Blood lipid profile, HbA1c, fasting glucose, and diabetes: a cohort study and a two-sample Mendelian randomization analysis.

PURPOSE: The prevalence of diabetes is increasing worldwide. The associations between the lipid profile and glycated hemoglobin (HbA1c), fasting glucose, and diabetes remain unclear, so we aimed to perform a cohort study and a two-sample Mendelian randomization (MR) study to investigate the causality between blood lipid profile and HbA1c, fasting glucose, and diabetes. METHODS: A total of 25,171 participants from the Taiwan Biobank were enrolled. We applied a cohort study and an MR study to assess the association between blood lipid profile and HbA1c, fasting glucose, and diabetes. The summary statistics were obtained from the Asian Genetic Epidemiology Network (AGEN), and the estimates between the instrumental variables (IVs) and outcomes were calculated using the inverse-variance weighted (IVW) method. A series of sensitivity analyses were performed. RESULTS: In the cohort study, high-density lipoprotein cholesterol (HDL-C) was negatively associated with HbA1c, fasting glucose, and diabetes, while the causal associations between HDL-C and HbA1c (ßIVW = - 0.098, p = 0.003) and diabetes (ßIVW = - 0.594, p < 0.001) were also observed. Furthermore, there was no pleiotropy effect in this study using the MR-Egger intercept test and MR-PRESSO global test. CONCLUSIONS: Our results support the hypothesis that a genetically determined increase in HDL-C is causally related to a reduction in HbA1c and a lower risk of diabetes.

Increased incidence of ischaemic heart disease and cerebrovascular disease in psoriasis patients with depression: a nationwide retrospective cohort study.

BACKGROUND: Psoriasis is known to confer a higher risk of cardiovascular and cerebrovascular diseases. However, very few studies have investigated whether the development of depression in psoriasis patients may further increase this vascular risk. OBJECTIVE: We investigated the risk of ischaemic heart disease and cerebrovascular disease in Taiwanese psoriasis patients with and without depression. METHODS: A nationwide population-based retrospective cohort study was performed using the National Health Insurance Research Database. We included 604 psoriasis patients with depression, who were matched to 2416 psoriasis patients without depression (1 : 4 ratio). Relative risks (RR) with 95% confidence intervals (CI) were determined using the Cox proportional hazards regression model, with adjustment for demographic characteristics and comorbidities. RESULTS: Compared with psoriasis patients without depression, psoriasis patients with depression had greater risk of developing incident ischaemic heart disease (19.5% vs. 8.3%, adjusted RR 1.98, 95% CI 1.57-2.49), cerebrovascular disease (15.6% vs. 5.9%, adjusted RR 2.29, 95% CI 1.76-2.98), and either ischaemic heart disease or cerebrovascular disease (28.3% vs. 12.5%, adjusted RR 1.94, 95% CI 1.60-2.35). Subgroup analysis showed that in psoriasis patients with depression, a higher risk of incident ischaemic heart disease or cerebrovascular disease was present in age groups 30-100 years, in both males and females, and in both lower and higher income categories. CONCLUSION: Depression is an independent risk factor for incident ischaemic heart disease and cerebrovascular disease in patients with psoriasis. Therefore, clinicians need to be vigilant for the increased vascular risk in psoriasis patients with depression.

Association between psoriasis, psoriatic arthritis and gout: a nationwide population-based study.

