Han-Tan Chai

Early Combined Treatment with Cilostazol and Bone Marrow- Derived Endothelial Progenitor Cells Markedly Attenuates Pulmonary Arterial Hypertension in Rats

We investigated whether early combined cilostazol and bone marrow-derived endothelial progenitor cell (BMDEPC) treatment offers synergistic benefit in ameliorating monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats. Male Sprague-Dawley rats (n = 10/group) were randomized to receive saline injection only (group 1), MCT (70 mg/kg) (group 2), and MCT plus cilostazol (20 mg/kg/day) (group 3), MCT plus BMDEPCs (2.0 × 106 cells) (group 4), and MCT plus combined cilostazol/BMDEPCs (group 5). Intravenous BMDEPCs and oral cilostazol were given on day 3 after MCT administration. By day 42, connexin43 protein expression in right ventricle (RV) was reduced in group 2 compared with other groups and also was decreased in groups 3 and 4 compared with groups 1 and 5 (all p < 0.05). In addition, mRNA expressions of matrix metalloproteinase-9, tumor necrosis factor-α, and caspase-3 were higher, whereas Bcl-2 and endothelial nitric-oxide synthase were lower in lung and RV in group 2 compared with the other groups (all p < 0.05). The number of alveolar sacs and lung arterioles was lower in group 2 than in other groups and lower in groups 3 and 4 than in group 5 (all p < 0.05). RV systolic pressure (RVSP) and weight were increased in group 2 compared with the other groups (all p < 0.0001). Moreover, RVSP and RV-to-left ventricle plus septum weight ratio were higher in groups 3 and 4 than in groups 1 and 5 (p < 0.001) but showed no difference between groups 1 and 5. In conclusion, early combined autologous BMDEPC/cilostazol treatment is superior to BMDEPC or cilostazol only for preventing MCT-induced PAH.

Effect of obesity reduction on preservation of heart function and attenuation of left ventricular remodeling, oxidative stress and inflammation in obese mice

BackgroundObesity is an important cardiovascular risk factor. This study tested the effect of obesity reduction on preserving left ventricular ejection fraction (LVEF) and attenuating inflammation, oxidative stress and LV remodeling in obese mice.Methods and resultsEight-week-old C57BL/6 J mice (n=24) were equally divided into control (fed a control diet for 22 weeks), obesity (high-fat diet, 22 weeks), and obese reduction (OR) (high-fat diet, 14 weeks; then control diet, 8 weeks). Animals were sacrificed at post 22-week high-fat diet and the LV myocardium collected. Heart weight, body weight, abdominal-fat weight, total cholesterol level and fasting blood glucose were higher in obesity than in control and OR (all p<0.001). Inflammation measured by mRNA expressions of IL-6, MMP-9, PAI-1 and leptin and protein expression of NF-κB was higher, whereas anti-inflammation measured by mRNA expressions of adiponectin and INF-γ was lower in obesity than in control and OR (all p<0.003). Oxidative protein expressions of NOX-1, NOX-2 and oxidized protein were higher, whereas expression of anti-oxidant markers HO-1 and NQO-1 were lower (all p<0.01); and apoptosis measured by Bax and caspase 3 was higher, whereas anti-apoptotic Bcl-2 was lower in obesity as compared with control and OR (all p<0.001). The expressions of fibrotic markers phosphorylated Smad3 and TGF-β were higher, whereas expression of anti-fibrotic phosphorylated Smad1/5 and BMP-2 were lower (all p<0.02); and LVEF was lower, whereas the LV remodeling was higher in obesity than in control and OR (all p<0.001).ConclusionImpaired LVEF, enhanced LV remodeling, inflammation, fibrosis, oxidative stress and apoptosis were reversed by reduction in mouse obesity.

