Forgetting is regulated through Rac activity in Drosophila.

Initially acquired memory dissipates rapidly if not consolidated. Such memory decay is thought to result either from the inherently labile nature of newly acquired memories or from interference by subsequently attained information. Here we report that a small G protein Rac-dependent forgetting mechanism contributes to both passive memory decay and interference-induced forgetting in Drosophila. Inhibition of Rac activity leads to slower decay of early memory, extending it from a few hours to more than one day, and to blockade of interference-induced forgetting. Conversely, elevated Rac activity in mushroom body neurons accelerates memory decay. This forgetting mechanism does not affect memory acquisition and is independent of Rutabaga adenylyl cyclase-mediated memory formation mechanisms. Endogenous Rac activation is evoked on different time scales during gradual memory loss in passive decay and during acute memory removal in reversal learning. We suggest that Rac's role in actin cytoskeleton remodeling may contribute to memory erasure.

Fibroblast-Derived Extracellular Vesicle-Packaged Long Noncoding RNA Upregulated in Diabetic Skin Enhances Keratinocyte MMP-9 Expression and Delays Diabetic Wound Healing.

Accurate communication between fibroblasts and keratinocytes is crucial for diabetic wound healing. Extracellular vesicles are being explored as essential mediators of intercellular communication in the skin. However, the mechanisms underlying wound healing mediated by fibroblast-derived extracellular vesicles (Fib-EVs) remain unclear. The present study evaluated the role of long noncoding RNA upregulated in diabetic skin (lnc-URIDS) packed in Fib-EVs in the wound healing of streptozotocin-induced diabetes and the potential mechanisms of the effects. We demonstrated that high glucose induced the enrichment of lnc-URIDS in Fib-EVs, facilitated the transfer of lnc-URIDS to primary rat epidermal keratinocytes, and increased the expression of matrix metalloproteinase-9. Mechanistically, the binding of lnc-URIDS to YTH domain family protein-2 enhanced the degradation of YTH domain family protein-2 in the lysosomes, which increased the translational activity of the messenger RNA of matrix metalloproteinase-9 and ultimately induced the degradation of collagen for wound healing. The results provided an insight into the crosstalk and cooperation between fibroblasts and keratinocytes in collagen homeostasis in diabetic wounds and clarified the mechanism by which lnc-URIDS degrades collagen for diabetic wound healing.

Fotagliptin monotherapy with alogliptin as an active comparator in patients with uncontrolled type 2 diabetes mellitus: a randomized, multicenter, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Dipeptidyl peptidase-4 inhibitors (DPP-4i) have become firmly established in treatment algorithms and national guidelines for improving glycemic control in type 2 diabetes mellitus (T2DM).To report the findings from a multicenter, randomized, double-blind, placebo-controlled phase 3 clinical trial, which was designed to assess the efficacy and safety of a novel DPP-4 inhibitor fotagliptin in treatment-naive patients with T2DM. METHODS: Patients with T2DM were randomized to receive fotagliptin (n = 230), alogliptin (n = 113) or placebo (n = 115) at a 2:1:1 ratio for 24 weeks of double-blind treatment period, followed by an open-label treatment period, making up a total of 52 weeks. The primary efficacy endpoint was to determine the superiority of fotagliptin over placebo in the change of HbA1c from baseline to Week 24. All serious or significant adverse events were recorded. RESULTS: After 24 weeks, mean decreases in HbA1c from baseline were -0.70% for fotagliptin, -0.72% for alogliptin and -0.26% for placebo. Estimated mean treatment differences in HbA1c were -0.44% (95% confidence interval [CI]: -0.62% to -0.27%) for fotagliptin versus placebo, and -0.46% (95% CI: -0.67% to -0.26%) for alogliptin versus placebo, and 0.02% (95%CI: -0.16% to 0.19%; upper limit of 95%CI < margin of 0.4%) for fotagliptin versus alogliptin. So fotagliptin was non-inferior to alogliptin. Compared with subjects with placebo (15.5%), significantly more patients with fotagliptin (37.0%) and alogliptin (35.5%) achieved HbA1c < 7.0% after 24 weeks of treatment. During the whole 52 weeks of treatment, the overall incidence of hypoglycemia was low for both of the fotagliptin and alogliptin groups (1.0% each). No drug-related serious adverse events were observed in any treatment group. CONCLUSIONS: In summary, the study demonstrated improvement in glycemic control and a favorable safety profile for fotagliptin in treatment-naive patients with T2DM. TRIAL REGISTRATION: ClinicalTrail.gov NCT05782192.