BACKGROUND: Psoriasis is a common skin disease that has been recently found to be associated with various systemic inflammatory disorders. However, the association between psoriasis and gout has not been well defined. OBJECTIVE: We investigated whether there is an association between psoriasis, psoriatic arthritis and gout in a large population of patients in Taiwan. METHODS: A nationwide population-based cross-sectional study was performed using the Taiwanese National Health Insurance Research Database (NHIRD). A total of 114 623 patients with gout and 114 623 patients without gout (1 : 1 propensity score-matched according to age, sex, income category and urbanization level) were identified. The prevalence of psoriasis, psoriatic arthritis and other comorbid diseases in these two groups of patients was compared. Adjusted odds ratios (OR) were calculated using conditional logistic regression. RESULTS: There was an increased prevalence of psoriasis in patients with gout compared with patients without gout (1.6% vs. 1.1%, P < 0.0001). Subgroup analysis showed an increased prevalence of psoriatic arthritis (0.3% vs. 0.1%, P < 0.0001) in patients with gout compared with patients without gout. In addition, multiple conditional logistic regression analysis showed that gout was significantly associated with psoriasis (adjusted OR 1.30, 95% CI 1.20-1.42) and psoriatic arthritis (adjusted OR 2.50, 95% CI 1.95-3.22). After stratification by age and sex, it was found that the strength of the association between gout and psoriasis was similar among males and females but varied according to age group, with patients aged 41-50 years having the strongest association. CONCLUSION: Gout is significantly associated with psoriasis and psoriatic arthritis in the Taiwanese population, and the strength of the association varies with the patient's age. Further studies are warranted to elucidate the molecular mechanisms underlying this association.

Risk of developing psoriasis in patients with schizophrenia: a nationwide retrospective cohort study.

BACKGROUND: Schizophrenia is a complex disease which proceeds from an interaction between genetic background and environmental factors. Recent studies showed T helper 17 (Th17) signalling, which is the main downstream immune response of psoriasis, is activated in schizophrenia. OBJECTIVE: To investigate whether patients with schizophrenia have higher risk of psoriasis. METHODS: In this nationwide retrospective cohort study, we analysed the 1 million enrollees' cohort from Taiwan's National Health Insurance Research Database. Psoriasis and schizophrenia were ascertained by International Classification of Diseases, 9th revision, Clinical Modification coding. The study cohort was comprised of enrollees diagnosed with schizophrenia during the period from 1 January 1996 through 31 December 2010, while the comparison population consisted of enrollees who had not been diagnosed with schizophrenia during the study period. Hazard ratio (HR) and 95% confidence interval (CI) were calculated for the risk of psoriasis associated with schizophrenia using Cox proportional hazard regression. RESULTS: The adjusted HR of psoriasis associated with schizophrenia was 2.32 (95% CI = 1.81-2.98). After 15 years, the cumulative incidence of psoriasis in patients with schizophrenia and comparison population was 2.82% and 1.17%, respectively. The Kaplan-Meier curves for the cumulative incidence of psoriasis in individuals with and without schizophrenia differed significantly (P < 0.0001, log-rank test). CONCLUSIONS: Patients with schizophrenia have higher risk of psoriasis, which may be due to common genetic susceptibilities and/or immunologic mechanisms in both diseases. Th17 signalling and pro-inflammatory cytokines may act as a link between these two diseases and are potential therapeutic targets for schizophrenia.

Effect of high glucose, Porphyromonas gingivalis lipopolysaccharide and advanced glycation end-products on production of interleukin-6/-8 by gingival fibroblasts.

BACKGROUND AND OBJECTIVE: It is known that chronic periodontal infection can magnify the cytokine responses in patients with diabetes. Hyperglycemia increases the proinflammatory status, including the levels of advanced glycation end-products (AGEs), in patients with periodontitis. However, whether AGEs have additional effects on the production of those proinflammatory cytokines in diabetic patients with periodontitis is still unknown. To examine in vitro the effect of hyperglycemia and AGEs on the amounts of interleukin (IL)-6 and IL-8 produced in periodontally infected gingiva, human gingival fibroblasts (HGFs) were stimulated with glucose, AGE-modified bovine serum albumin (AGE-BSA) and Porphyromonas gingivalis LPS in the present study. MATERIAL AND METHODS: Primary culture of HGFs was incubated with various concentrations of AGE-BSA (0, 50, 100 and 200 µg/mL) and LPS (0, 10, 100 or 1000 ng/mL) at two different glucose concentrations - normal glucose (5 mm) and high glucose (25 mm). The amounts of IL-6 and IL-8 produced by HGFs were evaluated using ELISA. Expression of the AGE receptor on HGFs was determined by flow cytometry. RESULTS: High glucose stimulated a significant increase in the production of IL-6 and IL-8 by HGFs compared with normal glucose. This enhanced production of IL-6 and IL-8 could also be observed in the presence of LPS and/or AGE-BSA. When both LPS and AGE-BSA were present, especially at high concentrations (≥ 500 µg/mL of LPS and ≥ 25 µg/mL of AGE-BSA), a synergistic effect on IL-8 production was found in the high-glucose condition. CONCLUSIONS: A synergistic effect of the production of IL-8 could be induced in HGFs with the combination of high glucose, LPS and AGEs.

