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*

Ferroptosis, a regulated cell death process distinct from apoptosis, is characterized by iron dysregulation and reactive oxygen species (ROS) accumulation. After intracerebral hemorrhage (ICH), decreased cerebral blood flow and iron released from erythrocytes trigger lipid peroxidation-particularly of polyunsaturated fatty acids (PUFAs)-through a cascade of reactions in local brain tissues, promoting ferroptosis. Mitochondrial dysfunction and neuroinflammation further elevate ROS, exacerbating lipid peroxidation and accelerating neuronal ferroptosis. Thus, PUFA peroxidation and associated metabolic pathways play a critical role in ICH-related neuronal damage. This review summarizes current understanding of how PUFA peroxidation contributes to ferro-ptosis after ICH, discusses key regulatory mechanisms involving lipid and iron metabolism, and highlights potential therapeutic strategies targeting ferroptosis to improve neurological outcomes.
Ferroptosis/physiology* ; Humans ; Cerebral Hemorrhage/pathology* ; Lipid Peroxidation ; Fatty Acids, Unsaturated/metabolism* ; Reactive Oxygen Species/metabolism* ; Iron/metabolism* ; Animals ; Mitochondria/metabolism*

OBJECTIVE: To investigate the inhibitory effect of Tanreqing Injection (TRQ) on the activation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome in macrophages infected with influenza A virus and the underlying mechanism based on mitophagy pathway. METHODS: The inflammatory model of murine macrophage J774A.1 induced by influenza A virus [strain A/Puerto Rico/8/1934 (H1N1), PR8] was constructed and treated by TRQ, while the mitochondria-targeted antioxidant Mito-TEMPO and autophagy specific inhibitor 3-methyladenine (3-MA) were used as controls to intensively study the anti-inflammatory mechanism of TRQ based on mitophagy-mitochondrial reactive oxygen species (mtROS)-NLRP3 inflammasome pathway. The levels of NLRP3, Caspase-1 p20, microtubule-associated protein 1 light chain 3 II (LC3II) and P62 proteins were measured by Western blot. The release of interleukin-1β (IL-1β) was tested by enzyme linked immunosorbent assay, the mtROS level was detected by flow cytometry, and the immunofluorescence and co-localization of LC3 and mitochondria were observed under confocal laser scanning microscopy. RESULTS: Similar to the effect of Mito-TEMPO and contrary to the results of 3-MA treatment, TRQ could significantly reduce the expressions of NLRP3, Caspase-1 p20, and autophagy adaptor P62, promote the expression of autophagy marker LC3II, enhance the mitochondrial fluorescence intensity, and inhibit the release of mtROS and IL-1β (all P<0.01). Moreover, LC3 was co-localized with mitochondria, confirming the type of mitophagy. CONCLUSION TRQ could reduce the level of mtROS by promoting mitophagy in macrophages infected with influenza A virus, thus inhibiting the activation of NLRP3 inflammasome and the release of IL-1β, and attenuating the inflammatory response.
Mitophagy/drug effects* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Animals ; Macrophages/virology* ; Inflammasomes/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Mitochondria/metabolism* ; Reactive Oxygen Species/metabolism* ; Influenza A virus/physiology* ; Interleukin-1beta/metabolism* ; Cell Line ; Injections

Skeletal muscle dysfunction is a common extrapulmonary comorbidity of chronic obstructive pulmonary disease (COPD) and is associated with decreased quality-of-life and survival in patients. The autophagy lysosome pathway is one of the proteolytic systems that significantly affect skeletal muscle structure and function. Intriguingly, both promoting and inhibiting autophagy have been observed to improve COPD skeletal muscle dysfunction, yet the mechanism is unclear. This paper first reviewed the effects of macroautophagy and mitophagy on the structure and function of skeletal muscle in COPD, and then explored the mechanism of autophagy mediating the dysfunction of skeletal muscle in COPD. The results showed that macroautophagy- and mitophagy-related proteins were significantly increased in COPD skeletal muscle. Promoting macroautophagy in COPD improves myogenesis and replication capacity of muscle satellite cells, while inhibiting macroautophagy in COPD myotubes increases their diameters. Mitophagy helps to maintain mitochondrial homeostasis by removing impaired mitochondria in COPD. Autophagy is a promising target for improving COPD skeletal muscle dysfunction, and further research should be conducted to elucidate the specific mechanisms by which autophagy mediates COPD skeletal muscle dysfunction, with the aim of enhancing our understanding in this field.
Pulmonary Disease, Chronic Obstructive/physiopathology* ; Autophagy/physiology* ; Humans ; Muscle, Skeletal/pathology* ; Mitophagy ; Animals ; Mitochondria/metabolism* ; Lysosomes

