Objective To investigate the correlation between regulatory T （Treg） cells and postmenopausal osteoporosis and the antiosteoporotic effect of 1,25-dihydroxyvitamin D3 [1,25（OH）2D3] in relation to Treg cells. Metho...Objective To investigate the correlation between regulatory T （Treg） cells and postmenopausal osteoporosis and the antiosteoporotic effect of 1,25-dihydroxyvitamin D3 [1,25（OH）2D3] in relation to Treg cells. Methods Fifty female BALB/c mice were randomly divided into five groups： the basal control （BAS）, Sham, ovariectomy （OVX）, OVX＋diethylstilbestrol （OVX＋DES）, and OVX＋I,2S（OH）2D3. Tibias were harvested and processed with decalcification for quantitative bone histomorphometry. Femurs were stained by immunohistochemistry to detect Foxp3 protein expression. Spleens were used to detect Treg and Foxp3 gene expression by flow cy：ometry and quantitative RT-PCR, respectively. Results In comparison with the Sham group, a significant decrease was found in the OV~ group in such indices as trabecular bone volume/tc,tal tissue area （BV/TV）, trabecular number （Tb.N） and trabecular thickness （Tb.Th）. 1,25（OH）2D3 and DES partly prevented the decrease in BV/TV, Tb.N, Tb.Th in OVX mice. Treg cell number, Foxp3 mRI~：A expression in spleen and Foxp3 protein expression in femur significantly decreased in the OVX-tr^ated group compared with those in the sham group. 1,25（OH）2D3 and DES significantly increased Treg cell number and Foxp3 expression. Treg cells and Foxp3 gene expression were related to bone histomorphometric parameters. Conclusion The decrease in Treg cell numbers is relevant to the postmenopausal osteoporosis. The antiosteoporosis of 1,25（OH）2D3 is related to regulatory T cells.展开更多
Low-dose cytarabine combined with differentiating or DNA hypomethylating agents,such as vitamin D compounds,is a potential regimen to treat acute myeloid leukemia(AML)patients who are unfit for high-intensity chemothe...Low-dose cytarabine combined with differentiating or DNA hypomethylating agents,such as vitamin D compounds,is a potential regimen to treat acute myeloid leukemia(AML)patients who are unfit for high-intensity chemotherapy.The present study aimed to determine which subset of AML would be most responsive to low-dose cytarabine with the differentiating agent 1,25-dihydroxyvitamin D3(1,25-D3).Here,firstly,c Bio Portal database was used and we found out that vitamin D receptor(VDR)was highly expressed in acute monocytic leukemia(M5)and high VDR expression was associated with a poor survival of AML patients.Then,we confirmed that 1,25-D3 at clinical available concentration could induce more significant differentiation in acute monocytic leukemia cell lines(U937,MOLM-13,THP-1)and blasts from M5 patients than in non-monocytic cell lines(KG1 a and K562)and blasts from M2 patient.Finally,it was shown that the combination of 1,25-D3 and low-dose cytarabine further increased the differentiating rate,growth inhibition and G0/G1 arrest,while mild changes were found in the apoptosis in acute monocytic leukemia cell lines.Our study demonstrates that the enhanced response of acute monocytic leukemia cells to low-dose cytarabine by 1,25-D3 might indicate a novel therapeutic direction for patients with acute monocytic leukemia,especially for elderly and frail ones.展开更多
Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D ...Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D response element-binding protein （VDRE-BP）. hnRNPC acts a tetramer of hnRNPC1 （huC1） and hnRNPC2 （huC2）, and organization of these subunits is critical to in vivo nucleic acid-binding. Overexpression of either huC1 or huC2 in human osteoblasts is sufficient to confer VDRE-BP suppression of 1,25（OH）2D-mediated transcription. However, huC1 or huC2 alone did not suppress 1,25（OH）2D-induced transcription in mouse osteoblastic cells. By contrast, overexpression of huC1 and huC2 in combination or transfection with a bone-specific polycistronic vector using a ＂self-cleaving＂ 2A peptide to co-express huC1/C2 suppressed 1,25D-mediated induction of osteoblast target gene expression. Structural diversity of hnRNPC between human/NWPs and mouse/rat/rabbit/dog was investigated by analysis of sequence variations within the hnRNP CLZ domain. The predicted loss of distal helical function in hnRNPC from lower species provides an explanation for the altered interaction between huC1/C2 and their mouse counterparts. These data provide new evidence of a role for hnRNPC1/C2 in 1,25（OH）2D-driven gene expression, and further suggest that species-specific tetramerization is a crucial determinant of its actions as a regulator of VDR-directed transactivation.展开更多
