The present study aimed to investigate the change of cytochrome c in postconditioning-attenuated ischemia-reperfusion (I/R)-induced mucosal apoptosis in rat intestine compared with ischemic preconditioning (IPC).Using rat model of intestine I/R injury,male Sprague-Dawley rats weighing 220-250 g were divided into 4 groups which were Sham operation group,I/R group,IPC group and ischemic postconditioning (IPOST) group.In these groups,I/R procedure was performed by the occlusion of the superior mesenteric artery (SMA) for 45 min followed by reperfusion for 1 h.In Sham group,there was no intervention.In IPC group,SMA was occluded for 5 min and reperfused for 5 min,for two cycles,before the prolonged occlusion.In IPOST group,three cycles of 30-s reperfusion and 30-s reocclusion were preceded at the start of reperfusion.After the reperfusion,the small intestines were sampled for experimental detection.Intestinal mucosal mitochondrial membrane potential was detected by confocal laser scanning microscopy.Expressions of cytochrome c and caspase-3 proteins were detected using Western-blot method.The apoptosis of intestinal mucosal cells was deter- mined with agarose gel electrophoresis and deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeling (TUNEL) technique.Compared with I/R group,the mitochondrial membrane potentials and the expressions of cytochrome c protein were significantly increased,while the expressions of caspase-3 and the apoptotic rates were decreased in IPOST and IPC groups (P0.05).There were no significant differences between IPOST and IPC groups (P0.05).These data provide substantial evidence that IPOST attenuates I/R-induced mucosal apoptosis by reducing the release of cytochrome c from mitochondria in the rat small intestine.
Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal carcinomas, with high mortality and poor prognoses worldwide. Succinate dehydrogenase (SDH) consists of four nuclear-encoded subunits and it is the only complex involved in both the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS). Previous studies have shown decreased SDH activity in ccRCC. However, the role and underlying molecular mechanisms of SDH in ccRCC initiation and development remain unclear. In the present study, pan-cancer analysis of SDH gene expression was analyzed and the relationship between SDH gene expression and clinicopathological parameters was assessed using different databases. cBioPortal, UACLAN, and Tumor Immune Estimation Resource (TIMER) were subsequently utilized to analyze genetic alterations, methylation, and immune cell infiltration of SDH genes in ccRCC patients. We found SDHs were significantly downregulated in ccRCC tissues and correlated with ccRCC progression. Increased methylation and high SDH promoter mutation rates may be the cause of reduced expression of SDHs in ccRCC. Moreover, the interaction network showed that SDH genes were correlated with ferroptosis-related genes. We further demonstrated that SDH inhibition dampened oxidative phosphorylation, reduced ferroptotic events, and restored ferroptotic cell death, characterized by eliminated mitochondrial ROS levels, decreased cellular ROS and diminished peroxide accumulation. Collectively, this study provides new insights into the regulatory role of SDH in the carcinogenesis and progression of ccRCC, introducing a potential target for advanced antitumor therapy through ferroptosis.
Histone deacetylase 6 (HDAC6) has emerged as a promising drug target for various human diseases, including diverse neurodegenerative diseases and cancer. Herein, we reported a series of 2,4-imidazolinedione derivatives as novel HDAC6 isoform-selective inhibitors based on structure-based drug design. Most target compounds exhibit good profiles in a preliminary screening concerning HDAC6 inhibitory activities. Moreover, the most active compound 10c increases the acetylation level of α-tubulin with little effect on the acetylation of histone H3. Further biological evaluation suggested that potent compound 10c, which possesses good antiproliferative activity, could induce apoptosis in HL-60 cell by activating caspase 3.
Ferroptosis is a newly discovered form of non-apoptotic regulated cell death and is characterized by iron-dependent and lipid peroxidation. Due to the enhanced dependence on iron in cancer cells, induction of ferroptosis is becoming a promising therapeutic strategy. However, the precise underlying molecular mechanism and regulation process of ferroptosis remains largely unknown. In the present study, we demonstrate that the protein Frataxin (FXN) is a key regulator of ferroptosis by modulating iron homeostasis and mitochondrial function. Suppression of FXN expression specifically repressed the proliferation, destroyed mitochondrial morphology, impeded Fe-S cluster assembly and activated iron starvation stress. Moreover, suppression of FXN expression significantly enhanced erastin-induced cell death through accelerating free iron accumulation, lipid peroxidation and resulted in dramatic mitochondria morphological damage including enhanced fragmentation and vanished cristae. In addition, this type of cell death was confirmed to be ferroptosis, since it could be pharmacologically restored by ferroptotic inhibitor Fer-1 or GSH, but not by inhibitors of apoptosis, necrosis. Vice versa, enforced expression of FXN blocked iron starvation response and erastin-induced ferroptosis. More importantly, pharmacological or genetic blocking the signal of iron starvation could completely restore the resistance to ferroptosis in FXN knockdown cells and xenograft graft in vivo. This paper suggests that FXN is a novel ferroptosis modulator, as well as a potential provided target to improve the antitumor activity based on ferroptosis.
Non-coding RNAs (ncRNAs) have been emerging players in cell development, differentiation, proliferation and apoptosis. Based on their differences in length and structure, they are subdivided into several categories including long non-coding RNAs (lncRNAs >200nt), stable non-coding RNAs (60-300nt), microRNAs (miRs or miRNAs, 18-24nt), circular RNAs, piwi-interacting RNAs (26-31nt) and small interfering RNAs (about 21nt). Therein, miRNAs not only directly regulate gene expression through pairing of nucleotide bases between the miRNA sequence and a specific mRNA that leads to the translational repression or degradation of the target mRNA, but also indirectly affect the function of downstream genes through interactions with lncRNAs and circRNAs. The latest studies have highlighted their importance in physiological and pathological processes. MiR-374 family member are located at the X-chromosome inactivation center. In recent years, numerous researches have uncovered that miR-374 family members play an indispensable regulatory role, such as in reproductive disorders, cell growth and differentiation, calcium handling in the kidney, various cancers and epilepsy. In this review, we mainly focus on the role of miR-374 family members in multiple physiological and pathological processes. More specifically, we also summarize their promising potential as novel prognostic biomarkers and therapeutic targets from bench to bedside.