Paeoniflorin alleviates TGF-ß2-mediated extracellular matrix remodeling and oxidative stress in human trabecular meshwork cells.

BACKGROUND: The multifunctional profibrotic cytokine transforming growth factor-beta2 (TGF-ß2) is implicated in the pathophysiology of primary open angle glaucoma. Paeoniflorin (PAE) is a monoterpene glycoside with multiple pharmacological efficacies, such as antioxidant, anti-fibrotic, and anti-inflammatory properties. Studies have demonstrated that paeoniflorin protects human corneal epithelial cells, retinal pigment epithelial cells, and retinal microglia from damage. Here, the biological role of PAE in TGF-ß2-dependent remodeling of the extracellular matrix (ECM) within the trabecular meshwork (TM) microenvironment. METHODS: Primary or transformed (GTM3) human TM (HTM) cells conditioned in serum-free media were incubated with TGF-ß2 (5 ng/mL). PAE (300 µM) was added to serum-starved confluent cultures of HTM cells for 2 h, followed by incubation with TGF-ß2 for 22 h. SB-431542, a TGF-ß receptor inhibitor (10 µM), was used as a positive control. The levels of intracellular ROS were evaluated by CellROX green dye. Western blotting was used to measure the levels of TGF-ß2/Smad2/3 signaling-related molecules. Collagen 1α1, collagen 4α1, and connective tissue growth factor (CTGF) expression was evaluated by RT-qPCR. Immunofluorescence assay was conducted to measure collagen I/IV expression in HTM cells. Phalloidin staining assay was conducted for evaluating F-actin stress fiber formation in the cells. RESULTS: PAE attenuated TGF-ß2-induced oxidative stress and suppressed TGF-ß2-induced Smad2/3 signaling in primary or transformed HTM cells. Additionally, PAE repressed TGF-ß2-induced upregulation of collagen 1α1, collagen 4α1, and CTGF expression and reduced TGF-ß2-mediated collagen I/IV expression and of F-actin stress fiber formation in primary or transformed HTM cells. CONCLUSION: PAE alleviates TGF-ß2-induced ECM deposition and oxidative stress in HTM cells through inactivation of Smad2/3 signaling.

Controlled release by novel lysostaphin-loaded hydroxyapatite/chitosan composites.

Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.

MicroRNA-193b-3p reduces oxidative stress and mitochondrial damage in rats with cerebral ischemia-reperfusion injury via the seven in absentia homolog 1/Jun N-terminal kinase pathway.

Ischemic stroke is one of the major causes of death and disability among adults. This study sought to explore the mechanism of microRNA (miR)-193b-3p in rats with cerebral ischemia-reperfusion (I/R) injury. The cerebral I/R injury models of rats were established using the suture-occluded method. The pathological changes were observed, and oxidative stress (OS) and mitochondrial function indexes in rat brain tissue were examined. The levels of miR-193b-3p and seven in absentia homolog 1 (SIAH1) were detected. miR-193b-3p agomir or antagomir was injected into the lateral ventricle of I/R rats to overexpress or inhibit miR-193b-3p expression. The targeting relationship between miR-193b-3p and SIAH1 was verified. The effect of SIAH1 overexpression on brain injury in I/R rats was investigated by injecting the lentivirus vector into the lateral ventricle. The phosphorylation level of Jun N-terminal kinase (JNK) was identified. miR-193b-3p was lowly expressed in I/R rats. Overexpression of miR-193b-3p alleviated the pathological damage of I/R rats and limited the OS and mitochondrial damage. miR-193b-3p targeted SIAH1. Overexpression of SIAH1 partially reversed the protection of miR-193b-3p overexpression against cerebral I/R injury. p-JNK was up-regulated in I/R rats and overexpression of miR-193b-3p inhibited p-JNK. Overall, overexpression of miR-193b-3p targeted SIAH1 to inhibit the activation of the JNK pathway and protect rats against cerebral I/R injury.

[Expert consensus on gastrointestinal dysfunction secondary to sepsis with integrating Traditional Chinese Medicine and Western medicine].