An estimation of the incidence of tuberous sclerosis complex in a nationwide retrospective cohort study (1997-2010).

BACKGROUND: Tuberous sclerosis complex (TSC) is caused by mutations in TSC1 and TSC2, leading to mammalian target of rapamycin hyperactivation. Patients with TSC develop hamartomas in brain, lungs, liver and skin. Two epidemiological studies, performed in Minnesota, U.S.A., have estimated the incidence of TSC to be 0·28-0·56 per 100 000 person-years (PY), based on < 12 patients. Furthermore, whether common comorbidities are associated with this rare disease is not known. OBJECTIVES: To estimate the incidence of TSC and investigate the associations of TSC with other comorbidities, including diabetes, peptic ulcers, stroke and myocardial infarction. METHODS: We estimated the incidence and prevalence of TSC and its comorbidities from 1997 to 2010, based on the Catastrophic Illness Certificate disease database and a beneficiary cohort of 1 million people. RESULTS: The incidence of TSC in Taiwan is 0·153 per 100 000 PY. The number of patients identified with TSC in Taiwan doubled from 206 in 2006 to 471 in 2010. In 2010, the prevalence of TSC in Taiwan was estimated to be 1·58 in 100 000. We confirmed that female patients with TSC are more likely to develop renal tumours than male patients. Surprisingly, patients with TSC have a significantly decreased risk of developing peptic ulcers compared with controls. CONCLUSIONS: This is the first large-scale and longitudinal incidence study of TSC. This study provides compelling evidence that TSC mutations in humans are associated with a decreased risk of peptic ulcers.

A Salvia miltiorrhiza ethanol extract ameliorates tissue destruction caused by experimental periodontitis in rats.

BACKGROUND AND OBJECTIVE: Salvia miltiorrhiza Bunge (Labiatae), or Danshen, is a Chinese medicine used for treatment of cardiac diseases by improving blood circulation and inhibiting inflammatory responses. In this study, we aimed to determine whether an ethanol extract of S. miltiorrhiza can ameliorate tissue damage caused by periodontitis. MATERIAL AND METHODS: An ethanolic extract of S. miltiorrhiza roots was prepared, and its major constituents were determined by HPLC analysis, by comparison with known standards for the major bioactive components. The activity of the extract was evaluated in a rat model in which periodontitis was induced by ligation of a silk suture around the neck of molar teeth. The effects of the S. miltiorrhiza extract on periodontitis were assessed by dental radiography, micro-computed tomography and histology. RESULTS: The cemento-enamel junction-bone distances among the four different groups of rats were significantly different: the distance was shorter in groups treated with ligation + S. miltiorrhiza extract than in the group treated with ligation only, but was longer than in the nonligated group, regardless of the radiographic methods used. Histology and histometry also indicated a similar trend of less gingival inflammation and alveolar bone destruction in the histological sections from the S. miltiorrhiza extract groups than in those from the ligation group. CONCLUSION: Because the S. miltiorrhiza extract reduced tissue damage and bone loss caused by ligation-induced periodontitis in rats, we suggest that the S. miltiorrhiza extract might have an ameliorative effect on periodontal tissue destruction during the process of periodontitis.

