Disease Duration Affects the Clinical Phenotype of Primary Sjögren Syndrome: A Medical Records Review Study of 952 Cases.

OBJECTIVES: To investigate the impact of disease duration on clinical phenotypes in Chinese patients with primary Sjögren syndrome (pSS) and examine the correlation between clinical phenotypes and onset age, age at diagnosis, and disease duration. METHODS: Data from 952 patients diagnosed with pSS in China between January 2013 and March 2022 were analyzed based on medical records. Patients were categorized into 3 groups based on disease duration: short (<5 years), moderate (≥5 and <10 years), and long (≥10 years) group. Clinical characteristics were compared among the 3 groups, and pSS patients with a long disease duration were compared with the other patients after matching age at diagnosis and age at onset. RESULTS: Among the patients, 20.4% had a disease duration over 10 years. After matching for age at onset and age at diagnosis, pSS patients with a long disease duration exhibited a significantly higher prevalence of dry mouth ( p <0.001), dry eyes ( p <0.001), fatigue ( p <0.001), arthralgia ( p <0.001), and dental caries ( p <0.001) and higher rates of anti-Sjögren syndrome A ( p < 0.05), anti-Ro52 ( p < 0.05), and anti-SSB ( p < 0.05) positivity than their control groups, with prevalence increasing with disease duration ( ptrend < 0.001). However, no differences were noted in the prevalence of interstitial lung disease and leukopenia between different disease duration groups after matching for age at onset, although differences were shown when matching for age at diagnosis. CONCLUSION: Longer disease duration in pSS patients correlates with increased prevalence of sicca symptoms, fatigue, and arthralgia and higher positivity of autoantibodies associated with pSS. However, the prevalence of interstitial lung disease and leukopenia did not correlate with disease duration after matching for age at onset.

Network pharmacology-based strategy to investigate the mechanisms of artemisinin in treating primary Sjögren's syndrome.

OBJECTIVE: The study aimed to explore the mechanism of artemisinin in treating primary Sjögren's syndrome (pSS) based on network pharmacology and experimental validation. METHODS: Relevant targets of the artemisinin and pSS-related targets were integrated by public databases online. An artemisinin-pSS network was constructed by Cytoscape. The genes of artemisinin regulating pSS were imported into STRING database to construct a protein-protein interaction (PPI) network in order to predict the key targets. The enrichment analyses were performed to predict the crucial mechanism and pathway of artemisinin against pSS. The active component of artemisinin underwent molecular docking with the key proteins. Artemisinin was administered intragastrically to SS-like NOD/Ltj mice to validate the efficacy and critical mechanisms. RESULTS: Network Pharmacology analysis revealed that artemisinin corresponded to 412 targets, and pSS related to 1495 genes. There were 40 intersection genes between artemisinin and pSS. KEGG indicated that therapeutic effects of artemisinin on pSS involves IL-17 signaling pathway, HIF-1 signaling pathway, apoptosis signaling pathway, Th17 cell differentiation, PI3K-Akt signaling pathway, and MAPK signaling pathway. Molecular docking results further showed that the artemisinin molecule had higher binding energy by combining with the key nodes in IL-17 signaling pathway. In vivo experiments suggested artemisinin can restored salivary gland secretory function and improve the level of glandular damage of NOD/Ltj mice. It contributed to the increase of regulatory T cells (Tregs) and the downregulated secretion of IL-17 in NOD/Ltj model. CONCLUSION: The treatment of pSS with artemisinin is closely related to modulating the balance of Tregs and Th17 cells via T cell differentiation.

[Spatial-temporal variations of vegetation coverage and its driving force in Inner Mongolia grassland, China]. / å† è’™å¤è‰åŽŸåŒºæ¤è¢«è¦†ç›–åº¦æ—¶ç©ºæ¼”å˜åŠå ¶é©±åŠ¨åŠ›.