Acute gastrointestinal dysfunction is a common and important complication of sepsis. As no exiting formal definition and classification of gastrointestinal dysfunction, most of the treatment strategies for gastrointestinal dysfunction are not based on clinical evidence, but on their own clinical experience. Experts of traditional Chinese medicine, integrated traditional Chinese and Western medicine and Western medicine from various disciplines in Shanghai are organized by the Shanghai Society of Integrated Traditional Chinese and Western Medicine and the Emergency Department Branch of Shanghai Physicians Association. After repeated discussion, literature search and formulation of the outline, we developed consensus on gastrointestinal dysfunction secondary to sepsis with integrating Traditional Chinese Medicine and Western medicine by consulting extensively on clinical experts in the fields of emergency medicine, gastroenterology, general surgery, infectious medicine and traditional Chinese medicine, and holding several expert forums and consultation meetings. This clinical expert consensus focused on acute gastrointestinal injury (AGI) classification and inducer of sepsis. In this consensus, the common symptoms, diagnosis, classifications, treatment strategies and suggestions of acute gastrointestinal injury or dysfunction secondary to sepsis were explored from the aspect of both Traditional Chinese Medicine and Western medicine.

Mechanistic study of endogenous skin lesions in diabetic rats.

Pathological and physiological changes in dermal tissue in a rat model of diabetes mellitus (DM) were investigated. Sixteen male 8-week-old Sprague-Dawley rats were randomized into two groups of eight, the DM group (Group DM) and the normal control group (Group (NC) normal control). Group DM rats were injected with streptozotocin (STZ) intraperitoneally at a dose of 65 mg/kg body weight. Group NC rats were injected with the same volume of citric acid buffer. All rats were sacrificed 12 weeks later. The impact of exposure to (AGE) advanced glycation end products-modified human serum albumin (AGE-HSA) on epidermal cells and ECV304 cells was evaluated in cell culture experiments. The diabetic rats exhibited changes in skin tissue, including a decrease in thickness, disappearance of the multilayer epithelium structure, degeneration of collagen fibres and an increase in the infiltration of inflammatory cells, in addition to a significant increase in skin glucose and AGEs. Moreover, diabetic rats had increased plasma glycosylated protein (GSP) and malondialdehyde (MDA) and decreased plasma glutathione (GSH). The percentage of epidermal cells in S phase was similar between the two group rats; however, there was a marked decrease in the G2/M phase in Group DM. Additionally, exposure of ECV304 cells to AGE-HSA led to a time-dependent and dose-dependent increase in apoptosis. Therefore, the high glucose in the skin tissue, coupled with the accumulation of toxic substances such as AGEs, promote the dysfunction of dermal cells and/or the matrix. This may be a significant mechanism of diabetes-induced early-stage endogenous skin damage.

Effects of extracellular matrix glycosylation on proliferation and apoptosis of human dermal fibroblasts via the receptor for advanced glycosylated end products.

The balance between proliferation and apoptosis of skin cells is responsible for skin turnover and the success of the wound healing process. Recent reports have shown that advanced glycosylation end product (AGE) formation participates in dermatologic problems in diabetes. However, the effect on proliferation and apoptosis of dermal fibroblasts remains unclear. The aim of this study was to investigate the effects of dermal microenvironment glycosylation on the balance of cellular proliferation and apoptosis. Histology and immunohistochemical staining were performed on type II diabetic and nondiabetic skin tissue specimens to determine the distributions of proliferating cell nuclear antigen, apoptotic cells, AGEs, and receptors for AGEs (RAGEs). Matrix secreted by cultured human fibroblasts was glycosylated by 0.5 M D-ribose. RAGE-blocking antibodies were applied to inhibit the interaction of RAGE and AGEs in this system and then cell viability, cell cycle phase distribution, and apoptosis were measured. Diabetic skin has degenerative, loosely arranged collagen and increased apoptotic cells compared with normal skin. Expression of AGE and RAGE in diabetic skin tissue increased. Glycosylated matrix induced cell cycle arrest and apoptosis of cultured dermal fibroblasts, whereas application of RAGE-blocking antibodies redressed these changes. The accumulation of glycosylated extracellular matrix in diabetic skin tissue is a critical mediator of cellular function. Mediation of RAGE affects the balance of cellular proliferation and apoptosis, which confirms that diabetic wounds possess atypical origin in the repair process.

AhGLK1 affects chlorophyll biosynthesis and photosynthesis in peanut leaves during recovery from drought.

