OBJECTIVES: Osteoarthritis (OA) is one of the most common chronic degenerative diseases, with chondrocyte apoptosis and extracellular matrix (ECM) degradation as the major pathological changes. The mechanical stimulation can attenuate chondrocyte apoptosis and promote ECM synthesis, but the underlying molecular mechanisms remain unclear. This study aims to investigate the role of primary cilia (PC) in mediating the effects of mechanical stimulation on OA progression. METHODS: In vivo, conditional knockout mice lacking intraflagellar transport 88 (IFT88^flox/flox IFT88 knockout; i.e., primary cilia-deficient mice) were generated, with wild-type mice as controls. OA models were established via anterior cruciate ligament transection combined with destabilization of the medial meniscus, followed by treadmill exercise intervention. OA progression was evaluated by hematoxylin-eosin staining, safranin O-fast green staining, and immunohistochemistry; apoptosis was assessed by TUNEL staining; and limb function by rotarod testing. In vitro, primary articular chondrocytes were isolated from mice and transfected with lentiviral vectors to suppress IFT88 expression, thereby constructing a primary cilia-deficient cell model. Interleukin-1β (IL-1β) was used to induce an inflammatory environment, while cyclic tensile strain (CTS) was applied via a cell stretcher to mimic mechanical loading on chondrocytes. Immunofluorescence and Western blotting were used to detect the protein expression levels of type II collagen α1 chain (COL2A1), primary cilia, IFT88, and caspase-12; reverse transcription polymerase chain reaction was performed to assess COL2A1 mRNA levels; and flow cytometry was used to evaluate apoptosis. RESULTS: In vivo, treadmill exercise significantly reduced Osteoarthritis Research Society International (OARSI) scores and apoptotic cell rates, and improved balance ability in wild-type OA mice, whereas IFT88-deficient OA mice showed no significant improvement. In vitro, CTS inhibited IL-1β-induced ECM degradation and apoptosis in primary chondrocytes; however, this protective effect was abolished in cells with suppressed primary cilia expression. CONCLUSIONS Mechanical stimulation delays OA progression by mediating signal transduction through primary cilia, thereby inhibiting cartilage degeneration and chondrocyte apoptosis.
Animals ; Chondrocytes/cytology* ; Apoptosis/physiology* ; Mice ; Cilia/metabolism* ; Osteoarthritis/pathology* ; Extracellular Matrix/metabolism* ; Mice, Knockout ; Disease Progression ; Interleukin-1beta ; Male ; Cells, Cultured

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and advanced fibrosis, is a leading cause of chronic liver disease worldwide, progressing to cirrhosis and ultimately hepatocellular carcinoma (HCC). Excessive accumulation of fatty acids in the liver triggers multiple forms of hepatocyte death and exacerbates NAFLD progression, with pyroptosis and apoptosis considered key events. Recent studies show that cysteine aspartic acid specific protease-3 (caspase-3) is a central regulator of both pyroptosis and apoptosis in NAFLD. Activated caspase-3 not only directly induces apoptosis but also cleaves the N-terminal domain of gasdermin E (GSDME), disrupts cell membranes, releases inflammatory factors, and thereby mediates pyroptosis. Inhibiting caspase-3 expression in NAFLD can alleviate hepatocyte injury (such as ballooning degeneration), dampen pro-inflammatory signaling, and reduce apoptosis. Caspase-3 acts as a key node coordinating pyroptosis and apoptosis and may serve as a novel therapeutic target for the prevention and treatment of NAFLD.
Non-alcoholic Fatty Liver Disease/metabolism* ; Humans ; Pyroptosis/physiology* ; Apoptosis/physiology* ; Caspase 3/physiology* ; Animals ; Gasdermins

Hypoxic-ischemic (HI) brain damage poses a high risk of death or lifelong disability, yet effective treatments remain elusive. Here, we demonstrated that miR-100-5p levels in the lesioned cortex increased after HI insult in neonatal mice. Knockdown of miR-100-5p expression in the brain attenuated brain injury and promoted functional recovery, through inhibiting the cleaved-caspase-3 level, microglia activation, and the release of proinflammation cytokines following HI injury. Engineered extracellular vesicles (EVs) containing neuron-targeting rabies virus glycoprotein (RVG) and miR-100-5p antagonists (RVG-EVs-Antagomir) selectively targeted brain lesions and reduced miR-100-5p levels after intranasal delivery. Both pre- and post-HI administration showed therapeutic benefits. Mechanistically, we identified protein phosphatase 3 catalytic subunit alpha (Ppp3ca) as a novel candidate target gene of miR-100-5p, inhibiting c-Fos expression and neuronal apoptosis following HI insult. In conclusion, our non-invasive method using engineered EVs to deliver miR-100-5p antagomirs to the brain significantly improves functional recovery after HI injury by targeting Ppp3ca to suppress neuronal apoptosis.