Inner Mongolia grassland is rich in natural vegetation and mineral resources. Based on Landsat5/7/8 NDVI data, we used pixel binary model to invert vegetation coverage of Inner Mongolia grassland area, investigated the stability, spatial distribution, and future evolution trend of vegetation coverage by using Sen+MK and Hurst index, and analyzed the driving factors of the spatial differentiation of vegetation coverage by the optimal parameters-based geographical detector. The results showed that vegetation coverage of Inner Mongolia grassland showed an increasing trend from 2006 to 2020, and the overall spatial pattern was high in the east and low in the west, mainly with great fluctuation. The regions with slight or obvious improvement characteristics (64.8%) were much more than those with slight or severe degradation characteristics (23.2%). Compared with that in the past 15 years, the proportion of degraded vegetation in the future is expected to increase to 36.6%. The central part of Xilin Gol League and Wulanqab in the central grassland area, the western part of Hulunbuir and Erdos in the eastern grassland area, and Wuhai in the western grassland area were at the risk of degradation, which should be paid more attention. Precipitation was the dominant factor of spatial differentiation in Inner Mongolia grassland, while soil type, land use, and air temperature had the most significant synergistic effect.

Sex Difference in Primary Sjögren Syndrome: A Medical Records Review Study.

OBJECTIVES: The aim of this study was to study clinical and biological differences between men and women with primary Sjögren syndrome (pSS) in China and perform a literature review to confirm if the clinical phenotypes are affected by sex in patients with pSS. METHODS: Data from 961 patients with pSS treated at a tertiary hospital in China between January 2013 and March 2022 were analyzed based on medical records. Clinical characteristics, including disease manifestations and serological parameters of the disease, were compared between men and women with pSS using the Mann-Whitney U test and χ 2 test. RESULTS: This study included 140 (14.6%) men and 821 (85.4%) women with pSS. Women with pSS demonstrated a higher prevalence of dry mouth, dry eyes, arthralgia, and dental caries ( p < 0.05); higher erythrocyte sedimentation rate and immunoglobulin M levels ( p < 0.05); higher prevalence of leukopenia, neutropenia, anemia, low complement 3, and low complement 4 ( p < 0.05); and higher titers of antinuclear antibody, anti-Sjögren syndrome A, anti-Ro52, and rheumatoid factor positivity ( p < 0.05) than men, whereas men with pSS had a higher prevalence of parotid enlargement and interstitial lung disease ( p < 0.05). CONCLUSIONS: Women with pSS are associated with more dryness, cytopenia, hypocomplementemia, and autoantibody positivity. Although men with pSS probably have lighter sicca symptoms and lower immunoactivity and serologic responses, regular monitoring of interstitial lung disease in men is vital.

Knowledge mapping of biological disease-modifying anti-rheumatic drugs for axial spondyloarthritis: a bibliometric study.

Various biological disease-modifying anti-rheumatic drugs (bDMARDs) have been applied for treating axial spondyloarthritis (axSpA). However, there is a glaring absence of a bibliometric analysis on bDMARDs against axSpA. Articles related to use of bDMARDs in treating axSpA published from 2004 to 2022 were searched from the Web of Science Core Collection. VOS viewer 1.6.18 and CiteSpace 6.1.R2 were used to analyze and visualize the quantity and citations of publications, as well as to identify "research hotspots" and trends in this field. BibExcel version 1.0.0 and gCLUTO version 1.0 were used to build matrices for bi-clustering analysis. A total of 2546 articles referring to bDMARDs for treatment of axSpA were included in this bibliometric analysis. Overall, the number of publications has been increasing steadily annually. The USA (23.21%, 591 publications) ranked first with the largest output of papers, followed by Germany, and the Netherlands. Rheumazentrum Ruhrgebiet ranked first as the most frequent publisher (119 articles). Annals of the Rheumatic Diseases published the most documents (6.76%, 172 publications) in this field. The predominant hotspots have been "tuberculosis," "IL-17," and "quality of life" in the field until 2020. Since 2015, "biosimilar pharmaceuticals" has retained the popularity. Current research hotspots are "spinal radiographic progression," Janus kinase (JAK) inhibitors, and adverse events (AEs). Machine learning has become popular gradually. Globally, there has been a steady increase in the number of studies on bDMARDs use against axSpA. JAK inhibitors, spinal radiographic progression, biosimilar pharmaceuticals, and AEs are current research hotspots. Machine learning is emerging research hotspots and trends in this field.

Distinct clinical phenotypes of primary Sjögren's syndrome differ by onset age: a retrospective study of 742 cases and review of the literature.