Peanut is an important edible oil crop plant whose quality and yield are greatly affected by drought. The process and molecular mechanisms of recovery from drought are also critical to its productivity, but are currently poorly characterized. Here, we investigate the involvement of peanut AhGLK1 in recovery from drought, and in particular its relationship with AhPORA, which encodes a key enzyme in chlorophyll biosynthesis. We found that chlorophyll content, chlorophyll fluorescence, AhPORA protein level and genes related to chlorophyll biosynthesis and photosynthesis declined markedly under drought conditions, but all increased during recovery. Consistent with this, AhGLK1 expression decreased during water stress and increased when the stress was removed. When AhGLK1 was transformed into Arabidopsis glk1glk2 mutant, it increased the survival rate of the mutant during recovery from drought and fully rescued the mutant's pale-green phenotype. In addition, chlorophyll content and fluorescence, and the expression of genes related to chlorophyll biosynthesis and photosynthesis, were all increased. Bioinformatics analysis and experimental evidence suggested that AhGLK1 augments the expression of AhPORA by binding to its promoter. Our findings confirm that AhGLK1 plays a role as a transcription factor that upregulates expression of AhPORA during post-drought recovery, thereby stimulating chlorophyll biosynthesis and photosynthesis.

Application of optical tweezers in the research of molecular interaction between lymphocyte function associated antigen-1 and its monoclonal antibody.

Lymphocyte function associated antigen-1 (CD11a/CD18, LFA-1) plays an important role in the structure of the immunological synapse and is required for efficient lysis of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. To study the activation mode of LFA-1 on the NK cell surface, optical tweezers were used in the work. As an emerging technology, optical tweezers are widely used to manipulate microscopic objects and measure the forces of molecular interactions in the field of biological research. In our study, a new platform was constructed to study the single molecular behavior of receptor on cell surface using optical tweezers. Based on the platform, the interaction between an NK cell and a polystyrene microsphere coated with anti-LFA-1 antibody was observed. The result confirmed that the adhesion forces between an NK cell and a polystyrene bead were time-dependent. According to our findings, we propose that anti-LFA-1 antibody may cause the clustering of LFA-1 on NK cell surface.

[Study on the biological function of dermal fibroblasts in the wounds of diabetic and non-diabetic rats with deep burns].

OBJECTIVE: To explore the changes of the biological function of dermal fibroblasts (FBs) in the wounds of diabetic and non-diabetic burned rats and the pathogenesis of impaired wound healing in diabetes. METHODS: 80 Sprague-Dawley (SD) rats weighing 220 g were randomly divided into control and STZ-induced diabetic groups, and then deep partial thickness scald involving 10% TBSA was reproduced in the two groups. The diabetic groups were randomized into pre-scalding, post-scalding day (PSD 3), PSD 7, PSD 14 and PSD 21 groups, with 6 rats in each group. Controls were also randomized into 5 groups. Skin specimens from the wound were harvested at each time point. Cell cycles of FBs were analyzed with flow cytometry. The amount of hydroxyproline in the skin tissue was assessed on 0, 3, 7, 14, and PSD 21. The type I and III collagens were determined by ELISA. The expression of alpha-SMA in the dermal fibroblasts of each group was assessed by immunohistochemistry method. Transmission electron microscopy was used to observe the ultrastructure changes of FBs. RESULTS: Compared with that in the normal rats, the percentage of the cells in G(0)/G(1) phase in the DM group was evidently lower on PSD 0 (65.79 +/- 5.24 vs 82.43 +/- 9.68, P < 0.01). After the scalding, the percentage of the cells in G(0)/G(1) phase in DM group was significantly higher (70.00 +/- 4.27 vs 42.04 +/- 12.96, on PSD 3, P < 0.01), meanwhile the percentage of S phase was remarkably lower than those in C group on 3, 7, 14, 21PSD (P < 0.05, P < 0.01). The amount of hydroxyproline in the diabetic skin tissue was obviously lower than those of the responding control groups before (0.72 +/- 0.06 vs 1.42 +/- 0.28, P < 0.01) and after burn injury (P < 0.01). Furthermore, the rate of I/III collagen on 7, 14 and PSD 21 was much higher in DM group than that in C group (P < 0.01). The expression of alpha-SMA in DM groups on PSDS 3, 7, 14 and PSD 21 was evidently lower than those of the controls (levels 10.28 +/- 3.99, C group 28.42 +/- 2.73, on PSD 14, P < 0.01), although that inclined to be heightened after burn injury. Ultrastructure changes of FBs in the wounds of diabetic rats could be observed, such as the outstretched endoplasmic reticulum, un development of Golgi's body, lackness of microtubule and microfilament, a sharp increase of cytolysosomes, and so on. CONCLUSION: The FB proliferation in the diabetic skin is abnormal, the synthetical ability of collagen is weakened, the expression of alpha-SMA is insufficient, the microtubule and microfilament is lack, and the number of cytolysosomes increases. The pathogenesis of impaired-wound healing in diabetics might be related with the above mentioned factors.

