Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinases during wound healing in diabetic rats

AIM: To investigate the imbalance between the expression of metalloproteinases (MMPs) and that of tissue inhibitors of metalloproteinase (TIMPs) during wound healing in diabetic rats. METHODS: Diabetic rats were induced with streptozotocin. All rats were maintained for 6 weeks. A full-thickness excisional wound was created on the back of each rat. Every group was randomly divided into 3 subgroups of 7 rats: 3 d group, 7 d group, 14 d group and animals were killed at 3rd, 7th and 14th day. Routine pathological examination, Masson′s trichrome staining and immunohistochemistry were made to calculate the score of epidermal and dermal regeneration, granulation tissue thickness, angiogenesis, matrix density, and infiltrated cells at different time points. RT-PCR and Western blotting were used to detect the expression of mRNA and protein of MMP-9 and TIMP-1 in the skin at those time points. RESULTS: Six weeks after streptozotocin treatment, Three days after injury, the wound healing rate of normal rats was faster than that of diabetic rats. From 3rd to 14th day, there were a lot of fibroblast and macrophage in normal skin, while few such cells were observed in diabetic skin. The other histological scores in normal skin were higher than those in diabetic rats at 7th and 14th day. Both MMP-9 and TIMP-1 had minimally detectable levels before wounding but exhibited rapid, significantly large increases within 3 d after wounding. Subsequently, they showed a rapid decline by 14 d. The relative values of expression of MMP-9 mRNA and protein in diabetic group were higher than those in normal group at different time points. However, the values of TIMP-1 mRNA and protein in diabetic group were significantly lower than those in control group. Significant difference was observed between two groups with the ratio of MMP-9/TIMP-1, higher in diabetic group than that in normal group. CONCLUSION: Abnormal reepithelialization, angiogenesis, inflammatory cell infiltration, collagen fibers generation, granulation tissue deposition, seem to be the basic histopathology that delays wound healing. The imbalance between MMPs and TIMPs in diabetic skin tissue before and after injury may be one of the important reasons of these alterations of histopathology.     

Apoptosis in diabetic foot ulcers and human fibroblast cells treated with AGEs

AIM：To investigate cell apoptosis in diabetic foot ulcers and the effect of advanced glycosylation end products (AGEs) on apoptosis in human fibroblast cells. METHODS：Diabetic foot patients (n=18) and 18 age-matched non-diabetic controls were recruited. The clinical and biochemical features were compared by statistics methods. Skin biopsies were obtained from foot. Cleaved caspase-3 was measured by immunohistochemistry using the technique of streptavidin-biotin complex (SABC) staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique was used to detect apoptosis of the skin tissues. Human primary foreskin fibroblasts were isolated and cultured in the presence of 5.6 mmo/L glucose, 25 mmo/L glucose, fluctuant glucose (changing the glucose from 5.6 mmo/L to 25 mmo/L every 8 h) or AGEs (150 mg/L, containing 5.6 mmo/L glucose). After 72 h treatment, Western blotting was used to determine the levels of the apoptotic protein cleaved-caspase-3. Other cells were trypsinized, washed with cold PBS and incubated with PI and Annexin V-FITC, then analyzed by flow cytometry to detect cell apoptosis. RESULTS：Diabetic patients had higher levels of fasting blood glucose (FBG), 2-hour postprandial blood glucose (2 h PBG) and glycosylated hemoglobin A1c (HbA1c), and longer wound duration. The protein level of cleaved caspase-3 was significantly higher in diabetic group, suggesting that apoptosis was increased in diabetic skin tissues. TUNEL analysis showed that apoptotic index was higher in diabetic group compared with that in non-diabetic group (8.4%±1.5% vs 3.8%±08%), which further confirmed that cell apoptosis was increased in diabetic foot tissues. In human fibroblasts, the levels of cleaved caspase-3 in normal group, sustained high glucose group, fluctuant high glucose group and AGEs group were 080±0.13, 1.22±0.18, 1.46±0.32 and 1.83±0.25, respectively. The apoptotic rates detected by flow cytometry were 2.43%±0.19%, 2.89%±0.51%, 3.99%±0.24% and 6.83%±0.36%, respectively. Both the level of cleaved caspase-3 and the apoptotic rate in AGEs group were higher than those in normal glucose group and sustained high glucose group. CONCLUSION：Increased apoptosis in diabetic foot ulcers is one of the most important reasons for impaired wound healing. As compared to sustained high glucose and glucose fluctuations, AGEs induce greater apoptosis in human fibroblast cells.     