The effects of diallyl sulfide upon Porphyromonas gingivalis lipopolysaccharide stimulated proinflammatory cytokine expressions and nuclear factor-kappa B activation in human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: Diallyl sulfide (DAS), a flavor compound from garlic, has varied potential therapeutic activities. Periodontitis is a disease that develops because of host-mediated inflammation to periodontal pathogens. In this study, the effects of DAS on the common proinflammatory cytokines and nuclear factor-kappa B (NF-κB) in human gingival fibroblasts (HGFs) being stimulated with lipopolysaccharide from Porphyromonas gingivalis, a potent periodontal pathogen, were evaluated. MATERIAL AND METHODS: Cytotoxicities of DAS and lipopolysaccharide on HGFs were measured with MTS assay. The mRNA and protein expressions of proinflammatory cytokines, including interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α, from the HGFs treated with lipopolysaccharide with and without DAS were examined with reverse transcription-polymerase chain reaction and immunocytochemistry, respectively. In addition, the activation and nuclear translocation of NF-κB with and without DAS were compared. RESULTS: DAS and lipopolysaccharide treatments within 3 mm and 10 µg/mL, respectively, did not affect the survival rate of HGFs. Lipopolysaccharide (1 µg/mL) significantly increased the mRNA expressions of IL-1ß, IL-6 and TNF-α; however, DAS (1 mm) inhibited these expressions. The protein expressions of TNF-α, IL-1ß, as well as the NF-κB nuclear translocation were increased after lipopolysaccharide treatment, but decreased when there was a DAS pretreatment. CONCLUSION: DAS diminished P. gingivalis lipopolysaccharide-stimulated cytokine expression and NF-κB activation in HGFs; we therefore suggest DAS may be beneficial on periodontal inflammation.

Increased level of MSU crystal-bound protein apolipoprotein A-I in acute gouty arthritis.

BACKGROUND: Gout is a common form of inflammatory arthritis that is triggered by the crystallization of monosodium urate (MSU). We investigated the potential proteins that relate to the pathogenesis or the spontaneous resolution of acute gouty arthritis. METHOD: We screened for differentially expressed proteins in the plasma of patients with acute gouty arthritis using two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) identification. We confirmed these findings in a population study of 209 subjects, and further determined the protein profile of the synovial fluid (SF) from 24 gouty patients during acute attack by liquid chromatography coupled with tandem MS (LC/MS/MS). RESULTS: The highly expressed apolipoprotein A-I (apoA-I) was identified in the plasma of acute gouty patients compared with healthy controls. Moreover, we detected high levels of SF apoA-I in 83.3% of acute gouty patients during attack. From the population study, apoA-I was increasingly associated with normouricaemia, hyperuricaemia, and acute gouty arthritis (ptrend < 0.001), and plasma uric acid (UA) and apoA-I were positively correlated (p = 0.0156). We used a human liver cell model and found that UA enhanced the hepatic apoA-I mRNA expression level (ptrend < 0.01) and apoA-I secretion level (ptrend = 0.002) in a dose-dependent manner. An elevated MSU concentration caused the endogenous apoA-I to deplete gradually. CONCLUSIONS: Based on the role of apoA-I in anti-inflammation, our observational data in acute gout support the hypothesis that apoA-I expression can be induced under the condition of a high concentration of UA and its elevated level may be implicated in the spontaneous resolution of acute gouty arthritis.

Persistent mechanical allodynia positively correlates with an increase in activated microglia and increased P-p38 mitogen-activated protein kinase activation in streptozotocin-induced diabetic rats.

BACKGROUND: In experimental early painful diabetic neuropathy, persistent hyperglycaemia induces dys-regulated sodium channel (Navs) expression in the dorsal root ganglion (DRG) and activates microglia in the spinal dorsal horn (SDH). However, information on diabetes-induced chronic neuropathic pain is limited. Therefore, we investigated abnormal Navs in the DRG and activated glial cells in the SDH of diabetic rats with chronic neuropathic pain. METHODS: Sixty-six rats were divided into diabetic and control groups: control rats (n = 18; 1 mL of normal saline via the right femoral vein) and diabetic rats [n = 48; 60 mg/kg streptozotocin (STZ) via the right femoral vein]. Hindpaw behavioural tests, Navs expression in the DRG, activation of glial cells in the SDH and the number of neurons in the SDH were measured at 1 and 2 weeks, and 1, 2, 3 and 6 months following saline and STZ administration. RESULTS: All diabetic rats exhibited hyperglycaemia from day 7 to 6 months. The diabetic rats decreased withdrawal threshold to mechanical stimuli but had blunted responses to thermal stimuli. Consistent up-regulation of Nav1.3 and down-regulation of Nav1.8 was observed. Microglial cells were activated early in the SDH and lasted for 6 months. A positive correlation between mechanical allodynia, Nav1.3 and microglial activation was observed. In addition, microglia activation in the SDH of STZ-induced diabetes was mediated, in part, by phosphorylation of p-38 mitogen-activated protein kinase. CONCLUSIONS: Diabetic rats showed hindpaw mechanical allodynia for 6 months. Persistent mechanical allodynia was positively associated with sustained increased activation of Nav1.3 and increased p38 phosphorylation in activated microglia.

