Search Results (3,859)

Gemykibivirus, an emerging single-stranded DNA (ssDNA) virus of the recently established genus in the family of Genomoviridae, had been discovered in human blood and cerebrospinal fluid and a variety of other body fluids. However, the molecular mechanisms of gemykibivirus entrance into the host cells and its pathogenicity remain poorly understood. To investigate the host response of gemykibivirus, we used an infectious clone of gemykibivirus previously established through molecular biology techniques to rescue virus in HEK293T cells and analyzed the changes in the host transcriptome during the infection period by RNA-Seq. Our findings indicate that gemykibivirus can both express viral proteins and accomplish replication, and high-throughput transcriptome analysis identified a total 1732 significantly different genes. Functional enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for differentially expressed genes (DEGs) showed gemykibivirus involving several important pathways, including MAPK signaling pathway, Chemical carcinogenesis-reactive oxygen species and Oxidative phosphorylation. Interestingly, mitochondrial DNA-encoded mRNAs exhibited varying levels of upregulation, suggesting that gemykibivirus may be involved in mitochondrial fission and the regulation of mitochondrial function. Subsequently, a series of experiments proved that gemykibivirus can lead an increase in mitochondrial DNA copy number, promote the release of mtDNA into the cytoplasm, enhance reactive oxygen species production and trigger other cellular antiviral responses. Overall, we lay a foundation for revealing the relationship between Gemykibivirus and human diseases through mitochondrial functional alterations. Full article

Exposure to hypoxia at high altitudes is significantly associated with impairments in learning and memory functions, as well as abnormalities in neuronal function and synaptic plasticity. Recent research has indicated that mitochondrial reactive oxygen species (mtROS) play a role in regulating microglial activation and mediating neurotoxic damage in the hippocampal CA1 region. Nicotinamide riboside (NR), upon absorption, is rapidly converted into nicotinamide adenine dinucleotide (NAD+), which is involved in the production of mitochondrial adenosine triphosphate (ATP). The potential of NR to protect dendritic spine plasticity in hippocampal CA1 neurons following hypoxia exposure, potentially through the inhibition of microglial activation, warrants further investigation. To this end, a mouse model simulating hypoxia at an altitude of 6000 m over a two-week period, along with a BV2 cells and conditional co-culture of BV2 cells and HT22 cells 1%O₂ hypoxia model, was developed. Behavioral assessments indicated that, relative to the normoxia group, mice subjected to hypoxia exhibited a significant reduction in the time spent in the target quadrant, the distance traveled within the target quadrant, the number of platform crossings, and the novel object recognition index. Furthermore, Golgi staining revealed a marked decrease in the density of dendritic spines in the hippocampal CA1 region in the hypoxia-exposed mice compared to the normoxia group. Subsequently, A daily dosage of 400 mg/kg of NR was administered for two weeks and 0.5 mM NR was used in a conditional co-culture model. Results demonstrated that, in comparison to the hypoxia group, the group receiving combined hypoxia and NR treatment showed significant improvements in the time spent in the target quadrant, the distance traveled within the target quadrant, the number of platform crossings, the novel object recognition index, and the density of dendritic spines in the hippocampal CA1 region. Additionally, transmission electron microscopy indicated a significant increase in the synaptic density of hippocampal neurons in the combined hypoxia exposure and NR treatment group compared to the hypoxia exposure group. Simultaneously, when compared to the hypoxia group, the combination of hypoxia and NR treatment resulted in an increased concentration of mitochondrial ATP. This treatment also partially restored mitochondrial membrane integrity, reduced mtROS levels, decreased the percent of Iba1⁺CD68⁺Iba1⁺ microglia, and lowered the interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), and inducible nitric oxide synthase (iNOS) mRNA levels. These findings indicate that NR treatment may mitigate neurotoxic damage in the hippocampal CA1 region induced by hypoxia exposure, primarily through the attenuation of microglial activation and the reduction in mtROS production. Full article

