Terminal Labeling Research Articles

Di Huang Yi Zhi Fang improves cognitive function in APP/PS1 mice by inducing neuronal mitochondrial autophagy through the PINK1-parkin pathway.

Alzheimer's disease (AD) is an irreversible age-related neurodegenerative condition characterized by the deposition of amyloid-β (Aβ) peptides and neurofibrillary tangles. Di Huang Yi Zhi (DHYZ) formula, a traditional Chinese herbal compound comprising several prescriptions, demonstrates properties that improve cognitive abilities in clinical. Nonetheless, its molecular mechanisms on treating AD through improving neuron cells mitochondria function have not been deeply investigated. This study administered DHYZ to APP/PS1 mice to explore its potential therapeutic mechanisms in AD treatment. APP/PS1 transgenic mice were given DHYZ (L, M, H), donepezil, or distilled water for a consecutive 12-week period. The Morris water maze test was used to assess memory capacity, transmission electron microscopy was used to observe mitochondrial and synaptic structures, immunohistochemistry and western blot detected proteins involved in the mitochondrial autophagy pathway, ELISA measured serum Aβ content, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assessed neuronal cell apoptosis. DHYZ demonstrates a notable therapeutic impact on mice with AD, effectively improving cognitive and memory impairments. DHYZ decreases Aβ accumulation in the hippocampus by reducing BACE1 activity and enhancing Aβ clearance through the blood-brain barrier. Additionally, DHYZ significantly suppresses neuronal apoptosis, enhances synaptic structure, and increases synapse numbers, processes strongly linked to the activation of mitochondrial PINK1-Parkin autophagy. DHYZ enhances cognitive function in APP/PS1 mice by stimulating neuronal mitochondrial autophagy through the PINK1-Parkin pathway.

Gintonin-Enriched Panax ginseng Extract Induces Apoptosis in Human Melanoma Cells by Causing Cell Cycle Arrest and Activating Caspases

Gintonin, a non-saponin glycolipoprotein from Panax ginseng, acts as a lysophosphatidic acid ligand. However, its anticancer effects, especially in melanoma, remain unclear. This study investigated the anti-proliferative effects and intracellular signaling mechanisms of a gintonin-enriched fraction (GEF) from Panax ginseng in human melanoma cell lines. In vitro, GEF treatment significantly inhibited cell proliferation, reduced clonogenic potential, and delayed wound healing in melanoma cells. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining showed that GEF induced apoptosis, as evidenced by increased apoptotic cell populations and nuclear changes. GEF also caused cell cycle arrest in the G1 phase for A375 cells and the G2/M phase for A2058 cells. It triggered apoptotic signaling via activation of caspase-3, -9, poly (ADP-ribose) polymerase cleavage, and downregulation of B cell lymphoma-2 (Bcl-2). GEF treatment also raised intracellular reactive oxygen species (ROS) levels and mitochondrial stress, which were mitigated by N-acetyl cysteine (NAC), an ROS inhibitor. In vivo, GEF suppressed tumor growth in A375- and A2058-xenografted mice without toxicity. These findings suggest that GEF from Panax ginseng has potential antitumor effects in melanoma by inducing apoptosis and cell cycle arrest, presenting a promising therapeutic avenue.

Dexamethasone-loaded fibroin nanoparticles promote retinal reattachment in rats by regulating the Th17/Treg balance

Retinal detachment (RD) is a common acute blinding eye disease, and dexamethasone (DEX), an adrenocorticosteroid, shows protective effects against RD. However, its poor water solubility and low bioavailability limit its effectiveness. To address this, we developed SF@DEX nanomaterials and investigated their therapeutic potential and mechanisms in RD. The nanomaterials were successfully synthesized and characterized, achieving 90% encapsulation efficiency and releasing 60% of DEX within 12 h.In vitro, phagocytosis was measured by flow cytometry, and enzyme-linked immunosorbent assay determined interleukin-17 (IL-17) and interleukin-10 (IL-10) levels. A rat RD model was established surgically, followed by oral administration of silk fibroin (SF), SF@DEX, and DEX. Polymerase chain reaction (PCR) assessed IL-17A and forkhead box P3 (FOXP3) expression, while Western blot analysed transforming growth factor-β1 (TGF-β1), IL-10, IL-17A, and FOXP3 levels. Apoptosis of retinal ganglion cells was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and confocal microscopy detected colocalization of IL-17A and FOXP3. SF@DEX treatment significantly reduced Th17 cells and IL-17A while increasing Tregs, FOXP3, TGF-β1, and IL-10 levels. The severity of RD in rats was notably alleviated by SF@DEX, demonstrating its anti-inflammatory effects through modulation of the Th17/Treg immune balance. These results highlight SF@DEX as a promising nano-based therapy for RD.

Sivelestat sodium protects against renal ischemia/reperfusion injury by reduction of NETs formation.

