Cellular Physiology and Biochemistry最新文献

Background/aims: Hypoxia-inducible factor isoforms HIF1 and HIF2 are crucial in the hypoxia response but might also support cancer progression, including breast cancer. O-GlcNAcylation, a post-translational modification regulated by the OGT enzyme, is also emerging as a contributor to breast cancer malignancy. This study aimed to elucidate the role of HIF1 and HIF2 in breast cancer progression and their relationship to O-GlcNAcylation.

Methods: We analyzed clinical breast cancer samples, assessing HIF1, HIF2, OGT, and the total O-GlcNAcylation levels by the Western Blot method and their association with clinicopathological characteristics. Additionally, we employed in vitro silencing of OGT, HIF1, and HIF2 in breast cancer cell lines (MCF-7 and MDA-MB-231) to examine their effects on genes expression and cell migration (wound healing assay). A p-value < 0.05 was considered to indicate a statistically significant difference.

Results: In breast cancer samples, both HIF isoform levels were elevated in tumors, but HIF2 was associated with lymph node metastasis. A negative correlation was found between HIF2 and O-GlcNAcylation. Silencing HIF2 slowed cell migration, increased O-GlcNAcylation, and decreased the expression of metastasis-related genes. Silencing HIF1 or OGT resulted in the increased expression of these genes, potentially due to increased levels of HIF2.

Conclusion: Our findings suggest that the HIF-O-GlcNAc axis plays a critical role in breast cancer progression and metastasis, with HIF1 and HIF2 exhibiting distinct functions.

Background/aims: Phloroglucinol is a phenolic derivative isolated from brown algae and reportedly has the potential to induce apoptosis in cancer cells, but its mechanism is unclear. This study aimed to elucidate the complete anticancer mechanism of phloroglucinol in Hep3B human hepatocellular carcinoma (HCC) cells.

Methods: We investigated whether phloroglucinol inhibits the proliferation of Hep3B cells by inducing DNA damage and apoptosis, and conducted a study on the mechanism involved. We also explored whether phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway is involved in phloroglucinol-induced apoptosis. In addition, we evaluated whether reactive oxygen species (ROS) was involved in the anticancer activity of phloroglucinol.

Results: Our results revealed that phloroglucinol disrupted mitochondrial integrity and induced caspase-dependent apoptosis by altering the expression of Bcl-2 family proteins and increasing the cytosolic release of cytochrome c . Phloroglucinol also inactivated the PI3K/Akt/mTOR signaling pathway, and pretreatment with a PI3K inhibitor remarkably augmented the phloroglucinol-induced cytotoxic effect in Hep3B cells. In addition, phloroglucinol significantly stimulated generation of ROS and reduced glutathione ratios. However, a ROS scavenger attenuated phloroglucinol-induced oxidative stress, DNA damage, and apoptosis, thus restoring the reduced cellular viability by blockading phloroglucinol-mediated inactivation of PI3K/Akt/mTOR signaling.

Conclusion: Our findings support a mechanism in which phloroglucinol enhances Hep3B cell apoptosis by inactivating the ROS-dependent PI3K/Akt/mTOR pathway, which implies that ROS generation acts as an inducer of phloroglucinol-mediated anticancer activity. Taken together, our findings support further research on the potential of phloroglucinol as a candidate for treating HCC.

Background/aims: Osteosarcoma is the most common primary bone cancer affecting children and adolescents worldwide. Although many treatments for osteosarcoma have been explored, the overall survival rate for patients with metastatic osteosarcoma is only 20% due to the lack of understanding of the biological mechanisms by which osteosarcoma metastasis occurs. Therefore, it is important to uncover the molecular mechanism of metastasis in osteosarcoma.

Methods: We compared the migration ability of primary osteosarcoma cells from p53 knockout (p53null) and p53^N236S knock-in (p53S) mice. Furthermore, via RNA-sequencing (RNA-seq) data from mouse embryonic fibroblast (MEF) cells, we explored the mechanism by which p53S regulates the cholesterol synthesis pathway and the Hedgehog signaling pathway in primary osteosarcoma cells.

Results: We found that the migration ability of primary tumor cells from p53S mice was increased both in vivo and in vitro . Further investigations revealed that the cholesterol content in p53S sarcoma tissue and primary cells was increased following the upregulation of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR). We subsequently observed that elevated cholesterol levels can regulate the Hedgehog (HH) pathway and lead to tumor metastasis. We subsequently treated p53S sarcoma cells with the cholesterol neutralizer methyl-β-cyclodextrin (MβCD) and an HH pathway inhibitor; consequently, we reported that total cholesterol levels reduced both Hedgehog pathway activity and cell migration, whereas HH pathway activity reduced only cell migration.