Effects of Coriaria sinica Maxim’s extract on burn wound healing and scar hyperplasia in rats based on ILK signaling pathway

AIM: To explore the mechanism of Coriaria sinica Maxim’s extract (CSME) promoting burn wound healing in the early stage and inhibiting excessive scar hyperplasia in the later stage, based on the signaling pathways, such as transforming growth factor-β₁ (TGF-β₁) regulated by integrin-linked kinase (ILK) and ILK regulated by PI3K/AKT. METHODS: Female SD rats (n=180; 180~200 g) were randomly divided into 6 groups: normal control (NC) group, vaseline (VL) group, silver sulfadiazine (SS) group and low-, medium- and high-dose of CSME (CSME-L, CSME-M and CSME-H) groups, with 30 rats in each group. Except for the rats in NC group, VL, SS, and 3 doses of CSME were applied to the wound surface of the rats in the corresponding groups every day after II° burn model was made on their waist-back in the condition of chloral hydrate anesthesia. To calculate the healing rate (HR), 10 rats in each experimental group were randomly selected to remove their wound skin for observing the pathologic change, detecting the expression of related proteins by Western blot and RT-qPCR, and checking the collagen shrinkage (SK) by fibroblast culture at the 7th, 14th, and 21st days. RESULTS: The expression of ILK, fibronectin (FN), TGF-β₁, α-smooth muscle actin (α-SMA) and integrin-β₁ (ITG-β₁) at protein and mRNA levels in wound skin of CSME groups was stronger than that in VL group and SS group at the 7th day in a dose-dependent manner, but weaker than that in VL group and SS group at the 21st day (P<0.05). Meanwhile, the protein and mRNA expression of collagen type I (Col I) in CSME groups was stronger than that in VL group and SS group from the 7th day to the 14th day, but weaker than that in VL group and SS group at the 21st day in a dose-dependent manner (P<0.05). However, the protein and mRNA expression of collagen type III (Col III) in CSME groups was weaker than that in VL group and SS group from the 7th day to the 14th day, but stronger than that in VL group and SS group at the 21st day in a dose-dependent manner (P<0.05). The SK of fibroblasts in VL group and SS group was increased continuously over time and reached its peak at 96 h. SK in CSME groups was only higher than that in VL group and SS group at 24 h and 48 h in a dose-dependent manner, but lower than that in VL group and SS group at 96 h (P<0.05). CONCLUSION: CSME promotes burn wound healing in the early stages and inhibits the scar hyperplasia in the later stages. The mechanisms may be related to its multicomponents or multiple-targets to intervene in the signaling pathways such as TGF-β₁ regulated by ILK and ILK regulated by PI3K/AKT. It may also be related to the ratio of Col I and Col III expression.     

Effect of lentivirus-mediated DKK3 overexpression on apoptosis of hypertrophic scar fibroblasts

AIM:To investigate the effect of lentivirus-mediated DKK3 overexpression on the apoptosis of hypertrophic scar fibroblasts. METHODS:Human hypertrophic scar fibroblasts were isolated and cultured in vitro. The cells were divided into control group, vector (negative control lentivirus infection) group and DKK3 (pcDNA3.1-DKK3 lentivirus infection) group. The overexpression effect was determined by RT-qPCR and Western blot. The cell viability was measured by MTT assay. The apoptosis was analyzed by flow cytometry. The protein levels of cleaved caspase-9, collagen type Ⅱ (COL Ⅱ), COL I and cleaved caspase-3 in the cells, and cytochrome C in the cytoplasm and mitochondrion were detected by Western blot. RESULTS:After transfection with pcDNA3.1-DKK3, the expression of DKK3 at mRNA and protein levels was increased in the hypertrophic scar fibroblasts (P<0.05). The viability of hypertrophic scar fibroblasts in DKK3 group was decreased, and the apoptotic rate was increased. The protein levels of cleaved caspase-9 and cleaved caspase-3 were increased in the cells, and the protein levels of COL Ⅱ and COL I were decreased. The protein level of cytochrome C was increased in the cytoplasm, while the protein level of cytochrome C in the mitochondrion decreased. Compared with vector group, these differences were statistically significant (P<0.05). CONCLUSION:Lentivirus-mediated DKK3 overexpression induces apoptosis and reduces collagen synthesis in the fibroblasts from hypertrophic scars.     