Cyclosporine-A inhibits MMP-2 and -9 activities in the presence of Porphyromonas gingivalis lipopolysaccharide: an experiment in human gingival fibroblast and U937 macrophage co-culture.

BACKGROUND AND OBJECTIVE: Studies have shown that bacterial plaque and the associated gingival inflammation increase the severity of gingival overgrowth induced by cyclosporine-A (CsA). This in vitro study aimed to evaluate the effect of CsA on the activities of MMPs from the co-culture of human gingival fibroblasts and U937 macrophages in the presence or absence of Porphyromonas gingivalis lipopolysaccharide (LPS). MATERIAL AND METHODS: Activities of pro-MMP-2, MMP-2 and pro-MMP-9 in the supernatants of independent cultures and co-cultures were examined by zymography. RT-PCR was selected to evaluate the expression of mRNA for membrane type-1 (MT1) MMP in the co-cultures. RESULTS: Activities of MMPs in the co-cultures were significantly greater when compared with any of the independent cultures. Lipopolysaccharide significantly increased the MMP activities in a dose-dependent manner in the co-cultures, whereas CsA inhibited these activities. In the presence of both CsA and LPS, the MMP activities inhibited by CsA could still be observed in the co-cultures. In the individual cultures, in contrast, the CsA-inhibited MMP activities, in the presence of LPS, were minimally detected. The mRNA expression of MT1-MMP was significantly enhanced after LPS treatment; however, this enhancement was inhibited by CsA. CONCLUSION: This study demonstrated that, in co-cultures of human gingival fibroblasts and U937 macrophages, CsA could inhibit MMP activities in the presence of P. gingivalis LPS. It might be part of the underlying reason for the persistent overgrowth of gingiva seen when bacterial plaque and local inflammation are present during CsA therapy.

Nrf-2 regulates cyclosporine-stimulated HO-1 expression in gingiva.

Cyclosporine-A (CsA) stimulates heme oxygenase-1 (HO-1) expression in the gingiva, but the regulation and the role of HO-1 in gingival overgrowth are not well-understood. HO-1 is regulated by several transcription factors, such as nuclear factor-κB (NF-κB) and nuclear factor erythroid-2-related factor 2 (Nrf-2). The aim of this study was to examine the role of Nrf-2 in the regulation of CsA-stimulated HO-1 expression in human gingival fibroblasts. Nrf-2 siRNA (siNrf-2), NF-κB, kinase inhibitors, and sulforaphane (SFN) were used to examine the nuclear translocation of Nrf-2 and expression of HO-1 and transforming growth factor-ß1 (TGF-ß1) in cells. Treatment with siNrf-2, but not with an NF-κB inhibitor, reduced CsA-stimulated HO-1 mRNA expression. ERK inhibition significantly decreased CsA-stimulated Nrf-2 nuclear translocation and HO-1 mRNA expression. Pre-treatment with SFN showed that HO-1 plays a role in attenuating CsA-mediated TGF-ß1 expressions. These findings suggest that CsA-stimulated HO-1 expression is mediated through the activation of ERK, and that Nrf-2 plays a protective role against CsA-induced gingival fibrosis by modulating collagen turnover-related genes.

Up-regulation of retinoblastoma protein phosphorylation in gingiva after cyclosporine A treatment: an in vivo and in vitro study.