Periodontitis is a common oral disease caused by bacteria coupled with an excessive host immune response. Stem cell therapy can be a promising treatment strategy for periodontitis, but the relevant mechanism is complicated. This study aimed to explore the therapeutic potential of mitochondria from human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs) for the treatment of periodontitis. The gingival tissues of periodontitis patients are characterized by abnormal mitochondrial structure. Human gingival fibroblasts (HGFs) were exposed to 5 μg/mL lipopolysaccharide (LPS) for 24 h to establish a cell injury model. When treated with hESC-MSCs or mitochondria derived from hESC-MSCs, HGFs showed reduced expression of inflammatory genes, increased adenosine triphosphate (ATP) level, decreased reactive oxygen species (ROS) production, and enhanced mitochondrial function compared to the control. The average efficiency of isolated mitochondrial transfer by hESC-MSCs was determined to be 8.93%. Besides, a therapy of local mitochondrial injection in mice with LPS-induced periodontitis showed a reduction in inflammatory gene expression, as well as an increase in both the mitochondrial number and the aspect ratio in gingival tissues. In conclusion, our results indicate that mitochondria derived from hESC-MSCs can reduce the inflammatory response and improve mitochondrial function in HGFs, suggesting that the transfer of mitochondria between hESC-MSCs and HGFs serves as a potential mechanism underlying the therapeutic effect of stem cells.
Humans ; Gingiva/cytology* ; Fibroblasts/metabolism* ; Mitochondria/physiology* ; Mesenchymal Stem Cells/cytology* ; Animals ; Periodontitis/therapy* ; Mice ; Reactive Oxygen Species/metabolism* ; Inflammation ; Lipopolysaccharides ; Human Embryonic Stem Cells/cytology* ; Cells, Cultured ; Adenosine Triphosphate/metabolism* ; Male

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an intracellular transcription factor that helps protect against oxidative stress in different types of cells under pathological conditions. Mitochondria are vital organelles that function in diverse metabolic processes in the body, including redox reactions, lipid metabolism, and cell death. Mitophagy, a specific form of autophagy for damaged mitochondria, plays a critical role in the pathophysiology of liver diseases. In this review, we explain in detail the roles of the Nrf2 signaling pathway and mitophagy, and the relationship between them, in various hepatic diseases (nonalcoholic fatty liver disease, viral hepatitis, alcoholic liver disease, drug-induced liver injury, autoimmune hepatitis, hepatic ischemia‒reperfusion injury, and liver cancer). We also offer some potential insights and treatments relevant to clinical applications.
Humans ; NF-E2-Related Factor 2/metabolism* ; Mitophagy/physiology* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Signal Transduction ; Liver Diseases/etiology* ; Animals ; Oxidative Stress ; Mitochondria/metabolism* ; Non-alcoholic Fatty Liver Disease ; Liver Neoplasms

Acute mitochondrial damage and the energy crisis following axonal injury highlight mitochondrial transport as an important target for axonal regeneration. Syntaphilin (Snph), known for its potent mitochondrial anchoring action, has emerged as a significant inhibitor of both mitochondrial transport and axonal regeneration. Therefore, investigating the molecular mechanisms that influence the expression levels of the snph gene can provide a viable strategy to regulate mitochondrial trafficking and enhance axonal regeneration. Here, we reveal the inhibitory effect of microRNA-146b (miR-146b) on the expression of the homologous zebrafish gene syntaphilin b (snphb). Through CRISPR/Cas9 and single-cell electroporation, we elucidated the positive regulatory effect of the miR-146b-snphb axis on Mauthner cell (M-cell) axon regeneration at the global and single-cell levels. Through escape response tests, we show that miR-146b-snphb signaling positively regulates functional recovery after M-cell axon injury. In addition, continuous dynamic imaging in vivo showed that reprogramming miR-146b significantly promotes axonal mitochondrial trafficking in the pre-injury and early stages of regeneration. Our study reveals an intrinsic axonal regeneration regulatory axis that promotes axonal regeneration by reprogramming mitochondrial transport and anchoring. This regulation involves noncoding RNA, and mitochondria-associated genes may provide a potential opportunity for the repair of central nervous system injury.
Animals ; Zebrafish ; MicroRNAs/genetics* ; Nerve Regeneration/physiology* ; Mitochondria/metabolism* ; Zebrafish Proteins/genetics* ; Axons/metabolism* ; Signal Transduction/physiology* ; Axonal Transport/physiology* ; Nerve Tissue Proteins/genetics*