OBJECTIVES: To study the clinical characteristics of primary Sjögren's syndrome (pSS) with different onset age, and perform a review of the literature to confirm if the clinical phenotypes are affected by onset age in patients with pSS. METHODS: Data of 742 patients with pSS were retrospectively analysed. Patients were divided into three groups according to onset age: young-onset pSS (YopSS, <35 years), adult-onset pSS (AopSS, ≥35 and ≤65 years), and elderly-onset pSS (EopSS, >65 years). Clinical characteristics were compared among three groups and further multiple comparisons were conducted by Bonferroni adjustment. The Chi-squared test for linear-by-linear association was used to explore variation tendency. RESULTS: This study included 105 (14.2%), 533 (71.8%), and 104 (14.0%) cases of YopSS, AopSS, and EopSS, respectively. YopSS demonstrated lower prevalence of dry mouth, abnormal Schirmer I tests, and interstitial lung disease (ILD), but higher proportions of low C3 and C4 levels, and ANA, anti-SSA, anti-SSB, and rheumatoid factor (RF) positivity than AopSS and EopSS. The proportions of dry mouth (p=0.004), abnormal Schirmer I tests (p=0.002), and ILD (p<0.001) tended to increase with the increase of onset age, while the prevalence of leukopenia (p=0.011), low C3 (p=0.001), low C4 (p=0.001), and ANA (p<0.001), anti-SSA (p<0.001), anti-SSB (p<0.001) and RF (p<0.001) positivity tended to decrease with an increase in onset age. CONCLUSIONS: YopSS demonstrated less dryness and ILD, but more immunologic disorders. ILD prevalence were directly proportional to onset age of pSS; however, leukopenia, hypocomplementaemia, and autoantibody positivity showed opposite trends.

[Understory plant diversity and soil physicochemical properties of Pinus tabuliformis artificial water conservation forests in the upper reaches of Miyun Reservoir, China]. / å¯†äº‘æ°´åº“ä¸Šæ¸¸æ²¹æ¾äººå·¥æ°´æºæ¶µå »æž—æž—ä¸‹æ¤ç‰©å¤šæ ·æ€§ä¸ŽåœŸå£¤ç†åŒ–ç‰¹æ€§.

We examined the characteristics of understory plant diversity and physicochemical properties and analyzed the correlation between understory plant diversity and soil factors across four Pinus tabuliformis artificial water conservation forests (P. tabuliformis × Larix gmelinii plantation, P. tabuliformis × Quercus mongolica plantation, P. tabuliformis × Armeniaca sibirica plantation, and P. tabuliformis plantation) in Fengning County, upstream of Miyun reservoir. The results showed that the composition and structure of understory community of the four forests were significantly different. The understory community in the P. tabuliformis × A. sibirica plantation was the richest in species composition, with Spiraea salicifolia, Ostryopsis davidiana, and Carex lanceolata as the main dominant species. In terms of species richness, Simpson index, Shannon diversity index, and Pielou index, plant diversity in the P. tabuliformis × A. sibirica plantation was the highest. Species diversity in the shrub layer and the herb layer was the highest in the P. tabuliformis × Q. mongolica plantation and the P. tabuliformis × Q. mongolica plantation, respectively. All physical and chemical indicators except total phosphorus differed significantly among the four forests. Soil physical and chemical properties of the P. tabuliformis × A. sibirica plantation were the best overall, and that in the P. tabuliformis × Q. mongolica plantation was the worst. Soil capillary porosity, pH, and organic matter were the main factors affecting species diversity in the shrub layer, while soil pH and capillary moisture capacity were the main factors affecting plant species diversity in the herb layer. The construction of P. tabuliformis × A. sibirica plantation was more conducive to increasing the diversity of understory plants and promoting soil improvement. Soil pH, organic matter, capillary porosity, and capillary moisture capacity were the dominant soil factors affecting the diversity of understory plants in the study area.

Vitamin E and selenium partially prevent cytotoxicity, oxidative stress and DNA damage induced by T-2 toxin in bovine Leydig cells.

