The Roles of Exosome-Derived microRNAs in Cardiac Fibrosis.

Cardiovascular disease (CVD) stands as the foremost cause of patient mortality, and the lack of early diagnosis and defined treatment targets significantly contributes to the suboptimal prevention and management of CVD. Myocardial fibrosis (MF) is not only a complex pathogenic process with no effective treatment currently available but also exerts detrimental effects on the progression of various cardiovascular diseases, thereby escalating their mortality rates. Exosomes are nanoscale biocommunication vehicles that facilitate intercellular communication by transporting bioactive substances, such as nucleic acids and proteins, from specific cell types. Numerous studies have firmly established that microRNAs (miRNAs), as non-coding RNAs, wield post-transcriptional regulatory mechanisms and exhibit close associations with various CVDs, including coronary heart disease (CHD), atrial fibrillation (AF), and heart failure (HF). MiRNAs hold significant promise in the diagnosis and treatment of cardiovascular diseases. In this review, we provide a concise introduction to the biological attributes of exosomes and exosomal miRNAs. We also explore the roles and mechanisms of distinct cell-derived exosomal miRNAs in the context of myocardial fibrosis. These findings underscore the pivotal role of exosomes in the diagnosis and treatment of cardiac fibrosis and emphasize their potential as biotherapies and drug delivery vectors for cardiac fibrosis treatment.

Leptin Promotes the Proliferation and Neuronal Differentiation of Neural Stem Cells through the Cooperative Action of MAPK/ERK1/2, JAK2/STAT3 and PI3K/AKT Signaling Pathways.

The potential of neural stem cells (NSCs) for neurological disorders the treatment has relied in large part upon identifying the NSCs fate decision. The hormone leptin has been reported to be a crucial regulator of brain development, able to influence the glial and neural development, yet, the underlying mechanism of leptin acting on NSCs' biological characteristics is still poorly understood. This study aims to investigate the role of leptin in the biological properties of NSCs. In this study, we investigate the possibility that leptin may regulate the NSCs' fate decision, which may promote the proliferation and neuronal differentiation of NSCs and thus act positively in neurological disorders. NSCs from the embryonic cerebral cortex were used in this study. We used CCK-8 assay, ki67 immunostaining, and FACS analysis to confirm that 25-100 ng/mL leptin promotes the proliferation of NSCs in a concentration-dependent pattern. This change was accompanied by the upregulation of p-AKT and p-ERK1/2, which are the classical downstream signaling pathways of leptin receptors b (LepRb). Inhibition of PI3K/AKT or MAPK/ERK signaling pathways both abolished the effect of leptin-induced proliferation. Moreover, leptin also enhanced the directed neuronal differentiation of NSCs. A blockade of the PI3K/AKT pathway reversed leptin-stimulated neurogenesis, while a blockade of JAK2/STAT3 had no effect on it. Taken together, our results support a role for leptin in regulating the fate of NSCs differentiation and promoting NSCs proliferation, which could be a promising approach for brain repair via regulating the biological characteristics of NSCs.

Fufang Zhenzhu Tiaozhi (FTZ) capsule ameliorates diabetes-accelerated atherosclerosis via suppressing YTHDF2-mediated m6A modification of SIRT3 mRNA.

ETHNOPHARMACOLOGICAL RELEVANCE: Fufang Zhenzhu TiaoZhi (FTZ), a Chinese medicinal decoction, has continuously been used to treat metabolic syndrome. Atherosclerosis is the main pathological basis of cardiovascular disease. The N6 methyladenosine (m6A) modification is a highly dynamic and reversible process involving a variety of important biological processes. AIM OF THE STUDY: Here, we investigated the therapeutic effects and mechanism of FTZ in diabetes-accelerated atherosclerosis. MATERIALS AND METHODS: Doppler ultrasonography was used to examine the carotid intima-media thickness and plaque area in diabetic atherosclerosis patients. HFD mice were injected with streptozotocin to induce diabetes. HE and Oil red O staining were used to assess the effect of FTZ on lipid deposition. HUVECs were induced with HG/ox-LDL as a model of diabetic atherosclerosis. Furthermore, application of m6A methylation level kit, qRT-PCR, Western blot, tunel staining, reactive oxygen species staining and mPTP staining were performed to analyze the detailed mechanism. RESULTS: Clinical trials of FTZ have shown obvious effect of lowering blood glucose and blood lipids. These effects were reversed after FTZ intervention. Compared with the control, lipid deposition decreased significantly after FTZ administration. FTZ reduced endothelial cell apoptosis. At the same time, we found that FTZ reversed the increase of methylation reader YTHDF2 caused by ox-LDL treatment. Subsequently, we discovered that YTHDF2 degraded SIRT3 mRNA, leading to endothelial cell apoptosis and oxidative stress. CONCLUSION: FTZ attenuated diabetes-accelerated atherosclerosis by decreasing blood glucose and serum lipids levels, and increased endothelial cell antioxidant capacity, inhibited endothelial cell apoptosis via inhibiting YTHDF2-mediated m6A modification of SIRT3 mRNA, which reduced mRNA degradation.

