Objective To evaluate the therapeutic effect of poloxamer hydrogel loaded with exosomes derived from human dental pulp stem cells genetically modified with human hepatocyte growth factor against radiation skin injuries.Methods Human dental pulp stem cells derived exosomes(DPSC-Exo)and hepatocyte growth factor modified DPSC-Exo(HGF-DPSC-Exo)were extracted via ultracentrifugation separation,identified in terms of particle size and morphology,and analyzed separately by means of nanoparticle tracking analysis and scanning electron microscopy(SEM),while exosome marker proteins were determined by Western blot.Then,the effect of exosomes on radiation-damaged skin cells was assessed.The poloxamer hydrogel was prepared and its safety was evaluated with CCK-8.A mouse model of injury combined with radiation injury was established,and the therapeutic effect of hydrogel loaded with exosomes was determined based on wound size,HE and Masson staining.Furthermore,the underlining therapeutic mechanism was explored with Tunnel assay,malondialdehyde content and peroxidase activity.Results The diameter exosomes ranged from 30 to 150 nm and their morphology was a disc-shaped vesicle under SEM.Moreover,CD9,CD63 and TSG101 were expressed.The results of cellular experiments showed that exosomes significantly promoted the proliferation and migration of radiation-damaged skin keratinocytes and fibroblasts,and reduced their apoptosis.HGF modification enhanced the healing effect of exosomes.Poloxamer hydrogel showed good temperature-sensitive properties and biocompatibility.The results of animal experiments showed that exosomes significantly accelerated the healing of radiation-combined injuries in mice,inhibited inflammatory infiltration and mitigated collagen deposition in the wound.Interestingly,the healing effect in the group treated with hydrogel loaded with exosomes was the best.The underlining mechanism was possibly related to promotion of cell proliferation and inhibition of apoptosis and oxidative stress.Conclusion A novel poloxamer hydrogel loaded HGF-DPSC-Exo has been prepared and its therapeutic effect against radiation combined injury has been proved,thus providing a new strategy for the treatment of radiation skin injury in clinic.

Objective To explore the effect and mechanism of berberine combined with curcumin on ath-erosclerosis(AS)by mediating M1 macrophages polarization.Methods M1-type macrophages were obtained from mouse mononuclear macrophages(RAW264.7)induced by lipopolysaccharide(LPS,100 ng/mL)and interferon(IFN)-γ(20 ng/mL).A cell model was established.The cells were divided into a control group,model group,berberine group,curcumin group and berberine plus curcumin group.Concentrations of berberine and curcumin were detected by CCK-8 assay.The expression levels of M1-type macrophage markers iNOS,TNF-α,CXCL9 and p-STAT6/STAT6 in macrophage supernatant were detected by ELISA.Levels of iNOS,TNF-α and CXCL9 mRNA were detected by RT-PCR.Levels of iNOS,STAT6 and p-STAT6 proteins in each group were detected by Western blot.After down-regulation of STAT6 level by siRNA technology,expression of p-STAT6 protein was detected by Western blot.Expression levels of iNOS,TNF-α,CXCL9 and p-STAT6 were detected by ELISA.Results In the polarization of M1 macrophages induced by LPS and IFN-γ,berberine(25 μmol/L)and curcumin(20 μmol/L)were the best concentrations as compared with other drug concentration groups,and neither alone nor combined use could significantly inhibit the viability of RAW264.7 cells(P<0.05).As compared with the normal group,iNOS,TNF-α and CXCL9 mRNA and protein levels were increased in the model group,while P-STAT6/STAT6 levels were decreased,with statistical differences(P<0.05).As compared with the model group,iNOS,TNF-α and CXCL9 mRNA and protein levels in the berberine group,curcumin group,and berberine plus curcumin group were decreased,while P-STAT6/STAT6 levels were increased,and the changes were more obvious in berberine plus curcumin group,with statistical difference(P<0.05).After transfection of STAT6 siRNA in M1 macrophages in the berberine plus curcumin group,P-STAT6 levels were down-regulated,while expressions of iNOS,TNF-α and CXCL9 were up-regulated,with statistical differences(P<0.05).Conclusions Both berberine and curcumin can inhibit the activity of M1-type macrophages and reduce inflammatory response.The action of berberine combined with curcumin is more advantageous than that of either drug alone,which may be the main mechanism of action through activation of STAT6.

BACKGROUND:Skin damage caused by radiation therapy and nuclear accidents is still a serious medical problem.It is difficult to achieve effective treatment results with single prevention and treatment methods.It is an important research direction to find new comprehensive treatment methods. OBJECTIVE:To observe the protective effect and the underlying mechanism of 1,2-propanediol combined with hepatocyte growth factor-modified exosomes derived from dental pulp stem cells on human epidermal radiation damage cell models. METHODS:(1)After infection of human dental pulp stem cells using recombinant adenovirus of human hepatocyte growth factor gene,exosomes,i.e.,Ad.HGF DPSC-Exo,were isolated with ultracentrifugation.(2)HaCat cells were irradiated with X-ray.The cells were treated with 1,2-propanediol before irradiation and Ad.HGF DPSC-Exo after irradiation.Cell proliferative activity was determined by CCK-8 assay.Cell apoptosis was detected by flow cytometry.Cell migration was detected by cell scratch assay.The expression levels of P21 and P53 were detected by PCR. RESULTS AND CONCLUSION:1,2-Propanediol,Ad.HGF.DPSC-Exo,Ad.HGF.DPSC-Exo + 1,2-propanediol could significantly improve the growth inhibition of HaCaT cells,reduce cell apoptosis,elevate cell proliferation and migration,and exhibit a good radiation protection effect.Moreover,the combined effect of Ad.HGF.DPSC-Exo + 1,2-propanediol was better.Furthermore,Ad.HGF.DPSC-Exo + 1,2-propanediol alleviated the cellular G2/M phase block and decreased the expression of cell cycle genes P53 and P21.In conclusion,1,2-propanediol pretreatment combined with Ad.HGF.DPSC-Exo had significant protective effects on radiation-induced HaCaT cell injury and it provided novel ideas and potential methods for the prevention and treatment of radiation-induced skin damage.