Background/Objectives: Sarcopenia, defined as the progressive loss of muscle mass and function, is increasingly recognized in pediatric cancer patients as a significant clinical and prognostic factor. Sarcopenia in children arises from malignancy-related inflammation, malnutrition, and treatment toxicity, negatively affecting treatment response, recovery, and quality of life. Methods: We searched MEDLINE and Scopus for English-written articles published over the last five years using synonyms for the terms “sarcopenia” and “pediatric cancer”. Screening and data extraction were performed in a duplicate-blinded method. We qualitatively synthesized eligible articles. Results: Recent studies identify pre-treatment sarcopenia as a marker of poor prognosis, especially in hepatoblastoma and neuroblastoma. Total psoas muscle area (tax) and skeletal muscle index (SMI) are emerging diagnostic tools, though standardized methods remain lacking. Sarcopenia’s etiology is multifactorial, involving impaired mitochondrial metabolism, chemotherapy-induced appetite loss, and systemic inflammation. Sarcopenic obesity is common, particularly among leukemia survivors, often masked by normal BMI. Survivors also face reduced bone density, impaired immunity, and persistent muscle loss, linked to prior therapies such as radiotherapy and hematopoietic stem cell transplantation. Increase in muscle mass post-treatment correlates with better survival outcomes. Conclusions: Early detection of sarcopenia can support timely interventions such as nutritional support and physical activity. Yet, significant diagnostic heterogeneity across existing studies hampers definitive conclusions regarding its true prevalence and the optimal assessment method. Standardized diagnostic criteria are urgently needed to enable more reliable prevalence estimates and evidence-based clinical strategies. Full article

Porcine rotavirus (PoRV) is one of the most devastating enteric pathogens causing gastroenteritis in pigs, particularly the sudden occurrence in recent years in China. To elucidate host–pathogen interactions and molecular mechanisms underlying PoRV pathogenesis, four-dimensional (4D) data-independent acquisition (DIA) proteomic (4D-DIA) analysis was performed to comprehensively quantify the differentially abundant proteins (DAPs) in PoRV-infected IPEC-J2 cells. A total of 8725 cellular proteins were identified with 279 more abundant and 356 down abundant proteins. A Western blot showed that the abundance of SA100A8, DAPK2, and FTL were in accordance with the acquired proteomic data using 4D-DIA analysis. Bioinformatics analyses of GO and KEGG demonstrated that various DAPs are involved in crucial biological processes and signaling pathways, such as immune response, signal transduction, metabolic pathways, autophagy, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, inflammatory features of host response upon PoRV infection were highlighted, with RT-qPCR confirming the significant upregulation of IL-1α, IL-6, IL-8, TNF-α, STAT1, and IRF9 transcript levels during infection. Altogether, our preliminary findings advance our understanding of PoRV pathogenesis and may shed light on identifying potential targets for the prevention and control of PoRV-associated gastroenteritis. Full article

Neutrophils are among the first cells to be recruited to the lungs during Chlamydia pneumoniae infection in mouse models; however, their regulatory functions are not yet fully understood. This study examined the mechanisms and significance of IL-10-producing neutrophils throughout C. pneumoniae pulmonary infection in C57BL/6 mice. Our findings revealed that infection with C. pneumoniae induces IL-10 secretion in bone marrow-derived neutrophils, depending on Toll-like receptor 2 (TLR2) activation. This process involves TLR2-dependent mitochondrial reactive oxygen species (ROS) production, which triggers the endoplasmic reticulum (ER) stress pathway, including IRE1α and subsequent Xbp1 splicing. Inhibition of this pathway or depletion of neutrophils (using the 1A8 monoclonal antibody) significantly reduces IL-10 levels in bronchoalveolar lavage fluid (BALF) in vivo. Conversely, the absence of IL-10-producing neutrophils, whether through depletion or TLR2 deficiency, leads to increased IL-12p70 and IFN-γ-positive NK cells, along with decreased regulatory T cells and M2-like macrophages. This results in a lower bacterial burden in the lungs but causes more severe pulmonary damage and decreased survival rates. These findings highlight that IL-10 produced by neutrophils via the TLR2-mitochondrial ROS–ER stress pathway is essential for modulating pulmonary immune responses and maintaining immune homeostasis during C. pneumoniae infection, thereby preventing excessive inflammation and tissue damage. Full article