[Mechanism of Qingwei Powder in treatment of periodontitis based on UPLC-Q-TOF-MS, GC-MS, network pharmacology and molecular docking].

The present study explored the mechanism of Qingwei Powder(QP) in the treatment of periodontitis based on chromatography-mass spectrometry and network pharmacology-molecular docking techniques. UPLC-Q-TOF-MS and GC-MS were used to identify the chemical constituents of QP. The active components and targets were screened out through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and their targets were predicted using SwissTargetPrediction. Targets related to periodontitis were obtained from GeneCards, OMIM, and DisGeNET. Venn diagram was constructed using Venny 2.1 to obtain the intersection targets. Cytoscape 3.7.2 was used to construct the "chemical component-target-disease" network. The targets were analyzed for Gene Ontology(GO) function and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment by clusterProfiler R, and the "chemical component-target-pathway" network was constructed. The binding activity of the active components to the target proteins was verified by molecular docking. A total of 189 chemical components were obtained by UPLC-Q-TOF-MS and GC-MS, including 39 active components with 180 potential targets related to periodontitis. Target enrichment analysis of the active components yielded 92 KEGG pathways. Twenty KEGG pathways, 34 active components, and 99 targets were involved in the "chemical component-target-pathway" network. Molecular docking verified a good binding ability of the key targets to the key compounds. This study preliminarily indicates that QP is effective in treating periodontitis through multiple components, multiple targets, and multiple pathways, which reflects the complex system of Chinese medicine. This study provides the theoretical foundation for the subsequent research on the material basis and key quality attributes of QP.

Association of gonadal hormones and sex hormone binding globulin with risk of diabetes: A cohort study in middle-aged and elderly Chinese males.

AIM: Late-onset hypogonadism in men is related to the development of diabetes. The association of gonadal hormones, sex hormone binding globulin with diabetes has been studied in various studies. However, there is no cohort study on the relationship between gonadal hormone, sex hormone binding globulin and diabetes in Chinese. We aimed to provide an insight into the possible association in middle-aged and elderly Chinese males. METHODS: We included a population sample of 673 subjects aged 40 years or older. Total testosterone (TT), sex hormone binding globulin (SHBG), follicle-stimulating hormone (FSH) and luteinising hormone (LH) were detected. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated to estimate insulin sensitivity. Diabetes was diagnosed according to the 2010 American Diabetes Association criteria. RESULTS: With an average follow-up time of 3.2 ± 0.5 years, 9.8% of participants had developed diabetes. The prevalence of diabetes was decreased according to increasing SHBG quartiles (Q1:13.1%, Q2: 12.0%, Q3: 11.2%, Q4: 3.0%, P for trend < .0001) and TT (Q1:16.0%, Q2: 7.9%, Q3: 9.0%, Q4: 6.4%, P for trend < .0001). The ORs of diabetes for increasing SHBG quartiles were 4.52 (95% CI 1.40-14.57), 4.32 (95% CI 1.33-14.06), 3.89 (95% CI 1.21-12.50) and 1.00 (reference) respectively. But the odds of prevalent diabetes were not increased in different quartiles of TT, FSH and LH. In subgroup analyses, the relationship between SHBG and risk of incident diabetes was significantly increased in the population aged over 60, without insulin resistance and with eGFR < 90 mL/min per 1.73 m2 . CONCLUSIONS: Compared with gonadal hormones, a lower level of SHBG is independently associated with the risk of diabetes in middle-aged and elderly Chinese males.