Voluntary Exercise to Reduce Anxiety Behaviour in Traumatic Brain Injury Shown to Alleviate Inflammatory Brain Response in Mice.

Traumatic brain injury is a leading cause of neuroinflammation and anxiety disorders in young adults. Immune-targeted therapies have garnered attention for the amelioration of TBI-induced anxiety. A previous study has indicated that voluntary exercise intervention following TBI could reduce neuroinflammation. It is essential to determine the effects of voluntary exercise after TBI on anxiety via inhibiting neuroinflammatory response. Mice were randomly divided into four groups (sham, TBI, sham + voluntary wheel running (VWR), and TBI + VWR). One-week VWR was carried out on the 2nd day after trauma. The neurofunction of TBI mice was assessed. Following VWR, anxiety behavior was evaluated, and neuroinflammatory responses in the perilesional cortex were investigated. Results showed that after one week of VWR, neurofunctional recovery was enhanced, while the anxiety behavior of TBI mice was significantly alleviated. The level of pro-inflammatory factors decreased, and the level of anti-inflammatory factors elevated. Activation of nucleotide oligomerization domain-like thermal receptor protein domain associated protein 3 (NLRP3) inflammasome was inhibited significantly. All these alterations were consistent with reduced microglial activation at the perilesional site and positively correlated with the amelioration of anxiety behavior. This suggested that timely rehabilitative exercise could be a useful therapeutic strategy for anxiety resulting from TBI by targeting neuroinflammation.

The kinase inhibitory region of SOCS3 attenuates reactive astrogliosis and astroglial scar in mice after traumatic brain injury.

Traumatic brain injury (TBI) leads to reactive astrogliosis that impedes neural repair/regeneration. It has been proven that SOCS3 attenuates astrocyte activation by inhibiting the JAK2-STAT3 pathway. However, whether the kinase inhibitory region (KIR) of SOCS3 can be directly applied to mediate astrocyte activation after TBI is not clear. The present study aimed at investigating the inhibitory effect of KIR on reactive astrogliosis and its potential neuroprotection after TBI insult. For this purpose, A TBI model was developed by the free impact of heavy objects in adult mice. KIR was linked to the TAT peptide (TAT-KIR) to facilitate cell membrane penetration and intracranially injected into the cerebral cortex adjacent to the TBI lesion. Then reactive astrogliosis, activity of JAK2-STAT3 pathway, neuron loss, and function deficit were observed. Our results showed a decrease in neuron loss and an improvement in neural function. Meanwhile, Intracranial injection of TAT-KIR in TBI mice demonstrated a reduction of GFAP-positive astrocytes as well as C3/GFAP double-labeled A1 reactive astrocytes. Western blot analysis illustrated that the activity of the JAK2-STAT3 pathway was significantly inhibited by TAT-KIR. We conclude that exogenous treatment TAT-KIR, through suppression of JAK2-STAT3 activity, inhibits TBI -induced reactive astrogliosis induced, thereby alleviating the loss of neurons and relieving the neural function deficit. This investigation suggests that TAT-KIR could be a potential therapeutic strategy for enhancing neural regeneration following.

Kinase inhibit region of SOCS3 attenuates IL6-induced proliferation and astrocytic differentiation of neural stem cells via cross talk between signaling pathways.