目的:1,25-二羟维生素D3[1,25-(OH)2D3]对连续多次小剂量链脲菌素(the mu ltip le low dose streptozotoc in,MLDS)诱导的自身免疫性糖尿病小鼠的预防作用及其机制初探。方法:小鼠分为三组。正常对照组:连续5天腹腔注射与糖尿病组等容...目的:1,25-二羟维生素D3[1,25-(OH)2D3]对连续多次小剂量链脲菌素(the mu ltip le low dose streptozotoc in,MLDS)诱导的自身免疫性糖尿病小鼠的预防作用及其机制初探。方法:小鼠分为三组。正常对照组:连续5天腹腔注射与糖尿病组等容量柠檬酸盐缓冲液;糖尿病组:连续5天腹腔注射STZ(40mg.kg-1),以血糖水平持续高于16.7mmol/L为成模标准;预防组:先隔日腹腔注射1,25-(OH)2D3(5μg.kg-1),共15次,然后再连续5天腹腔注射STZ(40mg.kg-1)。实验结束后各组动物处死收集血清并采集胰腺检测诱导型一氧化氮合酶(iNOS)活性及血清胰岛素水平。结果:MLDS诱发的自身免疫性糖尿病模型在第四周基本建成。MLDS使小鼠血糖、血清及胰腺iNOS活性升高,血清胰岛素水平下调;预防组小鼠注射STZ前给予1,25-(OH)2D3有明显降血糖和上调血清胰岛素水平作用,同时抑制血清及胰腺iNOS活性,与糖尿病组比较有显著性差异(P<0.05)。结论:1,25-(OH)2D3可有效预防MLDS诱导的自身免疫性糖尿病的发生。该效应可能与1,25-(OH)2D3抑制iNOS活性有关。展开更多
Objective:To explore the effect of 1,25-dihydroxyvitamin D3 on the mast cell tryptase(MCT) in asthmatic guinea pigs.Methods:A total of 60 male or female healthy guinea pigs were randomly divided into control group(gro...Objective:To explore the effect of 1,25-dihydroxyvitamin D3 on the mast cell tryptase(MCT) in asthmatic guinea pigs.Methods:A total of 60 male or female healthy guinea pigs were randomly divided into control group(group A),asthmatic group(group B).and 1,25-dihydroxyvitamin D3 group(group C),with 20 cases in each group.To establish asthmatic guinea pig models,1ml peanut oil was tilled into stomach in the morning in group A and group B.and 1 ml peanut oil with 1,25-dihydroxyvitamin D3 was filled into stomach in group C.Airway resistance(Re) of asthmatic guinea pigs was detected,and the bronchoalveolar lavage fluid(BALF) cells were counted.Lung tissue with HE and MCT immunohistochemical staining were used to observe the pathological changes in lung tissue and the distribution of MCT.Results:After injection of different concentration of acetylcholine chloride,the Re in group B and group C were increased significantly compared with group A(P<0.05):compared with group B.the Re in group C were decreased significantly(t=-5.385.-5.761.-6.184.-13.574.P<0.05):the total number of BALF cells and eosinophils were increased significantly in group B and C(t=19.618.9.598.10.854.5.388.P<0.05);compared with group B.the total number of BALF cells and eosinophils in group C was decreased significantly(t=-5.555.-5.392.P<0.05):the number of tryptase positive cells in group B was increased significantly than that in group A(t=21.312,P<0.05),and in addition to the alveolar septum and submucosa,the cells were also distributed around blood vessels and outside the cells:the number of tryptase positive cells in group C was decreased significantly compared with group B.and the difference was statistically significant(t=5.043.P<0.05).Conclusions:After the asthmatic guinea pigs arc treated with 1,25-dihydroxyvitamin D3,their BALF.Re.infiltration degree of inflammatory cells in the trachea and lung tissue and airway inflammatory reaction are reduced significantly.1,25-dihydroxyvitamin D3 has a certain inhibiting effect on the activation of mast cells and the release of MCT granules.展开更多
In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indic...In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.展开更多
Vitamin D_3 has been found to produce therapeutic effects on obesity-associated insulin resistance and dyslipidemia through its potent anti-inflammatory activity, but the precise immunomodulatory mechanism remains poo...Vitamin D_3 has been found to produce therapeutic effects on obesity-associated insulin resistance and dyslipidemia through its potent anti-inflammatory activity, but the precise immunomodulatory mechanism remains poorly understood. In the present study we found that 1,25-dihydroxyvitamin D_3[1,25(OH)_2D_3], the biologically active form of vitamin D_3, significantly attenuated monosodium glutamate(MSG)-induced obesity and insulin resistance as indicated by body weight reduction, oral glucose tolerance improvement, and a glucose infusion rate increase as detected with hyperinsulinemiceuglycemic clamp. Moreover, 1,25(OH)_2D_3 not only restored pancreatic islet functions but also improved lipid metabolism in insulin-targeted tissues. The protective effects of 1,25(OH)_2D_3 on glycolipid metabolism were attributed to its ability to inhibit an obesity-activated inflammatory response in insulin secretory and targeted tissues, as indicated by reduced infiltration of macrophages in pancreas islets and adipose tissue while enhancing the expression of Tgf-β1 in liver tissue, which was accompanied byincreased infiltration of Treg cells in immune organs such as spleen and lymph node as well as in insulintargeted tissues such as liver, adipose, and muscle. Together, our findings suggest that 1,25(OH)_2D_3 serves as a beneficial immunomodulator for the prevention and treatment of obesity or metabolic syndrome through its anti-inflammatory effects.展开更多