Isolation of an ABA Transporter-Like 1 Gene from Arachis hypogaea That Affects ABA Import and Reduces ABA Sensitivity in Arabidopsis.

Abscisic acid (ABA) transporters are essential for the transport of ABA from its sites of synthesis to its multiple sites of action within plants and are key players in plant stress responses. Despite their importance, there is limited information on ABA transporters in crop plants. In this study, we isolated and characterized an ABA transporter-like 1 (AhATL1) gene from peanut (Arachis hypogaea L.) whose cognate protein, AhATL1, is a member of the ATP-binding cassette transporter G subfamily and localizes to the plasma membrane. The expression of both the AhATL1 transcript and the corresponding protein were upregulated by water stress and treatment with exogenous ABA. Overexpression of AhATL1 in ecotype Columbia (Col) Arabidopsis (AhATL1-OX) plants reduced ABA sensitivity. When AhATL1-OX and Arabidopsis Col plants were subjected to dehydration stress, the expression of 9-cis-epoxycarotenoid dioxygenase 3 (AtNCED3) and responsive to desiccation 29 A (AtRD29A) accumulated rapidly in rosette leaves of both lines. In contrast, while expression of ATP-binding cassette G 40 (AtABCG40) was increased in Col rosette leaves, there was no change in expression of AtABCG40 in AhATL1-OX leaves. Similarly, water loss from detached leaves of AhATL1-OX plants was more rapid than from Col leaves. Therefore, we suggest that the function of AhATL1 is probably to modulate ABA sensitivity by specifically influencing ABA import into cells.

The site of water stress governs the pattern of ABA synthesis and transport in peanut.

Abscisic acid (ABA) is one of the most important phytohormones involved in stress responses in plants. However, knowledge of the effect on ABA distribution and transport of water stress at different sites on the plant is limited. In this study, water stress imposed on peanut leaves or roots by treatment with PEG 6000 is termed "leaf stress" or "root stress", respectively. Immunoenzyme localization technolony was first used to detect ABA distribution in peanut. Under root stress, ABA biosynthesis and distribution level were all more pronounced in root than in leaf. However, ABA transport and the ability to induce stomatal closure were still better in leaf than in root during root stress; However, ABA biosynthesis initially increased in leaf, then rapidly accumulated in the vascular cambium of leaves and induced stomatal closure under leaf stress; ABA produced in root tissues was also transported to leaf tissues to maintain stomatal closure. The vascular system was involved in the coordination and integration of this complex regulatory mechanism for ABA signal accumulation. Water stress subject to root or leaf results in different of ABA biosynthesis and transport ability that trigger stoma close in peanut.

Negative feedback regulation of ABA biosynthesis in peanut (Arachis hypogaea): a transcription factor complex inhibits AhNCED1 expression during water stress.

Abscisic acid (ABA), a key plant stress-signaling hormone, is produced in response to drought and counteracts the effects of this stress. The accumulation of ABA is controlled by the enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). In Arabidopsis, NCED3 is regulated by a positive feedback mechanism by ABA. In this study in peanut (Arachis hypogaea), we demonstrate that ABA biosynthesis is also controlled by negative feedback regulation, mediated by the inhibitory effect on AhNCED1 transcription of a protein complex between transcription factors AhNAC2 and AhAREB1. AhNCED1 was significantly down-regulated after PEG treatment for 10 h, at which time ABA content reached a peak. A ChIP-qPCR assay confirmed AhAREB1 and AhNAC2 binding to the AhNCED1 promoter in response to ABA. Moreover, the interaction between AhAREB1 and AhNAC2, and a transient expression assay showed that the protein complex could negatively regulate the expression of AhNCED1. The results also demonstrated that AhAREB1 was the key factor in AhNCED1 feedback regulation, while AhNAC2 played a subsidiary role. ABA reduced the rate of AhAREB1 degradation and enhanced both the synthesis and degradation rate of the AhNAC2 protein. In summary, the AhAREB1/AhNAC2 protein complex functions as a negative feedback regulator of drought-induced ABA biosynthesis in peanut.