Localization and expression of TGF-β1,2 in fetal and adult skins

AIM:To explore the localization and expression of transforming growth factor-β_1,2 (TGF-β_1,2) and alpha-smooth muscle actin (α-ASMA) in fetal and adult skins. METHODS:Skins of 15 cases of fetuses with different gestational ages and 5 cases of adults were taken, embedded with paraffin wax, and sectioned. Immunohistochemistry method and pathological method were used to detect the expression intensity and distribution of TGF-β_1,2 and α-ASMA. RESULTS: Positive immunohistochemical signals of TGF-β_{1, 2} and α-ASMA were found in fetal and adult skins. In skins derived from young fetus, the positive signals of these three proteins were very weak. Along with the increment in gestational age, the positive cellular rates of TGF-β_1,2M and α-ASMA were elevated progressively. In elder fetal and adult skins, TGF-β_1,2 were mostly distributed in epidermal cells, endothelial cells and some fibroblasts, while α-ASMA was mainly located in myofibroblasts and sweat gland epithelial cells. CONCLUSION:The endogenous TGF-β_1,2might be involved in the cutaneous development at embryonic stage, in the cutaneous structure maintenance at adult stage, and in the wound healing after injury.     

Histochemical changes of skin in diabetic rats

AIM: To explore the histochemical changes of diabetic skin and the pathogenesis of impaired wound healing in diabetes. METHODS: 54 male Sprague-Dawley (SD) rats weighing 200-220 g were randomized into control and STZ-induced diabetic groups. The shaved skin specimens from the back of rats were collected in 4, 8 and 12 weeks post STZ-induction, respectively. Hematoxylin-eosin dye was used for histological examination. Meanwhile, the skin glucose contents were measured by Beckman’s autoanalyzer. Skin AGEs concentrations were assessed by detecting total fluorescence in tissue collagen and immunohistochemistry assay. RESULTS: The skin thickness in diabetic animals was decreased, with the features of multilayer epithelium structure disappeared in epidermis and collagen fibers atrophied, swollen and degenerated in dermis; The inflammatory responses in the dermis of diabetic animals were increased obviously. The results also revealed that skin glucose contents in diabetic rats ［(2.64±1.03）mg/g skin］ were 2-3 times higher than those in the controls ［(0.74±0.33)mg/g skin］ (P<0.01). The collagen fluorescence and AGEs positive expressions in diabetic skin enhanced significantly when compared with age-matched controls over the whole experimental course (P<0.05). CONCLUSIONS: A histochemical changes had already been occurred in diabetic skin before injury, which may be result from the local biochemical factors such as high concentrations of glucose and AGEs. These might be an important mechanism in the pathogenesis of impaired wound healing in diabetes.     

miR-129-3p targets Smad3 to inhibit viability and migration of NIH3T3 cells during TGF-β-induced transformation into myofibroblasts

AIM: To explore the effects of microRNA-129-3p (miR-129-3p) on the viability and migration of NIH3T3 cells during transforming growth factor-β (TGF-β)-induced transformation into myofibroblasts and the underlying molecular mechanisms. METHODS: RT-qPCR was used to examine the relative expression of miR-129-3p in renal cell carcinoma (RCC)-adjacent tissues and fibrotic renal tissue. NIH3T3 cells were stimulated with TGF-β to transform into myofibroblasts, and miR-129-3p expression level was detected. After transfection with miR-129-3p mimics for 48 h in vitro, the cell viability was measured by MTT assay, the protein expression level of Ki-67 was determined by Western blot, and the cell migration was observed by wound healing assay. The direct target of miR-129-3p was predicted by online database TargetScan and confirmed by dual-luciferase reporter assay. The expression level of target protein was further confirmed by Western blot. RESULTS: Compared with the RCC-adjacent tissues, the expression of miR-129-3p was down-regulated in fibrotic renal tissue (P<0.01). In TGF-β-induced NIH3T3 cell transformation into myofibroblasts, the expression of miR-129-3p was also decreased (P<0.01). Transfection with miR-129-3p mimics followed by TGF-β stimulation in the NIH3T3 cells inhibited the viability, Ki-67 expression and migration. TargetScan analysis showed miR-129-3p had binding sites in the 3'-UTR of Smad3, which was confirmed by dual-luciferase reporter assay. The results of Western blot further confirmed that miR-129-3p affected the expression of Smad3. CONCLUSION: miR-129-3p inhibits the viability and migration ability of NIH3T3 cells during TGF-β-induced transformation into myofibroblasts by directly targeting Smad3.     