Impact of apoptotic adipose-derived mesenchymal stem cells on attenuating organ damage and reducing mortality in Rat sepsis syndrome induced by cecal puncture and ligation

BackgroundWe tested whether apoptotic adipose-derived mesenchymal stem cells (A-ADMSCs) were superior to healthy (H)-ADMSCs at attenuating organ damage and mortality in sepsis syndrome following cecal ligation and puncture (CLP).MethodsAdult male rats were categorized into group 1 (sham control), group 2 (CLP), group 3 [CLP + H-ADMSC administered 0.5, 6, and 18 h after CLP], group 4 [CLP + A-ADMSC administered as per group 3].ResultsCirculating peak TNF-α level, at 6 h, was highest in groups 2 and 3, and higher in group 4 than group 1 (p < 0.0001). Immune reactivity (indicated by circulating and splenic helper-, cytoxic-, and regulatory-T cells) at 24 and 72 h exhibited the same pattern as TNF-α amongst the groups (all p < 0.0001). The mononuclear-cell early and late apoptosis level and organ damage parameters of liver (AST, ALT), kidney (creatinine) and lung (arterial oxygen saturation) also displayed a similar pattern to TNF-α levels (all p < 0.001). Protein levels of inflammatory (TNF-α, MMP-9, NF-κB, ICAM-1), oxidative (oxidized protein) and apoptotic (Bax, caspase-3, PARP) biomarkers were higher in groups 2 and 3 than group 1, whereas anti-apoptotic (Bcl-2) biomarker was lower in groups 2 and 3 than in group 1 but anti-oxidant (GR, GPx, HO-1, NQO-1) showed an opposite way of Bcl-2; these patterns were reversed for group 4 (all p < 0.001). Mortality was highest in group 3 and higher in group 2 than group 4 than group 1 (all p < 0.001).ConclusionsA-ADMSC therapy protected major organs from damage and improved prognosis in rats with sepsis syndrome.

Protective effect of melatonin-supported adipose-derived mesenchymal stem cells against small bowel ischemia-reperfusion injury in rat

We tested the hypothesis that combined melatonin and autologous adipose‐derived mesenchymal stem cells (ADMSC) was superior to either alone against small bowel ischemia‐reperfusion (SBIR) injury induced by superior mesenteric artery clamping for 30 min followed by reperfusion for 72 hr. Male adult Sprague Dawley rats (n = 50) were equally categorized into sham‐operated controls SC, SBIR, SBIR‐ADMSC (1.0 × 106 intravenous and 1.0 × 106 intrajejunal injection), SBIR‐melatonin (intraperitoneal 20 mg/kg at 30 min after SI ischemia and 50 mg/kg at 6 and 18 hr after SI reperfusion), and SBIR‐ADMSC‐melatonin groups. The results demonstrated that the circulating levels of TNF‐α, MPO, LyG6+ cells, CD68+ cells, WBC count, and gut permeability were highest in SBIR and lowest in SC, significantly higher in SBIR‐ADMSC group and further increased in SBIR‐melatonin group than in the combined therapy group (all P < 0.001). The ischemic mucosal damage score, the protein expressions of inflammation (TNF‐α, NF‐κB, MMP‐9, MPO, and iNOS), oxidative stress (NOX‐1, NOX‐2, and oxidized protein), apoptosis (APAF‐1, mitochondrial Bax, cleaved caspase‐3 and PARP), mitochondrial damage (cytosolic cytochrome C) and DNA damage (γ‐H2AX) markers, as well as cellular expressions of proliferation (PCNA), apoptosis (caspase‐3, TUNEL assay), and DNA damage (γ‐H2AX) showed an identical pattern, whereas mitochondrial cytochrome C exhibited an opposite pattern compared to that of inflammation among all groups (all P < 0.001). Besides, antioxidant expressions at protein (NQO‐1, GR, and GPx) and cellular (HO‐1) levels progressively increased from SC to the combined treatment group (all P < 0.001). In conclusion, combined melatonin‐ADMSC treatment offered additive beneficial effect against SBIR injury.

