Identification of miR-20b-5p as an inhibitory regulator in cardiac differentiation via TET2 and DNA hydroxymethylation.

BACKGROUND: Congenital heart disease (CHD) is a prevalent congenital cardiac malformation, which lacks effective early biological diagnosis and intervention. MicroRNAs, as epigenetic regulators of cardiac development, provide potential biomarkers for the diagnosis and treatment of CHD. However, the mechanisms underlying miRNAs-mediated regulation of cardiac development and CHD malformation remain to be further elucidated. This study aimed to explore the function of microRNA-20b-5p (miR-20b-5p) in cardiac development and CHD pathogenesis. METHODS AND RESULTS: miRNA expression profiling identified that miR-20b-5p was significantly downregulated during a 12-day cardiac differentiation of human embryonic stem cells (hESCs), whereas it was markedly upregulated in plasma samples of atrial septal defect (ASD) patients. Our results further revealed that miR-20b-5p suppressed hESCs-derived cardiac differentiation by targeting tet methylcytosine dioxygenase 2 (TET2) and 5-hydroxymethylcytosine, leading to a reduction in key cardiac transcription factors including GATA4, NKX2.5, TBX5, MYH6 and cTnT. Additionally, knockdown of TET2 significantly inhibited cardiac differentiation, which could be partially restored by miR-20b-5p inhibition. CONCLUSIONS: Collectively, this study provides compelling evidence that miR-20b-5p functions as an inhibitory regulator in hESCs-derived cardiac differentiation by targeting TET2, highlighting its potential as a biomarker for ASD.

Prevalence and risk factors of elder abuse in survivors of stroke: A cross-sectional study.

Background and Aims: The understanding of the prevalence and risk factors associated with elder abuse in stroke survivors is currently lacking. Therefore, the objective of this study is to ascertain the prevalence and potential risk factors of elder abuse in stroke survivors, while also examining its correlation with insomnia. Methods: In this cross-sectional study, a total of 485 stroke survivors aged 65 years and older, who received treatment at the Emergency department of Shunde Hospital, Southern Medical University, were subjected to face-to-face interviews using the questionnaire on elder abuse from the Third Survey on Chinese Women's Social Status. A logistic regression analysis was employed to examine the association between risk factors and elder abuse among stroke survivors. Results: 62.27% of the participants reported experiencing elder abuse, with 14.85% of them indicating suffering from more than two subtypes of abuse. Factors such as residing in nursing homes, lower income, and smoking were found to increase the likelihood of experiencing elder abuse and all four subtypes of abuse. Additionally, advancing age was associated with a higher risk of experiencing all four subtypes of abuse, although it did not affect the occurrence of overall abuse. It is worth noting that the self-reported prevalence of the four types of abuse by the elderly themselves was higher compared to the reports provided by caregivers. Conclusion: Elder abuse is prevalent among stroke survivors, especially those who are residing in nursing homes, with lower income, and smokers. Elder abuse significantly increased the prevalence of insomnia in stroke survivors. Further research is needed to better explore effective measures to reduce the prevalence of elder abuse of stroke survivors.

[Mitochondrial genome sequence characteristics and phylogenetic analysis of Schizothorax argentatus].

Schizothorax argentatus that only distributes in the Ili River basin in Xinjiang is one of the rare and endangered species of schizothorax in China, thus has high scientific and economic values. In this study, the complete mitochondrial genome sequence of S. argenteus with a length of 16 580 bp was obtained by high-throughput sequencing. The gene compositions and arrangement were similar to those of typical vertebrates. It contained 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a non-coding region (D-loop). The nucleotide compositions were A (30.25%), G (17.28%), C (27.20%), and T (25.27%), respectively, showing obvious AT bias and anti-G bias. Among the tRNA genes, only tRNA-Ser(GCU) could not form a typical cloverleaf structure due to the lack of dihydrouracil arm. The AT-skew and GC-skew values of the ND6 gene were fluctuating the most, suggesting that the gene may experience different selection and mutation pressures from other genes. The mitochondrial control region of S. argenteus contained three different domains, i.e., termination sequence region (ETAS), central conserved region (CSB-F, CSB-E, CSB-D, and CSB-B), and conserved sequence region (CSB1, CSB2, and CSB3). The conserved sequence fragment TT (AT) nGTG, which was ubiquitous in Cypriniformes, was identified at about 50 bp downstream CSB3. Phylogenetic relationships based on the complete mitochondrial genome sequence of 28 Schizothorax species showed that S. argenteus had differentiated earlier and had a distant relationship with other species, which may be closely related to the geographical location and the hydrological environment where it lives.

Remote cortical atrophy and language outcomes after chronic left subcortical stroke with aphasia.

Objective: Subcortical stroke can cause a variety of language deficits. However, the neural mechanisms underlying subcortical aphasia after stroke remain incompletely elucidated. We aimed to determine the effects of distant cortical structures on aphasia outcomes and examine the correlation of cortical thickness measures with connecting tracts integrity after chronic left subcortical stroke. Methods: Thirty-two patients and 30 healthy control subjects underwent MRI scanning and language assessment with the Western Aphasia Battery-Revised (WAB-R) subtests. Among patients, the cortical thickness in brain regions that related to language performance were assessed by the FreeSurfer software. Fiber tracts connecting the identified cortical regions to stroke lesions were reconstructed to determine its correlations with the cortical thickness measures across individual patient. Results: Cortical thickness in different parts of the left fronto-temporo-parietal (FTP) regions were positively related to auditory-verbal comprehension, spontaneous speech and naming/word finding abilities when controlling for key demographic variables and lesion size. Cortical thickness decline in the identified cortical regions was positively correlated with integrity loss of fiber tracts connected to stroke lesions. Additionally, no significant difference in cortical thickness was found across the left hemisphere between the subgroup of patients with hypoperfusion (HP) and those without HP at stroke onset. Conclusions: These findings suggest that remote cortical atrophy independently predicts language outcomes in patients with chronic left subcortical stroke and aphasia and that cortical thinning in these regions might relate to integrity loss of fiber tracts connected to stroke lesions.