Ischemia-reperfusion injury (IRI) often results in renal impairment. While the presence of neutrophil extracellular traps (NETs) is consistently observed, their specific impact on IRI is not yet defined. Sivelestat sodium, an inhibitor of neutrophil elastase which is crucial for NET formation, may offer a therapeutic approach to renal IRI, warranting further research. A mouse model was established for early-stage renal IRI, confirmed by injury markers and histological assessments. The involvement of NETs in renal I/R was demonstrated using immunofluorescence and Western blot. Renal function and pathology were further evaluated through a comprehensive set of methods, including Periodic Acid-Schiff staining (PAS) and Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling (TUNEL) staining, enzyme-linked immunosorbent assay (ELISA), Real time Glomerular Filtration Rate (RT-GFR) monitoring, Polymerase Chain Reaction (PCR), biochemical analysis, and additional Western blot and immunofluorescence assays. We firstly quantified NET expression in renal IRI mice, noting a peak at 24 hours. Subsequently, sivelestat sodium treatment was administered, resulting in decreased MPO, CitH3, and attenuated tubular damage. Moreover, it resulted in a decrease in serum levels of creatinine, blood urea nitrogen (BUN), as well as neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1). Additionally, it lowered the abundance of renal tissue inflammatory markers interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), and mitigated the levels of oxidative stress indicators malondialdehyde (MDA) and 4 Hydroxynonenal (4HNE), accompanied by a decline in renal cell apoptosis and an enhancement of GFR in renal I/R mice. Sivelestat sodium ameliorates renal IRI by downregulating neutrophil NETs, reducing inflammation, oxidative stress, and apoptosis, thereby enhancing renal function.

Apoptosis in kidney tissue of senior and geriatric cats with chronic kidney disease.

Apoptosis, an important pathological event associated with kidney disease progression, is expected to be a therapeutic target in chronic kidney disease (CKD). However, its role in naturally occurring CKD in aged cats remains unclear. Therefore, here, we investigated kidney tissues from aged cats (≥10 years) with or without azotemic CKD to evaluate apoptotic events using a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay. The positive TUNEL signals of the renal cells were quantified and statistically analyzed for correlation with the severity of plasma creatinine (pCre) concentration, renal lesions (glomerulosclerosis, interstitial cell infiltration, peritubular capillaries, and interstitial fibrosis), and oxidative damage of the kidney tissue. Oxidative damage was evaluated using immunohistochemistry for 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE). In the TUNEL assay, regardless of azotemia, positive nuclear signals were observed in the tubular epithelial and intraluminal cells, interstitial infiltrating cells, and glomerular cells. Quantitative TUNEL scores showed no significant differences between the azotemic and non-azotemic groups in any compartment of the kidney tissues. In the azotemic group, TUNEL scores did not correlate with pCre or renal lesion severity. However, the scores showed a significant positive correlation with the scores of 8-OHdG and 4-HNE. These findings suggest that apoptosis associated with oxidative damage in renal tissue is an initial pathological event that leads to CKD, rather than a change following CKD progression, in aged cats. Inhibiting apoptosis by antioxidant treatment may be a key strategy to prevent the development of CKD.

P0113 Maintained microglial homeostasis and adult neurogenesis despite chronic ileocolitis

Abstract Background Inflammatory bowel diseases (IBD), such as Crohn‘s disease and ulcerative colitis, are associated with neuropsychiatric comorbidities, including depression, anxiety, and Parkinson’s disease [1]. These are presumably mediated along the gut-immune-brain axis by the transition of inflammation across gastrointestinal and CNS-surrounding barriers, causing the activation of microglia [1]. Adult hippocampal neurogenesis, the generation of new neurons in the hippocampus throughout life, is impaired by peripheral inflammation [2] and linked to affective and neurodegenerative disorders [3]. In the context of IBD, adult hippocampal neurogenesis has only been investigated in chemically induced animal models mimicking ulcerative colitis, leading to heterogeneous results [1]. Methods In this study, we used the Casp8∆IEC ileocolitis mouse model which is characterized by a specific knockout of caspase 8 in intestinal epithelial cells, leading to ileocolitis that resembles Crohn’s disease [4]. We investigated the effects of ileocolitis on microglia and on adult neurogenesis in the hippocampal dentate gyrus (DG). The hippocampi of 14- and 24-week-old Casp8∆IEC mice were compared to wild-type (wt) mice using immunohistochemistry and immunofluorescence analyses. Microglial density and proliferation were assessed by quantifying ionized calcium-binding adapter molecule 1 (Iba1)+ and Iba1+Mcm2+ myeloid cells, respectively. Additionally, microglial phagocytic activation was examined by co-staining Iba1 with the lysosomal marker CD68. To evaluate adult hippocampal neurogenesis, progenitor cell proliferation and maturation were analyzed by quantifying Mcm2+ proliferating cells and doublecortin (DCX)+ neuroblasts in the DG. Cells undergoing cell death during maturation were quantified by co-staining DCX with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Results Microglial density and proliferation in the dentate gyrus region were preserved between Casp8∆IEC and wt mice at both 14 and 24 weeks of age. Likewise, microglial activation state and phagocytosis remained unchanged between the two groups at both time points Adult hippocampal neurogenesis was maintained between the two groups. The proliferation and maturation of progenitor cells, as well as the rate of cell death during maturation in the dentate gyrus, remained similar between Casp8∆IEC and wt mice. Conclusion These results demonstrate that key aspects of hippocampal immune function and adult hippocampal neurogenesis are resilient to experimental ileocolitis induced by the deletion of Casp8 in intestinal epithelial cells. References (1)Masanetz RK, Winkler J, Winner B, Günther C, Süß P. The Gut-Immune-Brain Axis: An Important Route for Neuropsychiatric Morbidity in Inflammatory Bowel Disease. Int J Mol Sci. 2022;23(19):11111. Published 2022 Sep 21. doi:10.3390/ijms231911111 (2)Ekdahl CT, Claasen JH, Bonde S, Kokaia Z, Lindvall O. Inflammation is detrimental for neurogenesis in adult brain. Proc Natl Acad Sci U S A. 2003;100(23):13632-13637. doi:10.1073/pnas.2234031100 (3)Toda T, Parylak SL, Linker SB, Gage FH. The role of adult hippocampal neurogenesis in brain health and disease. Mol Psychiatry. 2019;24(1):67-87. doi:10.1038/s41380-018-0036-2 (4)Günther C, Martini E, Wittkopf N, et al. Caspase-8 regulates TNF-α-induced epithelial necroptosis and terminal ileitis. Nature. 2011;477(7364):335-339. Published 2011 Sep 14. doi:10.1038/nature10400