Obesity suppresses circulating level and function of endothelial progenitor cells and heart function

Background and aimThis study tested the hypothesis that obesity suppresses circulating number as well as the function of endothelial progenitor cells (EPCs) and left ventricular ejection fraction (LVEF).MethodsHigh fat diet (45 Kcal% fat) was given to 8-week-old C57BL/6 J mice (n = 8) for 20 weeks to induce obesity (group 1). Another age-matched group (n = 8) were fed with control diet for 20 weeks as controls (group 2). The animals were sacrificed at the end of 20 weeks after obesity induction.ResultsBy the end of study period, the heart weight, body weight, abdominal fat weight, serum levels of total cholesterol and fasting blood sugar were remarkably higher in group 1 than in group 2 (all p<0.01). The circulating level of EPCs (C-kit/CD31, Sca-1/KDR, CXCR4/CD34) was significantly lower in group 1 than in group 2 (p<0.03) at 18 h after critical limb ischemia induction. The angiogenesis and migratory ability of bone marrow-derived EPCs was remarkably impaired in group 1 compared to that in group 2 (all p<0.01). The repair ability of aortic endothelium damage by lipopolysaccharide was notably attenuated in group 1 compared with that in group 2 (p<0.01). Collagen deposition (Sirius red staining) and fibrotic area (Massons Trichrome staining) in LV myocardium were notably increased in group 1 compared with group 2 (p<0.001). LVEF was notably lower, whereas LV end-diastolic and end-systolic dimensions were remarkably higher in group 1 than in group 2 (all p<0.001).ConclusionsObesity diminished circulating EPC level, impaired the recovery of damaged endothelium, suppressed EPC angiogenesis ability and LVEF, and increased LV remodeling.

Direct implantation versus platelet-rich fibrin-embedded adipose-derived mesenchymal stem cells in treating rat acute myocardial infarction.

BACKGROUND This study tested whether adipose-derived mesenchymal stem cells (ADMSC) embedded in platelet-rich fibrin (PRF) scaffold is superior to direct ADMSC implantation in improving left ventricular (LV) performance and reducing LV remodeling in a rat acute myocardial infarction (AMI) model of left anterior descending coronary artery (LAD) ligation. METHODS Twenty-eight male adult Sprague Dawley rats equally divided into group 1 [sham control], group 2 (AMI only), group 3 (AMI+direct ADMSC implantation), and group 4 (AMI+PRF-embedded autologous ADMSC) were sacrificed on day 42 after AMI. RESULTS LV systolic and diastolic dimensions and volumes, and infarct/fibrotic areas were highest in group 2, lowest in group 1 and significantly higher in group 3 than in group 4, whereas LV performance and LV fractional shortening exhibited a reversed pattern (p<0.005). Protein expressions of inflammation (oxidative stress, IL-1β, MMP-9), apoptosis (mitochondrial Bax, cleaved PARP), fibrosis (Smad3, TGF-β), and pressure-overload biomarkers (BNP, MHC-β) displayed a pattern similar to that of LV dimensions, whereas anti-inflammatory (IL-10), anti-apoptotic (Bcl-2), and anti-fibrotic (Smad1/5, BMP-2) indices showed a pattern similar to that of LV performance among the four groups (all p<0.05). Angiogenesis biomarkers at protein (CXCR4, SDF-1α, VEGF), cellular (CD31+, CXCR4+, SDF-1α+), and immunohistochemical (small vessels) levels, and cardiac stem cell markers (C-kit+, Sca-1+) in infarct myocardium were highest in group 4, lowest in group 1, and significantly higher in group 3 than in group 2 (all p<0.005). CONCLUSION PRF-embedded ADMSC is superior to direct ADMSC implantation in preserving LV function and attenuating LV remodeling.