Wound Documentation by Using 3G Mobile as Acquisition Terminal: An Appropriate Proposal for Community Wound Care.

The increasing numbers of cases of wound disease are now posing a big challenge in China. For more convenience of wound patients, wound management in community health care centers under the supervision of a specialist at general hospitals is an ideal solution. To ensure an accurate diagnosis in community health clinics, it is important that "the same language" for wound description, which may be composed of unified format description, including wound image, must be achieved. We developed a wound information management system that was built up by acquisition terminal, wound description, data bank, and related software. In this system, a 3G mobile phone was applied as acquisition terminal, which could be used to access to the data bank. This documentation system was thought to be an appropriate proposal for community wound care because of its objectivity, uniformity, and facilitation. It also provides possibility for epidemiological study in the future.

The use of negative pressure in critical necrotizing fasciitis treatment: a case presentation.

Surgery complemented by antibiotics forms the backbone of the successful management of necrotizing fasciitis. But it will be very difficult to clear away extensive necrotizing tissue thoroughly in critically ill patients when their vital signs are unstable. The authors report the case of a 33-year-old woman who had extensive necrotizing fasciitis of the right lower limb with septic shock. The patient was severely anemic and malnutrition and had been given conservative debridement at bedside, that is, only detached necrotizing tissues was taken away while some other necrotizing tissue still remained, so that the skin tissue within the same area could be saved as much as possible. After debridement, negative pressure was applied at 125 mm Hg. Broad-spectrum antibiotics and effective supplementation were also complemented, thus controlling the septic shock. All necrotizing tissues were detached, and the sparing vital skin on necrotizing fascia was preserved successfully after negative pressure treatment. The patient was finally saved. In conclusion, negative pressure treatment may help diminish toxin absorbance, detach gangrene tissue, and preserve sparing vital tissue. This case suggests the value of combined use of negative pressure therapy and conservative debridement in critically ill patients with extensive necrotizing fasciitis.

[Influence of advanced glycosylation end products on wound healing of burn rats with diabetes].

OBJECTIVE: To understand the influence of accumulation of advanced glycosylation end products (AGE) on wound healing of burn rats complicated with diabetes. METHODS: Seventy-five SD rats were divided into control, diabetes, and aminoguanidine-interfered groups in completely randomized method, with 25 rats in each group. All rats were subjected to deep partial-thickness scald. Diabetes was reproduced in rats of diabetes and aminoguanidine-interfered groups. Rats in aminoguanidine-interfered group were fed with 100 mg x kg(-1) xd (-1) aminoguanidine. Rats were sacrificed on post-scald day (PSD) 0, 3, 7, 14, and 21, and portrait of the wounds were taken. Full-thickness skin tissue specimens were obtained for determination. Specimens of epidermis from back of SD rats were obtained for KC cultivation and verification. Wound healing rate, glucose content in skin tissue, morphologic change in wound tissue, AGE distribution in skin tissue, influence of AGE on proliferation and apoptosis of KC were observed. RESULTS: Wound healing rate of rats was respectively lower in diabetes group than that in control group on PSD 7, 14, and 21 (P < 0.01), but it was obviously higher in aminoguanidine-interfered group than that in the former 2 groups (P < 0.01). Glucose content of rat skin in diabetes group was (2.62 +/- 0.19) mmol/g, and it was (2.58 +/- 0.07) mmol/g in aminoguanidine-interfered group, both higher than that in control group [(1.04 +/- 0.09) mmol/g, P < 0.01]. In control group, limited intensive infiltration of inflammatory cells was found in the wound with necrotic tissue formation which fell off in time, and with no obvious delay of wound healing. In diabetes group, infiltration of inflammatory cells in wounds of rats appeared slowly, but diffusely and persistently; necrotic tissue formed and fell off late in time, with obvious delay of wound healing. In aminoguanidine-interfered group, intensive infiltration of inflammatory cells was observed in time, and the time of necrotic tissue formation and sloughing, and wound healing were respectively earlier than that in diabetes group. Sporadic disposition of small amount of AGE was found in rats in control group. AGE accumulation increased significantly in rats in diabetes group. AGE content decreased significantly in rats in aminoguanidine-interfered group after administration of aminoguanidine. KC proliferation decreased significantly in concentration dependent manner 48 hours after AGE stimulation. Absorbance value of AGE decreased in each AGE-interfered group (P < 0.01). Early Annexin-V positive apoptotic KC rate was obviously higher in 100 ug/mL AGE-interfered group (15.1 +/- 2.3)% than that in control group [(11.2 +/- 1.2)%, P < 0.05]. There was no statistical significance between 100 ug/mL AGE-interfered group (14.3 +/- 3.5)% and control group (15.2 +/- 2.4)% in respect of the rate of double-positive cells apoptosis at final stage (P > 0.05). CONCLUSIONS: Hyperglycemia may inhibit proliferation of repairing cells such as KC through AGE accumulation, thus impedes wound healing. Reduction of AGE accumulation could ameliorate wound healing delay due to diabetes.