Background/Objectives: Enhancement of cellular NAD⁺ mediated by NMN has emerged as a pivotal strategy in modulating the aging process. This study aimed to systematically investigate the anti-aging effects of NMN on human skin fibroblasts, focusing on how the former contributes to the improvement of cellular health and function. This study elucidated the molecular and functional mechanisms by which NMN contributes to the attenuation of skin aging. Methods: We performed extensive in vitro and transcriptomic analyses. Human skin fibroblasts were treated with NMN, and the induced biological responses were observed under oxidative stress/photo-aging models. Results: Transcriptome analysis revealed distinct gene expression patterns for NAD⁺ and its precursors (NMN, NR, and NAM), showing significant differences between NMN and other precursors (NR and NMN). NMN seemed to be significantly involved in cytokine and chemokine activity. It significantly elevated cellular NAD⁺ levels, activated sirtuin and autophagy pathways, and enhanced mitochondrial function, collectively maintaining cellular homeostasis under stress. Furthermore, it suppressed cellular senescence, promoted cell proliferation, supported extracellular matrix integrity, and accelerated wound healing. Conclusions: The study provided essential mechanistic evidence supporting the anti-aging effects of NMN in skin cells and addressed the current lack of scientific validation of NMN-based topical applications. The findings established a solid academic background for future translational research and the development of NMN-based therapeutics and cosmeceuticals. Full article

Shikonin, a dietary naphthoquinone phytochemical from the roots of Lithospermum erythrorhizon, has gained attention for its anticancer potential. Preclinical studies show that shikonin regulates multiple programmed cell death pathways, including apoptosis, necroptosis, ferroptosis, and pyroptosis, through mechanisms involving reactive oxygen species (ROS) accumulation, mitochondrial dysfunction, and kinase-mediated signalling. Beyond cytotoxicity, shikonin suppresses metastasis by blocking epithelial–mesenchymal transition (EMT) and downregulating matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). It also disrupts tumour metabolism by targeting pyruvate kinase isoform M2 (PKM2) and modulating the Warburg effect. Evidence further indicates that shikonin can enhance the efficacy of chemotherapy, targeted therapy, immunotherapy, and radiotherapy, thereby contributing to the reversal of therapeutic resistance. To address limitations related to solubility and bioavailability, novel formulations such as nanoparticles, liposomes, and derivatives like β,β-dimethylacrylshikonin have been developed, showing improved pharmacological profiles and reduced toxicity in experimental models. Overall, the current literature identifies shikonin as a promising dietary phytochemical with diverse anticancer activities, therapeutic synergy, and formulation advances, while highlighting the need for clinical studies to establish its translational potential. Full article