Conclusion: In summary, we confirmed the enhanced metastatic ability of p53S sarcoma primary cells via in vivo and in vitro experiments and preliminarily confirmed the mechanism by which p53S promotes cholesterol synthesis and further activates the HH signaling pathway, thus leading to sarcoma metastasis. This study provides a theoretical basis for further revealing the function and mode of action of p53 mutations in the process of sarcoma metastasis, thereby providing a new potential target for the targeted diagnosis and treatment of sarcoma.

Lung cancer, one of the leading causes of cancer-related deaths globally, is notorious for its poor prognosis and limited response to conventional therapies. Despite advancements in chemotherapy, targeted therapies, and immunotherapy, the efficacy of these treatments is often undermined by the development of resistance, particularly multidrug resistance (MDR). MDR in lung cancer is primarily driven by various mechanisms, including the overexpression of ATP-binding cassette (ABC) transporters like P-glycoprotein (ABCB1), which actively pump chemotherapeutic drugs out of cancer cells, reducing their intracellular concentration and effectiveness. Additionally, genetic mutations, enhanced DNA repair mechanisms, and alterations in drug targets contribute to this phenomenon. The complexity of MDR not only complicates treatment regimens but also contributes to the high mortality rate associated with lung cancer. Understanding the underlying mechanisms of MDR and developing strategies to overcome this resistance are critical for improving patient outcomes. The objective of this review is to present a comprehensive summary of the current knowledge on conventional and emerging mechanisms of drug resistance, with a particular focus on the involvement of exosomes and exosome-mediated factors that mediate drug resistance in lung cancer. Exosomes, tiny vesicles secreted by cells, play a critical role in drug resistance, especially in lung cancer. They carry genetic material and proteins that can alter the behavior of recipient cells, promoting resistance. In lung cancer, exosomes transfer miRNAs and other molecules that enhance survival pathways and inhibit cell death, contributing to chemoresistance. Recent research highlights the potential of targeting exosomal pathways to develop new therapeutic strategies.

Background/aims: Asthma is a multifactorial disease influenced by both genetic and environmental factors. This study aimed to investigate the association between the IL4 gene polymorphism (rs2243250) and asthma susceptibility, along with serum IL-4 levels. Additionally, it explored Mycoplasma pneumoniae infection as a potential risk factor for asthma.

Methods: A total of 118 individuals were enrolled, including 60 asthma patients and 58 healthy controls. Genotyping for IL4 rs2243250 was performed using allele-specific PCR (AS-PCR). Previous Mycoplasma pneumoniae infection was assessed serologically, and serum IL-4 levels were measured using ELISA.

Results: No significant differences were observed between groups in terms of age, sex, or residence. Smoking (OR: 7.85, P = 0.001) and family history of asthma (OR: 5.33, P = 0.004) were identified as significant risk factors. Mycoplasma pneumoniae infection was significantly more prevalent in asthma patients (41.7%) than in controls, with a strong association with asthma risk (OR: 8.75, P < 0.0001). Genotype frequencies of rs2243250 differed significantly: CC (36.7% vs. 68.9%), CT (41.7% vs. 24.2%), and TT (21.6% vs. 6.9%) in patients versus controls, respectively. The T allele was more frequent among patients (42.5%) than controls (18.97%), increasing asthma risk (OR: 3.16, P = 0.0001). Both CT (OR: 3.25) and TT (OR: 5.91) genotypes were strongly associated with asthma. Moreover, individuals with the TT genotype had significantly higher serum IL-4 levels (P < 0.001).

Conclusion: The IL4 rs2243250 polymorphism is associated with increased asthma susceptibility and elevated serum IL-4 levels in the Iraqi population. Mycoplasma pneumoniae infection also appears to be a significant contributing factor. Larger-scale studies are warranted to confirm these findings and further explore the role of this infection in asthma pathogenesis.

Natural killer (NK) cells are cytotoxic lymphocytes of the innate immune system. Along with their cardinal role in eliminating virally infected and cancerous cells, they are considered as a bridge between innate and adaptive immunity. Nutrition is linked to the effective immune response, and it is known that nutrition is among the environmental factors that influence the immune function and physiology. The function of nutrients, which are dissected into micronutrients (e.g. vitamins and minerals) and macronutrients (e.g. fat, protein and carbohydrates), is to maintain the metabolism and energy which are prime to fuel NK cells. In this review, we are going to recapitulate the recent findings and available data regarding the effect of common micro and macronutrients` examples on the NK cells development and function to provide an insight into diet-immune system crosstalk.

Background/aims: Caloric restriction (CR) has proven to be the most effective dietary intervention for reducing cardiovascular disease (CVD) associated with obesity. Depending on the age of the mice the effect of caloric restriction was diverse. Therefore, the effect of CR on the development of atherosclerosis in young and adult ApoE/LDLr^-/- mice was evaluated.

Methods: Eight-week-old and 20-week-old male mice received a control diet. Young mice were fed for eight weeks, whereas adult mice for 5 weeks. To assess whether individual housing influenced the tested parameters, control animals were housed in colony cages (AL) or individually (stressAL; sAL) and fed ad libitum. Individually housed caloric restriction (CR) mice received a 30% less diet compared to AL group.