Arsenic trioxide preconditioning attenuates hepatic ischemia- reperfusion injury in mice: Role of ERK/AKT and autophagy.

Arsenic trioxide (ATO) is indicated as a broad-spectrum medicine for a variety of diseases, including cancer and cardiac disease. While the role of ATO in hepatic ischemia/reperfusion injury (HIRI) has not been reported. Thus, the purpose of this study was to identify the effects of ATO on HIRI. In the present study, we established a 70% hepatic warm I/R injury and partial hepatectomy (30% resection) animal models in vivo and hepatocytes anoxia/reoxygenation (A/R) models in vitro with ATO pretreatment and further assessed liver function by histopathologic changes, enzyme-linked immunosorbent assay, cell counting kit-8, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. Small interfering RNA (siRNA) for extracellular signal-regulated kinase (ERK) 1/2 was transfected to evaluate the role of ERK1/2 pathway during HIRI, followed by ATO pretreatment. The dynamic process of autophagic flux and numbers of autophagosomes were detected by Green fluorescent protein-monomeric Red fluorescent protein-LC3 (GFP-mRFP-LC3)staining and transmission electron microscope. A low dose of ATO (0.75μmol/L in vitro and 1mg/kg in vivo)significantly reduced tissue necrosis, inflammatory infiltration, and hepatocyte apoptosis during the process of hepatic I/R. Meanwhile, ATO obviously promoted the ability of cell proliferation and liver regeneration. Mechanistically, in vitrostudies have shown that nontoxic concentrations of ATO can activate both ERK and phosphoinositide 3-kinase-serine/threonine kinase (PI3K-AKT) pathways and further induce autophagy. The hepatoprotective mechanism of ATO, at least in part, relies on the effects of ATO on the activation of autophagy, which is ERK-dependent. Low, non-toxic doses of ATO can activate ERK/PI3K-AKT pathways and induce ERK-dependent autophagy in hepatocytes, protecting liver against I/R injury and accelerating hepatocyte regeneration after partial hepatectomy.

Esmolol upregulates the α7 nAChR/STAT3/NF-κB pathway by decreasing the ubiquitin and increasing the ChAT+CD4+ T lymphocyte to alleviate inflammation in septic cardiomyopathy.