Obesity-associated secondary hypogonadism in young and middle-aged men in Guangzhou: A single-centre cross-sectional study.

AIM: Male obesity-associated secondary hypogonadism (MOSH) is becoming a public health issue. We aimed to know MOSH among young and middle-aged men in our hospital, to analyse their sex hormones and other index, and to determine leptin as a risk factor for MOSH. METHODS: In total, 258 men (ages ranging from 20 to 60, mean 38 ± 15) were enrolled in this study, and 242 of these men had their complete data, body mass index (BMI), waist circumference and sex hormones retrospectively investigated. The leptin and lipid levels were also evaluated, and comparisons were made between young (20-39 years old) and middle-aged (40-60 years old) men. RESULTS: Among all the participants, 7 were thin, with a BMI < 18.5 kg/m2 , 95 had a normal BMI (18.5 ≤ BMI < 23.9 kg/m2 ), 87 (35.9%) were overweight (24 ≤ BMI ≤ 27.9 kg/m2 ) and 53 (21.9%) were obese (BMI ≥ 28 kg/m2 ), 173 (71.5%) had a waist sized ≥ 85 cm. Among the 242 men, 104 (43%) had hypogonadism (TT ≤ 331.412 ng/dL). Compared with the men of normal weight, the level of testosterone of the obese men decreased (P = .006), while the level of serum lipids (including total cholesterol, TG and low-density lipoprotein cholesterol, P < .05) was elevated, higher UA, FSH and leptin were also present in the obese men. There were 83 (34.2%) men with MOSH. Compared with middle-aged men with MOSH, the FSH in young men was significantly reduced (P < .05); no significant increase in estradiol was observed in the MOSH group. The leptin levels in the MOSH group were significantly higher than those in the hypogonadism only group (P < .001). CONCLUSION: Obesity increases the prevalence of hypogonadism. The decrease in testosterone levels in young men maybe due to inhibition of the hypothalamic pituitary gonadal axis. Leptin is an independent risk factor for MOSH.

Matrix metalloproteinase 9 induces keratinocyte apoptosis through FasL/Fas pathway in diabetic wound.

Apoptosis is a mechanism to remove unwanted cells in the tissue. In diabetic wound, which is characterized by delayed healing process, excessive apoptosis is documented and plays a crucial role. Matrix metalloproteinase 9 (MMP9), which is elevated in non-healed diabetic wound, is necessary for healing process but its abnormality resulted in a delayed healing. The classical function of MMP9 is the degradation of extracellular matrix (ECM). However, there is some literature evidence that MMP9 triggers cell apoptosis. Whether the excessive MMP9 contributes to epidermis cell apoptosis in delayed healing diabetic wound and the underlying mechanisms is not clear. In this study, we aimed to explore whether MMP9 induced keratinocyte apoptosis and investigate the plausible mechanisms. Our in vitro study showed that advanced glycation end products (AGEs) induced keratinocyte apoptosis and enhanced MMP9 level. Besides, MMP9, both intra-cellular expressions and extra-cellular supplement, promoted cell apoptosis. Further, MMP9 resulted in an increased expression of FasL, other than Fas and p53. These findings identified a novel effect that MMP9 exerted in delayed diabetic wound healing, owing to a pro-apoptotic effect on keratinocyte, which was mediated by an increase of FasL expression. This study increases understanding of elevated MMP9 which is involved in diabetic wound repair and offers some insights into novel future therapies.

Endothelial cell-derived small extracellular vesicles suppress cutaneous wound healing through regulating fibroblasts autophagy.