AIMS: Efficiency of neural stem cells (NSCs) therapy for brain injury is restricted by astrogliosis around the damaged region, in which JAK2/STAT3 signaling plays a key role. The SOCS3 that can directly inhibit JAK/STAT3 pathway. Here, we investigated the effects of a fusion peptide that combined kinase inhibitory region (KIR) of SOCS3 and virus trans-activator of transcription (TAT) on biological behavior of cultured NSCs under inflammatory conditions. METHODS: NSCs were isolated from embryonic brain of SD rats, TAT-KIR was synthesized, and penetration rate was evaluated by flow cytometry (FACS). CCK8, immunostaining, and FACS were used to detected of TAT-KIR on the proliferation of NSCs. The expressions of GFAP and ß tubulin III positive cells induced by IL6 with/without TAT-KIR were examined by immunostaining and Western blotting to observe the NSCs differentiation, and the effect of TAT-KIR on signaling cross talk was observed by Western blotting. RESULTS: Penetration rate of TAT-KIR into primary cultured NSCs was up to 94%. TAT-KIR did not affect the growth and viability of NSCs. It significantly reduced the NSCs proliferation that enhanced by IL-6 stimulation via blocking the cell cycle progression from the G0/G1 to S phase. In addition, TAT-KIR attenuated astrocytic differentiation and kept high level of neuronal differentiation derived from IL-6-induced NSCs. The fate of NSCs differentiation under inflammatory conditions was affected by TAT-KIR, which was associated with synchronous inhibition of STAT3 and AKT, while promoting JNK expression. CONCLUSION: TAT-KIR mimetic of SOCS3 could be a promising approach for brain repair via regulating the biological behaviors of exogenous NSCs.

Maternal High-Fat Diet Reduces Type-2 Neural Stem Cells and Promotes Premature Neuronal Differentiation during Early Postnatal Development.

Maternal obesity or exposure to a high-fat diet (HFD) has an irreversible impact on the structural and functional development of offspring brains. This study aimed to investigate whether maternal HFD during pregnancy and lactation impairs dentate gyrus (DG) neurogenesis in offspring by altering neural stem cells (NSCs) behaviors. Pregnant Sprague-Dawley rats were fed a chow diet (CHD) or HFD (60% fat) during gestation and lactation. Pups were collected on postnatal day 1 (PND 1), PND 10 and PND 21. Changes in offspring body weight, brain structure and granular cell layer (GCL) thickness in the hippocampus were analyzed. Hippocampal NSCs behaviors, in terms of proliferation and differentiation, were investigated after immunohistochemical staining with Nestin, Ki67, SOX2, Doublecortin (DCX) and NeuN. Maternal HFD accelerated body weight gain and brain structural development in offspring after birth. It also reduced the number of NSCs and their proliferation, leading to a decrease in NSCs pool size. Furthermore, maternal HFD intensified NSCs depletion and promoted neuronal differentiation in the early postnatal development period. These findings suggest that maternal HFD intake significantly reduced the amount and capability of NSCs via reducing type-2 NSCs and promoting premature neuronal differentiation during postnatal hippocampal development.

Maternal high-salt diet during pregnancy impairs synaptic plasticity and memory in offspring.

Excess salt intake harms the brain health and cognitive functions, but whether a maternal high-salt diet (HSD) affects the brain development and neural plasticity of offspring remains unclear. Here, using a range of behavioral tests, we reported that the offspring of maternal HSD subjects exhibited short- and long-term memory deficits, especially in spatial memory in adulthood. Moreover, impairments in synaptic transmission and plasticity in the hippocampus were observed in adult offspring by using in vivo electrophysiology. Consistently, the number of astrocytes but not neurons in the hippocampus of the offspring from the HSD group were significantly decreased, and ERK and AKT signaling pathways involved in neurodevelopment were highly activated only during juvenile. In addition, the expression of synaptic proteins decreased both in juvenile and adulthood, and this effect might be involved in synaptic dysfunction. Collectively, these data demonstrated that the maternal HSD might cause adult offspring synaptic dysfunction and memory loss. It is possibly due to the reduction of astrocytes in juvenile.

Dynamics expression of DmFKBP12/Calstabin during embryonic early development of Drosophila melanogaster.