Results: The body weight of CR mice was significantly lower compared to the AL and sAL groups. TCh and LDL levels were significantly increased in young CR mice. No differences in adult animals were observed. TAG levels significantly decreased in both young and adult CR mice. CR induced atherosclerosis in young mice. The FMO3 gene was upregulated in young animals. Microbiota composition changed. At the genus level, compared to the control, CR group exhibited a higher relative abundance of the Enterococcus, Clostridium_sensu_stricto_1 , Rikenella and a lower relative abundance of the CAG_352 (P< 0.05) genera.

Conclusion: Caloric restriction exacerbated atherosclerosis in young ApoE/LDLr^-/- mice.

Background/aims: Flozins (sodium-glucose cotransporter 2 inhibitors, SGLT2i) are a new class of antidiabetic drugs that reduce cardiovascular mortality and hospitalization rates in heart failure, regardless of type 2 diabetes status. Besides lowering glycemia by inhibiting renal glucose reabsorption, SGLT2 inhibitors may exert sodium-dependent hemodynamic effects and improve cardiomyocyte energy metabolism, substrate preference, and mitochondrial function. However, their impact on endothelial cells remains largely unknown. This study aimed to analyse the effects and mechanisms of SGLT2i on endothelial cell metabolism and function.

Methods: Mouse cardiac endothelial cells (H5V) were used to test the impact of dapagliflozin on endothelial cell metabolism and function in the presence of hypoxia-mimicking conditions. The concentration of intracellular nucleotides was measured using high-performance liquid chromatography. Mitochondrial and glycolytic activity were assessed using Seahorse XFp, while nitric oxide (NO) production was determined by 4-Amino-5-Methylamino-2',7'-Difluorofluorescein (DAF-FM) fluorescence staining. The effects of dapagliflozin treatment on endothelial NO synthesis were also analysed in patients with chronic heart failure and left ventricular ejection fraction above 40% and C57Bl/6J mice.

Results: Dapagliflozin augmented adenosine triphosphate (ATP) levels and the ATP/ADP (adenosine diphosphate) ratio in cultured endothelial cells correlated to increased NO production. Dapagliflozin-treated endothelial cells produced ATP through both mitochondrial respiration and glycolysis. Interestingly, mitochondrial respiration was enhanced, while glycolysis was unaffected in endothelial cells after in vitro dapagliflozin treatment. In a murine model, dapagliflozin doubled the rate of coronary NO synthesis and tended to improve coronary capillary density. In humans with chronic heart failure, 3-month treatment with dapagliflozin revealed many metabolic effects, suggesting potential mechanisms related to nitric oxide homeostasis, mitochondrial function, and L-arginine metabolism.

Conclusion: This study demonstrated the beneficial effect of dapagliflozin on endothelial cell metabolism and function. Regulation of endothelial cell bioenergetics may be an undervalued mechanism of SGLT2i to delay heart failure progression and support cardiac regeneration. These may accelerate endothelial-targeted strategies to support heart failure treatment.

Ligaments are biomechanically specialized connective tissues that maintain joint stability and guide motion under complex loading conditions. At the cellular and molecular levels, ligament homeostasis is governed by fibroblast-like cells (ligamentocytes) embedded in an intricately organized ECM composed predominantly of type I collagen, with contributions from type III collagen, elastin, proteoglycans, and glycoproteins. These cells continuously sense and respond to mechanical stimuli-tension, compression, and shear-through mechanotransduction pathways involving integrins, focal adhesions, cytoskeletal remodeling, and mechanosensitive ion channels. Downstream signaling cascades, including MAPKs and PI3K/AKT, integrate biomechanical cues with growth factor and cytokine signaling to fine-tune gene expression, collagen fibrillogenesis, and ECM turnover. Distinct from tendons, ligaments must adapt to multidirectional loads, resulting in unique ECM compositions and cellular phenotypes. Appropriate mechanical loading maintains collagen alignment, promotes ECM integrity, and stabilizes the ligament cell phenotype. By contrast, insufficient or excessive load alters the molecular balance, triggering catabolic processes, inflammation, and disorganized ECM assembly. This delicate equilibrium also underlies the ligamentization observed in ACL graft remodeling, where controlled mechanical environments and molecular interventions accelerate the acquisition of ligamentous properties. Emerging insights into transcriptional and epigenetic regulation, growth factor-mediated cues, and cytokine-driven responses offer avenues to engineer ligament-like tissues and optimize recovery strategies. By leveraging molecular knowledge of cell-matrix interactions, growth factor profiles, and genetic/epigenetic modulators, clinicians and researchers can design tailored loading protocols, biomimetic scaffolds, and regenerative therapies. These approaches aim to restore ligament functionality, enhance graft integration, and prevent degenerative changes, ultimately improving patient outcomes in ligament injury repair and reconstruction.