Diabetic foot ulcer is a life-threatening clinical problem in diabetic patients. Endothelial cell-derived small extracellular vesicles (sEVs) are important mediators of intercellular communication in the pathogenesis of several diseases. However, the exact mechanisms of wound healing mediated by endothelial cell-derived sEVs remain unclear. sEVs were isolated from human umbilical vein endothelial cells (HUVECs) pretreated with or without advanced glycation end products (AGEs). The roles of HUVEC-derived sEVs on the biological characteristics of skin fibroblasts were investigated both in vitro and in vivo We demonstrate that sEVs derived from AGEs-pretreated HUVECs (AGEs-sEVs) could inhibit collagen synthesis by activating autophagy of human skin fibroblasts. Additionally, treatment with AGEs-sEVs could delay the wound healing process in Sprague-Dawley (SD) rats. Further analysis indicated that miR-106b-5p was up-regulated in AGEs-sEVs and importantly, in exudate-derived sEVs from patients with diabetic foot ulcer. Consequently, sEV-mediated uptake of miR-106b-5p in recipient fibroblasts reduces expression of extracellular signal-regulated kinase 1/2 (ERK1/2), resulting in fibroblasts autophagy activation and subsequent collagen degradation. Collectively, our data demonstrate that miR-106b-5p could be enriched in AGEs-sEVs, then decreases collagen synthesis and delays cutaneous wound healing by triggering fibroblasts autophagy through reducing ERK1/2 expression.

Patterns and trends in OSHA occupational noise exposure measurements from 1979 to 2013.

OBJECTIVES: Noise is one of the most common exposures, and occupational noise-induced hearing loss (NIHL) is highly prevalent. In addition to NIHL, noise is linked to numerous non-auditory health effects. The Occupational Safety and Health Administration (OSHA) maintains the Integrated Management Information System (IMIS) database of compliance-related measurements performed in various industries across the USA. The goal of the current study was to describe and analyse personal noise measurements available through the OSHA IMIS, identifying industries with elevated personal noise levels or increasing trends in worker exposure over time. METHODS: Through a Freedom of Information Act request, we obtained OSHA's noise measurements collected and stored in IMIS between 1979 and 2013 and analysed permissible exposure limit (PEL) and action level (AL) criteria measurements by two-digit industry code. RESULTS: The manufacturing industry represented 87.8% of the 93 920 PEL measurements and 84.6% of the 58 073 AL measurements. The highest mean noise levels were found among the agriculture, forestry, fishing and hunting industry for PEL (93.1 dBA) and the mining, quarrying and oil and gas extraction group for AL (93.3 dBA). Overall, measurements generally showed a decreasing trend in noise levels and exceedances of AL and PEL by year, although this was not true for all industries. CONCLUSIONS: Our results suggest that, despite reductions in noise over time, further noise control interventions are warranted both inside and outside of the manufacturing industry. Further reductions in occupational noise exposures across many industries are necessary to continue to reduce the risk of occupational NIHL.

Hearing Protector Attenuation and Noise Exposure Among Metal Manufacturing Workers.

OBJECTIVES: This study utilized personal noise measurements and fit-testing to evaluate the association between noise exposures and personal attenuation rating (PAR) values among participating workers, and second, to compare the attenuated exposure levels received by the workers and the British Standards Institute's recommended noise exposure range of 70 to 80 dBA. DESIGN: We measured hearing protection device (HPD) attenuation among a sample of 91 workers at 2 US metal manufacturing facilities, through performance of personal noise dosimetry measurements and HPD fit-testing over multiple work shifts. We compared this testing with participant questionnaires and annual audiometric hearing threshold results. RESULTS: The average 8-hr time-weighted average noise exposures for study participants was 79.8 dBA (SD = 7.0 dBA), and the average PAR from fit-testing was 20.1 dB (±6.7 dB). While differences existed between sites, 84% of the 251 PAR measurements resulted in effective protection levels below the recommended 70 dBA (indicating overprotection), while workers were underprotected (i.e., effective exposures >80 dBA) during <1% of monitored shifts. Our results also demonstrated a significant positive relationship between measured noise exposure and PAR among non-custom-molded plug users (p = 0.04). Non-custom-molded plug wearers also showed a significant increase in PAR by sequential fit-test interaction (p = 0.01), where on average, subsequent fit-testing resulted in increasingly higher HPD attenuation. Workers at site 1 showed higher PARs. PARs were significantly related to race, even when adjusting for site location. While age, hearing threshold level, task, and self-reported tinnitus showed no significant effect on individual PAR in an unadjusted model, site, race, and sand- or water-blasting activities were significant predictors in adjusted models. Within-worker variability in time-weighted averages and PARs across repeated measurements was substantially lower than variability between workers. CONCLUSIONS: Careful selection of HPDs is necessary to minimize instances of overprotection to workers in low and moderate occupational noise environments. The use of fit-testing in hearing conservation programs to evaluate PAR is recommended to avoid overprotection from noise exposure while also minimizing instances of under-attenuation.