BACKGROUND AND OBJECTIVE: Cyclosporine A can induce gingival cell proliferation; however, the precise molecular regulation of the proliferation is uncertain. Therefore, this study was carried out to examine, in vivo and in vitro, the expression of genes and proteins associated with gingival cell proliferation after treatment with cyclosporine A. MATERIAL AND METHODS: Forty Sprague Dawley rats with right maxillary posterior edentulous gingivae were assigned to a cyclosporine A group (30 mg/kg daily of cyclosporine A, administered orally) or a control group (administered mineral oil only). The animals were killed 4 wk after treatment. The edentulous gingivae were dissected out and analyzed for the expression of proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin-dependent kinase 4 (CDK4) and retinoblastoma protein (Rb1) mRNA and/or protein, and phosphorylated Rb1 (pRb1), by real-time RT-PCR or immunohistochemistry. In human gingival fibroblast (HGF) cultures, the expression of PCNA, CDK4, cyclin D1 and Rb1 proteins and Rb1 phosphorylation were determined by western blotting after cyclosporine A treatment (0-10(4) ng/mL). RESULTS: Proliferating cell nuclear antigen and cyclin D1 mRNAs (Pcna and Ccnd1, respectively) were expressed more strongly in the gingivae of cyclosporine A-treated animals than in the gingivae of the controls. Immunohistochemical analyses showed that a greater number of gingival cells stained positive for cyclin D1, CDK4 and pRb1 in the cyclosporine A group than in the control group. Increased expression of cyclin D1, CDK4 and PCNA proteins was observed in HGFs after cyclosporine A treatment. The phosphorylation of Rb1 was enhanced in HGFs after treatment with cyclosporine A at concentrations of 10(2)-10(3) ng/mL. CONCLUSION: The increases in cyclin D1, PCNA and CDK4, together with the enhanced phosphorylation of Rb1, suggest that cyclosporine A promotes cell-cycle progression through the G(1)/S transition in the gingiva.

Cyclosporine A enhances apoptosis in gingival keratinocytes of rats and in OECM1 cells via the mitochondrial pathway.

BACKGROUND AND OBJECTIVE: We reported previously that cyclosporine A induces a high level of expression of p21 in rat gingival keratinocytes and in OECM1 cells. In this study, the apoptosis of gingival keratinocytes after treatment with cyclosporine A was evaluated using the same models. MATERIAL AND METHODS: Forty Sprague-Dawley rats with right edentulous ridges were assigned into cyclosporine A (30 mg/kg) and control groups. Four weeks later, gingivae were screened for expression of apoptotic genes using microarray analyses and DNA fragmentation. The expression of bcl2-associated X protein (Bax), apoptosis-inducing factor (AIF) and Caspase 3 mRNAs, and the expression of Bax, AIF, Caspase 9 and Fas proteins, were analyzed using the reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. Apoptosis in OECM1 cells (keratinocytes of a gingival carcinoma cell line), after treatment with cyclosporine A, was evaluated by 4',6-diamidino-2-phenylindole (DAPI) staining and flow cytometry, whereas the expression of Bax, AIF, Caspase 3 and 8, Bcl-2 and Fas proteins were examined using western blotting. RESULTS: According to microarray analyses, the expression of certain apoptotic genes was altered in the gingiva of rats who received cyclosporine A, and increased number of DNA fragments were detected. Expression of mRNA or protein for Bax, AIF and Caspase 3 and 9 in the gingivae of rats increased after treatment with cyclosporine A. An increased number of apoptotic bodies and of OECM1 cells in the sub-G1 phase was observed after treatment with cyclosporine A. Increased expression of AIF, Bax and Caspase 3 protein, but not of bcl-2, Caspase 8 or Fas protein, was observed in cells after treatment with cyclosporine A. CONCLUSION: Based on the above findings, we suggest that cyclosporine A might enhance the apoptosis of gingival keratinocytes, mainly via the mitochondrial pathway.

Association study between keratinocyte-derived growth factor gene polymorphisms and susceptibility to vitiligo vulgaris in a Taiwanese population: potential involvement of stem cell factor.