Alcohol metabolism in the body is a key theme in medical research on alcohol. It is primarily regulated by the alcohol dehydrogenase (ADH) and mitochondrial NADH reoxidation in the liver. Class I ADH1 is a well-known ADH isozyme and a key enzyme in alcohol metabolism, with the lowest Kms for ethanol and the highest sensitivity to pyrazole (Pz) among the ADH isozymes. However, a Pz-insensitive metabolic pathway also plays a role in systemic alcohol metabolism, with increasing metabolic contributions at higher blood alcohol concentrations (BACs) and under chronic alcohol consumption (CAC). The Pz-insensitive pathway is referred to as the non-ADH pathway—specifically, it is a non-ADH1 pathway—and is assumed to involve the microsomal ethanol oxidizing system (MEOS) or catalase, as both enzymes are insensitive to Pz and exhibit higher Kms than ADH1. The MEOS is a favored candidate for this pathway, as its activity markedly increases with the rate of alcohol metabolism under CAC. However, the role of the MEOS in alcohol metabolism has not been proven in vivo (even under CAC conditions), nor has that of catalase. Here, we report Class III ADH3 as a new candidate in the non-ADH1 pathway, as it also has a lower sensitivity to Pz and a higher Km. It is markedly activated by lowering Km following the addition of amphiphilic substances, which increases the solution’s hydrophobicity in the reaction medium; additionally, Nile red staining demonstrates a higher solution hydrophobicity in the cytoplasm of mouse liver cells. The rate of alcohol metabolism in ADH1 knockout (Adh1^−/−) mice—which depends solely on the non-ADH1 pathway—increased by more than twice under CAC and was significantly correlated with the amount of liver ADH3 protein, but not with CYP2E1 protein (a main component of the MEOS). The rate of alcohol metabolism in Adh3^−/− mice lacking ADH3 decreased in a dose-dependent manner compared with wild mice. The liver ADH3 protein in wild-type mice increased in line with the ADH1 protein under CAC. These data suggest that ADH3 contributes to alcohol metabolism in vivo as a non-ADH1 pathway and to the enhancement of alcohol metabolism under CAC through activation of the ADH1/ADH3/NADH reoxidation system. In alcoholic liver diseases, ADH1 activity decreased with the progression of liver disease, while ADH3 activity increased or was maintained even in alcoholic liver cirrhosis. Therefore, the role of ADH3 in alcohol metabolism may be increased in the context of alcoholic liver diseases, complementing the reduced role of ADH1. It has also been suggested that Class II ADH2, Class IV ADH4, and aldehyde dehydrogenase (ALDH) 2 play roles in alcohol metabolism in vivo under certain limited conditions. However, ADH2 and 4 may not contribute to the enhancement of alcohol metabolism through CAC. Full article

Background: Carrimycin is a mixture of spiramycin derivatives with antibacterial functions. However, recent studies have shown that it possesses certain anticancer properties. The specific mechanism of the anticancer activity is unknown. Methods: To study the anticancer mechanism of carrimycin, we synthesized a derivative of spiramycin, n-hexyl spiramycin (h-SPM), and used a combination of metabolomics and transcriptomics methods. Capillary electrophoresis–mass spectrometry (CE-MS) was used to detect polar small molecule metabolites, and liquid chromatography–mass spectrometry (LC-MS) was used to detect lipid metabolites in cells. Transcriptomics was used to measure mRNA content in cells. Finally, by processing these data using specific bioinformatics methods, the mechanism underlying anticancer effect of carrimycin was determined. Results: Metabolomics and transcriptomic results showed that lipid metabolism and mitochondrial biogenesis pathways in the cells changed after hSPM treatment, NR1D1 genes and ceramide were enriched from these pathways, implicating the involvement of ROS and pro-inflammatory response. Western blotting verified that the protein levels of NR1D1 decreased after h-SPM treatment, and ROS stating and qPCR demonstrated that ROS levels and the mRNA levels of pro-inflammatory genes were greatly induced by h-SPM. Conclusions: h-SPM reduced the protein level of NR1D1, disrupted metabolic regulation, accumulating ceramide, and the subsequent increased ROS generation promoted apoptosis and pro-inflammatory-like response of cells. Our findings unveiled the anticancer mechanism of a potent anticancer derivative of spiramycin and unveiled its mechanism of action. Full article