Esmolol has been demonstrated to mitigate inflammation damage and T lymphocyte apoptosis in septic cardiomyopathy. It has been established that the activation of α7 nicotinic acetylcholine receptor (nAChR) by cluster of differentiation 4(CD4) + T lymphocytes expressing choline acetyltransferase (ChAT) can prevent excessive inflammation and reduce splenocyte apoptosis in septic cardiomyopathy. Given the similar anti-inflammatory effects, we hypothesized that esmolol might be associated with α7 nAChR and thereby exert its cardioprotective functions. In the cecal ligation puncture (CLP)-induced rat septic cardiomyopathy model, esmolol was found to attenuate myocardial injury as evidenced by Hematoxylin and Eosin (HE) staining, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, and the reduced concentration of interleukin (IL)-1, IL-6, and Tumor Necrosis Factor (TNF)-α detected by enzyme-linked immunosorbent assay (ELISA). Western blotting (WB) revealed that esmolol enhanced the expression of α7 nAChR, elevated the level of Phosphorylated-Signal transducer and activator of transcription 3 (P-STAT3)/STAT3, and decreased the level of Nuclear factor-κB (NF-κB), which led to the reduction of plasma IL-1, IL-6, and TNF-α. Methyl lycaconitine Citrate (MLA, an α7 nAChR inhibitor) suppressed the level of P-STAT3/STAT3, while stattic (a STAT3 inhibitor) inhibited the level of P-STAT3/STAT3 and up-regulated the expression of NF-κB. Real-time quantitative PCR (RT-qPCR) results indicated no significant difference in the mRNA level of α7 nAChR, but immunofluorescence and WB results verified the upregulation of α7 nAChR by esmolol and the reduction of ubiquitin induced by esmolol. In the spleen, esmolol decreased splenocyte apoptosis and increased the expression of α7 nAChR as shown by immunofluorescence. In isolated CD4+ T cells obtained through magnetic cell separation, esmolol enhanced the expression of ChAT mRNA. In conclusion, esmolol upregulates α7 nAChR by decreasing ubiquitin and increasing ChAT+CD4+ T lymphocytes and then increases the P-STAT3/STAT3 which inhibits NF-κB thus alleviating inflammation in septic cardiomyopathy.

Inhibition of p70 Ribosomal S6K1 Protects the Myocardium against Ischemia/Reperfusion-Induced Necrosis through Downregulation of RIP3.

Myocardial ischemia-reperfusion (I/R) injury refers to cell damage that occurs as a consequence of the restoration of blood circulation following reperfusion therapy for cardiovascular diseases, and it is a primary cause of myocardial infarction. The search for nove therapeutic targets in the context of I/R injury is currently a highly active area of research. p70 ribosomal S6 kinase (S6K1) plays an important role in I/R induced necrosis, although the specific mechanisms remain unclear. This study aims to explore the effects of inhibiting S6K1 on myocardial I/R injury and its potential mechanisms. A rat myocardial I/R model was created and treated with the S6K1-specific inhibitor PF-4708671. Hematoxylin-eosin (H&E) staining was applied to evaluate the pathological changes in cardiac tissues. 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to measure the area of myocardial infarction (MI). Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of increase in left ventricular pressure (+dp/dtmax), and the maximum rate of the decrease in left ventricular pressure (-dp/dtmax) were measured using ultrasonic echocardiography. The expression levels of cardiac troponin-1 (cTn-1), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), and aspartate aminotransferase (AST) were determined by enzyme-linked immunosorbent assay (ELISA). Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and propidium iodide (PI) staining were used to examine the apoptosis and necrosis of myocardial tissues. The expressions of apoptotic-related proteins, and key molecules of necrosis were detected by western blot. The relationship between S6K1 and receptor-interacting protein kinase 3 (RIP3) was analyzed by immunoprecipitation. Inhibition of S6K1 reduces I/R-induced myocardial tissue damage, improves myocardial function, and inhibits myocardial tissue necrosis (p < 0.05). In addition, RIP3 is a direct target of S6K1, and activation of RIP3 blocked the protective effect of the S6K1 inhibitor PF-4708671 against myocardial I/R injury (p < 0.05). Inhibition of S6K1 protects against myocardial I/R injury by down-regulating RIP3, suggesting that targeting S6K1 may offer a novel approach for intervention in myocardial I/R injury.

N-terminomics profiling of host proteins targeted by excretory-secretory proteases of the nematode Angiostrongylus vasorum identifies points of interaction with canine coagulation and complement cascade.

The cardiopulmonary nematode Angiostrongylus vasorum can cause severe disease in dogs, including coagulopathies manifesting with bleeding. We analysed A. vasorum excretory/secretory protein (ESP)-treated dog plasma and serum by N-terminome analysis using Terminal Amine Isotopic Labelling of Substrates (TAILS) to identify cleaved host substrates. In plasma and serum samples 430 and 475 dog proteins were identified, respectively. A total of eight dog proteins were significantly cleaved at higher levels upon exposure to A. vasorum ESP: of these, three were coagulation factors (factor II, V and IX) and three were complement proteins (complement C3, C4-A and C5). Comparison with human motif sequence orthologues revealed known cleavage sites in coagulation factor IX and II (prothrombin). These and further identified cleavage sites suggest direct or indirect activation or proteolysis of complement and coagulation components through A. vasorum ESP, which contains several proteases. Further studies are needed to validate their substrate specificity.

Thymoquinone-PLGA-PF68 Nanoparticles Induce S Phase Cell Cycle Arrest and Apoptosis, Leading to the Inhibition of Migration and Colony Formation in Tamoxifen-Resistant Breast Cancer Cells.

