Chinese Medical Journal最新文献

Background: Intrauterine growth restriction (IUGR) is associated with adverse metabolic outcomes during adulthood. Histone modifications and changes in DNA methylation-affected genes are important for fetal development. This study aimed to confirm the epigenetic mechanisms in IUGR.

Methods: IUGR models were established in Sprague-Dawley rats using a maternal nutritional restriction approach during pregnancy. The abundance of insulin-like growth factor 2 (IGF2), phosphoinositide 3-kinase (PI3K), AKT serine/threonine kinase 2 (AKT2), and PPAR gamma coactivator 1 alpha (PGC-1α) was examined by real-time polymerase chain reaction (RT-PCR) and Western blotting analysis. Chromatin immunoprecipitation RT-PCR was employed to analyze histone modification in CCCTC-binding factor (CTCF)1-4 binding sites of the IGF2/H19 imprinting control region (ICR). The methylation states of CTCF1-4 binding sites were studied by pyrosequencing.

Results: The IUGR models were constructed successfully. IGF2 mRNA abundance in the placenta, fetal liver, and newborn liver was decreased in the IUGR group (P <0.01). Meanwhile, as compared with the control group, the expression levels of AKT2, PI3K, and PGC-1α were lower in newborn and 8-week-old livers in the IUGR group (P <0.05). In addition, knocking down IGF2 reduced the protein expression levels of AKT2-P and PGC-1α (P <0.05). In CTCF binding sites 1-4 of the IGF2/H19 ICR, AcH3 enrichment was significantly lower in CTCF1-3 in newborn and 8-week-old IUGR rats. H3K4me3 enrichment was significantly lower in the CTCF1-4 of newborn and 8-week-old IUGR groups (P <0.01). H3K9me2 enrichment was significantly higher in the IUGR group (P <0.01). The CpG dinucleotide methylation levels of CTCF1 and CTCF3, but not those of CTCF2 and CTCF4 binding sites in IUGR rat fetal, 4-week old, and 8-week-old livers decreased significantly (P <0.05).

Conclusion: The methylation status and histone modification in the IGF2/H19 ICR are related to growth and lipid metabolism via the PGC-1α/PI3K/AKT2 pathway in IUGR rats.

Background: Renal ischemia-reperfusion (R-I/R) injury is the most prevalent cause of acute kidney injury, with high mortality and poor prognosis. However, the underlying pathological mechanisms are not yet fully understood. Therefore, this study aimed to investigate the role of N-myc downstream-regulated gene 2 ( Ndrg2 ) in R-I/R injury.

Methods: We examined the expression of Ndrg2 in the kidney under normal physiological conditions and after R-I/R injury by immunofluorescence staining, real-time polymerase chain reaction, and western blotting. We then detected R-I/R injury in Ndrg2-deficient ( Ndrg2-/- ) mice and wild type ( Ndrg2+/+ ) littermates in vivo , and detected oxygen and glucose deprivation and reperfusion (OGD-R) injury in HK-2 cells. We further conducted transcriptomic sequencing to investigate the role of Ndrg2 in R-I/R injury and detected levels of oxidative stress and mitochondrial damage by dihydroethidium staining, biochemical assays, and western blot. Finally, we measured the levels of mitophagy in Ndrg2+/+ and Ndrg2-/- mice after R-I/R injury or HK-2 cells in OGD-R injury.

Results: Ndrg2 was primarily expressed in renal proximal tubules and its expression was significantly decreased 24 h after R-I/R injury. Ndrg2-/- mice exhibited significantly attenuated R-I/R injury compared to Ndrg2+/+ mice. Transcriptomics profiling showed that Ndrg2 deficiency induced perturbations of multiple signaling pathways, downregulated inflammatory responses and oxidative stress, and increased autophagy following R-I/R injury. Further studies revealed that Ndrg2 deficiency reduced oxidative stress and mitochondrial damage. Notably, Ndrg2 deficiency significantly activated phosphatase and tensin homologue on chromosome ten-induced putative kinase 1 (PINK1)/Parkin-mediated mitophagy. The downregulation of NDRG2 expression significantly increased cell viability after OGD-R injury, increased the expression of heme oxygenase-1, decreased the expression of nicotinamide adenine dinucleotide phosphate oxidase 4, and increased the expression of the PINK1/Parkin pathway.

Conclusion: Ndrg2 deficiency might become a therapy target for R-I/R injury by decreasing oxidative stress, maintaining mitochondrial homeostasis, and activating PINK1/Parkin-mediated mitophagy.

Abstract: Moyamoya disease (MMD) is a cerebrovascular disorder characterized by a steno-occlusive internal carotid artery and compensatory vascular network formation. Although the precise pathogenic mechanism remains elusive, genetic association studies have identified RNF213 as the principal susceptibility gene for MMD, with the single nucleotide polymorphism p.R4810K recognized as the founder variant predominantly in the Asian populations. Distinct genotype-phenotype correlations are observable in RNF213 -related MMD. The clinical manifestations linked to p.R4810K bear commonalities within Asian cohort, including familial predisposition, earlier age of onset, ischemic episodes, and involvement of the posterior cerebral artery (PCA). However, despite these shared phenotypic characteristics, there is significant heterogeneity in RNF213 -related MMD presentations. This diversity manifests as variations across ethnic groups, inconsistent clinical symptoms and prognosis, and occurrence of other vasculopathies involving RNF213 . This heterogeneity, in conjunction with the observed low disease penetrance of RNF213 mutations, suggests that the presence of these mutations may not be sufficient to cause MMD, underscoring the potential influence of other genetic or environmental factors. Although the current research might not have fully identified these additional contributors, experimental evidence points toward the involvement of RNF213 in angiogenesis, lipid metabolism, and the immune response. Future research is required to unveil the molecular mechanisms and identify the factors that synergize with RNF213 in the pathogenesis of MMD.

Abstract: Colorectal cancer (CRC), a major global health concern, necessitates innovative treatments. Chimeric antigen receptor (CAR) T cells have shown promise, yet they grapple with challenges. The spotlight pivots to the rising heroes: CAR natural killer (NK) cells, offering advantages such as higher safety profiles, cost-effectiveness, and efficacy against solid tumors. Nevertheless, the specific mechanisms underlying CAR NK cell trafficking and their interplay within the complex tumor microenvironment require further in-depth exploration. Herein, we provide insights into the design and engineering of CAR NK cells, antigen targets in CRC, and success in overcoming resistance mechanisms with an emphasis on the potential for clinical trials.