BACKGROUND: Vitiligo vulgaris is a depigmentary disorder resulting from the disappearance of functional melanocytes. Currently, the pathogenesis of this disorder remains obscure. OBJECTIVES: Genetic analysis of patients with vitilgo may provide important clues for elucidating the complex pathomechanisms involved in the disease process. Because dysfunctional keratinocytes have recently been implicated in the pathogenesis of vitiligo vulgaris, we conducted a case-control association study to investigate this phenomenon. PATIENTS AND METHODS: Fifty-one patients with vitiligo vulgaris and 118 healthy controls from Taiwan were recruited to investigate the association between relevant keratinocyte-related genes and the occurrence of vitiligo vulgaris. This study genotyped 11 single-nucleotide polymorphisms (SNPs) in five genes including stem cell factor (SCF, also known as KITLG), basic fibroblast growth factor (bFGF, also known as NuDT6), endothelin-1 (EDN1), hepatocyte growth factor (HGF) and stem cell growth factor (SCGF, also known as CLEC11A). RESULTS: Our results revealed that the A allele for SNP rs11104947 in the SCF gene and the T allele for SNP rs13866 in the SCGF gene were, respectively, associated with a 1.95- and a 2.14-fold risk of developing vitiligo vulgaris. A higher risk was also detected among subjects who carried the SCF rs995029/rs11104947 C/A haplotype (odds ratio = 2.45). Furthermore, the at-risk alleles for SCF rs11104947 (A allele) and for SCGF SNP rs13866 (T allele) were found to display a 7.92-fold increased gene-gene combined risk. No significant relationship between polymorphic frequency for genes bFGF, EDN1 as well as HGF and occurrence of vitiligo vulgaris was observed. CONCLUSIONS: These novel genetic findings provide new insights in relation to the mechanisms that might be involved in the development of vitiligo vulgaris.

Cyclosporine A inhibits the expression of membrane type-I matrix metalloproteinase in gingiva.

BACKGROUND AND OBJECTIVE: Membrane type-I matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) regulate the activation of MMP-2; however, their roles in the activation of MMP-2 in gingiva during treatment with cyclosporine A are still unknown. Therefore, the expressions of membrane type-I MMP and TIMP-2, as well as MMP-2, in gingivae upon treatment with cyclosporine A were examined in vivo and in vitro. MATERIAL AND METHODS: Thirty-four rats were divided into two groups after edentulous ridges were established. The experimental group received 30 mg/kg/d of cyclosporine A and the control group received vehicle. At the end of the experimental period, the rats were killed, the gingivae were obtained and the expression of mRNA and protein of membrane type-I MMP, TIMP-2 and MMP-2 in gingiva were examined using real-time polymerase chain reaction and immunohistochemistry. In human gingival fibroblasts, the activity of MMP-2 and the expression of MMP-2, membrane type-I MMP and TIMP-2 mRNAs were examined (using zymography and reverse transcription-polymerase chain reaction, respectively) after treatment with cyclosporine A. RESULTS: In gingivae of rats, cyclosporine A significantly decreased the expression of mRNA and protein of membrane type-I MMP, but not of TIMP-2. The expression of MMP-2 mRNA was unaffected but the expression of MMP-2 protein showed a significant decrease upon treatment with cyclosporine A. In fibroblast culture medium, the presence of cyclosporine A induced a decrease in MMP-2 activity in a dose-dependent manner. The expression of MMP-2, membrane type-I MMP and TIMP-2 mRNAs in fibroblasts was not significantly affected by cyclosporine A; however, in fibroblasts the ratio of mRNA expression of membrane type-I MMP to that of TIMP-2 decreased as the cyclosporine A dose was increased. CONCLUSION: Cyclosporine A inhibits the expression of membrane type-I MMP in gingiva and it may further reduce the activation of MMP-2.

Expression and bioactivities of endothelin-1 in gingiva during cyclosporine A treatment.

