Different therapeutic effects between diabetic and non-diabetic adipose stem cells in diabetic wound healing.

OBJECTIVE: This study aimed to investigate how adipose tissue-derived stem cells (ASCs) from diabetic and from non-diabetic rats affect wound healing in different microenvironments. METHOD: The two types of ASC-rich cells were distinguished by characteristic surface antigen detection. The ASC-rich cells were transplanted into the wounds of diabetic and non-diabetic rats. Wound healing rates were compared and the healing process in the wound margin sections was used to determine how ASC-rich cells affect wound healing in different microenvironments. RESULTS: ASC density was decreased in diabetic rats. The generation time of ASC-rich cells from diabetic rats (d-ASC-rich cells) was longer than that of ASC-rich cells from non-diabetic rats. The number of pre-apoptotic cells in the third generation (passage 3) of d-ASC-rich cells was higher than that among the ASC-rich cells from non-diabetic rats. CD31 and CD34 expression was higher in d-ASC-rich cells than in ASC-rich cells from non-diabetic rats, whereas CD44 and CD105 expression was lower than that in ASC-rich cells from non-diabetic rats. Transplantation of ASC-rich cells from non-diabetic rats promoted wound healing in both non-diabetic and diabetic rats. In contrast, d-ASC-rich cells and enriched nuclear cells only promoted wound healing in non-diabetic rats. ASC-rich cell transplantation promoted greater tissue regeneration than d-ASC-rich cell transplantation. CONCLUSION: ASC-rich cells promoted wound healing in diabetic and non-diabetic rats. ASC density was lower in the adipose tissue of diabetic rats compared with non-diabetic rats. d-ASC-rich cells did not promote wound healing in diabetic rats, suggesting that caution is warranted regarding the clinical use of diabetic adipose stem cell transplantation for the treatment of diabetic wounds.

WoundCareLog APP - A new application to record wound diagnosis and healing.

The incidence of chronic wounds has been increasing over the past 20 years. However, the standardized diagnosis and treatment practice of chronic refractory wounds have not been established. In addition, the properties of the wound are characterized by morphology and thus correct description of the wound in medical history collection plays a vital role, which directly affects the definitive diagnosis. To develop more accurate format of clinical history record which can correctly reflect a patient's course and treatment progress, and to standardize the medical history record of chronic refractory wounds, at the national or regional level, we designed the WoundCareLog APP. It acts as a recording and communication tool for wound healing specialists at all levels of medical institutions in China. The WoundCareLog APP is fully compatible to meet the criteria and requirements of conventional medical records by embedding 9 modules. In addition, the demands for morphological description of wounds in wound healing diagnosis and treatment have been fulfilled by enroll of digital imaging technology to overcome the inadequacies of traditional medical history records.

Histomorphological observation of surgical debridement combined with negative pressure therapy in treatment of diabetic foot.

PURPOSE: To further study the mechanism of epithelization on the fascia side of the flap after surgical incision and the treatment of the negative pressure therapy. METHODS: With the patients' informed consent, parts of tissue samples were obtained from a 51-year-old diabetic patient who was suffering lower extremity ulcers. The samples were processed with hematoxylin and eosin (HE) staining and Masson trichrome staining. The keratin 19, keratin 15 and carcino-embryonic antigen (CEA) were immunohistochemically detected. RESULTS: The results of HE staining showed that the specimen was divided into two regions, newborn area and original epithelial area. There were more inflammatory cells infiltrating in the dermis in the newborn epithelial area, compared with the original epithelial area. Cells in newborn epithelial area were more active and many dinuclear and polynuclear cells were observed in newborn epithelial area. But there were more cuticular layers and obvious rete pegs in original epithelial area. In addition, the cells with keratin 19 and CEA positive were found around hair follicle, while keratin 15 was negative. Masson trichrome staining showed that there was a lot of de novo collagen in newborn epithelial area. CONCLUSION: Epidermal cells on the fascia side of the flap could be derived from the stem cells. Negative pressure wound therapy would attract not only cells but also other elements such as growth factors, cytokines, some nutrients and extracellular matrix. With the formation of the appropriate microenvironment after debridement, the migrated cells can grow, differentiate and spread, eventually leading to the epithelization on the fascia side of the flap in diabetic foot.