Male infertility has become a global concern, accounting for 20-70% of infertility. Dysfunctional spermatogenesis is the most common cause of male infertility; thus, treating abnormal spermatogenesis may improve male infertility and has attracted the attention of the medical community. Mitochondria are essential organelles that maintain cell homeostasis and normal physiological functions in various ways, such as mitochondrial oxidative phosphorylation (OXPHOS). Mitochondrial OXPHOS transmits electrons through the respiratory chain, synthesizes adenosine triphosphate (ATP), and produces reactive oxygen species (ROS). These mechanisms are vital for spermatogenesis, especially to maintain the normal function of testicular Sertoli cells and germ cells. The disruption of mitochondrial OXPHOS caused by external factors can result in inadequate cellular energy supply, oxidative stress, apoptosis, or ferroptosis, all inhibiting spermatogenesis and damaging the male reproductive system, leading to male infertility. This article summarizes the latest pathological mechanism of mitochondrial OXPHOS disorder in testicular Sertoli cells and germ cells, which disrupts spermatogenesis and results in male infertility. In addition, we also briefly outline the current treatment of spermatogenic malfunction caused by mitochondrial OXPHOS disorders. However, relevant treatments have not been fully elucidated. Therefore, targeting mitochondrial OXPHOS disorders in Sertoli cells and germ cells is a research direction worthy of attention. We believe this review will provide new and more accurate ideas for treating male infertility.
Male ; Humans ; Infertility, Male/metabolism* ; Oxidative Phosphorylation ; Mitochondria/metabolism* ; Spermatogenesis/physiology* ; Sertoli Cells/metabolism* ; Oxidative Stress/physiology* ; Animals ; Reactive Oxygen Species/metabolism*

Chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH) are both chronic progressive respiratory diseases that cannot be completely cured. COPD is characterized by irreversible airflow limitation, chronic airway inflammation, and gradual decline in lung function, whereas PH is characterized by pulmonary vasoconstriction, remodeling, and infiltration of inflammatory cells. These diseases have similar pathological features, such as vascular hyperplasia, arteriolar contraction, and inflammatory infiltration. Despite these well-documented observations, the exact mechanisms underlying the occurrence and development of COPD and PH remain unclear. Evidence that mitochondrial dynamics imbalance is one major factor in the development of COPD and PH. Mitochondrial dynamics is precisely regulated by mitochondrial fusion proteins and fission proteins. When mitochondrial dynamics equilibrium is disrupted, it causes mitochondrial and even cell morphological dysfunction. Mitochondrial dynamics participates in various pathological processes for heart and lung disease. Mitochondrial dynamics may be different in the early and late stages of COPD and PH. In the early stages of the disease, mitochondrial fusion increases, inhibiting fission, and thereby compensatorily increasing adenosine triphosphate (ATP) production. With the development of the disease, mitochondria decompensation causes excessive fission. Mitochondrial dynamics is involved in the development of COPD and PH in a spatiotemporal manner. Based on this understanding, treatment strategies for mitochondrial dynamics abnormalities may be different at different stages of COPD and PH disease. This article will provide new ideas for the potential treatment of related diseases.
Humans ; Mitochondrial Dynamics/physiology* ; Pulmonary Disease, Chronic Obstructive/metabolism* ; Hypertension, Pulmonary/metabolism* ; Mitochondria/metabolism* ; Animals

Mitochondria serve as multifunctional powerhouses within cells, coordinating essential biological activities that are critical for cell viability, including material metabolism, signal transduction, and the maintenance of homeostasis. They support cells in adapting to complex and fluctuating environments. Oocytes, being the largest cells in multicellular organisms, contain a high number of mitochondria with unique structural characteristics. Mitochondria play active roles in the development and maturation of oocytes. A decline in mitochondrial function negatively affects both the quality and quantity of oocytes, thereby contributing to ovarian aging. However, the specific mechanisms through which mitochondrial dysfunction influences the progression of ovarian aging and impacts reproductive longevity remain unclear. Furthermore, medical strategies aimed at rejuvenating mitochondria to restore ovarian reserve and improve female reproductive potential may open new avenues for clinical treatment. In this review, we summarize the current understanding and key evidence regarding the role of mitochondrial dysfunction in ovarian aging and present emerging medical approaches targeting mitochondria to alleviate premature ovarian aging and enhance reproductive performance.
Humans ; Female ; Mitochondria/physiology* ; Ovary/physiology* ; Aging/physiology* ; Animals ; Oocytes/metabolism*