Animals ; MicroRNAs/metabolism* ; Extracellular Vesicles/metabolism* ; Mice ; Recovery of Function/physiology* ; Hypoxia-Ischemia, Brain/therapy* ; Mice, Inbred C57BL ; Antagomirs/administration & dosage* ; Male ; Animals, Newborn ; Apoptosis/drug effects* ; Brain Injuries/metabolism* ; Glycoproteins ; Peptide Fragments ; Viral Proteins

OBJECTIVE: To explore mechanisms of acid-sensing ion channel 1 (ASIC1) mediated lumbar nucleus pulposus cell apoptosis through extracellular-signalregulated protein kinase 5 (ERK5) signaling pathway and mitochondrial dysfunction pathway. METHODS: Totally 34 patients with degenerative lumbar disc herniation (LDH) admitted from January 2020 to December 2022 were collected as research objects, including 21 males and 13 females;aged from 29 to 52 years old with an average of (37.43±4.75) years old;22 patients with grade Ⅱ and 12 patients with grade Ⅳ, according to Pfirrmann grading criteria;15 patients with L_4,5 and 19 patients with L₅S₁. The expression of ASIC1 in nucleus pulposus of LDH patients was measured by immunohistochemical staining. Nucleus pulposus cells were cultured by primary culture method, identified by toluidine blue staining and immunohistochemical staining, and the expression of ASIC1 protein was located by immunofluorescence staining. According to the addition of siRNA-ASIC1, ASIC1 overexpression plasmid, and ERK5 inhibitors, the nucleus pulpocyte was divided into three groups, named as SIRNA-silenced group, overexpression group, and inhibitor group, with 3 patients in each group. Cells of each group were collected at 72 h after intervention, expression of ASIC1, ERK5, BCL-xL/BCL-2-associated Death promoter (Bad), B-cell lymphoma-2 associated X (Bax) and B-cell lymphoblast-2 gene (Bcl-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR);intracellular calcium ion levels were detected by calcium ion kit, mitochondrial membrane potential was detected by JC-1 kit, and apoptosis was observed by AV-PI kit. RESULTS: In LDH patients with grade Ⅳ, nucleus pulposus tissue removed during operation revealed poor elasticity, white color and poor ductility, and immunohistochemical results showed increased ASIC1 expression. There was no significant difference in mRNA relative expression of ASIC1 between siRNA silencing group (0.31±0.03) and inhibitor group (0.39±0.05) (P>0.05). The mRNA relative expression level of ERK5 in siRNA silencing group(0.32±0.05) was significantly higher than that in inhibitor group (0.15±0.04)(P<0.05), which suggested ERK5 was the downstream molecule of ASIC1. The mRNA relative expression levels of apoptosis promoting factor Bad and Bax in siRNA silencing group and inhibitor group were lower than those in overexpression group(P<0.05), the relative expression level of anti-apoptosis factor Bcl-2 mRNA was significantly increased (P<0.05). The calcium content in overexpression group was higher than that in siRNA silencing and inhibitor groups (P<0.05), the normal proportion of mitochondrial membrane potential in overexpression group was lower than that in siRNA silencing and inhibitor group (P<0.05), and the apoptosis rate in overexpression group was higher than that in siRNA silencing and inhibitor group (P<0.05). CONCLUSION After the activation of ASIC1 channel protein, calcium ions could enter the cells and act as a second messenger molecule to regulate apoptosis of nucleus pulposus cells by ERK5 signaling pathway and mitochondrial disorder pathway.
