Spinal cord injury (SCI) remains a significant global health challenge with limited effective therapeutic options. Exosomes derived from mesenchymal stem cells (MSCs) hav... More
Spinal cord injury (SCI) remains a significant global health challenge with limited effective therapeutic options. Exosomes derived from mesenchymal stem cells (MSCs) have emerged as promising neuroprotective agents due to their biocompatibility and immunomodulatory properties. This study investigated the therapeutic potential of hypoxia-conditioned bone marrow MSC (BMSC)-derived exosomes in both in vitro and in vivo SCI models. Hypoxic preconditioning significantly enriched miR-615-3p in bone marrow mesenchymal stem cell (BMSC)-derived exosomes. In spinal neuron injury models, hypoxic exosomes enhanced cell viability, reduced apoptosis, and ameliorated dysfunction of the mitochondria-associated endoplasmic reticulum membranes (MAMs). Mechanistically, miR-615-3p directly targeted and suppressed phosphodiesterase 4 C (PDE4C), activating the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway. This in turn modulated calcium signaling, attenuated mitochondrial calcium overload, and reduced endoplasmic reticulum stress (ERS). In a mouse model of SCI, short-term treatment with hypoxic exosomes promoted functional recovery within a 14-day post-injury period, as evidenced by improved locomotor performance, reduced lesion volume, attenuated tissue edema, and decreased inflammatory cell infiltration. Furthermore, in vivo administration of hypoxic exosomes upregulated miR-615-3p and downregulated PDE4C expression in injured spinal cord tissues. These results demonstrate that hypoxia-conditioned BMSC-derived exosomes exert neuroprotective effects via the miR-615-3p/PDE4C axis, highlighting their potential as a novel therapeutic strategy for SCI by targeting calcium homeostasis and mitochondrial-ER dysfunction. These findings demonstrate the short-term therapeutic potential of hypoxia-conditioned exosomes in SCI. However, further preclinical studies, including long-term follow-up to assess the durability of recovery and potential late-onset effects, alongside clinical validation, are warranted before clinical translation. Less
The serine protease tissue-type plasminogen activator (t-PA) is involved in both vital physiological brain processes, such as synaptic plasticity, and pathophysiological ... More
The serine protease tissue-type plasminogen activator (t-PA) is involved in both vital physiological brain processes, such as synaptic plasticity, and pathophysiological conditions, such as neurodegeneration and ischemic stroke. Recent data suggest that epigenetic mechanisms play an important role in the regulation of t-PA in human endothelial cells. However, there are limited data on epigenetic regulation of t-PA in human brain-derived cells. We demonstrate that treatment of cultured human neurons and human astrocytes with the histone deacetylase inhibitors trichostatin A (TSA) and MS-275 resulted in a two- to threefold increase in t-PA mRNA and protein expression levels. Next, we performed a chromatin immunoprecipitation assay on treated astrocytes with antibodies directed against acetylated histones H3 and H4 (both markers of gene activation). Treatment with MS-275 and TSA for 24 hours resulted in a significant increase in H3 acetylation, which could explain the observed increase in t-PA gene activity after the inhibition of histone deacetylation. Furthermore, DNA methylation analysis of cultured human neurons and astrocytes, as well as human postmortem brain tissue, revealed a stretch of unmethylated CpG dinucleotides in the proximal t-PA promoter, whereas more upstream CpGs were highly methylated. Taken together, these results implicate involvement of epigenetic mechanisms in the regulation of t-PA expression in the human brain. Less
Autophagy, a type II programmed cell death, is essential for cell survival under stress, e.g. lung injury, and bone marrow-derived mesenchymal stem cells (BM-MSCs) have g... More
Autophagy, a type II programmed cell death, is essential for cell survival under stress, e.g. lung injury, and bone marrow-derived mesenchymal stem cells (BM-MSCs) have great potential for cell therapy. However, the mechanisms underlying the BM-MSC activation of autophagy to provide a therapeutic effect in ischaemia/reperfusion-induced lung injury (IRI) remain unclear. Thus, we investigate the activation of autophagy in IRI following transplantation with BM-MSCs. Seventy mice were pre-treated with BM-MSCs before they underwent lung IRI surgery in vivo. Human pulmonary micro-vascular endothelial cells (HPMVECs) were pre-conditioned with BM-MSCs by oxygen-glucose deprivation/reoxygenation (OGD) in vitro. Expression markers for autophagy and the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signalling pathway were analysed. In IRI-treated mice, administration of BM-MSCs significantly attenuated lung injury and inflammation, and increased the level of autophagy. In OGD-treated HPMVECs, co-culture with BM-MSCs attenuated endothelial permeability by decreasing the level of cell death and enhanced autophagic activation. Moreover, administration of BM-MSCs decreased the level of PI3K class I and p-Akt while the expression of PI3K class III was increased. Finally, BM-MSCs-induced autophagic activity was prevented using the inhibitor LY294002. Administration of BM-MSCs attenuated lung injury by improving the autophagy level via the PI3K/Akt signalling pathway. These findings provide further understanding of the mechanisms related to BM-MSCs and will help to develop new cell-based therapeutic strategies in lung injury. Less
Subacute sclerosing panencephalitis (SSPE) is caused by persistent measles virus (MV) infection in the central nervous system
Abstract Inflammation is a well-defined factor in Alzheimer’s disease (AD). There is a strong need to identify
Background: Prenatal exposure of the developing brain to cocaine causes morphological and behavioral abnormalities. Recent studies indicate that cocaine-induced prolifera... More
Background: Prenatal exposure of the developing brain to cocaine causes morphological and behavioral abnormalities. Recent studies indicate that cocaine-induced proliferation inhibition and/or apoptosis in neural progenitor cells may play a pivotal role in causing these abnormalities. To understand the molecular mechanism through which cocaine inhibits cell proliferation in neural progenitors, we sought to identify the molecules that are responsible for mediating the effect of cocaine on cell cycle regulation. Less