A biocompatible polymeric nanoparticle, TQ-PLGA-PF68, was developed through the interaction of the phytochemical thymoquinone (TQ) encapsulated in poly(L-lactide-co-glycolide)-b-poly(ethylene glycol) (PLGA-PEG) with Pluronics F68. So far, this combination has not been assessed on breast cancer cells resistant to anti-cancer drugs. Therefore, this study aimed to assess the cell death caused by TQ-PLGA-PF68 nanoparticles, particularly in resistant breast cancer cell lines expressing estrogen receptor (ER) positivity, such as TamR MCF-7. The antiproliferative activity of TQ-PLGA-PF68 nanoparticles was measured using the MTS assay. The cytotoxic effects were further evaluated through colony formation assay and scratch-wound healing assay. Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) assay was performed to determine the characteristics of the apoptosis as well as cell cycle arrest induced by TQ-PLGA-PF68 nanoparticles. The localization of these nanoparticles in the cells was examined using Transmission Electron Microscopy (TEM). With a TQ concentration of 58.5 μM encapsulated within the nanoparticles, cytotoxicity analysis revealed a significant inhibition of cell proliferation (p<0.05). This finding was corroborated by the results of the colony formation assay. Treatment with TQ-PLGA-PF68 nanoparticles significantly decreased the number of surviving TamR MCF-7 cells by 35% (p<0.001) compared to untreated TamR MCF-7 cells. Concurrently, the scratch-wound healing assay indicated a closure rate of 50% versus >80% (p<0.05) in untreated TamR MCF-7 cells at 12 hours post-wounding. The TUNEL assay successfully confirmed the apoptosis characteristics associated with cell cycle arrest. TEM observation confirmed the cellular internalization of these nanoparticles, suggesting the in vitro therapeutic potential of the formulation. In this study, a significant functional change in TamR MCF-7 cells induced by the TQ nanoparticles was observed. The unique incorporation of TQ into the PLGA-PEG and Pluronics F68 formulation preserved its bioactivity, thereby reducing the migratory and proliferative traits of drug-resistant cells. This discovery may pave the way for exploring the application of biocompatible polymeric TQ nanoparticles as a novel therapeutic approach in future studies pertaining to resistant breast cancer.

Targeting P21-Activated Kinase 2 as a Novel Therapeutic Approach to Mitigate Endoplasmic Reticulum Stress in Heart Failure With Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is linked to prolonged endoplasmic reticulum (ER) stress. P21-activated kinase 2 (Pak2) facilitates a protective ER stress response. This study explores the mechanism and role of Pak2 in HFpEF pathology. The HFpEF mouse model was established using a high-fat diet combined with the nitric oxide synthase inhibitor Nω-Nitro-l-arginine methyl ester (high-fat diet+Nω-Nitro-l-arginine methyl ester). The model exhibited the typical characteristics of HFpEF (cardiac hypertrophy, diastolic dysfunction with preserved systolic function, and lung edema) as determined by echocardiography and hemodynamic analysis. Terminal deoxynucleotidyl transferase dUTP nick end labeling and dihydroethidium staining results showed that cell death and reactive oxygen species generation were higher in the high-fat diet+Nω-Nitro-l-arginine methyl ester-treated group. Transmission electron microscopy revealed disruption of the ER subcellular structures in the HFpEF mouse model, while western blot analysis confirmed reduced Pak2 phosphorylation and impaired inositol-requiring enzyme 1/X-box binding protein 1 splicing ER stress response signaling. Furthermore, H9c2 cells subjected to the palmitic acid-mediated metabolic stress developed temporal changes in unfolded protein response proteins and Pak2 activity. The inositol requiring enzyme 1/X-box binding protein 1 splicing branch of unfolded protein response was impaired earlier than other branches. Overexpression of Pak2 by adenovirus in H9c2 cells sustained the activation of inositol requiring enzyme 1/X-box binding protein 1 splicing. Pak2 deficiency in the mouse heart accelerated the HFpEF progression, and this phenomenon occurred as early as 10 weeks in Pak2 cardiomyocyte-specific knockout mice. Conversely, adeno-associated virus serotype 9-mediated Pak2 overexpression mitigated HFpEF symptoms, underscoring its protective role against HFpEF progression. Pak2 prevents HFpEF progression, exerting cardioprotective effects against ER stress. These insights underscore the therapeutic value of Pak2 in HFpEF.

FTO Alleviates Hepatic Ischemia-Reperfusion Injury by Regulating Apoptosis and Autophagy.

