms and respiratory failure. In this study, we assessed whether the systemic immune-inflammation index (SII) is associated with respiratory failure in GBS patients. METHODS: We retrospectively analyzed clinicopathological data from GBS patients diagnosed in the First Affiliated Hospital of Kunming Medical University. SII was calculated based on counts of neutrophils (N), platelets (P), and lymphocytes (L). Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values for SII, N, P, and L. Univariate and multivariate logistic regression were performed to determine the ability of the SII to predict respiratory failure. RESULTS: Among the 369 GBS patients in this study, 61 (16.5%) suffered respiratory failure. Multivariate logistic regression showed that N ≥ 6.03 × 109/l, Hughes Functional Grading Scale (HFGS) score ≥ 3 at admission, and SII ≥ 863.04 × 109/l can independently predict respiratory failure in GBS patients. SII showed higher predictive ability than N, based on area under the ROC curve (0.75 vs. 0.72). CONCLUSION: SII may be a novel independent prognostic indicator of respiratory failure in GBS patients, helping physicians identify those at risk in a timely manner.

Inhibition of Peptidyl Arginine Deiminase 4-Dependent Neutrophil Extracellular Trap Formation Reduces Angiotensin II-Induced Abdominal Aortic Aneurysm Rupture in Mice.

Objective: Neutrophil infiltration plays an important role in the initiation and development of abdominal aortic aneurysm (AAA). Recent studies suggested that neutrophils could release neutrophil extracellular traps (NETs), leading to tissue injury in cardiovascular diseases. However, the role of NETs in AAA is elusive. This study aimed to investigate the role and underlying mechanism of NETs in AAA development. Methods and Results: An angiotensin II (Ang II) infusion-induced AAA model was established to investigate the role of NETs during AAA development. Immunofluorescence staining showed that citrullinated histone 3 (citH3), myeloperoxidase (MPO), and neutrophil elastase (NE) (NET marker) expressions were significantly increased in Ang II-infused ApoE -/- mice. The circulating double-stranded DNA (dsDNA) level was also elevated, indicating the increased NET formation during AAA. PAD4 inhibitor YW3-56 inhibited Ang II-induced NET formation. Disruption of NET formation by YW3-56 markedly reduced Ang II-induced AAA rupture, as revealed by decreased aortic diameter, vascular smooth muscle cell (VSMC) apoptosis, and elastin degradation. Apoptosis of VSMC was evaluated by TUNEL staining and Annexin V-FITC/PI staining through flow cytometry. Western blot and inhibition experiments revealed that NETs induced VSMC apoptosis via p38/JNK pathway, indicating that PAD4-dependent NET formation played an important role in AAA. Conclusions: This study suggests that PAD4-dependent NET formation is critical for AAA rupture, which provides a novel potential therapeutic strategy for AAA disease.

Serum Adropin as a Potential Biomarker for Predicting the Development of Type 2 Diabetes Mellitus in Individuals With Metabolic Dysfunction-Associated Fatty Liver Disease.

Background: Adropin, a peptide translated from the Energy Homeostasis Associated gene (ENHO), was mainly expressed in the liver and was a regulator in metabolic and energy homeostasis. This study aims to investigate the correlation between adropin and histological characteristics of the liver, and the clinical relevance of adropin in patients with metabolic dysfunction-associated fatty liver disease (MAFLD). Methods: A total of 62 subjects, including 32 healthy controls and 30 MAFLD patients, were enrolled in this case-control study. The MAFLD patients were further divided into two subgroups, including NGT-M group and T2DM-M group. Serum adropin levels, metabolic parameters and intrahepatic lipids, the liver ENHO mRNA expressions and histological characteristics were investigated. Results: MAFLD patients showed significantly lower circulating adropin compared with healthy controls (2.02 ± 2.92 vs. 5.52 ± 0.65 ng/mL, P < 0.0001). Subgroup analysis exhibited dramatically declined serum adropin levels in T2DM-M patients compared with NGT-M group (0.51 ± 0.73 vs. 4.00 ± 3.52 ng/mL, P < 0.001). H&E and Oil Red O staining show exacerbated steatohepatitis in T2DM-M patients in contrast with NGT-M group. Furthermore, serum adropin concentrations were negatively correlated with intrahepatic triglyceride (TG), total cholesterol (TC), and NAFLD activity score (NAS) (TG: r = -0.495; TC: r = -0.392; NAS: r = -0.451; all P < 0.05). Conclusions: MAFLD patients showed significantly lower adropin levels than the healthy controls, especially in T2DM patients. Adropin maybe a potential biomarker for predicting the development of MAFLD, especially in T2DM individuals.

Hypoxia inducible factor 1α in vascular smooth muscle cells promotes angiotensin II-induced vascular remodeling via activation of CCL7-mediated macrophage recruitment.