Coriaria sinica Maxim extract promotes burn wound healing in rats

AIM：To investigate the effects of Coriaria sinica Maxim extract (CSME) on burn wound healing in rats. METHODS：Forty male SD rats were randomly divided into normal saline (NS) group, white petrolatum jelly (WPJ) group, silver sulfadiazine (SSD) group and CSME group. After the animals were anesthetized, the skin of their backs was burnt to induce deep Ⅱ degree burn wounds. These wounds were treated respectively for 21 d by covering dressings with NS, WPJ, SSD and CSME, respectively. On the 1st, 3rd, 7th, 14th and 21st days, after the clinical symptoms of the animals and conditions of the wounds such as the epithelization rate, crusting and hair growth were observed, the wound tissues were also taken for histological examination. The content of malondialdehyde (MDA), the activity of superoxide dismutase (SOD), and the expression of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and collagen were detected. RESULTS：On the 21st day after burn, the new epithelial tissues in CSME group extraordinarily　developed and a great deal of hair also grew along the margin of the wounds. The epithelization rate of the wound tissues in CSME group was higher than that in other groups. There was rare new hair in the center of the wound area in SSD group, but intensive new hair was observed in CSME group. On the 14th day and 21st day after burn, multilayer of epithelial cells was entirely covered with the wound area in CSME group. Some of the healing signs, such as sufficient differentiation and a line up in order of collagen fibers, clear tissue structure, exceedingly active hyperplasia of sebaceous glands and hair follicles, and so on, were also observed in the wound area in CSME group. From the 1st day to 21st day after burn, the increase in protein expression of EGF and bFGF in the wound tissues was significantly higher than that in other groups in the early stage, which was quickly decreased and was obviously lower than other groups in the latter stage. The mRNA expression ratio of type I and III collagens in SSD group was significantly higher than that in other groups, while that in CSME group was significantly lower than that in other groups. CONCLUSION：CSME promotes burn wound healing without scarring. The effects of CSME are likely to associate with the expression reinforcement of EGF and bFGF at mRNA and protein levels in the early stage, and associate with the expression inhibition of them later. Moreover, CSME may also inhibit the mRNA expression of type I collagen and promote the synthesis of type III collagen in the wound tissues of burn.     

Tumor necrosis factor-related apoptosis-inducing ligand participates in injury of vascular endothelial cells induced by rapamycin in vitro

AIM: To investigate the effects of rapamycin on apoptosis, proliferation, migration ability and tumor related apoptosis inducing ligand(TRAIL) in cultured human umbilical vein endothelial cells(HUVECs). METHODS: Cultured HUVECs were treated with rapamycin at the concentrations of 0, 1, 10 and 100 μg/L for 24 h. The cell proliferation was measured by CCK-8 method. The cell migration ability was detected by Transwell chambers and wound healing test. The apoptotic index of HUVECs was quantitatively determined by measuring the activation of caspase-3. The morphological changes of the apoptotic cells were observed by DAPI staining. The expression of TRAIL was detected by Western blotting. RESULTS: A 24 h-incubation with rapamycin(1-100 μg/L) caused significant cell loss associated with the increase in apoptosis, as quantified by the determination of caspase-3 activity(P<0.01) in HUVECs. Obvious apoptotic morphology was observed by DAPI staining in HUVECs incubated with rapamycin. Rapamycin at the concentrations of 1-100 μg/L also impaired the migration ability of HUVECs(P<0.01). In addition, rapamycin(10-100 μg/L) inhibited the proliferation of HUVECs, whereas rapamycin at 1 μg/L had no such effect(P<0.01). Rapamycin(10-100 μg/L) also induced TRAIL expression in a dose-dependent manner(P<0.01). CONCLUSION: Rapamycin induces apoptosis, and inhibits the proliferation and migration of HUVECs. The up-regulation of TRAIL might be related to the injury of vascular endothelial cells caused by rapamycin.     