Number of parity is associated with low-grade albuminuria in middle-aged and elderly Chinese women.

BACKGROUND: Women with a higher number of pregnancies have a higher risk of developing cardiovascular diseases. Subtle fluctuations in albumin excretion could be related to pathophysiologic changes in the vascular system. We aimed to investigate the possible association of parity with low-grade albuminuria. METHODS: We conducted a community-based study in 6495 women aged 40 years or older. Low-grade albuminuria was defined according to the highest quartile of urine albumin-to-creatinine ratio in participants free of micro- or macro-albuminuria. RESULTS: Parous women with a higher number of pregnancies had increased age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), fasting plasma glucose (FPG), and fasting insulin, as well as decreased high-density lipoprotein cholesterol (HDL-C), estimated glomerular filtration rate (eGFR) levels, and proportion of menopause. The prevalence of low-grade albuminuria in parous women gradually increased with parity number. Compared with women with one childbirth, those with more than two childbirths were independently associated with a higher prevalent low-grade albuminuria (odds ratios [ORs] 1.41, 95% confidence interval [CI], 1.09-1.81) after multiple adjustments. In subgroup analysis after multiple adjustments, significant relation between parity number and prevalent low-grade albuminuria was detected in subjects age 55 years or older. CONCLUSION: Number of parity is associated with prevalent low-grade albuminuria in middle-aged and elderly Chinese women without micro- or macro-albuminuria.

Risk assessment of recordable occupational hearing loss in the mining industry.

Objective: To evaluate the hearing loss risk in different sectors and subunits in the mining industry and to identify associated occupations, in an attempt to locate gaps between hearing conservation efforts and hearing loss risks.Design: Descriptive statistics and frequency tables were generated by commodity types, subunit operations, and/or occupations. Temporal trends of the incidences of hearing loss were reported by commodity types.Study Sample: The MSHA Accident/Injury/Illness and MSHA Address/Employment databases from 2000 to 2014 were used.Results: Incidence rate of OHL was reported highest in the coal sector compared to other commodity types. Those members of the workforce that entered the mining industry after the year 2000 accounted for 6.5% and 19.0% of the total hearing loss records for coal and non-coal, respectively. High-risk occupations found in all three commodity sectors (coal; stone, sand, and gravel; and metal/non-metal) were electrician/helper/wireman, mechanic/repairman/helper, bulldozer/tractor operator, and truck driver.Conclusion: Hearing loss risks were not uniform across mining sectors, subunit operations, and occupations. In addition to the continuous efforts of implementing engineering controls to reduce machinery sound level exposure for operators, a multi-level approach may benefit those occupations with a more dynamic exposure profile - e.g., labour/utilityman/bullgang, electrician/helper/wireman, and mechanic/repairman/helper.

The potential use of a NIOSH sound level meter smart device application in mining operations.