The Influence of AGEs Environment on Proliferation, Apoptosis, Homeostasis, and Endothelial Cell Differentiation of Human Adipose Stem Cells.

The aim of this study was to evaluate the changes of proliferation, apoptosis, homeostasis, and differentiation of human adipose-derived stem cells (hASCs) in the simulated diabetic microenvironment and discuss the potential of the mesenchymal stem cell in the treatment of chronic diabetic wound. We simulated diabetic microenvironment with glycation end products (AGEs) in vitro and studied the changes of hASCs in proliferation and apoptosis. We found that AGEs inhibited the proliferation and lead to hASCs apoptosis, and the endothelial cell directed differentiation was also inhibited. AGEs upregulated growth-related oncogene and monocyte chemoattractant protein-1 and downregulated urokinase-type plasminogen activator receptor, which may inhibit the proliferation and transference of endothelial cells. The simulated diabetic microenvironment affects the proliferation, apoptosis, and homeostasis of hASCs, the endothelial cell migration, and the synthesis of collagen protein, leading to delayed wound healing.

[Proliferation-inhibiting effect of advanced glycation end products modified human serum albumin to vascular endothelial cell ECV304].

OBJECTIVE: To study the proliferation-inhibiting and apoptosis-inducing effects of advanced glycation end products (AGE) modified human serum albumin (AGE-HSA) on human vein endothelial cells. METHODS: Human umbilical vein endothelial cells ECV304 were cultured in vitro with AGE-HSA of the concentrations of 12.5, 25, 50, 100, and 200 micro g/ml for 6, 12, 24, or 48 hour, then 20 micro l of 5 mg/ml MTT were added and the optical density (OD) at each time point was determined. Another ECV304 cells were cultured with AGE-HAS for 2, 4, or 8 days and then were stained with trypan blue to calculate the number of dead cells so as to calculate the proliferation-inhibiting rate. Another ECV304 cells were cultured with AGE-HAS for 6, 12, 24, or 48 hours and then stained with annexin V Fitc and propidium iodide (PI). Flow cytometry was used to calculate the annexin V Fitc positive cells (early and middle stage apoptotic cells) and Annexin V Fitc/PL positive cells (late apoptotic cells). Inverted microscope, transmission electron microscope, and fluorescence microscope were used to observe the histological changes of apoptotic cells. FCV304 cells incubated with HSA of the above-mentioned and without addition of the other agents concentrations were used as controls. RESULTS: The OD values of ECV304 cells cultured for 48 h with low concentrations (12.5, 25, and 50 micro g/ml) of AGE-HSA were not significantly different from those of the control (1.104 +/- 0.080, 1.098 +/- 0.097 and 1.059 +/- 0.122 VS. 1.159 +/- 0.088, all P > 0.05). The OD values of ECV304 cells cultured with low concentrations of AGE-HSA for 4 days and 6 days were significantly lower than those in the control group. The OD values of ECV304 cells cultured with high concentrations (100 and 200 micro g/ml) of AGE-HSA for 6 - 48 hours decreased to 0.117 +/- 0.033 and 0.081 +/- 0.020 in comparison with that of the control group (P < 0.01). Flow cytometry and fluorescence microscopy showed higher proportions of apoptotic cells among the ECV304 cells cultured with high concentrations of AGE-HAS than among the control cells at each time point (P < 0.01). The numbers of cells in the control group exponentially increased after culture for 2, 4, and 6 days. The number of cells cultured with low concentrations of AGE-HAS for 2 days was not significantly different from that of the control group (P > 0.05), however, the numbers of cells cultured with low concentrations of AGE-HAS for 4 and 6 days were significantly lower than those of the control group (both P < 0.01). The numbers of cells cultured with 100 or 200 micro g/ml AGE-HAS for 2 days were significantly lower than those of the control group (both P < 0.01) with a proliferation-inhibiting rate of 39.56% +/- 2.82% and 60.32% +/- 4.51% respectively. The apoptotic rates in cells cultured with low concentrations of AGE-HAS for 48 hours were not significantly different from those in the control group. The apoptotic rates in cells cultured with 100 or 200 micro g/ml AGE-HAS for 6, 12, 24, or 48 hours were significantly higher than those in the control group (all P < 0.01). The apoptotic rates in 200 micro g/ml group at different time points were significantly higher than those in the 100 micro g/ml group (P < 0.05 or 0.01). The apoptotic rate and number of apoptotic cells increased along with the increase of culture time and concentration of AGE-HAS. Microscopy showed morphological changes among the cells cultured with 100 micro g/ml AGE-HAS for 6, 12, 24, and 48 hours and the numbers of apoptotic cells, mainly late apoptotic cells, and dead cells increased remarkably since the cells were cultured for 48 hours. CONCLUSION: AGE-HSA inhibits the proliferation of vascular endothelial cells and induces apoptosis in dose and time dependent manner. AGE modification-induced pathobiological cascade may be involved in the pathogenesis of impaired wound healing in diabetes by the mechanism of angiogenesis retardation.