Effects of hydrogen sulfide on wound healing of skin ulcer in diabetic rats

AIM: To study the effect of hydrogen sulfide on wound healing of skin ulcer in diabetic rats.METHODS: Male SD rats were randomly divided into 3 groups, including non-diabetic control(NDC) group, untreated diabetic control(UDC) group, and treated diabetic administration(TDA) group. Diabetic rats were induced by intraperitoneal injection of streptozotocin(STZ). After 1 week, wound healing model was prepared by making a round incision(2.0 cm in diameter) on the dorsal skin in full thickness. The rats from TDA group received 2% sodium bisulfide ointment on the skin ulcer wound, and the animals from UDC and NDC groups received control cream. After 21 d of treatment with sodium bisulfide, blood samples were collected for biochemical analysis, including prothrombin time(PT), thrombin time(TT), and fibrinogen(FIB) in plasma, as well as the activity of superoxide dismutase(SOD) and the content of malondialdehyde(MDA) in the serum. White blood cells(WBC) and lymphocytes were also counted. Granulation tissues from the wound were processed for histological examination and Western blot analysis was used to detect heme oxygenase-1(HO-1) and tumor necrosis factor α(TNF-α) expression.RESULTS: Compared with UDC group, sodium bisulfide treatment accelerated wound healing of skin ulcer(P<0.01), and increased the activity of SOD in serum(P<0.01) in the diabetic rats. The declined number of WBC and lymphocytes, prolonged PT and TT, and decreased FIB levels in rats treated with sodium bisulfied were also confirmed. Pathological section showed that there were inflammatory cell infiltration, and irregular and loose fibril alignment in the granulation tissue of rats from the UDC group, but there were regular fibril alignment and increased angiogenesis in the granulation tissue of rats from the TDA group(P<0.05). Furthermore, sodium bisulfide treatment raised HO-1 protein expression, and decreased TNF-α protein expression in the diabetic rats.CONCLUSION: Hydrogen sulfide accelerates the wound healing of skin ulcer in the rats with diabetes. The beneficial effect of H₂S may be associated with formation of granulation, anti-inflammation, and antioxidation.     

Correlation between Helicobacter pylori infection and apoptosis in gingival tissues

AIM:To observe the effects of Helicobacter pylori(Hp) on the apoptosis of human gingival tissue.METHODS:Gingival tissue samples were taken from 30 patients without chronic periodontitis,and Hp was detected by conventional PCR.The apoptosis of the gingivival cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to analyze the correlation between Hp infection and apoptosis of the gingival tissues.RESULTS:The Hp positive detections were 12 in the 30 patients without periodontitis,so the positive rate of Hp in the gingival tissue samples was 40%.The gingival tissue showed a large number of apoptotic cells in Hp positive group,and less apoptotic cells in Hp negative group.The apoptotic index in Hp positive group (0.498±0.092) was significantly higher than that in normal group (0.207±0.053)(P<0.05).CONCLUSION:Hp might play a role in the apoptosis of gingival tissues.     

Effects of high-glucose on proliferation and apoptosis in endothelial progenitor cells of type 2 diabetes mellitus

AIM: This study aimed to observe the effects of high-glucose on proliferation and apoptosis of endothelial progenitor cells (EPCs) in type 2 diabetes mellitus patients,and tried to elucidate their possible role.METHODS: Various concentrations of glucose were added to the culture system of EPCs from 25 cases of type 2 diabetes mellitus patients (DM group) and 25 cases of healthy volunteers (control group).MTT assays were used to detect the proliferative rates.Annexin-V/PI stains were used to detect the apoptotic rates,and RT-PCR to detect the expression level of bcl-2 and bax.RESULTS: Proliferative activity of EPCs in both control group and DM group were attenuated when concentration of glucose was 33 mmol/L,while apoptotic rates increased.No significant change of proliferative rate and apoptotic rate of EPCs in DM group and control group in the presence of 5 mmol/L glucose was observed.The expression level of bax of EPCs in both DM group and control group increased while expression level of bcl-2 did not change much in the presence of 33 mmol/L glucose.CONCLUSION: High-glucose attenuates proliferative activity of EPCs and increases the apoptotic rate.Upregulation of bax may be its possible role.     