The objective of this study was to explore the protective mechanism of Vitamin E (VE) and selenium (Se) against T-2 toxin-induced oxidative damage of bovine Leydig cells. Leydig cells were isolated, cultured and divided into five treatment groups such as: control, T-2, Se + T-2, VE + T-2 and VE + Se + T-2. After treatment for 24 h, the cells and supernatants were harvested to examine the cell viability, the activities and mRNA expression of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), the content of malondialdehyde (MDA) and DNA damage. Results showed that T-2 toxin exposure significantly reduced the cell viability, increased the MDA level, reduced GSH-Px, SOD and CAT activities and increased DNA damage (P < 0.05). Meanwhile, T-2 toxin was attributed to the down-regulation of the mRNA expression of GSH-Px, SOD and CAT (P < 0.05). However, VE and Se reduced T-2 toxin-induced oxidative damage and tended to maintain normal levels (P < 0.05). Furthermore, VE and Se substantially up-regulated the activities and mRNA expressions of the GSH-Px, SOD and CAT. In conclusion, VE and Se, due to its anti-oxidative ability, could ameliorate T-2 toxin-induced cytotoxicities by regulating oxidative stress in bovine Leydig cells.

Factors associated with secondary immune thrombocytopenia in patients with primary Sjögren's syndrome: a retrospective study of 639 cases.

OBJECTIVES: To investigate the clinical characteristics and relevant factors of secondary immune thrombocytopenia (ITP) in patients with primary Sjögren's syndrome (pSS). METHODS: Patients with pSS being treated between 2013 and 2020 in China-Japan Friendship Hospital were retrospectively analysed. Clinical characteristics were compared between pSS patients with and without secondary ITP. Logistic regression analysis was performed to identify factors associated with secondary ITP in patients with pSS. RESULTS: 639 patients with pSS were included in this study, among which 566 (88.6%) were women. The prevalence of secondary ITP in patients with pSS were 12.4%. Among pSS patients with secondary ITP, 55.7% had mucocutaneous bleeding and 8.9% experienced visceral bleeding. Lymphopenia (OR=3.154, 95% CI 1.185-8.395, p=0.021), anaemia (OR=2.416, 95% CI 1.250-4.668, p=0.009), low C4 (OR=2.904, 95% CI 1.563-5.394, p=0.001), and positive anti-RNP (OR=2.777, 95% CI 1.070-7.202, p=0.036) were significantly related to secondary ITP, while interstitial lung disease (ILD, OR=0.429, 95% CI 0.203-0.907, p=0.027), ANA ≥1:320 (OR=0.469, 95% CI 0.221-0.996, p=0.049) and positive anti-SSB (OR=0.288, 95% CI 0.126-0.685, p=0.003) were negatively associated with secondary ITP in patients with pSS. CONCLUSIONS: Over 10% of patients with pSS had secondary ITP, among whom visceral bleeding was comparatively rare. Lymphopenia and anaemia were positively related to secondary ITP, while ILD was negatively associated with secondary ITP. Low C4 and positive anti-RNP seem to be two potential risk factors for secondary ITP in patients with pSS, while ANA ≥1:320 and positive anti-SSB may be two potential protective factors.

L-Arginine protects mouse Leydig cells against T-2 toxin-induced apoptosis in vitro.

To explore the protective mechanism of L-arginine against T-2 toxin-induced apoptosis in mouse Leydig cells, we investigated whether L-arginine can prevent T-2 toxin-induced apoptosis in mouse Leydig cells and explored the underlying mechanisms. Leydig cells were isolated and cultured with control, T-2 toxin (10 nM), L-arginine (0.25, 0.5, and 1.0 mM), and T-2 toxin (10 nM T-2 toxin) + L-arginine (0.25, 0.5, or 1.0 mM) for 24 h. Cells and supernatants were harvested to examine proliferation of the cells, the apoptosis rate, activity of caspase-3 and mitochondria, and the gene expression levels of Bcl-2, Bax, PARP, and caspase-3. Results showed that proliferation and mitochondrial activity of Leydig cells were inhibited by administration of T-2 toxin. Bcl-2 gene expression levels was decreased, while the gene expression levels of Bax and PARP were increased, which could trigger mitochondria-mediated apoptosis, activate downstream caspase-3, and then increased caspase-3 at both activity and gene expression levels. The expression of the Bcl-2 gene was upregulated and the expression of Bax, caspase-3, and PARP gene were downregulated when L-arginine was added to the cultured cells. The results of this study showed that L-arginine could block T-2 toxin-induced apoptosis in mouse Leydig cells by regulating specific intracellular death-related pathways.

[Dynamic identification of double-early rice heat and its spatiotemporal characteristics in Jiangxi Province, China]. / 江西早稻高温热害等级动态判识及时空变化特征.