Combination of adipose-derived mesenchymal stem cells (ADMSC) and ADMSC-derived exosomes for protecting kidney from acute ischemia–reperfusion injury

BACKGROUND In this study, we tested the hypothesis that a combined adipose-derived mesenchymal stem cell (ADMSC) and ADMSC-derived exosome therapy protected rat kidney from acute ischemia-reperfusion (IR) injury (i.e., ligation of both renal arteries for 1h and reperfusion for 72h prior to euthanization). METHODS AND RESULTS Adult-male SD rats (n=40) were equally categorized into group 1 (sham control), group 2 (IR), group 3 [IR+exosome (100μg)], group 4 [IR+ADMSC (1.2×10(6) cells)], and group 5 (IR-exosome-ADMSC). All therapies were performed at 3h after IR procedure from venous administration. By 72h, the creatinine level and kidney injury score were the lowest in group 1 and the highest in group 2, significantly higher in group 3 than in groups 4 and 5, and significantly higher in group 4 than in group 5 (all P<0.0001). The protein expression of inflammatory (TNF-α/NF-κB/IL-1β/MIF/PAI-1/Cox-2), oxidative-stress (NOX-1/NOX-2/oxidized protein), apoptotic (Bax/caspase-3/PARP), and fibrotic (Smad3/TGF-β) biomarkers showed an identical pattern, whereas the anti-apoptotic (Smad1/5, BMP-2) and angiogenesis (CD31/vWF/angiopoietin) biomarkers and mitochondrial cytochrome-C showed an opposite pattern of creatinine level among the five groups (all P<0.001). The microscopic findings of glomerular-damage (WT-1), renal tubular-damage (KIM-1), DNA-damage (γ-H2AX), inflammation (MPO/MIF/CD68) exhibited an identical pattern, whereas the podocyte components (podocin/p-cadherin/synaptopodin) displayed a reversed pattern of creatinine level (all P<0.0001). CONCLUSION Combined exosome-ADMSC therapy was superior to either one for protecting kidney from acute IR injury.

Intravenous administration of xenogenic adipose-derived mesenchymal stem cells (ADMSC) and ADMSC-derived exosomes markedly reduced brain infarct volume and preserved neurological function in rat after acute ischemic stroke

We tested the hypothesis that combined xenogenic (from mini-pig) adipose-derived mesenchymal stem cell (ADMSC) and ADMSC-derived exosome therapy could reduce brain-infarct zone (BIZ) and enhance neurological recovery in rat after acute ischemic stroke (AIS) induced by 50-min left middle cerebral artery occlusion. Adult-male Sprague-Dawley rats (n = 60) were divided equally into group 1 (sham-control), group 2 (AIS), group 3 [AIS-ADMSC (1.2×106 cells)], group 4 [AIS-exosome (100μg)], and group 5 (AIS-exosome-ADMSC). All therapies were provided intravenously at 3h after AIS procedure. BIZ determined by histopathology (by day-60) and brain MRI (by day-28) were highest in group 2, lowest in group 1, higher in groups 3 and 4 than in group 5, but they showed no difference between groups 3 and 4 (all p < 0.0001). By day-28, sensorimotor functional results exhibited an opposite pattern to BIZ among the five groups (p < 0.005). Protein expressions of inflammatory (inducible nitric oxide synthase/tumor necrosis factor-α/nuclear factor-κB/interleukin-1β/matrix metalloproteinase-9/plasminogen activator inhibitor-1/RANTES), oxidative-stress (NOX-1/NOX-2/oxidized protein), apoptotic (caspase-3/ Poly-ADP-ribose polymerase), and fibrotic (Smad3/transforming growth factor-β) biomarkers, and cellular expressions of brain-damaged (γ-H2AX+/ XRCC1-CD90+/p53BP1-CD90+), inflammatory (CD11+/CD68+/glial fibrillary acid protein+) and brain-edema (aquaporin-4+) markers showed a similar pattern of BIZ among the groups (all n < 0.0001). In conclusion, xenogenic ADMSC/ADMSC-derived exosome therapy was safe and offered the additional benefit of reducing BIZ and improving neurological function in rat AIS.