Objective: Despite N6-methyladenosine (m6A) being closely involved in various pathophysiological processes, its potential role in liver injury is largely unknown. We designed the current research to study the potential role of fat mass and obesity-associated protein (FTO), an m6A demethylase, on hepatic ischemia-reperfusion injury (IRI). Methods: Wild-type mice injected with an adeno-associated virus carrying fat mass and obesity-associated protein (AAV-FTO) or adeno-associated virus carrying green fluorescent protein (GFP) (AAV-GFP) were subjected to a hepatic IRI model in vivo. Hematoxylin-eosin staining was performed to observe IRI. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to observe the cell apoptosis. Reverse transcription polymerase chain reaction (RT-PCR) was used to observe the expression of FTO. The protein levels of FTO, apoptosis, or autophagy-associated signaling proteins were detected by western blot. Reactive oxygen species (ROS) levels were determined by flow cytometry, and immunohistochemistry was used to detect the FTO and LC3-II expression. For in vitro experiments, cultured hepatocytes were subjected to hypoxia/reoxygenation (H/R) stimulation. Monodansylcadaverine (MDC) staining was used to visualize autophagic vesicles. Results: In the present study, we showed that FTO was involved in hepatic IRI, apoptosis, and autophagy. Specifically, the expression level of FTO was significantly reduced in the hepatic IRI. Besides, increasing FTO expression (AAV-FTO) ameliorated the hepatic IRI in animal models, accompanied by decreased apoptosis and autophagy. Furthermore, the FTO inhibitor (FB23-2) aggravated autophagy in hepatocytes upon H/R-induced damage. Conclusion: FTO could act as a protective effector during hepatic IRI, associated with decreased apoptosis and autophagy. FTO-mediated m6A demethylation modification may be an important therapeutic target for hepatic IRI.

Apigenin facilitates apoptosis of acute lymphoblastic leukemia cells via AMP-activated protein kinase-mediated ferroptosis.

The outcomes of pediatric patients with acute lymphoblastic leukemia (ALL) remain far less than favorable. While apigenin is an anti-cancer agent, studies on the mechanism by which it regulates ALL cell cycle progression are inadequate. Ferroptosis and AMP-activated protein kinase (AMPK) signaling are important processes for ALL patients. However, it remains unclear whether apigenin works by affecting AMPK and apoptosis. SUP-B15 and T-cell Jurkat ALL cells were treated with apigenin, and cell viability and apoptosis were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, respectively. The thiobarbituric acid-reactive substances (TBARS) assay was used to evaluate lipid peroxidation. Intracellular Fe2+ levels were measured using a commercial kit. Corresponding proteins were detected by western blotting. Results showed that apigenin reduced cell viability and the levels of Ki67 and proliferating cell nuclear antigen (PCNA) expression in a concentration-dependent manner in both types of ALL cells. Apigenin also exerted anti-apoptotic effects on SUP-B15 and Jurkat cells. Apigenin activated AMP-activated protein kinase (AMPK) signaling and induced ferroptosis, and those effects were attenuated by inhibition of AMPK. Eventually, the reduced cell proliferation and increased cell apoptosis caused by apigenin in ALL cells were partly abolished by AMPK inhibition. In summary, apigenin exerted anti-leukemia activity in ALL cells, and that effect was partially achieved by activation of AMPK signaling. Our findings suggest apigenin as a potential drug for treatment of ALL.

Hypomethylation of IL6ST promotes development of endometriosis by activating JAK2/STAT3 signaling pathway.

Endometriosis is a chronic inflammatory disorder characterized by presence of endometrial tissue outside the uterine cavity. Immunohistochemical analysis (IHC) revealed markedly elevated expression of IL6ST in endometrial tissue of patients with ovarian endometriosis. Level of methylation of IL6ST is diminished in patients with endometriosis, whereas level of mRNA expression is markedly elevated by RT-PCR. Cell Counting Kit-8, Transwell, Terminal deoxynucleotidyl transferase dUTP nick end labeling assays substantiated endometrial stromal cells stably transfected with 3*FLAG-IL6ST plasmid exhibited enhanced viability, augmented invasive capacity, and notable reduction in apoptosis rates. Furthermore, IL6ST facilitated progression of endometriosis by activating mitogen-activated protein kinase 9/Signal Transducer and Activator of Transcription 3 signaling pathway. Western blot analysis revealed significantly elevated protein levels of p-JAK2/JAK2, p-STAT3/STAT3, HIF-1α, and VEGF in IL6ST overexpression group. Conversely, JAK2/STAT3 inhibitor WP1066 had markedly reduced p-JAK2 and p-STAT3 protein levels in IL6ST overexpression group. Inhibiting JAK2/STAT3 signaling pathway had mitigating effect on proliferative and invasive enhancement of endometrial stromal cells, as well as inhibition of apoptosis induced by IL6ST. These findings offer novel potential targets and strategies for the treatment of endometriosis.

Anti-inflammatory effect of sea buckthorn in an HCl-induced cystitis rat model.