Constructing evaluation indicator for rice heat damage based on hot weather process (occurring time of hot weather and its duration) can realize the dynamic identification of rice high-temperature heat damage level, which is of great importance to the precisely monitoring, warning and assessment of rice heat. Meteorological, historical disaster and phenological data on double-early rice in Jiangxi Province were integrated to retrieve the historical heat of double-early rice. The dynamic index of high temperature heat injury on early rice based on high temperature weather process was constructed based on K-S distribution fitting test and confidence interval method. The results were verified with reserved independent samples. A rice heat index (M) was calculated, with which rice heat risk was analyzed. The results showed that the starting time and duration of hot weather were key factors affecting the occurrence of rice heat damage, with the effect of starting time greater than the duration. Light, moderate, and severe rice heat for 3-5 d was identified at 10-12, 5-9 and 2-4 d after heading respectively. Similarly, light, moderate and severe rice heat lasting for 6-8 d and >8 d started at 11-18, 8-10, 1-7 d after heading and 12-18, 8-11, 0-7 d after heading respectively. The coincident rate of rice heat damage indicator was 73.7%, and that verified to be identical or one grade different was 89.5%. The linear tendency rate of M from 1981 to 2015 was 0.04·a-1, with abrupt change from low to high around 1999. A high M (>0.18) was mainly found in the middle and the northeast part of the study area. Increasing trends of a high M occurred in the middle, northeast and south of Jiangxi, with tendency rates > 0.04·a-1. In general, the indicators constructed in this study realized the dynamic identification of process-based rice heat. The middle and northeast parts of Jiangxi Province were identified as high risk areas for double-early rice heat.

Protective effects of l-arginine against testosterone synthesis decreased by T-2 toxin in mouse Leydig cells.

The testosterone levels decreased by T-2 toxin in mouse Leydig cells were reported previously. It is not known, however, whether l-arginine improves the situation and what's the mechanism. Leydig cells were isolated and cultured with control, 10 nM T-2 toxin, 0.25, 0.5 or 1.0 mM l-arginine, and 10 nM T-2 toxin supplemented with 0.25, 0.5 or 1.0 mM l-arginine for 24 h. Cells and supernatants were collected to detect the mRNA expression and activities of P450scc (cholesterol side-chain cleavage enzyme), 3ß-HSD-1 (3ß-hydroxysteroid dehydrogenase/isomerase-1) and StAR (steroidogenic acute regulatory protein). Results revealed that l-arginine increased the testosterone levels declined by T-2 toxin and up-regulated the activities and mRNA expression of P450scc, 3ß-HSD-1 and StAR down-regulated by T-2 toxin in Leydig cells. Therefore, we concluded that l-arginine ameliorated the testosterone levels decreased by T-2 Toxin via regulating the mRNA expression and activities of P450scc, 3ß-HSD-1 and StAR in mouse Leydig cells.

Delayed effects of autophagy on T-2 toxin-induced apoptosis in mouse primary Leydig cells.

T-2 toxin is a type-A trichothecene produced by Fusarium found in several food commodities worldwide. T-2 toxin causes reproductive disorders, genotoxicity, and testicular toxicity in animals. Our previous research has reported that T-2 toxin can induce apoptosis via the Bax-dependent caspase-3 activation in mouse primary Leydig cells. However, little is known about the functions of autophagy and the cross talk between autophagy and apoptosis after exposure to T-2 toxin in Leydig cells. This study investigated these problems in mouse primary Leydig cells. Results showed that T-2 toxin treatment upregulated LC3-II and Beclin-1 expression, suggesting that T-2 toxin induced a high level of autophagy. Pretreatment with chloroquine (an autophagy inhibitor) and rapamycin (an autophagy inducer) increased and decreased the rate of apoptosis, respectively, in contrast to T-2 toxin-treated group. Autophagy delayed apoptosis in the T-2 toxin-treated Leydig cells. Therefore, autophagy may prevent cells from undergoing apoptosis by reducing T-2 toxin-induced cytotoxicity.

l-arginine protects against T-2 toxin-induced male reproductive impairments in mice.