Innate immune response after acute myocardial infarction and pharmacomodulatory action of tacrolimus in reducing infarct size and preserving myocardial integrity

BackgroundThis study investigated the association between innate immune reaction and myocardial damage after acute myocardial infarction (AMI) and anti-inflammatory role of tacrolimus in reducing infarct size. Male mini-pigs (n=18) were equally categorized into sham control (SC), untreated AMI (by ligation of left anterior descending coronary artery), and AMI-Tacrolimus (AMI-Tac) (0.5 mg intra-coronary injection 30 minutes post-AMI). Cardiac magnetic resonance imaging (MRI) was performed at post-AMI days 2, 5 and 21 before sacrificing the animals.ResultsBy post-AMI day 21, left ventricular ejection fraction (LVEF) was lowest in untreated AMI animals, significantly higher in SC than in AMI-Tac group (all p<0.003). Infarct areas at basal, middle, and apical levels, numbers of CD14+ and iNOS+ cells in infarct area (IA) and peri-IA, and protein expression of CD14, CD68, and Ly6g from circulating inflammatory cells showed an opposite pattern compared with that of LVEF in all groups (all p<0.005). Protein expressions of MCP-1, MIP-1, TNF-α, NF-κB, iNOS, and IL-12 in IA and peri-IA exhibited an identical pattern compared to that of CD14, CD68, and Ly6g from circulating inflammatory cells (all p<0.01). Expressions of myocardial damage biomarkers in IA and peri-IA [γ-H2AX, β-myosin heavy chain (MHC), Smad3, TGF-β] were highest in AMI and higher in AMI-Tac than in SC, whereas expressions of myocardial integrity biomarkers (connexin43, mitochondrial cytochrome-C, α-MHC, BMP-2, Smad1/5) were opposite to those of damage biomarkers (all p<0.001).ConclusionInnate immune responses were markedly augmented and LVEF was significantly reduced after AMI but were remarkably improved after tacrolimus treatment.

Tissue plasminogen activator enhances mobilization of endothelial progenitor cells and angiogenesis in murine limb ischemia

BACKGROUND It has been reported that plasmin induces migration of endothelial cells. We hypothesized that tissue plasminogen activator (tPA) enhanced endothelial progenitor cell (EPC) mobilization from bone marrow (BM) into the circulation and angiogenesis in murine critical limb ischemia (CLI). METHODS Forty male B6 mice were randomly divided into group 1 (control), group 2 [control+recombinant tPA (intra-venous 4 mg/kg)], group 3 (CLI) and group 4 (CLI+tPA). RESULTS The results demonstrated higher MMP-9 activity in BM and circulatory SDF-1α level in groups 2 and 3 than in group 1, and highest in group 4 (all p<0.01) at 18 h after CLI. Compared with circulation, SDF-1α level in BM showed an opposite trend (all p<0.03). The circulating EPC (C-kit/CD31, Sca-1/KDR, CXCR4/CD34) levels at 18 h after CLI were higher in group 2 than in groups 1 and 3, and highest in group 4 (all p<0.03). EPC (C-kit/CD31, Sca-1/KDR) levels in BM were lower in group 1 than in groups 2 to 4 (all p<0.03), whereas number of CXCR4/CD34-positive EPCs in BM did not differ among the four groups at 18 h after CLI. Protein expressions of SDF-1α, CXCR4, eNOS, and VEGF, numbers of CD31+, CXCR4+, SDF-1α+, and vWF+ cells through immunofluorescent staining, numbers of small vessels (<15 μm) and blood flow measured by Laser Doppler in an ischemic area were significantly higher in group 4 than in group 3 (all p<0.005) at day 14 after CLI. CONCLUSION tPA treatment enhanced number of circulating EPCs, angiogenesis, and blood flow to ischemic tissue in a murine model of limb ischemia.