Expression of connective tissue growth factor in the renal tissue of rats with unilateral ureteral obstruction

AIM: To detect the expression of connective tissue growth factor (CTGF), transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) in rat unilateral ureteral obstructive (UUO) nephropathy animal model, and to observe the kinetic changes at different stages of firosis. METHODS: Male SD rats were subjected to either left ureteral ligation or sham operation, then killed at 3, 7, 14, 21 or 28 days after UUO or sham operation (n=6 at each time point). HE, Masson or PAS staining were applied to the renal tissue sections. The extent of tubulointerstitial injury was determined by Banff classification. RESULTS: The extent of tubulinterstitial fibrosis became serious with the time of obstruction. Tubules were mostly atropic and replaced by proliferative fibrous tissue at day 28. The expression of CTGF and α-SMA were consistent with the damage of tubulointerstitial. The positive correlation among CTGF or α-SMA and the tubulointerstitial injury scores were significant. The expression of TGF-β1 came to peak at day 7 to 14, and gradually decreased at day 21 and 28. CONCLUSION: These results indicate that the expression of CTGF may be upregulated by TGF-β in UUO rats, and CTGF may be involved in tubulointerstitial fibrosis through the development of myofibroblasts.     

Effect of HDAC1 silencing on apoptosis of squamous cell carcinoma of skin via regulating STAT3 signaling pathway

AIM: To investigate the effect of histone deacetylase 1 (HDAC1) silencing on apoptosis of squamous cell carcinoma of skin. METHODS: Skin squamous cell carcinoma A431 cells were transfected with HDAC1 small interfering RNA (HDAC1 siRNA) or small interfering RNA negative control (siRNA NC). The expression levels of HDAC1 in transfected cells were detected by RT-PCR and Western blot. The cell viability was measured by MTT assay, and the apoptosis was analyzed by flow cytometry. The protein levels of STAT3, p-STAT3 and cleaved caspase-3 were determined by Western blot. The inhibitor of STAT3 signaling pathway was used to treat the A431 cells transfected with HDAC1 siRNA. The cell viability was detected by MTT assay, the apoptosis was analyzed by flow cytometry, and the protein levels of STAT3, p-STAT3 and cleaved caspase-3 were determined by Western blot. RESULTS: HDAC1 siRNA inhibited the expression of HDAC1 at mRNA and protein levels in the A431 cells. After interfering with the expression of HDAC1, the cell viability and the protein level of p-STAT3 in the cells decreased, while the apoptotic rate and the protein level of cleaved caspase-3 in the cells were increased. After treatment with the inhibitor of STAT3 pathway, the viability of A431 cells transfected with siRNA and the protein level of p-STAT3 decreased, while the apoptotic rate and the protein le-vel of cleaved caspase-3 in the cells were increased. CONCLUSION: Interference with HDAC1 expression may regulate the STAT3 signaling pathway to inhibit the viability of skin squamous cell carcinoma cells, thus promoting the apoptosis of squamous cell carcinoma of skin.     

Mutation of Npc1 gene causes abnormal lipid metabolism to induce apoptosis of renal cells and promote fibrosis

AIM: To investigate the dysfunction of renal cell and tissue in Npc1 mutant mice, in order to provide support for the treatment of Niemann-Pick disease type C1 (NPC1) patients.METHODS: The kidneys of wild-type (Npc1^+/+) and Npc1 mutant (Npc1^-/-) mice on postnatal day 60 were isolated. HE staining was performed to examine the morphological changes of the renal tissues. Oil red O staining was used to examine the lipid deposition in the renal tissues. The apoptosis of the renal cells was detected by TUNEL staining. The expression of apoptosis-related proteins in the renal tissue was determined by Western blot, and immunofluorescence was performed to examine the expression of α-smooth muscle actin (α-SMA) and vimentin in the renal tissues. RESULTS: Compared with Npc1^+/+ mice, the morphological observation showed obvious vacuoles and no lipid deposition in the renal tissue of Npc1^-/- mice. Subsequently, TUNEL staining showed significant increase in the apoptotic cells in the renal tissue of Npc1^-/- mice (P<0.01), and the expression levels of Bax and Bad were up-regulated in the renal tissues of Npc1^-/- mice (P<0.01), but Bcl-2 was down-regulated (P<0.05). Furthermore, the expression of α-SMA and vimentin was significantly up-regulated in the renal tissues of Npc1^-/- mice (P<0.01). CONCLUSION: Npc1 gene mutation causes abnormal lipid metabolism in the renal cells, which induces the apoptosis of renal cells and promotes the fibrosis of renal tissue.     