Many mobile sound measurement applications (apps) have been developed to take advantage of the built-in or fit-in sensors of the smartphone. One of the concerns is the accuracy of these apps when compared to professional sound measurement instruments. Previously, a research team from the National Institute for Occupational Safety and Health (NIOSH) developed the NIOSH Sound Level Meter (SLM) app for iOS smart devices. The team found the average accuracy of this app to be within ±1 dBA when using calibrated external microphones with a type 1 reference device and measuring pink noise at levels from 65 to 95 dBA in 5-dBA increments. The studies were conducted in a reverberant noise chamber at the NIOSH Acoustics Laboratory in Cincinnati. However, it is still unknown how this app performs in measuring industrial/mining sound levels outside of a controlled laboratory environment. The current NIOSH study evaluates the NIOSH SLM app to measure sound levels from a jumbo drill (a large mining machine). The study was conducted in a hemi-anechoic chamber at the NIOSH Pittsburgh Mining Research Division and followed by a field evaluation in an underground metal mine. Six different iOS smart devices were used with two types of external microphones chosen from previous studies to measure sound levels during jumbo drill operations, and the results were compared with a reference device. Results show that the average sound levels measured by the NIOSH SLM app are within ±1 dBA of the reference device both in the laboratory and field. However, the type of operation being performed, the selection and use of external microphones, distance from a noise source, and environmental factors (e.g., air movement) may all influence the accuracy of the app's performance. Although additional validation is still needed, the results from this study suggest a potential for using the NIOSH SLM app, with calibrated external microphones, to measure sound levels in mining operations.

Evaluating hearing loss risks in the mining industry through MSHA citations.

A new noise regulation for the mining industry became effective in 2000, providing a consistent regulatory requirement for both coal and non-coal mining divisions. The new rule required mines to implement hearing conservation programs, including a system of continuous noise monitoring, provision of hearing protection devices, audiometric testing, hearing loss training, and record keeping. The goal of this study was to assess hearing conservation program compliance, and excessive noise exposure and hearing loss risks for both coal and non-coal mining divisions through evaluating MSHA citations. We analyzed 13,446 MSHA citations from 2000-2014 pertinent to 30 CFR Part 62. Descriptive statistics were generated and comparisons were made among mines of different commodities. In addition, one-way ANOVA on ranks was conducted to estimate the correlation between excess risks and establishment size. Results showed that 25.6% of coal mines and 14.7% of non-coal mines were cited at least once during this period of time. Larger numbers of noncompliance were seen in stone, sand, and gravel mines (SSG). Results also suggested inadequate efforts in both audiometric testing and minimizing risk after excessive noise exposure. Finally, establishment size of mine was correlated with the increasing risk of noncompliance. We anticipate that this study can guide resource allocation for preventing noise-induced hearing loss, and help improve risk management in mining.

Aberrant Expression of Long Non-Coding RNAs in Newly Diagnosed Type 2 Diabetes Indicates Potential Roles in Chronic Inflammation and Insulin Resistance.

BACKGROUND/AIMS: Long non-coding RNAs (lncRNAs) have emerged as key players in several biological processes and complex diseases. The risk of type 2 diabetes (T2D) is determined by a combination of environmental factors and genetic susceptibility. The purpose of this study was to identify aberrant lncRNAs involved in T2D pathogenesis. METHODS: Microarray analysis was performed using whole blood samples from patients newly diagnosed with T2D and healthy controls. Pathway and Gene Ontology (GO) analyses were utilized to annotate the target genes. Coding non-coding co-expression (CNC) analysis was performed to construct a co-expression network. RESULTS: We found 55 lncRNAs and 202 mRNAs were differentially expressed in the T2D group compared to the healthy control group. Pathway and GO analyses demonstrated that dysregulated mRNAs were mainly associated with immune regulation, inflammation, and insulin resistance, whereas CNC analysis identified 10 pairs of co-expressed lncRNA-mRNAs in our patient cohort (R > 0.99). Furthermore, expression of the top three upregulated lncRNAs in the T2D group was correlated with measures of glycometabolism (P < 0.05). CONCLUSION: This study identified aberrantly expressed lncRNAs and mRNAs in Han Chinese patients with T2D, and demonstrated that dysregulated lncRNAs may have roles in T2D pathogenesis through regulation of inflammation and insulin resistance.