The change of break modulus drives human fibroblast differentiation in 3D collagen gels.

Extracellular matrix is one of the key environmental factors influencing cell survival and provides signals for cell morphological change, migration, proliferation and differentiation. However, the mechanism through which denatured collagen modulates the biological properties of fibroblasts, is unclear. We investigated the regulation of human fibroblast differentiation in vitro grown in collagen gels with different properties. The break modulus of collagen with denatured collagen and half-load normal collagen was reduced compared with that of normal collagen gel. Fibroblasts cultured in denatured collagen gels showed increased expression of matrix metalloproteinase9 ( MMP-9), tissue inhibitor of metalloproteinase 2 (TIMP2), α-smooth muscle actin (α-SMA), osteoblast cadherin, phosphorylated Myosin phosphatase target subunit1 (p-MYPT1), connective tissue growth factor, type I collagen, type III collagen, α-smooth muscle actin messenger RNA, RhoA, rho-associated protein kinase, and transforming growth factor ß receptors 1 and 2 compared with that in cells cultured in normal collagen gel. But there was no significant difference regarding expression level between denatured collagen gel and half-load normal collagen gel .These findings suggest that the change in break modulus caused by decreasing normal collagen concentration may be the key factor inducing fibroblast differentiation.

[Effects of advanced glycation end products and its receptor on oxidative stress in diabetic wounds].

OBJECTIVE: To investigate the accumulation of advanced glycation end products (AGE) and the inflammatory response of skin and wound in diabetic patients, and to analyze their relationship in vitro. METHODS: Histological staining and immunohistochemical staining was respectively performed on skin and wound tissue specimens collected from 10 patients with Type II diabetes mellitus (diabetes group) and 12 non-diabetic patients with skin injury (control group) to observe the arrangement of collagen and the distribution of inflammatory cells, and to determine the expression levels of AGE and its receptor (RAGE). Malondialdehyde (MDA) levels in skin and wound tissue homogenates were assayed by enzyme-linked immunosorbent assay. In vitro, human neutrophils were isolated and treated with RPMI-1640 culture medium or that containing AGE-human serum albumin in the concentration of 0.315, 0.625, 1.250 mg/mL, and they were identified as normal control (NC) group, low concentration (L) group, moderate concentration (M) group, and high concentration (H) group. Cell viability in each group was determined by MTT colorimetric assay, and the reactive oxygen species (ROS) in cell was measured with 2', 7'-dichlorofluorescein-diacetate. Data were processed with t test. RESULTS: Compared with those of skin in control group, collagens of skin tissues in diabetes group atrophied and disorderly arranged. Inflammatory cells in wounds in diabetes group were dispersed, in which collagens arranged loosely and irregularly, as compared with those of wounds in control group. Expression levels of AGE and RAGE of skin in diabetes group were higher than those in control group. In diabetes and control groups, especially in diabetes group, the numbers of RAGE-positive cells in wound tissue were more than those in skin tissue. Large amount of inflammatory cells with positive expression of RAGE were observed in diabetes group. MDA level of skin and wound tissue in diabetes group was respectively (6.3 ± 1.0), (7.1 ± 2.4) nmol per milligram protein, which were obviously higher than those in control group [(2.9 ± 1.0), (3.6 ± 1.4) nmol per milligram protein, with t value respectively 8.017, 4.349, P < 0.05 or P < 0.01]. Cell viability and ROS levels in neutrophils were increased in L, M, and H groups [(59 ± 8)%, (77 ± 5)%, (67 ± 6)% and 1.67 ± 0.14, 2.13 ± 0.17, 3.48 ± 0.48] as compared with those in NC group [(34 ± 5)% and 0.58 ± 0.06, with t value respectively 7.195, 14.890, 11.130 and 20.195, 24.905, 16.864, P < 0.05 or P < 0.01]. CONCLUSIONS: Abnormal oxidative stress in diabetic skin leads to an atypical origin of wound repair. AGE-RAGE effect is a critical mediator for oxidative stress in diabetic wound tissue during wound healing.