Although the mechanism underlying interstitial cystitis/bladder pain syndrome (IC/BPS) remains unclear, oxidative stress is suggested to be implicated in IC/BPS development. Sea buckthorn (SB; Hippophae rhamnoides L.) contains several compounds with antioxidant properties. In addition, intravesical application of hydrochloric acid (HCl) in rats induces histological changes similar to those observed in humans with IC. Therefore, the aim of this study was to evaluate the anti-inflammatory effects of SB in an HCl-induced rat cystitis model. Twenty 8-week-old female Sprague-Dawley rats were instilled with HCl in their bladders to create an IC/BPS model. The model rats were divided into three groups and orally administrated distilled water (control, n=4), concentrated SB (n=8), or pentosan polysulfate (PPS, n=8) daily. Pathologic inflammation grade (H&E staining), number of mast cells per square millimeter (toluidine blue staining), fibrotic changes (Masson's trichrome staining), and apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling staining) of bladder tissue samples were compared among the groups. Compared to the control group, the SB and PPS groups showed reduced edema (5.25±0.96 vs. 2.25±0.46 vs. 2.50±0.54, p=0.004, p=0.005, respectively), number of mast cells (12.5±3.6 vs. 6.8±1.9 vs. 6.6±1.8, p=0.010, p=0.002, respectively), ratio of fibrotic submucosal tissue (63.9%±7.0% vs. 43.6%±9.9% vs. 40.5%±5.2%, p<0.001, p<0.001, respectively), and ratio of apoptotic nucleus (40.7%±11.7% vs. 7.7%±6.5% vs. 5.1%±4.9%, p<0.001, p<0.001, respectively). SB exhibited anti-inflammatory effects comparable to those of PPS in the HCl-induced chemical cystitis model.

Pretreatment with tetramethylpyrazine alleviated the impairment of learning and memory induced by sevoflurane exposure in neonatal rats

Sevoflurane impairs learning and memory of the developing brain. However, strategies to mitigate these detrimental effects have been scarce. Herein, we investigated whether tetramethylpyrazine could alleviate the impairment of learning and memory and its underlying mechanisim in sevoflurane-exposed neonatal rats. Postnatal 7-day Sprague-Dawley (SD) rats or primary hippocampal neurons were pretreated with tetramethylpyrazine and then exposed to sevoflurane. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and lactate dehydrogenase (LDH) assays were used to detect neuronal injury. Learning and memory function were evaluated by novel object recognition and Morris water maze tests. Long-term potentiation (LTP) was recorded to evaluate synaptic plasticity electrophysiologically in the hippocampal slices. Golgi-Cox staining or PSD95 immunochemistry was used to detect the morphology of dendritic spines. Western blotting was employed to assess the expressions of cleaved Caspase-3, PSD95, NMDAR1, NMDAR2A and NMDAR2B in the hippocampus or cultured neurons. It was found that neonatal exposure of sevoflurane impaired learning and memory, increased neuronal apoptosis, altered the morphology of dendritic spine, upregulated the expressions of NMDAR2A and PSD95, and induced LTP deficits. Pretreatment with tetramethylpyrazine not only alleviated impairment of learning and memory, but also improved sevoflurane-induced changes in neuronal damage, dendritic spine morphology, NMDAR2A and PSD95 expressions, as well as LTP. These findings indicated that pretreatment with tetramethylpyrazine alleviated the impairment of learning and memory induced by sevoflurane through improvement of hippocampal synaptic plasticity in neonatal rats.

Increased Expression of MST1 in Patients With Epilepsy and in a Rat Model of Epilepsy.

Mammalian sterile20-like kinase 1 (MST1), a serine/threonine kinase frequently expressed, has emerged as pivotal modulator of multiple physiological and pathological conditions such as cellular growth, programmed cell death, oxidative stress, neurodegeneration, inflammation, and synaptic plasticity in the central nervous system. Various neurological diseases are associated with the activation of MST1. Epilepsy is a severe neurological disorder characterized by abrupt abnormal electrical activity in the brain and recurring spontaneous seizures. The most common pathological discoveries in patients and animal models with epilepsy are neuronal death, inflammation, neurodegeneration, neurogenesis, and axonal regrowth. The purpose of this study was to assess the levels of MST1 in serum and cerebrospinal fluid (CSF) specimens obtained from individuals diagnosed with epilepsy. In addition, it aimed to explore the expression pattern of MST1 in brain tissues of epileptic rats. We used enzyme-linked immunosorbent assay to measure the levels of CSF and serum MST1 in 10 epilepsy patients and 9 control patients. After creation of epilepsy models with healthy male Sprague-Dawley rats using lithium and pilocarpine, the expression of MST1 in the temporal cortex and hippocampus was evaluated at different time points (6h, 24h, 3days, 7days, 14days, and 30days after seizures) using immunofluorescence, immunohistochemistry, and Western blotting. In patients with epilepsy, the levels of CSF-MST1 were elevated (593.90±16.28 vs. 560.40±19.42pg/mL, p<0.05) compared to the control group. Accordingly, the serum-MST1 levels were 583.40±19.70pg/mL in the epilepsy group and 555.70±20.14pg/mL in the control group, demonstrating a statistically significant distinction (p<0.05). Levels of MST1 in CSF and serum could be of diagnostic help. Neuronal apoptosis in temporal cortex and hippocampus of epileptic rats was detected using terminal deoxynucleotidyl transferase dUTP nick end labeling staining. MST1 was expressed in the neuronal membrane and cytoplasm of the temporal cortex and hippocampus. The expression of MST1 increased after seizures, showing a relatively high level within 30days and reaching its highest point on the seventh day after status epilepticus. The findings of this study indicate that the increased expression of MST1 protein in patients with epilepsy and epileptic rats might play a role in the development of epilepsy.