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the expression and bioactivities of endothelin-1 (ET-1) in gingiva during cyclosporine A (CsA) treatment. MATERIAL AND METHODS: After establishing edentulous ridges, experimental rats were fed 30 mg/kg/day CsA while control animals received mineral oil for 4 weeks, after which a reverse transcription-polymerase chain reaction (RT-PCR) and/or immunohistochemistry was used to examine the expression of ET-1, its receptors, proliferating cell nuclear antigen (PCNA) and inducible nitric oxide synthase (iNOS) in gingivae. The roles of the endothelin receptors A and B (ET(A) and ET(B)) in CsA-enhanced expression of PCNA and iNOS were examined in cultured human gingival fibroblasts pretreated with receptor antagonists, by immunocytochemistry and RT-PCR, respectively. RESULTS: The mRNA expression of ET-1, ET(A) and ET(B), as well as of PCNA and iNOS, was significantly greater in edentulous gingiva that received CsA compared with control gingiva. Immunohistochemistry revealed more cells positively stained for ET-1 and its receptors in the tissues of CsA-treated rats than in those of control rats. In fibroblast cultures, enhanced mRNA expression of ET-1, ET(A) and ET(B) was observed after CsA treatment at the concentrations of 10 and 100 ng/mL. Cyclosporine A-enhanced PCNA expression was somewhat reduced by blockade of ET(A), but not ET(B), whereas iNOS expression was somewhat reduced by blockade of ET(B). CONCLUSION: Based on the present findings, we suggest that: (1) CsA upregulates the gingival expression of ET-1 and its receptors; and (2) ET(A) and ET(B) have different bioactivities, ET(A) being involved in cell proliferation and ET(B) being associated with iNOS expression.

Expression of p21 and p53 in rat gingival and human oral epithelial cells after cyclosporine A treatment.

BACKGROUND AND OBJECTIVE: Expression of p21 and p53 were examined, at gene and protein levels, in edentulous gingival epithelial cells from rats and from a human oral epidermoid carcinoma cell line, OECM1, after cyclosporine A therapy. MATERIAL AND METHODS: In vivo: 20 partially edentulous SD rats were assigned into cyclosporine A feeding and control groups. After the rats were killed, p21 and p53 in gingiva were evaluated by reverse transcription-polymerase chain reaction and immunohistochemistry. In vitro: after cyclosporine A treatment, p21 and p53 of OECM1 cells were evaluated by western blot and the luciferase assay. The distribution of OECM1 cells in each phase of the cell cycle was evaluated by flow cytometry. RESULTS: The mRNA expression of p21 was significantly higher in the cyclosporine A group than in the control group. A greater number of positive anti-p21-stained cells were observed in the gingival epithelium of the cyclosporine A group than in the control group. Significantly higher levels of p21 protein and activity were observed in OECM1 cells after cyclosporine A treatment than in cells without treatment. A relative increase of cells in G0/G1 phases, and a decrease of cells in G2/M phases, were observed in OECM1 cells after cyclosporine A treatment. CONCLUSION: In the present study, higher p21 mRNA and protein expressions were observed after cyclosporine A treatment. Thus, an up-regulation of p21 expression, via a p53-independent pathway, by cyclosporine A in gingival and oral epithelial cells was suggested.

Cyclosporin-A inhibits the expression of cyclooxygenase-2 in gingiva.

BACKGROUND AND OBJECTIVE: Various inflammatory mediators are involved in the development of cyclosporine A-induced gingival overgrowth. In this study, the gingival expression of cyclooxygenase-2 after cyclosporine A therapy was examined in vivo and in vitro. MATERIAL AND METHODS: After edentulous ridges on maxilla were established, 21 Sprague-Dawley rats received cyclosporine A daily for 4 wk, and a further 21 rats received solvent. After the rats were killed, the expression of cyclooxygenase-2 mRNA, interleukin-1beta mRNA, tumor necrosis factor-alpha mRNA, and interleukin-6 mRNA was examined in the edentulous gingiva. The expression of cyclooxygenase-2 protein and the production of prostaglandin E2 were also evaluated. RESULTS: In cultured human gingival fibroblasts and epithelial cells, the expression of cyclooxygenase-2 mRNA was measured after treatment with cyclosporine A. Significantly lower expression of cyclooxygenase-2 and interleukin-1beta mRNA, but higher interleukin-6 expression, were observed in gingiva from cyclosporine A-treated rats than in those from the control rats. Significantly less prostaglandin E2 production was observed in cyclosporine A-treated rats. Immunohistochemistry revealed that fewer gingival stromal cells were positively stained for cyclooxygenase-2 in cyclosporine A-treated rats. In cultured cells, significantly less cyclooxygenase-2 mRNA was detected after treatment with cyclosporine A. CONCLUSION: The expression of cyclooxygenase-2 was lower in the plaque nonretentive gingivae and the in vitro gingival cells upon treatment with cyclosporine A. Thus, we propose that cyclosporine A inhibits the expression of gingival cyclooxygenase-2.