l-arginine is beneficial for reproductive health; however, whether l-arginine may confer protection against T-2 toxin-induced reproductive impairment is not known. To address this, we used a mice model treated with T-2 toxin to investigate protective effects of l-arginine. Experimentally, we pre-treated mice with designed diet of l-arginine supplementation prior to the T-2 toxin-injected intraperitoneally exposure and then assessed semen quality, fertility and serum testosterone concentration. The results showed that l-arginine improved semen quality (e.g., live spermatozoa, abnormal spermatozoa, and acrosomal integrity of spermatozoa), testicular and cauda epididymal sperm counts, efficiency of sperm production and serum testosterone concentration in mice treated with T-2 toxin. In addition, l-arginine could increase pregnancy rate and decrease fetal resorption rate in females mated with T-2 toxin exposed males. Collectively, these findings suggest that dietary l-arginine supplementation may protect male reproductive impairments in mice treated with T-2 toxin through improving semen quality and serum testosterone levels.

l-arginine protects against oxidative damage induced by T-2 toxin in mouse Leydig cells.

To explore the protective mechanism of l-arginine against T-2 toxin-induced oxidative damage in mouse Leydig cells, Leydig cells were isolated and cultured with control, T-2 toxin (10 nM), l-arginine (0.25, 0.5, and 1.0 mM), and T-2 toxin (10 nM T-2 toxin) with l-arginine (0.25, 0.5, or 1.0 mM) for 24 hours. Cells and supernatants were harvested to examine cell viability, activities, and messenger RNA (mRNA) expression of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT), malondialdehyde (MDA) content, and DNA damage. Results showed that T-2 toxin significantly reduced cell viability, improved MDA content and DNA damage, and decreased activities and mRNA expression of GSH-Px, SOD, and CAT. However, l-arginine reduced T-2 toxin-induced oxidative damage and tended to maintain normal levels. Furthermore, l-arginine upregulated mRNA expressions of GSH-Px, SOD, and CAT. Collectively, l-arginine, due to its antioxidative ability, could ameliorate T-2 toxin-induced cytotoxicities in mouse Leydig cells by regulating oxidative stress.

T-2 toxin induces apoptosis via the Bax-dependent caspase-3 activation in mouse primary Leydig cells.

To explore the toxic effect of T-2 toxin on mouse Leydig cells and its underlying molecular mechanisms, we isolated Leydig cells from mature mice, set-up Leydig cells culture, treated cells with T-2 toxin, evaluated cell proliferation, detected the caspase-3 activity, mitochondrial activity and apoptosis rate, and measured the mRNA levels of Bcl-2, Bax, PARP and caspase-3. T-2 toxin inhibited cell proliferation at concentrations higher than 10-9 M or time more than 12 h, T-2 toxin also decreased Bcl-2 expression at the mRNA levels and mitochondrial activity at concentrations higher than 10-9 M. While, T-2 toxin increased the mRNA expressions of Bax and PARP at concentrations higher than 10-8 M and 10-9 M, respectively, triggered mitochondria-mediated apoptosis, activated downstream caspase-3, and then increased caspase-3 at the activity and mRNA levels at concentrations higher than 10-9 M. These data showed that T-2 toxin appears to activate specific intracellular death-related pathways leading to Bax-dependent caspase-3 activation and the induction of apoptosis in Leydig cells.

Toxicity and oxidative stress induced by T-2 toxin in cultured mouse Leydig cells.

To explore the toxic mechanism of T-2 toxin on Leydig cells of mice, we would investigate the toxicity and oxidative stress induced by T-2 toxin in the cells. Leydig cells were isolated and cultured with control or T-2 toxin (10-7 M, 10-8 M, or 10-9 M) for 24 h, then cells and supernatants were harvested to examine cell viability, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities, expression of messenger RNA (mRNA) related to oxidative stress, malondialdehyde (MDA) content and DNA damage. The cell viability was evaluated in mouse Leydig cells by MTT assay, MDA content and SOD, GSH-Px and CAT activities were measured by routine kits, expression of mRNA related to oxidative stress were examined by quantitative real-time polymerase chain reaction (PCR), and DNA damage was investigated by comet assay. Leydig cells treated with T-2 toxin showed significant reductions in cell viability, SOD, GSH-Px and CAT activities, and expression of mRNA related to oxidative stress, and remarkable increases in MDA content and levels of DNA damage. This study proves that T-2 toxin is toxic to Leydig cells of mice. Furthermore, oxidative stress plays an important role in the above-mentioned negative effects of T-2 toxin.

Effects of T-2 toxin on the regulation of steroidogenesis in mouse Leydig cells.

