Frontiers of Medicine最新文献

Exosome therapy holds great promise as a novel approach to improve acute skin wound healing. This review provides a comprehensive overview of the current understanding of exosome biology and its potential applications in acute skin wound healing and beyond. Exosomes, small extracellular vesicles secreted by various stem cells, have emerged as potent mediators of intercellular communication and tissue repair. One advantage of exosome therapy is its ability to avoid potential risks associated with stem cell therapy, such as immune rejection or stem cells differentiating into unwanted cell types. However, further research is necessary to optimize exosome therapy, not only in the areas of exosome isolation, characterization, and engineering, but also in determining the optimal dose, timing, administration, and frequency of exosome therapy. Thus, optimization of exosome therapy is critical for the development of more effective and safer exosome-based therapies for acute skin wound healing and other diseases induced by cancer, ischemia, or inflammation. This review provides valuable insights into the potential of exosome therapy and highlights the need for further research to optimize exosome therapy for clinical use.

Epstein-Barr virus (EBV)-associated lymphoproliferative diseases (EBV-LPDs) are common complications that occur after solid organ transplantation or allogeneic hematopoietic stem-cell transplantation (HSCT). However, their occurrence and treatment post-chimeric antigen receptor-modified T (CAR-T) cell therapy has not been reported. Two patients had been diagnosed with EBV-positive aggressive B-cell lymphoma and experienced relapses after multiple lines of treatment. After receiving CAR-T cell therapy in tandem with autologous HSCT, the patients achieved complete remission. However, with a median time of 38.5 months after CAR-T cell therapy, B-cell-derived EBV-LPDs were diagnosed, and they were relieved through the administration of immune checkpoint inhibitor or B-cell-depleting agents. Collectively, our report suggests that EBV-LPDs may represent a long-term adverse event after CAR-T cell therapy, especially in patients who previously had EBV-positive disorders, and they can be resolved by immune normalization strategy or B-cell depleting therapy.

This cohort study was performed to explore the influence of intensive care unit (ICU) quality on in-hospital mortality of veno-venous (V-V) extracorporeal membrane oxygenation (ECMO)-supported patients in China. The study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019, using data from the National Clinical Improvement System and China National Critical Care Quality Control Center. ICU quality was assessed by quality control indicators and capacity parameters. Among the 2563 V-V ECMO-supported patients in 318 hospitals, a significant correlation was found between ECMO-related complications and prognosis. The reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients (cutoff: 1.5% and 7.0%; 95% confidence interval: 1.05-1.48 and 1.04-1.45; odds ratios: 1.25 and 1.23; P = 0.012 and P = 0.015, respectively). Meanwhile, the V-V ECMO center volume was a protective factor (cutoff of ≥ 50 cases within the 3-year study period; 95% confidence interval: 0.57-0.83, odds ratio: 0.69, P = 0.0001). The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these findings. Thus, ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.

Amyotrophic lateral sclerosis (ALS) is a progressive neurogenerative disorder with uncertain origins. Emerging evidence implicates N6-methyladenosine (m⁶A) modification in ALS pathogenesis. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and liquid chromatography-mass spectrometry were utilized for m⁶A profiling in peripheral immune cells and serum proteome analysis, respectively, in patients with ALS (n = 16) and controls (n = 6). The single-cell transcriptomic dataset (GSE174332) of primary motor cortex was further analyzed to illuminate the biological implications of differentially methylated genes and cell communication changes. Analysis of peripheral immune cells revealed extensive RNA hypermethylation, highlighting candidate genes with differential m⁶A modification and expression, including C-X3-C motif chemokine receptor 1 (CX3CR1). In RAW264.7 macrophages, disrupted CX3CR1 signaling affected chemotaxis, potentially influencing immune cell migration in ALS. Serum proteome analysis demonstrated the role of dysregulated immune cell migration in ALS. Cell type-specific expression variations of these genes in the central nervous system (CNS), particularly microglia, were observed. Intercellular communication between neurons and glial cells was selectively altered in ALS CNS. This integrated approach underscores m⁶A dysregulation in immune cells as a potential ALS contributor.

