Reduced non-CpG methylation is a potential epigenetic target after spinal cord injury.

DNA methylation is a critical epigenetic regulator in the occurrence and development of diseases and is closely related to various functional responses in relation to spinal cord injury. To investigate the role of DNA methylation in spinal cord injury, we constructed a library with reduced-representation bisulfite sequencing data obtained at various time points (day 0-42) after spinal cord injury in mice. Global DNA methylation levels, specifically non-CpG (CHG and CHH) methylation levels, decreased modestly following spinal cord injury. Stages post-spinal cord injury were classified as early (day 0-3), intermediate (day 7-14), and late (day 28-42) based on similarity and hierarchical clustering of global DNA methylation patterns. The non-CpG methylation level, which included CHG and CHH methylation levels, was markedly reduced despite accounting for a minor proportion of total methylation abundance. At multiple genomic sites, including the 5' untranslated regions, promoter, exon, intron, and 3' untranslated regions, the non-CpG methylation level was markedly decreased following spinal cord injury, whereas the CpG methylation level remained unchanged at these locations. Approximately one-half of the differentially methylated regions were located in intergenic areas; the other differentially methylated regions in both CpG and non-CpG regions were clustered in intron regions, where the DNA methylation level was highest. The function of genes associated with differentially methylated regions in promoter regions was also investigated. From Gene Ontology analysis results, DNA methylation was implicated in a number of essential functional responses to spinal cord injury, including neuronal synaptic connection creation and axon regeneration. Notably, neither CpG methylation nor non-CpG methylation was implicated in the functional response of glial or inflammatory cells. In summary, our work elucidated the dynamic pattern of DNA methylation in the spinal cord following injury and identified reduced non-CpG methylation as an epigenetic target after spinal cord injury in mice.

LSD1 in beige adipocytes protects cardiomyocytes against oxygen and glucose deprivation.

Objectives: Epicardial adipose tissue (EpAT) is known for its role in supporting the cardiomyocytes. Lysine-specific demethylase 1 (LSD1), a typical lysine demethylase, is an essential regulator for the maintenance of beige adipocytes. However, the effect of LSD1 in the adipogenic differentiation of beige adipocytes in EpAT, and its function on oxygen and glucose deprivation (OGD)-injured cardiomyocytes remain unclear. Materials and Methods: Heart tissues from young mice and elder mice were collected for immunohistochemical staining. LSD1 in 3T3-L1 cells was knocked down by LSD1-shRNA lentivirus infection. The qRT-PCR, western blotting, and Oil Red O staining were employed to detect the adipogenic differentiation of 3T3-L1 cells and formation of beige adipocytes. The cardiomyocytes co-cultured with beige adipocytes were used for OGD treatment. Cell apoptosis was analyzed by flow cytometry. The lactate dehydrogenase (LDH) and superoxide dismutase (SOD) activity were analyzed using commercially available kits. Results: The decrease of LSD1 was related to the age-dependent loss of beige adipocytes in mice EpAT. LSD1 knockdown inhibited the adipogenic differentiation of 3T3-L1 cells and formation of beige adipocytes. The down-regulation of LSD1 in 3T3-L1 cells decreased the protective effect of mature adipocytes on OGD-injured cardiomyocytes. Conclusion: The decreased expression of LSD1 in mice EpAT was associated with age-dependent ablation of beige adipocytes. The protective effect of beige adipocytes on OGD-injured cardiomyocytes is reduced by knockdown of LSD1 in adipocytes. The present study provided exciting insights into establishing novel therapies against age-dependent cardiac diseases.

LSD1 regulates the expressions of core cardiogenic transcription factors and cardiac genes in oxygen and glucose deprivation injured mice fibroblasts in vitro.

Cardiac reprogramming has emerged as a novel therapeutic approach to regenerating the damaged heart by directly converting endogenous cardiac fibroblasts (CFs) into induced cardiomyocytes (iCMs). Cardiac reprogramming requires the activation of the cardiogenic transcriptional program in concert with the repression of the fibroblastic transcriptional program. Lysine-specific demethylase 1 (LSD1) plays an instrumental role in many physiological processes such as cell growth, differentiation and metabolism. The epigenetic modifications of histones are essential for the accurate expression of genes in cardiomyocytes and the normal functioning of the heart. However, the effect of LSD1 in regulating the cardiogenic transcriptional program under myocardial ischemia/reperfusion (I/R) injury remains unclear. Thus, mice I/R injury was induced by 4 and 24 h reperfusion after 1-h occlusion of the left anterior descending coronary artery. The primary CFs and CMs were exposed under oxygen and glucose deprivation (OGD) to mimic I/R injury. The expression of LSD1 significantly decreased in I/R injured heart tissue and OGD-injured primary CFs and CM, and methylated histone presented a notable increase in OGD-injured primary CFs. Overexpression of LSD1 inhibited the injury of primary CFs induced by OGD, but showed limited inhibition on injured primary CMs. Under the OGD condition, LSD1 overexpression significantly increased cell viability, decreased cell apoptosis and reactive oxygen species (ROS) production of primary CFs. The expression of core cardiogenic transcription factors and cardiac genes were significantly decreased in OGD injured primary CFs, whereas LSD1 overexpression reversed the decrease of transcription factors and cardiac genes under the OGD condition. In conclusion, the overexpression of LSD1 has a protective role in I/R injury by inhibiting the histone methylation of primary CFs and regulates the expressions of core cardiogenic transcription factors and cardiac genes, which can prove to be a potential approach for direct cardiac reprogramming.

