Deciphering the neuroprotective mechanisms of RACK1 in cerebral ischemia-reperfusion injury: Pioneering insights into mitochondrial autophagy and the PINK1/Parkin axis.

INTRODUCTION: Cerebral ischemia-reperfusion injury (CIRI) is a common and debilitating complication of cerebrovascular diseases such as stroke, characterized by mitochondrial dysfunction and cell apoptosis. Unraveling the molecular mechanisms behind these processes is essential for developing effective CIRI treatments. This study investigates the role of RACK1 (receptor for activated C kinase 1) in CIRI and its impact on mitochondrial autophagy. METHODS: We utilized high-throughput transcriptome sequencing and weighted gene co-expression network analysis (WGCNA) to identify core genes associated with CIRI. In vitro experiments used human neuroblastoma SK-N-SH cells subjected to oxygen and glucose deprivation (OGD) to simulate ischemia, followed by reperfusion (OGD/R). RACK1 knockout cells were created using CRISPR/Cas9 technology, and cell viability, apoptosis, and mitochondrial function were assessed. In vivo experiments involved middle cerebral artery occlusion/reperfusion (MCAO/R) surgery in rats, evaluating neurological function and cell apoptosis. RESULTS: Our findings revealed that RACK1 expression increases during CIRI and is protective by regulating mitochondrial autophagy through the PINK1/Parkin pathway. In vitro, RACK1 knockout exacerbated cell apoptosis, while overexpression of RACK1 reversed this process, enhancing mitochondrial function. In vivo, RACK1 overexpression reduced cerebral infarct volume and improved neurological deficits. The regulatory role of RACK1 depended on the PINK1/Parkin pathway, with RACK1 knockout inhibiting PINK1 and Parkin expression, while RACK1 overexpression restored them. CONCLUSION: This study demonstrates that RACK1 safeguards against neural damage in CIRI by promoting mitochondrial autophagy through the PINK1/Parkin pathway. These findings offer crucial insights into the regulation of mitochondrial autophagy and cell apoptosis by RACK1, providing a promising foundation for future CIRI treatments.

ETV4/NSUN2 Axis modulates aerobic glycolysis and malignancy in HSCC.

This study delves into the molecular intricacies of hypopharyngeal squamous cell carcinoma (HSCC), specifically focusing on the pivotal role played by ETS translocation variant 4 (ETV4) in aerobic glycolysis. The objective is to uncover new targets for early diagnosis and treatment of HSCC. ETV4 expression in HSCC tissues was rigorously examined, revealing its association with patient survival. Through comprehensive experimentation, we demonstrated that ETV4 activation promotes HSCC cell proliferation and invasion while inhibiting apoptosis. Furthermore, in vivo experiments confirmed the tumor-promoting effect of ETV4 activation. The study elucidated the binding of ETV4 to the NSUN2 promoter and its influence on PKM2 expression, thereby regulating glycolysis and cellular functions in HSCC.

Implementing Foundry: A cohort study describing the regional and virtual expansion of a youth integrated service in British Columbia, Canada.

AIM: Integrated youth services (IYS) have been identified as a national priority in response to the youth mental health and substance use (MHSU) crisis in Canada. In British Columbia (BC), an IYS initiative called Foundry expanded to 11 physical centres and launched a virtual service. The aim of the study was to describe the demographics of Foundry clients and patterns of service utilization during this expansion, along with the impact of the COVID-19 pandemic. METHODS: Data were analysed for all youth (ages 12-24) accessing both in-person (April 27th, 2018-March 31st, 2021) and virtual (May 1st, 2020-March 31st, 2021) services. Cohorts containing all clients from before (April 27th, 2018-March 16th, 2020) and during (March 17th, 2020-March 31st, 2021) the COVID-19 pandemic were also examined. RESULTS: A total of 23 749 unique youth accessed Foundry during the study period, with 110 145 services provided. Mean client age was 19.54 years (SD = 3.45) and 62% identified as female. Over 60% of youth scored 'high' or 'very high' for distress and 29% had a self-rated mental health of 'poor', with similar percentages seen for all services and virtual services. These ratings stayed consistent before and during the COVID-19 pandemic. CONCLUSIONS: Foundry has continued to reach the target age group, with a 65% increase in number of clients during the study period compared with the pilot stage. This study highlights lessons learned and next steps to promote youth-centred data capture practices over time within an integrated youth services context.