Studies have found a U-shaped relationship between sleep duration and chronic kidney disease (CKD) risk, but limited research evaluated the association of reallocating excessive sleep to other behavior with CKD. We included 104 538 participants from the nationwide cohort of the Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study, with self-reported time of daily-life behavior. Using isotemporal substitution models, we found that substituting 1 h of sleeping with sitting, walking, or moderate-to-vigorous physical activity was associated with a lower CKD prevalence. Leisure-time physical activity displacement was associated with a greater prevalence reduction than occupational physical activity in working population. In stratified analysis, a lower CKD prevalence related to substitution toward physical activity was found in long sleepers. More pronounced correlations were observed in long sleepers with diabetes than in those with prediabetes, and they benefited from other behavior substitutions toward a more active way. The U-shaped association between sleep duration and CKD prevalence implied the potential effects of insufficient and excessive sleep on the kidneys, in which the pernicious link with oversleep could be reversed by time reallocation to physical activity. The divergence in the predicted effect on CKD following time reallocation to behavior of different domains and intensities and in subpopulations with diverse metabolic statuses underlined the importance of optimizing sleeping patterns and adjusting integral behavioral composition.

Macrophages, a heterogeneous population of innate immune cells, exhibit remarkable plasticity and play pivotal roles in coordinating immune responses and maintaining tissue homeostasis within the context of metabolic diseases. The activation of inflammatory macrophages in obese adipose tissue leads to detrimental effects, inducing insulin resistance through increased inflammation, impaired thermogenesis, and adipose tissue fibrosis. Meanwhile, adipose tissue macrophages also play a beneficial role in maintaining adipose tissue homeostasis by regulating angiogenesis, facilitating the clearance of dead adipocytes, and promoting mitochondrial transfer. Exploring the heterogeneity of macrophages in obese adipose tissue is crucial for unraveling the pathogenesis of obesity and holds significant potential for targeted therapeutic interventions. Recently, the dual effects and some potential regulatory mechanisms of macrophages in adipose tissue have been elucidated using single-cell technology. In this review, we present a comprehensive overview of the intricate activation mechanisms and diverse functions of macrophages in adipose tissue during obesity, as well as explore the potential of drug delivery systems targeting macrophages, aiming to enhance the understanding of current regulatory mechanisms that may be potentially targeted for treating obesity or metabolic diseases.

Abstract

ALKBH5 is a master regulator of N6-methyladenosine (m⁶A) modification, which plays a crucial role in many biological processes. Here, we show that ALKBH5 is required for breast tumor growth. Interestingly, PRMT6 directly methylates ALKBH5 at R283, which subsequently promotes breast tumor growth. Furthermore, arginine methylation of ALKBH5 by PRMT6 increases LDHA RNA stability via m⁶A demethylation, leading to increased aerobic glycolysis. Moreover, PRMT6-mediated ALKBH5 arginine methylation is confirmed in PRMT6-knockout mice. Collectively, these findings identify a PRMT6-ALKBH5-LDHA signaling axis as a novel target for the treatment of breast cancer.

Lipin proteins including Lipin 1-3 act as transcriptional co-activators and phosphatidic acid phosphohydrolase enzymes, which play crucial roles in lipid metabolism. However, little is known about the function of Lipin3 in triglyceride (TG) metabolism. Here, we identified a novel mutation (NM_001301860: p.1835A>T/p.D612V) of Lipin3 in a large family with hypertriglyceridemia (HTG) and obesity through whole-exome sequencing and Sanger sequencing. Functional studies revealed that the novel variant altered the half-life and stability of the Lipin3 protein. Hence, we generated Lipin3 heterozygous knockout (Lipin3-heKO) mice and cultured primary hepatocytes to explore the pathophysiological roles of Lipin3 in TG metabolism. We found that Lipin3-heKO mice exhibited obvious obesity, HTG, and non-alcoholic fatty liver disorder. Mechanistic study demonstrated that the haploinsufficiency of Lipin3 in primary hepatocytes may induce the overexpression and abnormal distribution of Lipin1 in cytosol and nucleoplasm. The increased expression of Lipin1 in cytosol may contribute to TG anabolism, and the decreased Lipin1 in nucleoplasm can reduce PGC1α, further leading to mitochondrial dysfunction and reduced TG catabolism. Our study suggested that Lipin3 was a novel disease-causing gene inducing obesity and HTG. We also established a relationship between Lipin3 and mitochondrial dysfunction.