Effects of angiotensin II type 2 receptor blocker on wound healing in a mouse skin full-thickness injury model

AIM：To observe the effect of angiotensin II (Ang II) and its type 2 receptor (AT2R) on re-epithelialization, granulation tissue formation and growth factor production during wound healing, and to explore the possible mechanism by which Ang II and AT2R influence wound healing. METHODS：Two full-thickness skin wounds were created on the dorsum of C57BL/6J mice. The animals were treated with or without AT2R blocker PD123319 at a dose of 10 mg/kg daily after wounding. Specimens were taken from the wound of each mouse on days 3, 5, 7, 9, 11, 13 and 15 after wounding. Re-epithelialization and granulation tissue formation in the wounded skin tissues were evaluated by HE staining. The production of growth factors,epidermal growth factor (EGF),vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in wounded tissues during the healing process was detected by ELISA. RESULTS：Treatment with PD123319 significantly increased the rate of re-epithelialization and the area of granulation tissue compared with control group at 5 d and 7 d after wounding. Moreover, peritoneal application of PD123319 increased the production of EGF, VEGF and bFGF in the wounded tissues at the indicated time points after wounding. CONCLUSION：AT2R blocker PD123319 accelerates wound healing via promoting re-epithelialization,granulation tissue formation and growth factor production.     

羊栖菜联合姬松茸多糖对胰岛β细胞保护作用

探讨羊栖菜多糖、姬松茸多糖对高糖培养的胰岛β细胞的保护作用及其机制。将胰岛β细胞随机分为5组：正常对照组、模型组、SFPS组、ABP组、两药联合组。应用MTT法检测对胰岛β细胞增殖能力的影响,应用荧光显微镜检测胰岛β细胞凋亡情况,并用RT-PCR法检测bax、caspase-3基因表达量的变化。结果表明,SFPS、ABP能明显减轻高糖对胰岛βTc3细胞的生长抑制,抑制高糖诱导的胰岛β细胞凋亡,并明显降低bax、caspase-3基因表达（p〈0.01）,两药联合作用更明显,其作用机制可能与调控bax、caspase-3基因表达有关。     

Effect of ozone bath on pathological changes and expression of cytokines in rats with deep second-degree burns

AIM: To investigate the effect of ozone bath on the pathological changes and the expression of cytokines, platelet-derived growth factor (PDGF), transforming growth factor-β₃ (TGF-β₃), and tumor necrosis factor-α (TNF-α), in the wounds of deep second-degree burns in rats. METHODS: Male clean-grade SD rats (n=80) were randomly divided into 2 groups, ozone bath group and routine dressing group (control group), with 40 rats in each group. Deep second-degree burn wound was established on the back of the rats, and then the examinations were conducted at 3 d, 7 d, 14 d and 21 d after burn. For the routine dressing group, the wound was cleaned by normal saline and covered with iodophor vaseline gauze every 2 d. For the ozone bath group, before the dressing, the rats were put into the clean foam box to accept ozone fumigation for 20 min (50 mg/L), and then accepted dressing change as the same as that in control group every 2 d. At each time point, the tissue specimens from these rat wounds (at wound center) were taken. The rats in ozone bath group received cleaning by saline cotton and then the ozone bath fumigation, while the rats in control group only received cleaning by saline. After that, the tissue specimens were taken again for HE staining, immunohistochemical staining and semiquantitative observation combined with image data analysis. The concentrations of the cytokines PDGF, TGF-β₃ and TNF-α in the wound were measured by double-antibody sandwich ELISA. RESULTS: In ozone bath group, the wounds were smooth with clear edge and slight inflammatory reaction, swelling and exudation were weaker, and the wound healing rate was higher than that in control group with significant difference. Under microscopic observation with HE staining, slighter inflammatory reaction in ozone bath group was observed than that in control group at each time point, and the numbers of fresh capillaries, fibroblasts and epithelial cells were significantly larger than those in control group. The expression levels of PDGF and TGF-β₃ in the wound tissue homogenate in ozone bath group were higher, and the expression level of TNF-α was significantly lower than those in control group at each time point with significant difference. CONCLUSION: The ozone bath therapy improves the local pathological changes and promotes the expression of cytokines PDGF and TGF-β₃, which are associated with wound healing, as well as reduces the expression of inflammatory mediator TNF-α in the rats with deep second-degree burns, thus promoting the wound healing and anti-inflammatory responses.