Abnormal regulation of neo-vascularisation in deep partial thickness scalds in rats with diabetes mellitus.

OBJECTIVE: This study observed the degree of neo-vascularisation and differential expression of angiogenesis growth factors and their receptor in deep partial-thickness scald wound with diabetes mellitus. METHODS: Sixty Sprague-Dawley rats were randomised into a control group and an STZ-induced diabetic group, inflicted with partial-thickness scalding of 20% total body surface area (20% TBSA) on the back. Wound specimens were harvested immediately after scald and on 1, 3, 7, 10, 14 and 21 post-scald days (PSDs) to observe histological changes, and wound healing rates were calculated. The degree of neo-vascularisation in wound (labelled with blue microsphere) and the quantity of vascular endothelial cells (labelled with red CD31) were also measured by double-labelling immunofluorescence. Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Tie-2, vascular endothelial growth factor (VEGF) and Flt-1 messenger RNA (mRNA) were analysed by real-time RT-PCR. Ang-1, Ang-2 and VEGF protein expressions were measured by Western blotting. RESULTS: Wound healing was markedly impaired in diabetic rats. The diabetic rats show inhibited vascularity in the wound edge at every time point (the quantitation of vascularity was 60.0±3.0 in the control group and 12.0±1.4 in the diabetic group, p<0.01 on day 7). Although neo-vascularisation in the number of endothelial cells was not significantly different compared with the normal group, part of new vascular endothelial cells did not form the vascular function. After injury, expression of Ang-2 mRNA and protein were increased in both groups, and the normal group showed decreases on day 7, 14 and 21, whereas the diabetic group showed significant increases. Although the expression VEGF and its receptors before injury was higher than the normal group, the level at 1, 3 and 7 days after injury was significantly lower than that 14 days, and that at 21 days after injury was significantly higher than the normal group. CONCLUSION: Vascular endothelial cells can proliferate actively in the diabetic wound with deep partial-thickness burns, but it is still poor in blood supply due to lack of functional capillaries. The mechanism may be related to sustained abnormal high expression of Ang-2 and down-regulated VEGF.

[Effect of different immunomodulation on inflammatory response in burn rats with sepsis].

OBJECTIVE: To investigate the effect of Thymosin and growth hormone(GH) on inflammatory response in burn rats or burn rats with sepsis. METHODS: Sixty-four SD rats were randomly divided into normal control group (NC, without treatment), sepsis group (S, with injection of LPS), sepsis + Thymosin group (ST, with successive injection of Thymosin and LPS), sepsis + GH group [SGH, with successive injection of recombinant human GH (rhGH) and LPS], burn group, burn + sepsis group (BS, with injection of LPS after burn), burn + sepsis + Thymosin group (BST, with successive injection of Thymosin and LPS after burn), burn + sepsis + GH (BSGH, with successive injection of rhGH and LPS after burn), with 8 rats in each group. Specimens of spleen tissues were harvested to determine HLA-DR in lymphocyte and evaluate inflammatory cell infiltration (score). Specimens of peripheral blood were collected to determine Toll-like receptor 4 (TLR4) level in monocyte and serum level of TNF-alpha, IL-4, IL-6, IL-10. RESULTS: Compared with those in NC group, serum level of IL-10 in S group decreased obviously, while other indices increased obviously (P < 0.01). The levels of HLA-DR and TLR4 and serum level of TNF-alpha were similar between SGH and ST groups (P > 0.05). Compared with those in SGH group [(2.87 +/- 0.04) score, and IL-6 (0.0083 +/- 0.0018) microg/mg, IL-4 (0.0102 +/- 0.0021) microg/mg, IL-10 (0.0310 +/- 0.0027) microg/mg, respectively], degree of inflammatory cell infiltration (1.50 +/- 0.76) score and serum levels of IL-6, IL-4, IL-10 of rats in ST group decreased obviously (0.0064 +/- 0.0012, 0.0058 +/- 0.0024, 0.0230 +/- 0.0021 microg/mg, respectively, P < 0.01). The levels of HLA-DR, TLR4 and inflammatory cell infiltration degree of spleen in B group were respectively higher than those in NC group and lower than those in BS group. Compared with those in NC group, serum levels of TNF-alpha, IL-6 in B group increased significantly, while IL-4, IL-10 showed an opposite tendency. There was no obvious difference between BST and BSGH groups in serum levels of HLA-DR and IL-6 (P > 0.05). Compared with those in BST group, inflammatory cell infiltration degree in spleen and the levels of TLR, TNF-alpha obviously decreased (P < 0.01), while IL-4 and IL-10 levels increased in BSGH group (P < 0.01). CONCLUSIONS: Inhibitive effects between Thymosin and GH on extensive inflammatory reaction were similar with or without trauma, and GH has better effect as compared with Thymosin when with trauma.