Oxidative stress and mitochondrial dysfunction play a key role in the early stage of Doxorubicin (Doxo)-induced cardiotoxicity. Our study investigated the potential cardioprotective role of Simvastatin (Sim), widely known for its antioxidant properties, in an in vitro model of Doxo-induced acute cardiotoxicity. Human Cardiomyocytes (HCMs) were treated with Sim (10 µM, 4 h) and then co-exposed to Doxo (1 µM) and Sim for 20 h. Our data showed that Sim co-treatment significantly (p < 0.05) reduced both cytosolic and mitochondrial Doxo-induced reactive oxygen species overproduction. In Sim co-treated cells, significant reductions in nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression (p < 0.01) and catalase (CAT), heme-oxygenase 1 (HO-1), and superoxide dismutase 2 (SOD2) levels (p < 0.05) compared to Doxo-treated cells were also demonstrated, suggesting a decreased need for compensatory antioxidant defense responses. Moreover, significant reductions in Doxo-induced mitochondrial calcium overload, mitochondrial membrane depolarization (p < 0.005), and apoptosis (p < 0.005) confirmed the protective effects of Sim co-treatment on cardiomyocytes. These data confirm that Sim could be a valuable therapeutic strategy for reducing Doxo-induced HCM damage, preventing the development of dilated cardiomyopathy and long-term heart damage, which are the main limitations of anthracycline use. Finally, real-time PCR analysis revealed that Sim co-treatment significantly reduced (p < 0.001) the Doxo-induced overexpression of MAP4K4, a mitogen-activated protein kinase kinase kinase kinase-4 (MAP4K4) involved in oxidative stress-induced cell death, thus suggesting the involvement of other molecular mechanisms in Sim-mediated cardioprotection. Full article

Primary graft dysfunction (PGD) remains a major cause of early morbidity and mortality after a heart transplant (HTx). Understanding the donor-related mechanisms involved may help improve organ selection and post-HTx outcomes. This study aimed to explore the association between the donor serum biomarkers of cell death and inflammation and the incidence of PGD and rejection in HTx recipients. We conducted a retrospective, multicenter observational study of brain-dead (DBD) heart donors and corresponding recipients between 2013 and 2019. Donor blood samples were analyzed for inflammatory cytokines, cell death-related proteins, and mitochondrial (mtDNA) and genomic DNA (gDNA). A total of 39 donor–recipient pairs were included. Sixteen recipients developed severe PGD, and five experienced ≥2R cellular rejection. Donors whose recipients developed PGD had significantly lower serum Caspase-3 levels compared to those without PGD (391.6 [101.8–1003.3] vs. 65.3 [40.2–163.3] pg/mL; p = 0.04). A trend toward lower mtDNA/gDNA ratio was also observed in the same group (10.5 [5.4–24.6] vs. 6.5 [3.3–10.7]; p = 0.067). Lower Caspase-3 levels in donor serum were significantly associated with the development of severe PGD in recipients. This may suggest that the sublethal activation of apoptotic pathways in the donor could play a protective role, potentially conditioning the graft to tolerate ischemic injury. Full article

Cervical cancer remains the fourth most common cancer among women globally, disproportionately impacting low- and middle-income countries despite the existence of HPV vaccines. While DNA methylation has been studied extensively as a biomarker, other epigenetic mechanisms remain underexplored. This scoping review aims to report such underexplored epigenetic biomarkers linked to cervical cancer, shifting the focus beyond global nuclear DNA methylation. Literature searches were performed using Google Scholar via Publish or Perish software including studies published until January 2025. Our review focused on mitochondrial DNA, non-coding RNA, histone modifications, and repetitive elements. Mitochondrial DNA methylation has been proposed as a cervical cancer biomarker, although supporting evidence is limited. Histone modifications are more consistently reported to be involved both in cervical cancer onset and aggressiveness. Similarly, aberrant expression of lncRNAs, circRNAs, miRNAs, and piRNAs has been associated with poor prognosis. Finally, hypomethylation in repetitive elements such as LINE-1 and Alu is often observed in cervical cancer, contributing to genomic instability and tumorigenesis. Highlighting these alternative epigenetic mechanisms, our review emphasizes the importance of expanding biomarker discovery beyond the traditional nuclear DNA methylation. Understanding these mechanisms may improve early detection and personalized disease management strategies for cervical cancer. Full article