OBJECTIVE To study the protective effect and possible mechanism of soybean isoflavones against threatened miscarriage rats. METHODS Female mice were selected to promote estrus and mate with male mice. After pregnancy， they were randomly divided into normal group （purified water， i.g.， n＝10）， model group （purified water， i.g.， n＝9）， positive control drug group （progesterone 4 mg/kg， i.m.， n＝9）， low-， medium- and high-dose soybean isoflavone groups （25， 50 and 100 mg/kg， i.g.， n＝10）. Except for the normal group， the rest were given mifepristone+misoprostol on the 8th day of pregnancy to establish threatened miscarriage model， and then given purified water or drugs， once a day， on days 1-7 and 9-12 of pregnancy， respectively. At 14 days of pregnancy， the rates of fetal protection were counted. Serum levels of β-human chorionic gonadotrophin （β-HCG） and progesterone （P） in rats were detected. Pathological and morphological changes in rat placenta and decidua tissues were observed， and the apoptosis indexes of cells were detected； mRNA and protein expressions of factor of apoptosis related （Fas）， factor of apoptosis related ligand （FasL）， proliferating cell nuclear antigen （PCNA） and heparin binding epidermal growth factor （HB-EGF） were determined in placenta tissues， and mRNA and protein expressions of Fas， PCNA and HB-EGF in decidua tissues were detected. RESULTS In the model group， the placental tissues of rats were hyperemia and dilatation， with fewer and irregular blood vessels； severe stromal edema，inflammatory cell infiltration and iron-choledrin depositionwere observed. Compared with model group， the fetal survival rates， serum levels of β-HCG and P， the expressions of PCNA and HB-EGF mRNA and proteins in the placenta and decidua tissue of soybean isoflavone groups increased significantly （P＜ 0.05）， while pathological changes were improved significantly； cell apoptosis index in the placenta and decidua tissue， the expressions of Fas， FasL mRNA and proteins in the placenta and Fas mRNA and protein in the decidua tissue decreased significantly （P＜0.05）. The effect of soybean isoflavones was dose-dependent （P＜0.05）. CONCLUSIONS Soybean isoflavone has protective effect on threatened miscarriage， the mechanism of which is related to down-regulating the expressions of Fas and FasL mRNA and protein at the maternal-fetal interface， and up-regulating the expressions of mRNA and protein of PCNA and HB- EGF.

BACKGROUND: The effect of arteriosclerotic intracranial arterial vessel wall enhancement (IAVWE) on downstream collateral flow found in vessel wall imaging (VWI) is not clear. Regardless of the mechanism underlying IAVWE on VWI, damage to the patient's nervous system caused by IAVWE is likely achieved by affecting downstream cerebral blood flow. The present study aimed to investigate the effect of arteriosclerotic IAVWE on downstream collateral flow. METHODS: The present study recruited 63 consecutive patients at the Second Hospital of Hebei Medical University from January 2021 to November 2021 with underlying atherosclerotic diseases and unilateral middle cerebral artery (MCA) M1-segment stenosis who underwent an magnetic resonance scan within 3 days of symptom onset. The patients were divided into 4 groups according to IAVWE and the stenosis ratio (Group 1, n = 17; Group 2, n = 19; Group 3, n = 13; Group 4, n = 14), and downstream collateral flow was analyzed using three-dimensional pseudocontinuous arterial spin labeling (3D-pCASL) and RAPID software. The National Institutes of Health Stroke Scale (NIHSS) scores of the patients were also recorded. Two-factor multivariate analysis of variance using Pillai's trace was used as the main statistical method. RESULTS: No statistically significant difference was found in baseline demographic characteristics among the groups. IAVWE, but not the stenosis ratio, had a statistically significant significance on the late-arriving retrograde flow proportion (LARFP), hypoperfusion intensity ratio (HIR), and NIHSS scores ( F = 20.941, P <0.001, Pillai's trace statistic = 0.567). The between-subject effects test showed that IAVWE had a significant effect on the three dependent variables: LARFP ( R2 = 0.088, F = 10.899, P = 0.002), HIR ( R2 = 0.234, F = 29.354, P <0.001), and NIHSS ( R2 = 114.339, F = 33.338, P <0.001). CONCLUSIONS: Arteriosclerotic IAVWE significantly reduced downstream collateral flow and affected relevant neurological deficits. It was an independent factor affecting downstream collateral flow and NIHSS scores, which should be a focus of future studies. TRIAL REGISTRATION ChiCTR.org.cn, ChiCTR2100053661.
Humans ; Constriction, Pathologic/pathology* ; Magnetic Resonance Imaging/methods* ; Middle Cerebral Artery/pathology* ; Tomography, X-Ray Computed