[Effects of advanced glycosylation end products on the biological behavior of neutrophils].

OBJECTIVE: To investigate the effects of advanced glycation end products (AGE) on the biological behavior of neutrophils in vitro, to look for the relationship between accumulation of AGE and abnormal inflammation in wound healing in diabetic mellitus patients. METHODS: Neutrophils were isolated from SD rats and incubated in vitro. The cells were divided into four groups according to different concentrations of AGE in cell suspension: control group (C, with treatment of RPMI - 1640), A group (with treatment of 0.315 mg/mL AGE + RPMI - 1640), B group (with treatment of 0.625 mg/mL AGE + RPMI - 1640), D group (with treatment of 1.250 mg/mL AGE + RPMI - 1640). Activity of neutrophils were determined by MTT colorimetric assay. Selectin-L mRNA expressions were analyzed by reversible transcription polymerase chain reaction (RT -PCR) technique. The levels of reactive oxygen species (ROS) in neutrophils were measured with DCFH-DA method. The protein concentration of neutrophil elastase (NE) was assayed by ELISA. RESULTS: The activity of neutrophils were obviously increased in A, B, and D groups when compared with that in C group [(0.170 +/- 0.040) in C group, (0.320 +/- 0.030) in A group, (0.380 +/- 0.020) in B group, (0.290 +/- 0.010) in D group, P <0. 05]. The expression of Selectin-L mRNA in A, B, D groups were significantly higher than that in C group (0.95 +/- 0.08, 1.36 +/- 0.27, 0.50 +/- 0.26.vs.0.36 +/- 0.26, P < 0.05. respectively). The ROS levels in A, B, D groups was markedly higher than that in C group (1.64 +/- 0.20, 2.16 +/- 0.26, 3.26 +/- 0.75. vs. 0.72 +/- 0.15, P <0.05, respectively). The levels of NE in A, B, D groups were significantly increased when compared with that in C group(1.98 +/- 0.43, 2.50 +/- 0.43, 2.01 +/- 0.18 vs 0.91 +/- 0. 21, P <0.05, respectively). CONCLUSION: AGE can enhance the activity of neutrophil, with change in cellular biological behaviors, which may be one of main reasons for abnormal inflammation in wounds of diabetes mellitus patients.

[Study on the mechanism of scar formation: epidermis template defect theory].

Dermal defection and the degree of its loss determine the natural process of wound healing, which is the key reason leading to excess scar hyperplasia. The function of tri-dimensional structure in dermis acts as a template to regulate the properties of reparative cells. The template structure induces the reparative cells to grow into the structure which changes the skin mechanic status on wound area. Also, the component of extracellular matrix can affect behaviours of fibroblasts negatively or positively, for the reason that the structure of dermal tissue has a permissive effect on the dermal components in regulating behaviours of reparative cells. Therefore, the behaviors of cells depend on the structure of the template. The suitable tri-dimensional structure of dermis facilitates normal cell cycling. The more the structure of dermis closed to its physiological status, the better the biological behaviors of cells act. Moreover, the integrity as well as the continuity of dermal tissue is the prerequisite for serving as a template. The damage to the integrity and the continuity of dermal tissue may be one of the key reasons to lead abnormal tissue repair and scar formation. Thus, we hypothesize that the loss of dermal template may be one of the mechanism of abnormal scar formation and propose the theory of extracellular matrix framework deficiency or destruction.