Tetramethylpyrazine Improves Monocrotaline-Induced Pulmonary Hypertension through the ROS/iNOS/PKG-1 Axis.

Background: Tetramethylpyrazine (TMP), a potent anti-free radical and anti-inflammations substance, has been demonstrated to possess a direct vessel relaxation property. This study aimed to evaluate the effect of TMP treatment in pulmonary hypertension (PH) and test the hypothesis that TMP prevents or reverses the process of PH. Methods: Rats (n = 36) injected with 50 mg/kg of monocrotaline (MCT) subcutaneously 4 weeks to develop PH were then randomized to TMP (5 mg/kg per day) for another 4 weeks. Hemodynamics was evaluated via the right ventricle. Pulmonary vessels structural remodeling and inflammation were examined by histologic and transmission electron microscopy observation. The expression of inducible nitric oxide synthase (iNOS) and cGMP-dependent protein kinases 1 (PKG-1) was detected by immunohistochemical staining and Western blot. Generation of reactive oxygen species (ROS) and antioxidation species was measured by biochemical analyses. Results: MCT increased PH and right ventricle hypertrophy. TMP alleviated pulmonary arterial pressure elevation, leukocyte infiltration, and structural remodeling of pulmonary arterials induced by MCT successfully. TMP treatment significantly increased the PKG-1 expression and suppressed the iNOS expression. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT) was significantly higher than control group, while malondialdehyde (MDA) levels were lower compared with MCT group. Conclusion: TMP can suppress established MCT-induced PH through the ROS/iNOS/PKG axis. The underlying mechanisms may be associated with its anti-inflammatory, antioxidant, and antiproliferative properties in pulmonary arterial.

Alleviation of glucolipotoxicity-incurred cardiomyocyte dysfunction by Z-ligustilide involves in the suppression of oxidative insult, inflammation and fibrosis.

Diabetes mellitus ranks as a major risk cause for disability and death around the world due to its complications, especially diabetic cardiomyopathy (DCM). Glucolipotoxicity is one of the critical causal factors of DCM. Recent finding confirms the beneficial roles of Z-ligustilide in diabetes mellitus. Nevertheless, its efficacy in DCM remains elusive. Here, Z-ligustilide elevated high glucose/high palmitic acid (HG/P)-inhibited cell viability and attenuated HG/P-induced cell apoptosis, caspase-3 activity, pro-apoptotic Bax and anti-apoptotic Bcl-2 protein expression. Furthermore, Z-ligustilide alleviated HG/P-evoked oxidative damage by decreasing HG/P-induced elevation in ROS, lactate dehydrogenase (LDH) and malondialdehyde (MDA) leakage, but increasing antioxidant enzyme-superoxide dismutase (SOD) and glutathione (GSH) levels suppressed by HG/P. Concomitantly, Z-ligustilide attenuated HG/P-induced cardiomyocyte fibrosis by increasing MMP-14 expression and diminishing HG/P-enhanced fibrotic protein expression, including collagen I, collagen II and TGF-ß. Mechanistically, Z-ligustilide offset the adverse effects of HG/P on the activation of the AMPK/GSK-3ß/Nrf2 pathway. Importantly, blocking the AMPK signaling overturned the protective efficacy of Z-ligustilide against HG/P-induced cardiomyocyte oxidative damage, inflammation and fibrosis. Together, these findings highlight that Z-ligustilide may alleviate glucolipotoxicity-induced cardiomyocyte dysfunction by regulating cell oxidative injury, inflammation and fibrosis via the AMPK/GSK-3ß/Nrf2 pathway. Consequently, Z-ligustilide may represent a promising therapeutic agent against DCM by restoring cardiomyocyte dysfunction.

A narrative review of the research progress and clinical application of platelet-rich plasma.

As a traditional treatment invented in the 1970s, the usage of platelet-rich plasma (PRP) has been reported constantly in many medical areas, such as tissue regeneration, wound healing, ligament repair, hair loss, and so on. In this review, we focus on the administration of PRP in musculoskeletal recovery. As a part of autogenous blood plasma, PRP's platelet concentration is above the baseline. It is extracted from the host's blood sample collected before centrifugal separation. The history, mechanism and preparation of PRP, and existing clinical applications of it will become a helper for clinicians to better understand this therapy. However, the molecular mechanism of PRP treatment is still under debate. On the other hand, because of the safety concern during the PRP's preparation, the practical application of PRP is only applied in many rare cases, especially in spinal diseases. In this paper, we attempt to make a better understanding of the mechanism of PRP and the preparation of PRP; meanwhile, to raise existing questions about further application of PRP in the future. We recommend that PRP should be used in spinal diseases and other fields and in the future we ought to find a safe, simple, and standardized PRP preparation protocol.