Humans ; Acid Sensing Ion Channels/physiology* ; Male ; Female ; Apoptosis ; Middle Aged ; Adult ; Signal Transduction ; Mitogen-Activated Protein Kinase 7/physiology* ; Mitochondrial Diseases/genetics* ; Nucleus Pulposus/metabolism* ; Intervertebral Disc Degeneration/metabolism* ; Mitochondria/metabolism* ; Intervertebral Disc Displacement/genetics*

Objectives miR-207 has been identified as being expressed in natural killer (NK) cell exosomes that play a role in disease progression; however, to date, there are no studies specifically linking miR-207 to tuberculosis (TB). Methods Bioinformatics methods employed for prediction, followed by a dual luciferase reporter assay to determine whether lysosome-associated membrane protein 2 (LAMP2) is targeted by miR-207. The experiments were divided into four groups using the liposome transfection method (OP-LAMP2 group: co-transfected with miR-207 mimics and LAMP2 overexpression plasmid; EP group: co-transfected with mimics NC and null-loaded plasmid; siLAMP2 group: transfected with siLAMP2; and siLAMP2-NC group: transfected with siLAMP2-NC). TB infection was modeled using H37Ra-infected Ana-1 cells. The impact of LAMP2 on intracellular mycobacterial load and clearance of extracellular residual mycobacteria were assessed by tuberculosis colony-forming unit counting. Flow cytometry was used to assess the total apoptosis rate. Real-time fluorescent quantitative PCR was conducted to determine the relative expression of LAMP2, apoptosis genes, pyroptosis genes, and autophagy genes. Western blot analysis was performed to measure the relative expression of LAMP2 proteins, apoptosis proteins, pyroptosis proteins, and autophagy proteins. Results Dual luciferase reporter assay test showed that there was a targeting relationship between LAMP2 and miR-207. The transfection model was successfully constructed under real-time fluorescent quantitative PCR and Western blot statistical analysis, and microscopic observation. The infection model was successfully established under microscopic observation. Colony forming unit counting revealed that the number of colonies in the OP-LAMP2 group was lower than that in the EP group, while the number of colonies in the siLAMP2 group was higher than that in the siLAMP2-NC group. Flow cytometry assay revealed that the total apoptosis in OP-LAMP2 group was lower than that in EP group, and the total apoptosis in siLAMP2 group was higher than that in siLAMP2-NC group. Real-time fluorescence quantitative PCR and Western blot analysis revealed that the relative expression of apoptosis and pyroptosis-related proteins and genes in the control group was lower in the OP-LAMP2 group compared to the EP group, and higher in the siLAMP2 group compared to the siLAMP2-NC group. Real-time fluorescence quantitative PCR detected that the relative expression of autophagy positively regulated genes Microtubule-associated protein 1 light chain 3(LC3)and Beclin1 in the OP-LAMP2 group was higher in the OP-LAMP2 group compared to the EP group, and lower in the siLAMP2 group compared to the siLAMP2-NC group, while the relative expression of negatively regulated autophagy genes followed the opposite trend to that of autophagy positively regulated genes. The relative expression of autophagy-related proteins was consistent with the trend of autophagy genes. Conclusions miR-207 enhances macrophage apoptosis, cellular pyroptosis and inhibits autophagy, promoting survival of Mycobacterium tuberculosis by targeting the autophagy-related protein LAMP2, thus offering a novel therapeutic direction for tuberculosis.
Lysosomal-Associated Membrane Protein 2/metabolism* ; MicroRNAs/metabolism* ; Mycobacterium tuberculosis/physiology* ; Autophagy/genetics* ; Humans ; Macrophages/metabolism* ; Apoptosis/genetics* ; Tuberculosis/metabolism* ; Cell Line ; Pyroptosis/genetics*

Objective To explore the mechanism of lncRNA-BC200 (BC200) targeting the ubiquitination of Beta-site APP cleaving enzyme 1 (BACE1) and regulating the repair of nerve cell injury. Methods Mouse hippocampal neuron cell line HT22 was divided into four groups: control group, oxygen-glucose deprivation/reoxygenation(OGD/R) group, OGD/R+si-NC group and OGD/R+si-BC200 group. In order to further explore the relationship between BC200 and BACE1, HT22 cells were divided into four groups: OGD/R group, OGD/R+si-BC200 group, OGD/R+si-BC200+NC group and OGD/R+si-BC200+ BACE1 group. Twenty male C57BL/6J mice were randomly assigned to the following four groups: control group, middle cerebral artery