The process of vascular remodeling is associated with increased hypoxia. However, the contribution of hypoxia-inducible factor 1α (HIF1α), the key transcription factor mediating cellular hypoxic responses, to vascular remodeling is established, but not completely understood. In the angiotensin II (Ang II)-induced vascular remodeling model, HIF1α was increased and activated in vascular smooth muscle cells (VSMCs). Selective genetic disruption of Hif1a in VSMCs markedly ameliorated Ang II-induced vascular remodeling, as revealed by decreased blood pressure, aortic thickness, collagen deposition, inflammation, and aortic stiffness. VSMC Hif1a deficiency also specifically suppressed Ang II-induced infiltration of CD45+CD11b+F4/80+CD206- M1 macrophages into the vessel. Mechanistically, HIF1α deficiency in VSMCs dramatically suppressed the expression of CCL7, a chemokine critical for macrophage recruitment. Bioinformatic analysis and chromatin immunoprecipitation assays revealed three functional hypoxia-response elements in the Ccl7 promoter, indicating that Ccl7 is a direct HIF1α target gene. Blocking CCL7 with antibody in vivo alleviated Ang II-induced hypertension and vascular remodeling, coincident with decreased macrophage infiltration. This study provides direct evidence that HIF1α activation in VSMCs exacerbates Ang II-induced macrophage infiltration and resultant vascular remodeling via its target gene Ccl7, and thus may serve as a potential therapeutic target for remodeling-related vascular disease.

Hepatocyte peroxisome proliferator-activated receptor α regulates bile acid synthesis and transport.

Peroxisome proliferator-activated receptor alpha (PPARα) controls lipid homeostasis through regulation of lipid transport and catabolism. PPARα activators are clinically used for hyperlipidemia treatment. The role of PPARα in bile acid (BA) homeostasis is beginning to emerge. Herein, Ppara-null and hepatocyte-specific Ppara-null (Ppara∆Hep) as well as the respective wild-type mice were treated with the potent PPARα agonist Wy-14,643 (Wy) and global metabolomics performed to clarify the role of hepatocyte PPARα in the regulation of BA homeostasis. Levels of all serum BAs were markedly elevated in Wy-treated wild-type mice but not in Ppara-null and Ppara∆Hep mice. Gene expression analysis showed that PPARα activation (1) down-regulated the expression of sodium-taurocholate acid transporting polypeptide and organic ion transporting polypeptide 1 and 4, responsible for the uptake of BAs into the liver; (2) decreased the expression of bile salt export pump transporting BA from hepatocytes into the bile canaliculus; (3) upregulated the expression of multidrug resistance-associated protein 3 and 4 transporting BA from hepatocytes into the portal vein. Moreover, there was a notable increase in the compositions of serum, hepatic and biliary cholic acid and taurocholic acid following Wy treatment, which correlated with the upregulated expression of the Cyp8b1 gene encoding sterol 12α-hydroxylase. The effects of Wy were identical between the Ppara∆Hep and Ppara-null mice. Hepatocyte PPARα controlled BA synthesis and transport not only via direct transcriptional regulation but also via crosstalk with hepatic farnesoid X receptor signaling. These findings underscore a key role for hepatocyte PPARα in the control of BA homeostasis.

Anti-inflammatory treatment with ß-asarone improves impairments in social interaction and cognition in MK-801 treated mice.

The aim of this study investigates whether ß-asarone can improve cognition deficits in dizocilpine (MK-801) treated mice. Six-week-old male C57BL/6 mice were divided into four groups: control group (CON), MK-801-treated group (MK-801), MK-801 plus ß-asarone group (MK-801+ß-asa) and ß-asarone group (ß-asa). Behavioral tests, including sociability test, open field test (OPT) and Morris water-maze (MWM), were performed. Extracellular field excitatory postsynaptic potentials were recorded in the hippocampal dentate gyrus (DG) region. Western blot was employed to measure the expression of cognitive function-associated proteins and pro-inflammatory cytokines in the hippocampus. Immunofluorescence was performed to assess the microglial activation in the hippocampus DG region. The data show that social interactions and spatial learning and memory were impaired by MK-801. However, ß-asarone significantly mitigated the impairments. Furthermore, it was found that MK-801 aggravated the hyperactivity and anxiety-like behavior, but ß-asarone alleviated them. Moreover, ß-asarone alleviated the impairments of hippocampal synaptic plasticity and enhanced the expression of hippocampal synaptophysin (SYP) and postsynaptic density protein 95 (PSD95) in MK-801-treated mice. In addition, it suppressed the expression of interleukin-6 (IL-6), interleukin-1ß (IL-1ß), inducible nitric oxide synthase (i-Nos) and cyclo-oxygenase-2 (COX-2) expression in MK-801-treated mice. The results suggest that ß-asarone improved the impairment of cognition and synaptic plasticity possibly through modulating the excess release of pro-inflammatory cytokines and microglia activation in MK-801-treated mice.