What can 35 years and over 700,000 measurements tell us about noise exposure in the mining industry?

OBJECTIVE: To analyse over 700,000 cross-sectional measurements from the Mine Safety and Health Administration (MHSA) and develop statistical models to predict noise exposure for a worker. DESIGN: Descriptive statistics were used to summarise the data. Two linear regression models were used to predict noise exposure based on MSHA-permissible exposure limit (PEL) and action level (AL), respectively. Twofold cross validation was used to compare the exposure estimates from the models to actual measurement. The mean difference and t-statistic was calculated for each job title to determine whether the model predictions were significantly different from the actual data. STUDY SAMPLE: Measurements were acquired from MSHA through a Freedom of Information Act request. RESULTS: From 1979 to 2014, noise exposure has decreased. Measurements taken before the implementation of MSHA's revised noise regulation in 2000 were on average 4.5 dBA higher than after the law was implemented. Both models produced exposure predictions that were less than 1 dBA different than the holdout data. CONCLUSION: Overall noise levels in mines have been decreasing. However, this decrease has not been uniform across all mining sectors. The exposure predictions from the model will be useful to help predict hearing loss in workers in the mining industry.

AGEs trigger autophagy in diabetic skin tissues and fibroblasts.

OBJECTIVE: Accumulation of advanced glycation end products (AGEs) contributes to the development of diabetic ulcers. Recent evidence indicates that AGEs administration enhanced autophagy in many cell types. As a positive trigger of autophagy, the effect of AGEs on autophagy in skin tissues and fibroblasts remains unknown. METHODS: Skin tissues were isolated from Spreqne-Dawley rats and immunohistochemical staining was performed to analyze the location of LC3 and FOXO1 in skin tissues. Then primary cultured foreskin fibroblast cells with treated with AGEs and the effect of AGEs on autophagy was investigated. Protein level expressions of LC3, Beclin-1 and FOXO1 in fibroblasts were analyzed by Western blotting. Autophagic flux is detected with autophagy inhibitor chloroquine and mRFP-GFP-LC3 tandem construct. RESULTS: Compared with skin from normal rats, immunohistochemical staining shows a predominant LC3 localization in fibroblasts cytoplasm in diabetic rats. Elevated expression of FOXO1 also existed in diabetic rats dermis fibroblasts when compared with normal rats in immunohistochemical analysis. In human skin fibroblasts cells, AGEs administration stimulated the autophagy related LC3-II/LC3-I and Beclin-1 expressions and increased autophagy flux. In mRFP-GFP-LC3 puncta formation assays, both autolysosome and autophagosome were increased in human fibroblasts after treatment with AGEs. Fibroblasts exposed to AGEs also have increased FOXO1 expression compared with control group. CONCLUSION: AGEs could induce autophagy at least in part via regulating the FOXO1 activity in diabetic skin tissues and fibroblasts.

α-ketoglutarate is associated with delayed wound healing in diabetes.

AIM: A high level of matrix metalloproteinase 9 (MMP-9) is a predictor of poor wound healing in diabetic foot ulcers. In skin keratinocytes, site-specific DNA demethylation plays an important role in MMP-9 expression. Ten-eleven translocation enzyme 2 (TET2) protein, one member of TET family, could rely on α-ketoglutarate (α-KG) as cosubstrate to exhibit catalytic activity of DNA demethylation. Here, we aimed to explore the changes of α-KG and its relationship with MMP-9 and TET2 during diabetic wound healing. METHODS: Seventy-one cases of patients with diabetic foot ulcers and 53 cases of nondiabetic ulcers were enrolled. Serum, urine and wound fluids were collected for measurement of α-KG levels and MMP-9 expression. Skin tissues were collected for the measurement of TET2 and MMP-9 expression. Clinical parameters were collected, and transcutaneous oxygen pressure (TcPO2) levels of feet were detected. RESULTS: The levels of α-KG, TET2 and MMP-9 were significantly increased in diabetic wound compared with nondiabetic wound (P = 0·010, 0·016 and 0·025). There was a significant correlation between a low TcPO2 and a high α-KG level of wound fluids (r = -0·395, P = 0·002). Further analysis showed that α-KG concentration had a positive correlation with both haemoglobin A1c (HbA1C) and 2 h postprandial blood glucose (PBG) (r = 0·393, P = 0·005; r = 0·320, P = 0·025, respectively). CONCLUSIONS: The levels of α-KG, TET2 and MMP-9 were significantly increased in diabetic wound compared with nondiabetic wound. Elevated α-KG was related to local hypoxia ischaemia status and systematic poor glycaemic control.