T-2 toxin is one of the mycotoxins, a group of type A trichothecenes produced by several fungal genera including Fusarium species, which may lead to the decrease of testosterone secretion in primary Leydig cells derived from mouse testis. The previous study demonstrated T-2 toxin decrease the testosterone biosynthesis in the primary Leydig cells derived from the mouse testis directly. In this study, we further examined the direct biological effects of T-2 toxin on the process of steroidogenesis, primarily in Leydig cells of mice. Leydig cells of mature mouse were purified by Percoll gradient centrifugation and the cell purity was determined by 3ß-hydroxysteroid dehydrogenase (3ß-HSD) staining. To examine the decrease in T-2 toxin-induced testosterone secretion, we measured the transcription level of three key steroidogenic enzymes including 3ß-HSD-1, cytochrome P450 side-chain cleavage (P450scc) enzyme, and steroidogenic acute regulatory (StAR) protein in T-2 toxin/human chorionic gonadotropin (hCG) co-treated cells. Our previous study showed that T-2 toxin (10(-7), 10(-8), and 10(-9) M) significantly suppressed hCG (10 ng/ml)-induced testosterone secretion. The studies demonstrated that the suppressive effect is correlated with a decrease in the level of transcription of 3ß-HSD-1, P450scc, and StAR (p < 0.05).

[Level indicators construction and temporal-spatial distribution features of agricultural flood in the southwest of China].

Flood level indicators of southwest provinces were built in this study by using daily precipitation data of 341 weather stations in southwest agricultural areas from 1961 to 2010 combined with grey correlation analysis. In the process of building the indicators, we took single station flood indicators of Chongqing as the prototype. Through increasing and decreasing the precipitation threshold of Chongqing indicators by the amplitude of -50-+50 mm and the step size of 1 mm, each province got 101 groups of flood indicators. Based on the correlation between flood intensity calculated by all the indicators and crop flood real seriousness, coincidence between indicators and historical flood records and the comparability of different province indicators, we finally constructed agricultural flood level indicators of each province step by step. According to the flood indicators, we also analyzed temporal-spatial distribution features of flood disaster in southwest agricultural areas. The results were as follows: the final indicators of Yunnan were the original indicators plus 16 mm, while it was plus 30 mm for Guizhou and plus 40 mm for Sichuan-Chongqing. The correlation coefficients between flood index defined by indicators and affected ratio were 0.314 (P < 0.05), 0.553 (P < 0.01) and 0.305 (P < 0.05), respectively. The coincidence was relatively high between indicators and historical flood records. The ages in which flood disaster appeared very serious were 1980s in Yunnan, 1990s in Guizhou and 1980s and 2000s in Sichuan-Chongqing in the nearly 50 years. In the southwest and southeast of Yunnan, southwest of Guizhou and west and northeast of Sichuan Basin, the flood disaster was prevalent.

T-2 toxin inhibits gene expression and activity of key steroidogenesis enzymes in mouse Leydig cells.

T-2 toxin is one of the mycotoxins, a group of type A trichothecenes produced by several fungal genera including Fusarium species, which may lead to the decrease of the testosterone secretion in the primary Leydig cells derived from the mouse testis. The previous study demonstrated the effects of T-2 toxin through direct decrease of the testosterone biosynthesis in the primary Leydig cells derived from the mouse testis. In this study, we further examined the direct biological effects of T-2 toxin on steroidogenesis production, primarily in Leydig cells of mice. Mature mouse Leydig cells were purified by Percoll gradient centrifugation and the cell purity was determined by 3ß-hydroxysteroid dehydrogenase (3ß-HSD) staining. To examine T-2 toxin-induced testosterone secretion decrease, we measured the transcription levels of 3 key steroidogenic enzymes and 5 enzyme activities including 3ß-HSD-1, P450scc, StAR, CYP17A1, and 17ß-HSD in T-2 toxin/human chorionicgonadotropin (hCG) co-treated cells. Our previous study showed that T-2 toxin (10(-7) M, 10(-8) M and 10(-9) M) significantly suppressed hCG (10 ng/ml)-induced testosterone secretion. The studies demonstrated that the suppressive effect is correlated with the decreases in the levels of transcription of 3ß-HSD-1, P450scc, and StAR (P<0.05) and also in enzyme activities of 3ß-HSD-1, P450scc, StAR, CYP17A1, and 17ß-HSD (P<0.05).