RTN4/Nogo-A-S1PR2 negatively regulates angiogenesis and secondary neural repair through enhancing vascular autophagy in the thalamus after cerebral cortical infarction.

Cerebral infarction induces angiogenesis in the thalamus and influences functional recovery. The mechanisms underlying angiogenesis remain unclear. This study aimed to investigate the role of RTN4/Nogo-A in mediating macroautophagy/autophagy and angiogenesis in the thalamus following middle cerebral artery occlusion (MCAO). We assessed secondary neuronal damage, angiogenesis, vascular autophagy, RTN4 and S1PR2 signaling in the thalamus. The effects of RTN4-S1PR2 on vascular autophagy and angiogenesis were evaluated using lentiviral and pharmacological approaches. The results showed that RTN4 and S1PR2 signaling molecules were upregulated in parallel with angiogenesis in the ipsilateral thalamus after MCAO. Knockdown of Rtn4 by siRNA markedly reduced MAP1LC3B-II conversion and levels of BECN1 and SQSTM1 in vessels, coinciding with enhanced angiogenesis in the ipsilateral thalamus. This effect coincided with rescued neuronal loss of the thalamus and improved cognitive function. Conversely, activating S1PR2 augmented vascular autophagy, along with suppressed angiogenesis and aggravated neuronal damage of the thalamus. Further inhibition of autophagic initiation with 3-methyladenine or spautin-1 enhanced angiogenesis while blockade of lysosomal degradation by bafilomycin A1 suppressed angiogenesis in the ipsilateral thalamus. The control of autophagic flux by RTN4-S1PR2 was verified in vitro. Additionally, ROCK1-BECN1 interaction along with phosphorylation of BECN1 (Thr119) was identified in the thalamic vessels after MCAO. Knockdown of Rtn4 markedly reduced BECN1 phosphorylation whereas activating S1PR2 increased its phosphorylation in vessels. These results suggest that blockade of RTN4-S1PR2 interaction promotes angiogenesis and secondary neural repair in the thalamus by suppressing autophagic activation and alleviating dysfunction of lysosomal degradation in vessels after cerebral infarction.Abbreviations: 3-MA: 3-methyladenine; ACTA2/ɑ-SMA: actin alpha 2, smooth muscle, aorta; AIF1/Iba1: allograft inflammatory factor 1; BafA1: bafilomycin A1; BMVECs: brain microvascular endothelial cells; BrdU: 5-bromo-2'-deoxyuridine; CLDN11/OSP: claudin 11; GFAP: glial fibrillary acidic protein; HUVECs: human umbilical vein endothelial cells; LAMA1: laminin, alpha 1; MAP2: microtubule-associated protein 2; MBP2: myelin basic protein 2; MCAO: middle cerebral artery occlusion; PDGFRB/PDGFRß: platelet derived growth factor receptor, beta polypeptide; RECA-1: rat endothelial cell antigen-1; RHOA: ras homolog family member A; RHRSP: stroke-prone renovascular hypertensive rats; ROCK1: Rho-associated coiled-coil containing protein kinase 1; RTN4/Nogo-A: reticulon 4; RTN4R/NgR1: reticulon 4 receptor; S1PR2: sphingosine-1-phosphate receptor 2; SQSTM1: sequestosome 1.

Blockade of Nogo-A/Nogo-66 receptor 1 (NgR1) Inhibits Autophagic Activation and Prevents Secondary Neuronal Damage in the Thalamus after Focal Cerebral Infarction in Hypertensive Rats.

Focal cerebral infarction leads to autophagic activation, which contributes to secondary neuronal damage in the ipsilateral thalamus. Although Nogo-A deactivation enhances neuronal plasticity, its role in autophagic activation in the thalamus after ischemic stroke remains unclear. This study aimed to investigate the potential roles of Nogo-A/Nogo-66 receptor 1 (NgR1) in autophagic activation in the ipsilateral thalamus after cerebral infarction. Focal neocortical infarction was established using the middle cerebral artery occlusion (MCAO) method. Secondary damage in the ipsilateral thalamus was assessed by Nissl staining and immunostaining. The expression of Nogo-A, NgR1, Rho-A and Rho-associated coiled-coil containing protein kinase 1 (ROCK1) as well as autophagic flux were evaluated by immunofluorescence and immunoblotting. The roles of Nogo-A-NgR1 signaling in autophagic activation were determined by intraventricular delivery of an NgR1 antagonist peptide, NEP1-40, at 24 h after MCAO. The results showed that Nogo-A and NgR1 overexpression temporally coincided with marked increases in the levels of Beclin1, LC3-II and sequestosome 1 (SQSTM1)/p62 in the ipsilateral thalamus at seven and fourteen days after MCAO. In contrast, NEP1-40 treatment significantly reduced the expression of Rho-A and ROCK1 which was accompanied by marked reductions of LC3-II conversion as well as the levels of Beclin1 and SQSTM1/p62. Furthermore, NEP1-40 treatment significantly reduced neuronal loss and gliosis in the ipsilateral thalamus, and accelerated somatosensory recovery at the observed time-points after MCAO. These results suggest that blockade of Nogo-A-NgR1 signaling inhibits autophagic activation, attenuates secondary neuronal damage in the ipsilateral thalamus, and promotes functional recovery after focal cerebral cortical infarction.