Keratin 23 Is a Peroxisome Proliferator-Activated Receptor Alpha-Dependent, MYC-Amplified Oncogene That Promotes Hepatocyte Proliferation.

Chronic activation of the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARA) promotes MYC-linked hepatocellular carcinoma (HCC) in mice. Recent studies have shown that MYC can function as an amplifier of transcription where MYC does not act as an "on-off" switch for gene expression but rather accelerates transcription rates at active promoters by stimulating transcript elongation. Considering the possibility that MYC may amplify the expression of PPARA target genes to potentiate cell proliferation and liver cancer, gene expression was analyzed from livers of wild-type and liver-specific Myc knockout (MycΔHep ) mice treated with the PPARA agonist pirinixic acid. A subset of PPARA target genes was amplified in the presence of MYC, including keratin 23 (Krt23). The induction of Krt23 was significantly attenuated in MycΔHep mice and completely abolished in Ppara-null mice. Reporter gene assays and chromatin immunoprecipitation confirmed direct binding of both PPARA and MYC to sites within the Krt23 promoter. Forced expression of KRT23 in primary hepatocytes induced cell cycle-related genes. These data indicate that PPARA activation elevates MYC expression, which in turn potentiates the expression of select PPARA target genes involved in cell proliferation. Finally, KRT23 protein is highly elevated in human HCCs. Conclusion: These results revealed that MYC-mediated transcriptional potentiation of select PPARA target genes, such as Krt23, may remove rate-limiting constraints on hepatocyte growth and proliferation leading to liver cancer.

Hepatocyte Peroxisome Proliferator-Activated Receptor α Enhances Liver Regeneration after Partial Hepatectomy in Mice.

Peroxisome proliferator-activated receptor α (PPARα) is a key nuclear receptor involved in the control of lipid homeostasis. In rodents, PPARα is also a potent hepatic mitogen. Hepatocyte-specific disruption of PPARα inhibits agonist-induced hepatocyte proliferation; however, little is known about the exact role of PPARα in partial hepatectomy (PHx)-induced liver regeneration. Herein, using hepatocyte-specific PPARα-deficient (PparaΔHep) mice, the function of hepatocyte PPARα in PHx-induced liver regeneration was investigated. PPARα protein level and transcriptional activity were increased in the liver after PHx. Compared with the Pparafl/fl mice, PparaΔHep mice exhibited significantly reduced hepatocyte proliferation at 32 hours after PHx. Consistently, reduced Ccnd1 and Pcna mRNA and CYCD1 and proliferating cell nuclear antigen protein were observed at 32 hours after PHx in PparaΔHep mice. Furthermore, PparaΔHep mice showed increased hepatic lipid accumulation and enhanced hepatic triglyceride contents because of impaired hepatic fatty acid ß-oxidation when compared with that observed in Pparafl/fl mice. These results indicate that PPARα promotes liver regeneration after PHx, at least partially via regulating the cell cycle and lipid metabolism.

Enhanced Regeneration and Hepatoprotective Effects of Interleukin 22 Fusion Protein on a Predamaged Liver Undergoing Partial Hepatectomy.

Liver ischemia-reperfusion injury (IRI) and regeneration deficiency are two major challenges for surgery patients with chronic liver disease. As a survival factor for hepatocytes, interleukin 22 (IL-22) plays an important role in hepatoprotection and the promotion of regeneration after hepatectomy. In this study, we aim to investigate the roles of an interleukin 22 fusion protein (IL-22-FP) in mice with a predamaged liver after a two-third partial hepatectomy (PHx). Predamaged livers in mice were induced by concanavalin A (ConA)/carbon tetrachloride (CCl4) following PHx with or without IL-22-FP treatment. A hepatic IRI mouse model was also used to determine the hepatoprotective effects of IL-22-FP. In the ConA/CCl4 model, IL-22-FP treatment alleviated liver injury and accelerated hepatocyte proliferation. Administration of IL-22-FP activated the hepatic signal transducer and activator of transcription 3 (STAT3) and upregulated the expression of many mitogenic proteins. IL-22-FP treatment prior to IRI effectively reduced liver damage through decreased aminotransferase and improved liver histology. In conclusion, IL-22-FP promotes liver regeneration in mice with predamaged livers following PHx and alleviates IRI-induced liver injury. Our study suggests that IL-22-FP may represent a promising therapeutic drug against regeneration deficiency and liver IRI in patients who have undergone PHx.