EFFECTS OF LEVOSIMENDAN ON DIAPHRAGMATIC DYSFUNCTION IN PATIENTS WITH SEPSIS.

ABSTRACT: Objective: In this study, our aim was to examine the effects of levosimendan on diaphragmatic dysfunction in patients with sepsis, as well as assess its impact on respiratory muscle contractility and the outcome of weaning. Methods: This was a single-blind, randomized, controlled trial. Patients with diaphragmatic dysfunction and failure of spontaneous breathing trials (SBTs) were randomly and equally assigned to the experimental and control groups. The experimental group received levosimendan at a loading dose of 6 µg/kg for 10 min, followed by a continuous infusion at 0.2 µg/kg/min. The control group received an equivalent dose of a placebo. The preadministration and postadministration respiratory mechanics parameters of the patients were recorded. Evaluation of the effect of levosimendan on patients with sepsis-induced diaphragm dysfunction comprised arterial blood gas analysis as well as ultrasound measurements of diaphragm excursion (DE), diaphragm thickness (DT), diaphragm thickening fraction (TFdi), and diaphragm-rapid shallow breathing index (D-RSBI). Results: Forty-four patients were enrolled in the study. We found that postadministration of levosimendan, the patients' tidal volume (GCSMV) increased, whereas the D-RSBI decreased, and the partial pressure of carbon dioxide (PACO 2 ) decreased when compared to the preadministration levels. Additionally, following levosimendan administration, patients showed increased DE and pressure support (PS) when compared to before administration (1.14 ± 0.177 vs. 1.22 ± 0.170 cm and 0.248 ± 0.03 vs. 0.284 ± 0.06, respectively) and decreased D-RSBI (22.76 ± 6.14 vs. 20.06 ± 6.04, respectively), all of which were statistically significant ( P < 0.05). In contrast, in the control group of patients, there were no statistically significant differences in the postadministration levels of DE, TFdi, and D-RSBI as compared to the preadministration period ( P > 0.05). Furthermore, in terms of weaning outcomes, we did not find any statistically significant difference in the number of patients in the two groups who eventually underwent weaning ( P = 0.545). Conclusion: In this study, we found that levosimendan enhanced diaphragm contractile function. However, further investigations are required to explore its effect on weaning outcomes in patients undergoing mechanical ventilation.

EP300 restores the glycolytic activity and anti-tumor function of CD8+ cytotoxic T cells in nasopharyngeal carcinoma.

Competition for glucose may metabolically limit T cells during cancer progression. This study shows that culturing in the condition medium (CM) of NPC c6661 cells restricted glycolytic and immune activities of CD8+ T cells. These cells also exhibited limited tumor-eliminating effects in mouse xenograft tumor models. Glucose supplementation restored glycolysis and immune activity of CD8+ T cells in vitro and in vivo by rescuing the expression of E1A binding protein p300 (EP300). EP300 upregulated bromodomain PHD finger transcription factor (BPTF) expression by catalyzing H3K27ac modification, and BPTF further activated AT-rich interaction domain 1A (ARID1A) transcription. Either BPTF or ARID1A knockdown in CD8+ T cells reduced their glycolytic activity, decreased the secretion of cytotoxic molecules, and blocked the tumor-killing function in mice. Overall, this study demonstrates that EP300 restores the glycolytic and anti-tumor activities of CD8+ T cells in the glucose restriction condition in NPC through the BPTF/ARID1A axis.