occlusion (MCAO) group, MCAO+si-BC200 group and MCAO+si-BC200+BACE1 group. The mRNA expression levels of BC200 and BACE1 in cells were measured by real-time quantitative reverse transcription polymerase chain reaction. The expressions of c-caspase-3, B-cell lymphoma 2 (Bcl2), Bcl2 associated X protein(BAX) and BACE1 were detected by western blot, and the apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test. Results Compared with the control group, the activity of HT22 cells in OGD/R group decreased significantly, and the percentage of apoptotic cells increased significantly. Compared with OGD/R+si-NC group, the activity of HT22 cells in OGD/R+si-BC200 group increased significantly, and the percentage of apoptotic cells decreased significantly. Compared with the control group, the expression of BACE1 protein in HT22 cells in OGD/R group was significantly enhanced. Compared with OGD/R+si-NC group, the expression of BACE1 protein in HT22 cells in OGD/R+si-BC200 group decreased significantly. It was observed that after OGD/R treatment, the ubiquitination level of BACE1 decreased significantly and the expression of BACE1 protein increased significantly. After transfection with si-BC200, the ubiquitination level of BACE1 protein increased significantly, while the expression of BACE1 protein decreased significantly. Compared with OGD/R+si-BC200+NC group, the percentage of apoptotic cells, the expression of c-caspase-3 and Bax protein in HT22 cells in OGD/R+si-BC200+BACE1 group increased significantly, and the expression of Bcl2 protein decreased significantly. Compared with the control group, the number of cerebral infarction areas and TUNEL positive cells in MCAO group increased significantly, and the survival number of neurons decreased significantly. Compared with the MCAO group, the number of cerebral infarction areas and TUNEL positive cells in MCAO+si-BC200 group decreased significantly, and the survival number of neurons increased significantly, while the addition of BACE1 reversed the improvement of si-BC200 transfection. Conclusion The combination of BC200 and BACE1 inhibit the ubiquitination of BACE1, and participate in mediating the expression enhancement of BACE1 induced by OGD/R. Specific blocking of BC200/BACE1 axis may be a potential therapeutic target to protect neurons from apoptosis induced by cerebral ischemia/reperfusion.
Animals ; Amyloid Precursor Protein Secretases/genetics* ; RNA, Long Noncoding/physiology* ; Aspartic Acid Endopeptidases/genetics* ; Male ; Neurons/pathology* ; Mice ; Mice, Inbred C57BL ; Apoptosis/genetics* ; Ubiquitination ; Cell Line ; Hippocampus/metabolism* ; bcl-2-Associated X Protein/genetics* ; Caspase 3/genetics* ; Infarction, Middle Cerebral Artery/metabolism*

Objective To explore the effect of miR-582-5p on Mycobacterium tuberculosis (Mtb)-infected macrophages by regulating dual specificity phosphatase 1 (DUSP1). Methods THP-1 macrophages were divided into six groups: control group, Mtb group, inhibitor-NC group, miR-582-5p inhibitor group, miR-582-5p inhibitor+si-NC group, and miR-582-5p inhibitor+si-DUSP1 group. QRT-PCR was applied to detect the gene expression of miR-582-5p and DUSP1 in cells. ELISA kit was used to detect the levels of interferon γ (IFN-γ), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and interleukin 1β (IL-1β). CCK-8 method was applied to detect cell proliferation. Flow cytometry was applied to detect cell apoptosis rate. Western blot analysis was used to measure the protein expression levels of B-cell lymphoma 2 (Bcl2), Bcl2-associated X (BAX), and cleaved-caspase 3 (c-caspase-3) in cells. In addition, the target relationship between miR-582-5p and DUSP1 was verified. Results Compared with the control group, the expression of miR-582-5p, levels of IFN-γ, IL-6, TNF-α, IL-1β, bacterial load and OD450 values (24 h, 48 h), and the protein expression of Bcl2 in macrophages were higher in the Mtb group, while the mRNA expression of DUSP1, apoptosis rate, and the protein expression levels of c-caspase-3, BAX and DUSP1 were lower. Compared with the Mtb group and the inhibitor-NC group, the above-mentioned indicators in the miR-582-5p inhibitor group were partially reversed. Down-regulation of DUSP1 expression partially reversed the inhibitory effect of down-regulation of miR-582-5p expression on Mtb-infected macrophages. Conclusion Inhibiting the expression of miR-582-5p can up-regulate DUSP1, thereby inhibiting the proliferation and inflammatory response of Mtb-infected macrophages and promoting cell apoptosis.
