ObjectiveTo comprehensively analyze the recent advancements in the field of mesenchymal stem cells (MSCs) derived exosomes (MSCs-exosomes) in tissue repair. MethodsThe literature about MSCs-exosomes in tissue repair was reviewed and analyzed. ResultsExosomes are biologically active microvesicles released from MSCs which are loaded with functional proteins, RNA, and microRNA. Exosomes can inhibit apoptosis, stimulate proliferation, alter cell phenotype in tissue repair of several diseases through cell-to-cell communication. ConclusionMSCs-exosomes is a novel source for the treatment of tissue repair. Further research of MSCs-exosomes biofunction, paracellular transport, and treatment mechanism will help the transform to clinical application.
ObjectiveTo explore the phenotypic changes of epidermal stem cells (ESCs) differentiating into sweat glands cells (SGCs) in vitro and its mechanisms. MethodsESCs and SGCs were isolated and cultured in vitro, which were identified using immunofluorescence staining. ESCs at passage 2 were divided into 4 groups: ESCs and SGCs co-cultured by Transwell plates in group A, ESCs cultured by simply adding sweat supernatant in group B, ESCs and SGCs co-cultured on Transwell plate adding epidermal growth factor (EGF) (60 ng/mL) in group C, and ESCs and SGCs co-cultured on transwell plate adding PD98059 (10 mmol/L) in group D. The inverted microscope was used for observing the morphology of ESCs, flow cytometry for detecting ESCs positive phenotype, and Western blot for exploring mitogen-activated protein kinase/extracellular signal regulated kinase (MAPK/ERK) pathway. ResultsThe morphology observation and immunofluorescence staining suggested that cultured cells were ESCs and SGCs. The inverted phase contrast microscope observation showed that cells had similar morphological changes, with flat polygonal shape at 9 days in groups A, C, and D; cells had slow morphological change in group B, and had similar change to that of other groups at 12 days. Significant decreasing of β1-integrin expression and increasing of carcino-embryonic antigen (CEA) expression of ESCs were observed in group A when compared with group B, which was inhibited by EGF (group C) and enhanced by PD98059 (group D), and there were significant differences among groups A, C, and D (P<0.05). High level of ERK expression was displayed in 4 groups, but it was significantly lower in group B than the other 3 groups (P<0.05). The expression of phosphorylation ERK was the highest in group A and was the lowest in group C, showing significant difference among 4 groups (P<0.05). ConclusionESCs can be induced to differentiate into SGCs with the phenotypic changes under the condition of co-cultured by Transwell plates. The MAPK/ERK pathway plays a key role in the differentiation of ESCs into SGCs.
ObjectiveTo investigate the effect of burn on the fat metabolism by observing the effect of burn serum on the proliferation and adipose differentiation of 3T3-L1 preadipocytes. MethodsForty-eight male Sprague Dawley rats were randomly divided into sham burn group and burn at 1, 4, 7, 14, and 21 days groups, 8 rats in each group. The rats in burn groups were made the full-thickness thermal burns comprising 30% total body surface area. At 1, 4, 7, 14, and 21 days after burn, the serum of burn rats was collected. The rats in sham burn group were not treated as normal control. The proliferation activity of 3T3-Ll cells was detected using MTT method after treated by normal and burn serum. The burn serum having the highest proliferation inhibitory effect was chosen for subsequent study. The growth of 3T3-L1 cells in normal serum group (group A), burn serum group (group B), normal serum and adipogenic induction group (group C), burn serum and adipogenic induction group (group D) was observed using inverted microscope. After 7 days of treatment, the adipocytes was stained by oil red O and the absorbance (A) value was measured. The mRNA and protein levels of preoxisome proliferator-activated receptor γ (PPAR-γ) and lipoprotein lipase (LPL) were detected by real-time quantitative PCR and Western blot. ResultsThe proliferation ability of 3T3-L1 cells was significantly reduced in the group treated by 4-or 7-day burn serum (P<0.05), especially 7-day burn serum treatment group (P<0.05). Under inverted microscope, the cell morphology in group A and group B had no obvious change, but a large number of fat cells were observed in group C and a few were observed in group D. The positive or weak positive oil red O staining was observed in group C or group D, respectively. The cell counting and A value were significantly higher in group A than in group B, and in group C than in group D (P<0.05). The mRNA level of PPAR-γ in group B was significantly reduced when compared with that in group A (P<0.05). No significant difference was found in LPL mRNA levels and protein levels of PPAR-γ and LPL between group A and group B (P>0.05). The mRNA and protein levels of PPAR-γ and LPL were significantly attenuated in group D when compared with those in group C (P<0.05). ConclusionThe adipose differentiation of 3T3-L1 preadipocytes can be significantly reduced after treated by 7-day burn serum of rat.
ObjectiveTo investigate the effect of burn on brown adipose tissue (BAT) in BALB/c mice. MethodsForty 3-4 months old male BALB/c mice with initial body weight of (20±3) g were randomly divided into control group and burn group (n=20).BALB/c mice in burn group were subjected to a 30% total body surface area (TBSA) full-thickness thermal injury.BALB/c mice in control group were not treated.The body weight and temperature were observed before and after burn.At 7 days after burn,morphological changes of white adipose tissue (WAT) and BAT were observed,the gene and protein expressions of uncoupling protein 1 (UCP-1) were detected. ResultsThere was no significant difference in the body weight and body temperature before burn (P>0.05).At 1,2,3,and 4 weeks after burn,the body weight was significantly lower in burn group than in control group (P<0.05).At 1,2,3,and 7 days after burn,the body temperature was significantly higher in burn group than in control group (P<0.05).At 7 days after burn,the weight of WAT was significantly reduced,and the weight of BAT was significantly increased in burn group (P<0.05); WAT and BAT cells became smaller,cell number increased,the cytoplasm and mitochondria appeared as compact.The UCP-1 gene and protein expressions of burn group were significantly higher than those of control group (P<0.05). ConclusionBAT plays an important role in burn-induced hypermetabolism.