Regulation of keratinocyte proliferation in rats with deep, partial-thickness scald: modulation of cyclin D1-cyclin-dependent kinase 4 and histone H1 kinase activity of M-phase promoting factor.

BACKGROUND: Keratinocyte proliferation, which is undergone by its cell cycle transition, is considered a major event during re-epithelialization over the wound size. Cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitors interact to regulate the cell cycle. We investigated proliferative events associated with cell-cycle control in keratinocytes during wound healing in rats with deep, partial scald injuries. MATERIALS AND METHODS: Male Sprague Dawley rats with starting weights of 200 to 220 g were inflicted with standardized deep partial-thickness burns by scalding 10% of the skin surface. The full thickness skin biopsies were harvested for histological evaluation at following time points: 0 d, post-burn day 3, post-burn day 7, and post-burn day 14. Keratinocytes from wound edge were isolated for cell cycle examination. The cell cycle regulators and their activity were detected. RESULTS: Keratinocytes tended to proliferate and had enlarged nuclei and nucleoli from day 3 after injury. Morphological features became evident on day 14, with an increase in keratinocytes. The percentage of S-phase keratinocytes tended to increase on day 14. The percentage G2/M-phase keratinocytes increased from day 3 and significantly increased on days 7 and 14. Cyclin D1 expression markedly increased from day 3, with down-regulation of cyclin-dependent kinase 4, which re-elevated on day 14. Cyclin B1 expression did not dramatically vary. Histone H1 kinase activity of mitosis phase promoting factor markedly increased on day 14. CONCLUSIONS: These findings suggested early, active DNA synthesis and mitosis in keratinocytes, with marked proliferation on day 14, that depended on the modulation of cyclin D1-cyclin-dependent kinase 4 and histone H1 kinase activity of mitosis phase promoting factor. During wound healing, patterns of cell-cycle control expression differed from those previously known.

[Effect of advanced glycosylation end products on cell cycle of epidermal keratinocyte and the role of signal pathway].

OBJECTIVE: To investigate the effect of advanced glycosylation end products (AGE) on cell cycle of epidermal keratinocyte and its possible signal pathway. METHODS: 150 mg/L AGE-human serum albumin (AGE-HSA) was prepared in vitro. Primary cultured keratinocytes in logarithmic growth phase were harvested and divided randomly into: A group [with treatment of defined keratinocyte-SFM (DK-SFM) serum-free medium], B group (with treatment of DK-SFM medium including 150 mg/L AGE-HSA), C group (with DK-SFM medium after treatment of U0126) and group D (with D K-SFM medium including 150 mg/L AGE-HSA after treatment of U0126). Cell cycle distributions were analyzed by flow cytometer. The protein levels of cyclin D1, cyclin B1, CDK4 and p44/42 MAPK were measured by Western blot. RESULTS: Compared with those of A group, the percentage of S-phase and G2/M-phase keratinocytes were decreased obviously in B group, the percentages of G2/M -phase keratinocytes showed the same tendency in C and D groups [(9.7 +/- 1.1)% , (9.8 +/- 0.7)%, respectively, P <0.05]. Compared with that of A group, the expression of cyclin D1 were decreased significantly in other groups, among which a weak expression was showed in D group. There was no obvious difference between A and B groups in CDK4, or cyclin B1 and p44/42 MAPK protein levels ,which were significantly higher than those in C and D groups. CONCLUSION: AGEs inhibit the progress of cell cycle of keratinocytes by downregulation of cyclin D1 expression.