Humans ; Macrophages/metabolism* ; Dual Specificity Phosphatase 1/metabolism* ; MicroRNAs/metabolism* ; Mycobacterium tuberculosis/physiology* ; Tuberculosis/microbiology* ; Apoptosis/genetics* ; THP-1 Cells ; Cell Proliferation/genetics* ; Interferon-gamma/genetics* ; Tumor Necrosis Factor-alpha/genetics* ; Interleukin-1beta/genetics*

Objective To investigate the effect and mechanism of Efferocytosis Relatived LncRNA (EFRL) on homocysteine-induced atherosclerosis in macrophage efferocytosis. Methods RAW264.7 cells were cultured in vitro, and the Control group (0 μmol/L Hcy) and Hcy intervention group (100 μmol/L Hcy) were set up. After GapmeR transfection of macrophages with Hcy intervention, EFRL knockdown negative control group (Hcy combined with LNA-NC) and EFRL knockdown group (Hcy combined with LNA-EFRL) were set up. High-throughput sequencing was applied for different expression of LncRNA MSTRG. 88917.16 (EFRL), UCSC was used to analyze its conservation, CPC and CPAT were used to analyze its ability to encode proteins, and GO and KEGG were used to analyze related biological functions. The localization of LncRNA EFRL in macrophages was analyzed by nucleoplasmic separation and RNA-FISH. Quantitative real-time PCR was used to detect the expression levels of LncRNA EFRL and its target gene SPAST in Hcy-treated macrophages. The apoptosis rate of Jurkat cells induced by UV was detected by flow cytometry. In vitro efferocytosis assay combined with immunofluorescence technique was used to analyze macrophage efferocytosis. ELISA was used to detect the levels of interleukin 1β(IL-1β) and IL-18. Results The new LncRNA MSTRG.88917.16 was identified and named EFRL(Efferocytosis Relatived LncRNA). UCSC, CPC and CPAT analyses showed that LncEFRL is highly conserved and does not have the ability to encode proteins. GO and KEGG analyses suggested that LncEFRL may be involved in macrophage efferocytosis. LncRNA EFRL was localized in the nucleus of macrophages as determined by nucleoplasmic separation and RNA-FISH. In comparison to the Control group, the expression levels of LncRNA EFRL and its target gene SPAST in the Hcy group were increased. In comparison to the Control group (0 min), the apoptosis rate of the experimental group (15, 30 min) Annexin V is more than 85%. Compared with Hcy combined with LNA-NC group, Hcy combined with LNA-EFRL group had enhanced macrophage efferocytosis and reduced levels of inflammatory factors. Compared with Hcy combined with LNA-NC group, the expression level of SPAST in Hcy combined with LNA-EFRL group was decreased. Conclusion Inhibition of EFRL expression can alleviate the process of Hcy inhibiting macrophage efferocytosis, and the mechanism is related to the regulation of the downstream target gene SPAST by EFRL.
RNA, Long Noncoding/physiology* ; Animals ; Homocysteine ; Mice ; Macrophages/drug effects* ; Humans ; RAW 264.7 Cells ; Atherosclerosis/chemically induced* ; Apoptosis/genetics* ; Phagocytosis/genetics* ; Jurkat Cells ; Interleukin-1beta/genetics* ; Efferocytosis

In most types of erectile dysfunction, particularly in advanced stages, typical pathological features observed are reduced parenchymal cells coupled with increased tissue fibrosis. However, the current treatment methods have shown limited success in reversing these pathologic changes. Recent research has revealed that changes in autophagy levels, along with alterations in apoptosis and fibrosis-related proteins, are linked to the progression of erectile dysfunction, suggesting a significant association. Autophagy, known to significantly affect cell fate and tissue fibrosis, is currently being explored as a potential treatment modality for erectile dysfunction. However, these present studies are still in their nascent stage, and there are limited experimental data available. This review analyzes erectile dysfunction from a pathological perspective. It provides an in-depth overview of how autophagy is involved in the apoptotic processes of smooth muscle and endothelial cells and its role in the fibrotic processes occurring in the cavernosum. This study aimed to develop a theoretical framework for the potential effectiveness of autophagy in preventing and treating erectile dysfunction, thus encouraging further investigation among researchers in this area.
Male ; Humans ; Autophagy/physiology* ; Apoptosis/physiology* ; Erectile Dysfunction/physiopathology* ; Fibrosis ; Penis/pathology* ; Animals ; Endothelial Cells/pathology* ; Myocytes, Smooth Muscle/pathology*