Background: The human mitochondrial ClpP is a serine protease located in the mitochondrial matrix responsible for degrading short lived regulatory proteins as well as misfolded or damaged proteins, thereby maintaining cellular homeostasis. Proteastasis dysregulation is linked to tumor progression. Methods: We conducted a literature review (2020–2025) using PubMed and Scopus, focusing on studies addressing ClpP structure, function, activity modulation, and cancer relevance. Keywords included “ClpP”, “ClpP activators”, “ClpP inhibitors”, and “mitochondrial protease”. Results: ClpP is upregulated in many tumors compared to normal tissues. Cancer cells depend on ClpP for mitochondrial proteostasis, metabolic adaptation, and survival. ClpP proteolytic activity modulation—via activators or inhibitors—disrupts these processes showing efficacy even in clinical setting. Conclusions: ClpP is emerging as a key player in cancer pathophysiology and holds potential as a therapeutic target. Its selective overexpression in tumors, along with its involvement in mitochondrial homeostasis, makes it a compelling candidate for precision oncology. Full article

Cardiotoxicity is one of the most important adverse events of chemotherapy regimens, especially of anthracyclines. Different mechanisms are associated with chemotherapy-related cardiac dysfunction (CTRCD): oxidative stress, mitochondrial dysfunction, inhibition of topoisomerase 2 beta, abnormal iron metabolism, apoptosis, and fibrosis. Even after years of investigation, the early detection and prevention of cardiac impairment after chemotherapy through biomarkers remains an unmet need. The differential expression of microRNAs (miRs) in plasma at different timepoints (baseline, stable intervals during and at the end of chemotherapy) has been associated with CTRCD. Namely, some miRs, such as let-7, miR-29 and miR-30 family, miR-1 clusters, miR-34a, miR-126, miR-130a, miR-140, miR-320a, and miR-499, could play prognostic and/or diagnostic roles in CTRCD. Key miRs involved in apoptosis and oxidative stress include miR-1, miR-21, miR-30 and miR-130a, while let-7 family, miR-34a, miR-29b and miR-499 are associated with fibrosis and extracellular matrix remodeling. Additionally, mitochondrial function is regulated by miR-30, miR-130a and miR-499. Expanding its role, miR-130a could act as a therapeutic agent of CTRCD through its inhibition. This narrative review focuses on the current understanding of miRs’ involvement in CTRCD pathophysiology, summarizes the evidence linking miRs with cardiotoxicity risk, and explores the potential of miRs as biomarkers and therapeutic targets to improve early detection, risk stratification, and management of CTRCD. Full article

Reduced oxygen availability, or hypoxia, is an environmental stress factor that modulates cellular and systemic functions. It plays a significant role in both physiological and pathological conditions, including tissue regeneration, where it influences angiogenesis, metabolic adaptation, inflammation, and stem cell activity. Hypoxia-inducible factors (HIFs) orchestrate these responses by activating genes that promote survival and repair, although HIF-independent mechanisms, particularly those related to mitochondrial function, are also involved. Depending on its duration and severity, hypoxia may exert either beneficial or harmful effects, ranging from enhanced regeneration to fibrosis or maladaptive remodeling. This review explores the systemic and cellular effects of acute, chronic, intermittent, and preconditioning hypoxia in the context of tissue regeneration. Hypoxia-driven responses are examined across tissues, organs, and complex structures, including the heart, muscle, bone, vascular structures, nervous tissue, and appendages such as tails. We analyze findings from animal models and in vitro studies, followed by biomedical and pharmacological strategies designed to modulate hypoxia and their initial exploration in clinical settings. These strategies involve regulatory molecules, signaling pathways, and microRNA activity, which are investigated across species with diverse regenerative capacities to identify mechanisms that may be conserved or divergent among taxa. Lastly, we emphasize the need to standardize hypoxic conditions to improve reproducibility and highlight their therapeutic potential when precisely controlled. Full article