Post-TTM Rebound Pyrexia after Ischemia-Reperfusion Injury Results in Sterile Inflammation and Apoptosis in Cardiomyocytes

RBM3 Ameliorates Acute Brain Injury-induced Inflammation and Oxidative Stress by Stabilizing GAS6 mRNA Through Nrf2 Signaling Pathway

RNA-binding motif protein 3 (RBM3), as a cold-inducible protein, exhibits neuroprotective function in brain disorders. This study was conducted to investigate the effects of RBM3 on acute brain injury (ABI) and its underlying mechanism. The cerebral injury (CI) rat model and oxygen-glucose deprivation (OGD) cell model were established. The neurological severity score, wire-grip score, morris water maze test, and Y-maze test were used to detect the neurological damage, vestibular motor, learning, and memory functions. Cerebral injury, apoptosis, oxidative stress, and inflammatory level were evaluated by hematoxylin-eosin and TUNEL staining and specific kits. Flow cytometry was used to analyze the apoptosis rate. The relationship between RBM3 and growth arrest specific (GAS) 6 was analyzed by RNA immunoprecipitation assay. The results indicated that RBM3 recovered of neurological function and behaviour impairment of CI rats. Additionally, RBM3 reversed the increased oxidative stress, inflammatory level, and apoptosis induced by CI and OGD. RBM3 interacted with GAS6 to activate the Nrf2 signaling pathway, thus playing neuroprotection on ABI. Besides, the results of RBM3 treatment were similar to those of mild hypothermia treatment. In summary, RBM3 exerted neuroprotection and ameliorated inflammatory levels and oxidative stress by stabilizing GAS6 mRNA through the Nrf2 signaling pathway, suggesting that RBM3 might be a potential therapeutic candidate for treating ABI.

ThermomiR-377-3p-induced suppression of Cirbp expression is required for effective elimination of cancer cells and cancer stem-like cells by hyperthermia

BACKGROUND

In recent years, the development of adjunctive therapeutic hyperthermia for cancer therapy has received considerable attention. However, the mechanisms underlying hyperthermia resistance are still poorly understood. In this study, we investigated the roles of cold‑inducible RNA binding protein (Cirbp) in regulating hyperthermia resistance and underlying mechanisms in nasopharyngeal carcinoma (NPC).

METHODS

CCK-8 assay, colony formation assay, tumor sphere formation assay, qRT-PCR, Western blot were employed to examine the effects of hyperthermia (HT), HT + oridonin(Ori) or HT + radiotherapy (RT) on the proliferation and stemness of NPC cells. RNA sequencing was applied to gain differentially expressed genes upon hyperthermia. Gain-of-function and loss-of-function experiments were used to evaluate the effects of RNAi-mediated Cirbp silencing or Cirbp overexpression on the sensitivity or resistance of NPC cells and cancer stem-like cells to hyperthermia by CCK-8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay, and in subcutaneous xenograft animal model. miRNA transient transfection and luciferase reporter assay were used to demonstrate that Cirbp is a direct target of miR-377-3p. The phosphorylation levels of key members in ATM-Chk2 and ATR-Chk1 pathways were detected by Western blot.

RESULTS

Our results firstly revealed that hyperthermia significantly attenuated the stemness of NPC cells, while combination treatment of hyperthermia and oridonin dramatically increased the killing effect on NPC cells and cancer stem cell (CSC)‑like population. Moreover, hyperthermia substantially improved the sensitivity of radiation‑resistant NPC cells and CSC‑like cells to radiotherapy. Hyperthermia noticeably suppressed Cirbp expression in NPC cells and xenograft tumor tissues. Furthermore, Cirbp inhibition remarkably boosted anti‑tumor‑killing activity of hyperthermia against NPC cells and CSC‑like cells, whereas ectopic expression of Cirbp compromised tumor‑killing effect of hyperthermia on these cells, indicating that Cirbp overexpression induces hyperthermia resistance. ThermomiR-377-3p improved the sensitivity of NPC cells and CSC‑like cells to hyperthermia in vitro by directly suppressing Cirbp expression. More importantly, our results displayed the significantly boosted sensitization of tumor xenografts to hyperthermia by Cirbp silencing in vivo, but ectopic expression of Cirbp almost completely counteracted hyperthermia-mediated tumor cell-killing effect against tumor xenografts in vivo. Mechanistically, Cirbp silencing-induced inhibition of DNA damage repair by inactivating ATM-Chk2 and ATR-Chk1 pathways, decrease in stemness and increase in cell death contributed to hyperthermic sensitization; conversely, Cirbp overexpression-induced promotion of DNA damage repair, increase in stemness and decrease in cell apoptosis contributed to hyperthermia resistance.

CONCLUSION

Taken together, these findings reveal a previously unrecognized role for Cirbp in positively regulating hyperthermia resistance and suggest that thermomiR-377-3p and its target gene Cirbp represent promising targets for therapeutic hyperthermia.