AGE-induced keratinocyte MMP-9 expression is linked to TET2-mediated CpG demethylation.

Studies have documented that unusually high expression of matrix metalloproteinase-9 (MMP-9) suppresses wound healing during the late stages of diabetic foot ulcers. Recently, it has been reported that the presence of advanced glycation end products-bovine serum albumin (AGE-BSA) resulted in a higher expression of MMP-9 in skin primary keratinocytes. The aim of the present study was to elucidate the molecular machinery that is responsible for the inappropriately high AGE-BSA-induced expression of MMP-9. It has been demonstrated that site-specific DNA demethylation played an important role in MMP-9 expression in AGE-BSA-stimulated keratinocytes. Ten-eleven translocation-2 (TET2) was up-regulated, whereas the percentage of methylation in the MMP-9 promoter was reduced. Furthermore, TET2 directly bound to a fragment surrounding the transcriptional start site in the MMP-9 promoter region, contributing to the regulation of MMP-9 expression. In addition, evidence indicated that TET2 affected the migration and proliferation in vitro of cultured skin primary keratinocytes. These findings indicated that TET2 directly interacted with the promoter region of MMP-9 in diabetic tissues and may be a novel master regulator of wound healing.

Reducing major lower extremity amputations after the introduction of a multidisciplinary team in patient with diabetes foot ulcer.

BACKGROUND: Diabetic foot ulceration is receiving more attention because of its high amputation and mortality rate. It is essential to establish the frequency of amputations in people with diabetes after any change to the management of diabetic foot care. The present study aim to compare the frequency of lower-extremity amputations in patients with diabetes foot ulcer over a ten-year period. METHODS: Six hundred forty eight patients with diabetes foot ulcer were retrospectively studied from 2004 to 2013. The clinical features, laboratory results and the lower-extremity amputations were recorded. Major amputation was defined as amputations above the ankle while minor amputation was amputations below the ankle in the present study. RESULTS: Patients with diabetic foot ulcer were old (age 66.96 ± 11.96 years), with a long duration of diabetes (10.30 ± 6.94 years), high HbA1c (9.19 ± 2.62 %), SBP (144.05 ± 24.18 mmHg), DBP (79.53 ± 11.88 mmHg), LDL-C (2.71 ± 0.93 mmol/L) and had great frequency of neuropathy (62.7 %), retinopathy (45.0 %), nephropathy (39.5 %) and PAD (33.2 %). From 2004 to 2013, the frequency of all lower-extremity amputations is 12.0 % (5.2 % major amputation, 6.8 % minor amputation). The frequency of major amputations decreased from 9.5 % in 2004 and 14.5 % in 2005 to less than 5.0 % after 2006. In particular, there was a significant decline in major amputations of diabetic foot patient with Wagner 3 to 4 wounds. The frequency rate of major amputations in diabetic foot patient with Wagner 3 to 4 wounds fell from 35.7 % in 2004 to 4.4 % after 2007. The change in frequency of minor amputations was fluctuation. CONCLUSION: This study demonstrates that the introduction of a multidisciplinary team, coordinated by an endocrinologist and a podiatrist, for managing diabetic foot disease is associated with a reduction in the frequency of major amputations in patients with diabetes.