Human umbilical cord mesenchymal stem cells improve the ovarian function through oxidative stress-mediated PERK/eIF-2α/ATF4/CHOP signaling in premature ovarian insufficiency mice.

Premature ovarian insufficiency (POI) is a refractory disease that severely affects female fertility. The PERK/eIF-2α/ATF4/CHOP pathway is one of the classical pathways involved in the unfolded protein response to endoplasmic reticulum stress by regulating protein synthesis and promoting apoptosis. This study aimed to investigate the functional role and mechanism of human umbilical cord mesenchymal stem cells (hUCMSCs) in the POI animal model through the PERK/eIF-2α/ATF4/CHOP pathway. Forty-five sexually mature female C57 mice were divided into a blank control group, POI model group, and hUCMSCs intervention group. To establish the POI model, mice received intraperitoneal injections of cyclophosphamide (CTX) (70mg/kg) daily for 14 consecutive days, while the control group received saline only. In the hUCMSC intervention group, mice were given hUCMSCs on days 14 and 28, based on CTX modeling in the POI model group. The hUCMSCs were isolated, labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR) fluorescent dye, and tail vein-injected, and the distribution of the DiR signal was monitored in the mice using a fluorescence imaging detection method. The ovarian tissues were hematoxylin and eosin stained to observe the ovarian structure, and the number of primordial follicles were counted. An enzyme-linked immunosorbent assay was used to detect the serum levels of estradiol, anti-mullerian hormone, and follicle-stimulating hormone. Terminal deoxynucleotidyl transferase dUTP nick end labeling was used to detect the apoptosis of granulosa cells (GCs). The reactive oxygen species (ROS) content of ovarian tissue was detected by flow cytometry assay. The RNA expression of PERK, eIF-2α, ATF4, and CHOP was determined by quantitative real-time polymerase chain reaction, and protein levels of the targets were determined by western blot and immunohistochemistry. We identified hUCMSCs using surface antigenic markers (CD90, CD44, CD105, and CD73), and osteoblasts and chondroplast differentiation assays. Our studies demonstrated that hUCMSC intervention significantly restored ovarian function by improving the irregular estrous cycle, increasing the number of follicles, decreasing ROS, and inhibiting GC apoptosis in POI mice. Moreover, hUCMSCs suppressed CTX-induced PERK/eIF-2a/ATF4/CHOP pathway activation. HUCMSCs can migrate to the damaged ovaries of POI mice, and improve the ovarian function of POI mice by inhibiting oxidative stress, down-regulating the expression of the PERK/eIF-2α/ATF4/CHOP pathway, and reducing the apoptosis of GCs.

CLEC7A Knockdown Alleviates Ischemic Stroke by Inhibiting Pyroptosis and Microglia Activation.

Ischemic stroke (IS) is the leading cause of mortality worldwide. Herein, we aimed to identify novel biomarkers and explore the role of C-type lectin domain family 7 member A (CLEC7A) in IS. Differentially expressed genes (DEGs) were screened using the GSE106680, GSE97537, and GSE61616 datasets, and hub genes were identified through construction of protein-protein interaction networks. An IS model was established by middle cerebral artery occlusion and reperfusion (MCAO/R). Neural function was assessed using triphenyl tetrazolium chloride, hematoxylin-eosin, and terminal deoxynucleotidyl transferase-mediated nick-end labeling. A cell counting kit was used to detect cell viability following oxygen-glucose deprivation/reperfusion (OGD/R). Inflammatory factors were detected using enzyme-linked immunosorbent assay. The mRNA and protein expression levels were detected using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. Fc fragment of Immunoglobulin G (IgG) receptor IIIa (FCGR3A), Fc fragment of Immunoglobulin E (IgE) receptor Ig (FCER1G), Complement component 5a receptor 1 (C5AR1), CLEC7A, Plasminogen activator, urokinase (PLAU), and C-C motif chemokine ligand 6 (CCL6) were identified as important hub genes, from which CLEC7A was selected as the primary subject of this study. The activation of microglia and pyroptosis were observed in MCAO/R model with increased levels of interleukin (IL)-1β, IL-18, tumor necrosis factor-α, and lactate dehydrogenase. CLEC7A knockdown was found to promote cell viability in BV2 cells and inhibiting pyroptosis in HT22 cells. CLEC7A knockdown in microglia also decreased infarct volume and neurological deficit scores, and alleviated injury and neuronal apoptosis in IS rats. CLEC7A knockdown inhibited pyroptosis and microglial activation in the MCAO/R model. A pyroptosis activator reversed the effect of CLEC7A knockdown on the viability of OGD/R-treated HT22 cells. CLEC7A is a promising biomarker of IS. CLEC7A knockdown alleviates IS by inhibiting pyroptosis and microglial activation.