RBM3 interacts with Raptor to regulate autophagy and protect cardiomyocytes from ischemia-reperfusion-induced injury

Acute myocardial infarction (AMI) is a common disease with high morbidity and mortality worldwide. However, postinfarction pathogenesis remains unclear, and it is particularly important to identify new therapeutic targets. The RNA-binding motif protein RBM3 (also known as cold-inducible protein) is known to promote translation and is associated with tumor proliferation and neuroprotection. However, little is known about the biological effects of RBM3 on myocardial infarction. In the present study, we found that RBM3 expression was significantly upregulated in ischemia-reperfusion (I/R) condition and downregulation of RBM3 inhibited autophagy and promoted apoptosis in cardiomyocytes. We confirmed that RBM3 interacts with Raptor to regulate the autophagy pathway. Taken together, these findings illustrate the protective effects of RBM3 against I/R-induced myocardial apoptosis through the autophagy pathway.

Long Noncoding RNAs in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction, reperfusion therapy is currently the most effective way to save the ischemic myocardium; however, restoring blood flow may lead to a myocardial ischemia-reperfusion injury (MIRI). Recent studies have confirmed that long-chain noncoding RNAs (LncRNAs) play important roles in the pathophysiology of MIRIs. These LncRNA-mediated roles include cardiomyocyte apoptosis, autophagy, necrosis, oxidative stress, inflammation, mitochondrial dysfunction, and calcium overload, which are regulated through the expression of target genes. Thus, LncRNAs may be used as clinical diagnostic markers and therapeutic targets to treat or prevent MIRI. This review evaluates the research on LncRNAs involved in MIRIs and provides new ideas for preventing and treating this type of injury.

Oxymatrine pretreatment protects H9c2 cardiomyocytes from hypoxia/reoxygenation injury by modulating the PI3K/Akt pathway

Ischemia-reperfusion (I/R) plays an important role in myocardial damage, which has been widely recognized as a key procedure in the cardiovascular disease. A hypoxia/reoxygenation (H/R) model was established using H9c2 cardiomyocytes to investigate the possible positive effect of oxymatrine (OMT), an alkaloid originating from the traditional Chinese herb Sophora flavescens Aiton, on cardiomyocytes exposed to H/R injury and the underlying molecular mechanisms. Cell viability was measured using the MTT assay, lactate dehydrogenase release measurements and hematoxylin and eosin staining. Oxidative stress was detected by measuring cellular malondialdehyde (MDA) content, as well as superoxide dismutase (SOD) and catalase (CAT) activities. Apoptosis was detected using TUNEL staining and flow cytometric analysis, and the underlying mechanism was investigated using reverse transcription-quantitative PCR and western blot analyses. The results revealed that OMT increased the viability of H9c2 cardiomyocytes exposed to H/R. The OMT pretreatment decreased the production of MDA by reactive oxygen species and increased the activities of SOD and CAT. Furthermore, the OMT pretreatment reduced the expression of Bax and caspase-3, while inducing Bcl-2 expression. In addition, the protective effect of OMT was shown to be associated with the PI3K/Akt signaling pathway, and the PI3K inhibitor LY294002 attenuated the effects of OMT on the H9c2 cardiomyocytes exposed to H/R. These findings indicate that OMT could be a potential therapeutic candidate for the treatment of myocardial ischemia/reperfusion injury.

Contactless Thermometry by MRI and MRS: Advanced Methods for Thermotherapy and Biomaterials

Control of temperature variation is of primordial importance in particular areas of biomedicine. In this context, medical treatments such as hyperthermia and cryotherapy, and also the development and use of hydrogel-based biomaterials, are of particular concern. To enable accurate temperature measurement without perturbing or even destroying the biological tissue or material to be monitored, contactless thermometry methods are preferred. Among these, the most suitable are based on magnetic resonance imaging and spectroscopy (MRI, MRS). Here, we address the latest developments in this field as well as their current and anticipated practical applications. We highlight recent progress aimed at rendering MR thermometry faster and more reproducible, versatile, and sophisticated and provide our perspective on how these new techniques broaden the range of applications in medical treatments and biomaterial development by enabling insight into finer details of thermal behavior. Thus, these methods facilitate optimization of clinical and industrial heating and cooling protocols.

Role of RBM3 in the regulation of cell proliferation in hepatocellular carcinoma

RNA binding motif protein 3 (RBM3) has been shown to be upregulated in several types of human tumors. Using tissue microarrays and immunohistochemistry, we showed here that both nuclear and cytoplasmic RBM3 expression levels were higher in hepatocellular carcinoma (HCC) tissues than in adjacent non-tumorous tissues. High nuclear RBM3 was found to be correlated with larger tumor size (P = 0.030), high serum AFP levels (P = 0.011), and advanced Edmonson grading (P = 0.006). Cytoplasmic RBM3 was associated with advanced Edmonson grading (P = 0.003). Kaplan-Meier survival analysis revealed that, although not statistically significant, there was a trend toward shortened overall survival in the subset of HCC patients with high RBM3 expression (both nuclear and cytoplasmic). In addition, we found that RBM3 could promote YAP1 expression in HCC cells. Moreover, we found that YAP1 played an essential part in RBM3-induced proliferation of HCC cells. Furthermore, we demonstrated that Verteporfin, a YAP1 inhibitor, could repress RBM3-induced proliferation of HCC cells. Our findings provide a new experimental basis for further understanding of the possible role of RBM3-YAP1 in the regulation of HCC proliferation.