BACKGROUND: Calcium signaling are conserved from invertebrates to vertebrates and plays critical roles in many molecular mechanisms of embryogenesis and postnatal development. As a critical component of the signaling pathway, the RyR medicated calcium-induced calcium release signaling system, has been well studied along with their regulator FK506-binding protein 12 (FKBP12/Calstabin). Lack of FKBP12 is known to result in lethal cardiac dysfunction in mouse. However, precisely how FKBP12 is regulated and effects calcium signaling in Drosophila melanogaster remains largely unknown. RESULTS: In this study, we identified both temporal and localization changes in expression of DmFKBP12, a translational and transcriptional regulator of Drosophila RyR (DmRyR) and FKBP12, through embryonic development. DmFKBP12 is first expressed at the syncytial blastoderm stage and undergoes increased expression during the cellular blastoderm and early gastrulation stages. At late gastrulation, DmFKBP12 expression begins to decline until it reaches homeostasis, which it then maintains throughout the rest of development. Throughout these described changes in expression, DmFKBP12 mRNA remain stable, which indicates that protein dynamics are attributed to regulation at the mRNA to protein translation level. In addition to temporal changes in expression, dynamic expression profiles during Drosophila development also revealed DmFKBP12 localization. Although DmFKBP12 is distributed evenly between the anterior to posterior poles of the blastoderm egg, the protein is expressed more strongly in the cortex of the early Drosophila gastrula with the highest concentration found in the basement membrane of the cellular blastoderm. Fertilized egg, through the profile as under-membrane cortex distribution concentering onto basement at cellular blastoderm, to the profile as three-gem layer localization in primitive neuronal and digestion architecture of early Drosophila gastrula. By late gastrulation, DmFKBP12 is no longer identified in the yolk or lumen of duct structures and has relocated to the future brain (suboesophageal and supraesophageal ganglions), ventral nervous system, and muscular system. Throughout these changes in distribution, in situ DmFKBP12 mRNA monitoring detected equal distribution of DmFKBP12 mRNA, once again indicating that regulation of DmFKBP12 occurs at the translational level in Drosophila development. CONCLUSION: As a critical regulator of the DmRyR-FKBP complex, DmFKBP12 expression in Drosophila fluctuates temporally and geographically with the formation of organ systems. These finding indicate that DmFKBP12 and RyR associated calcium signaling plays an essential role in the successful development of Drosophila melanogaster. Further study on the differences between mammalian RyR-FKBP12 and Drosophila DmRyR-FKBP12 can be exploited to develop safe pesticides.

HIF-1α/Beclin1-Mediated Autophagy Is Involved in Neuroprotection Induced by Hypoxic Preconditioning.

Hypoxic preconditioning (HPC) exerts a protective effect against hypoxic/ischemic brain injury, and one mechanism explaining this effect may involve the upregulation of hypoxia-inducible factor-1 (HIF-1). Autophagy, an endogenous protective mechanism against hypoxic/ischemic injury, is correlated with the activation of the HIF-1α/Beclin1 signaling pathway. Based on previous studies, we hypothesize that the protective role of HPC may involve autophagy occurring via activation of the HIF-1α/Beclin1 signaling pathway. To test this hypothesis, we evaluated the effects of HPC on oxygen-glucose deprivation/reperfusion (OGD/R)-induced apoptosis and autophagy in SH-SY5Y cells. HPC significantly attenuated OGD/R-induced apoptosis, and this effect was suppressed by the autophagy inhibitor 3-methyladenine and mimicked by the autophagy agonist rapamycin. In control SH-SY5Y cells, HPC upregulated the expression of HIF-1α and downstream molecules such as BNIP3 and Beclin1. Additionally, HPC increased the LC3-II/LC3-I ratio and decreased p62 levels. The increase in the LC3-II/LC3-I ratio was inhibited by the HIF-1α inhibitor YC-1 or by Beclin1-short hairpin RNA (shRNA). In OGD/R-treated SH-SY5Y cells, HPC also upregulated the expression levels of HIF-1α, BNIP3, and Beclin1, as well as the LC3-II/LC3-I ratio. Furthermore, YC-1 or Beclin1-shRNA attenuated the HPC-mediated cell viability in OGD/R-treated cells. Taken together, our results demonstrate that HPC protects SH-SY5Y cells against OGD/R via HIF-1α/Beclin1-regulated autophagy.

Chronic central oxytocin infusion impairs sociability in mandarin voles.

Oxytocin (OT) has been reported to increase social contact, however some studies have related OT to reduced social contact, particularly with unfamiliar individuals. The underlying mechanisms of OT on social contact remain unclear. In this study, male mandarin vole (Microtus mandarinus), a socially monogamous rodent, was used as an animal model in which osmotic minipumps were used to intracerebroventricularly administer two dosages of OT or saline for 12 consecutive days. We examined the effect of long-term OT treatment on social behavior, anxiety levels, and levels of oxytocin, vasopressin (AVP) and dopamine (DA) receptors mRNA expression in the nucleus accumbens (NAcc), and medial amygdala (MeA). The data showed that chronic central OT infusion decreased social preference behavior (a reduction of preference for interacting with novel social stimulus relative to a novel object) concomitant to a reduction of OT receptors in the NAcc and MeA. We also found alterations in AVP and DA receptor levels in the NAcc and MeA after treatment with OT. Moreover, chronic central OT treatment did not affect levels of anxiety-related behavior in male voles. In conclusion, these results indicated that chronic OT treatment may differ from the treatment effects predicted in short-term studies, and significant dosage effects were observed.