Xiaoyun Zhao

Abstract Ex vivo-expanded mesenchymal stem cells (MSCs) have been demonstrated to be a heterogeneous mixture of cells exhibiting varying proliferative, multipotential, and immunomodulatory capacities. However, the exact characteristics of MSCs remain largely unknown. By single-cell RNA sequencing of 61,296 MSCs derived from bone marrow and Wharton’s jelly, we revealed five distinct subpopulations. The developmental trajectory of these five MSC subpopulations was mapped, revealing a differentiation path from stem-like active proliferative cells (APCs) to multipotent progenitor cells, followed by branching into two paths: 1) unipotent preadipocytes or 2) bipotent prechondro-osteoblasts that were subsequently differentiated into unipotent prechondrocytes. The stem-like APCs, expressing the perivascular mesodermal progenitor markers CSPG4/MCAM/NES, uniquely exhibited strong proliferation and stemness signatures. Remarkably, the prechondrocyte subpopulation specifically expressed immunomodulatory genes and was able to suppress activated CD3+ T cell proliferation in vitro, supporting the role of this population in immunoregulation. In summary, our analysis mapped the heterogeneous subpopulations of MSCs and identified two subpopulations with potential functions in self-renewal and immunoregulation. Our findings advance the definition of MSCs by identifying the specific functions of their heterogeneous cellular composition, allowing for more specific and effective MSC application through the purification of their functional subpopulations.

AIM: To study the effect of cholecystokinin-octapeptide (CCK-8) on systemic hypotension and cytokine production in lipopolysaccharide (LPS)-induced endotoxic shock (ES) rats. METHODS: The changes of blood pressure were observed using physiological record instrument in four groups of rats: LPS (8mg.kg(-1),iv) induced ES; CCK-8 (40 microg.kg(-1), iv) pretreatment 10 min before LPS (8mg.kg(-1)); CCK-8 (40 micro.kg(-1), iv) or normal saline (control) groups. Differences in tissue and circulating specificity of the proinflammatory cytokines (TNF-alpha, IL-1beta and IL-6) were assayed with ELISA kits. RESULTS: CCK-8 reversed LPS-induced decrease of mean artery blood pressure (MABP) in rats. Compared with control, LPS elevated the serum level of IL-6 significantly (3567 +/- 687 ng.L(-1) vs 128 +/- 22 ng.L(-1), P<0.01), while contents of TNF-alpha and IL-1beta elevated significantly (277 +/- 86 ng.L(-1) vs not detectable and 43 +/- 9 ng.L(-1) vsnot detectable, P<0.01) but less extent than IL-6. CCK-8 significantly inhibited the LPS-induced increase in serum TNF-alpha IL-1beta and IL-6. LPS elevated spleen and lung content of IL-1beta significantly (5184 +/- 85 ng.L(-1) vs 1047 +/- 21 ng.L(-1) and 4050 +/- 614 ng.L(-1) vs not detectable, P<0.01), while levels of TNF-alpha and IL-6 also rose significantly but in less extent than IL-1beta. CCK-8 inhibited the LPS-induced increase of the cytokines in spleen and lung. In the heart, CCK-8 significantly inhibited LPS-induced increase of TNF-alpha (864 +/- 123 ng.L(-1) in CCK-8+LPS group vs 1599 +/- 227 ng.L(-1) in LPS group, P < 0.01), and IL-1beta (282 +/- 93 ng.L(-1) in CCK-8+LPS group vs 621 +/- 145ng.L(-1) in LPS group, P < 0.01). CONCLUSION: CCK-8 reverses ES, which may be related to its inhibitory effect on the overproduction of cytokines.

The only food and drug administration (FDA)-approved drug currently available for the treatment of acute ischemic stroke is tissue plasminogen activator (tPA), yet the therapeutic benefits of this drug are partially outweighed by the increased risk of hemorrhagic transformation (HT). Analysis of the NIH trial has shown that cigarette smoking protected tPA-treated patients from HT; however, the underlying mechanism is not clear. Nicotinic acetylcholine receptors (nAChR) has shown anti-inflammatory effect and modulation nAChR could be a strategy to reduce ischemia/reperfusion-induced blood-brain barrier (BBB) damage. Since melatonin could regulate the expression of α7nAchR and melatonin's neuroprotective effect against ischemic injury is mediated via α7nAChR modulation, here, we aim to test the hypothesis that melatonin reduces ischemia and reperfusion (I/R)-induced BBB damage through modulation of α7nACh receptor (α7nAChR). Mice were subjected to 1.5 h ischemia and 24 h reperfusion and at the onset of reperfusion, mice received intraperitoneal administration (i.p.) of either drug or saline. Mice were randomly assigned into five groups: Saline; α7nAChR agonist PNU282987; Melatonin; Melatonin+Methyllycaconitine (MLA, α7nAChR antagonist), and MLA group. BBB permeability was assessed by detecting the extravasation of Evan's blue and IgG. Our results showed that I/R significantly increased BBB permeability accompanied by occludin degradation, microglia activation, and high mobility group box 1 (HMGB1) release from the neuron. In addition, I/R significantly induced neuronal loss accompanied by the decrease of CREB-regulated transcriptional coactivator 1 (CRTC1) and p-CREB expression. Melatonin treatment significantly inhibited the above changes through modulating α7nAChR. Taken together, these results demonstrate that melatonin provides a protective effect on ischemia/reperfusion-induced BBB damage, at least in part, depending on the modulation of α7nAChR.

OBJECTIVE: To explore the expression level of neuron-specific enolase (NSE), S100B and neuropeptide Y (NPY) in children with acute miliary tuberculosis and secondary tubercular meningitis. PATIENTS AND METHODS: 28 children diagnosed with acute miliary tuberculosis and secondary tubercular meningitis were included into group A, 25 children diagnosed with pure acute miliary tuberculosis were included into group B and 23 children diagnosed with suspected meningitis were included into group C. The levels of NSE, S100B and NPY in cerebrospinal fluid and serum were detected. RESULTS: The levels of NSE, S100B and NPY in cerebrospinal fluid and serum of group A were significantly higher than the levels in the other two groups, differences were statistically significant (p<0.05). A multifactor retrospective analysis suggested that secondary tubercular meningitis was significantly correlated with the high expression of S100B, NPY and NSE in cerebrospinal fluid and serum. CONCLUSIONS: Early detection of the expression levels of NSE, S100B and NPY in cerebrospinal fluid and serum was of great value for the diagnosis of tubercular meningitis secondary to acute miliary tuberculosis.