T-2 toxin is the most widespread mycotoxin in crops,feed and food,which poses a serious threat to body health.Bone is the main target tissue for T-2 toxin accumulation.Ingestion of food contaminated by T-2 toxin is th...T-2 toxin is the most widespread mycotoxin in crops,feed and food,which poses a serious threat to body health.Bone is the main target tissue for T-2 toxin accumulation.Ingestion of food contaminated by T-2 toxin is the main cause of Kashin-Beck disease.However,the specific mechanism of bone damage caused by T-2 toxin is still unclear.In this study,a total of 40 male C57BL/6N mice were divided into four groups and orally treated with 0,0.5,1.0 and 2.0 mg·kg^(-1) body weight T-2 toxin for 28 days.The results showed that exposure to T-2 toxin led to weight loss,bone mineral density reduction and femoral structural damage of mice.In addition,osteoblast-mediated bone formation was inhibited,and osteoclast-mediated bone resorption was enhanced.Meanwhile,the levels of bone metabolism-related hormones including parathyroid hormone,calcitonin and 1,25-dihydroxyvitamin D3 were reduced.More importantly,it was found that the level of neuropeptide Y(a neurohormone)was decreased.These results provided a new perspetive for understanding the osteotoxicity of T-2 toxin.展开更多
Objective:Vitiligo is a chronic autoimmune depigmenting skin disorder.In this disease,the destruction of functional melanocytes can lead to reduced or absent pigmentation of the skin.Vitamin D deficiency has been repo...Objective:Vitiligo is a chronic autoimmune depigmenting skin disorder.In this disease,the destruction of functional melanocytes can lead to reduced or absent pigmentation of the skin.Vitamin D deficiency has been reported in some autoimmune diseases.The association of eosinophils and basophils with autoimmune diseases has also been recently examined.The present study was performed to evaluate the serum vitamin D concentration and blood eosinophil and basophil counts in patients with vitiligo.Methods:Data from 30 patients aged 20 to 40 years with vitiligo and 30 healthy people were collected.Blood samples were obtained to evaluate the serum vitamin D concentration,and eosinophil and basophil counts.The serum vitamin D concentration was measured by enzyme-linked immunosorbent assay.Independent t-test was used to compare the quantitative variables between the groups.Results:This descriptive cross-sectional study involved 30 patients with vitiligo.The average serum vitamin D concentration was significantly lower in the case group than in the control group(P=0.01).Furthermore,the mean serum vitamin D concentration was significantly lower in women than in men(P=0.03).The average eosinophil and basophil counts were not significantly different between the case and control groups.Discussion:The results of this study showed that the serum vitamin D concentration is low in patients with vitiligo.However,whether this reduction is a factor in the promotion of vitiligo or occurs after the onset of vitiligo remains unknown.Further studies on the serum vitamin D concentration in patients with vitiligo are needed to clarity this issue and develop effective treatments.展开更多
Background:Vitamin D deficiency is associated with a range of systemic diseases including ocular disorders.The objective of this study is to measure tear vitamin D levels and investigate the correlation between serum ...Background:Vitamin D deficiency is associated with a range of systemic diseases including ocular disorders.The objective of this study is to measure tear vitamin D levels and investigate the correlation between serum and tear vitamin D levels.Methods:A total of 48 healthy volunteers without any systemic and ocular disease were recruited for this observational cohort study.Serum was collected using clot activator coated Vacutainer®Plus tubes.Tear fluid was collected using Schirmer’s strips.Serum and tear total 25-hydroxyvitamin D levels were measured by competitive chemiluminescent ELISA and the correlation between the levels were studied.Results:The measured serum 25-hydroxyvitamin D level ranged between 3.3 and 27.5 ng/ml(Mean±SEM,9.4±0.7 ng/ml;Median 8.4 ng/ml).Significantly(p<0.0001)higher level of 25-hydroxyvitamin D was detected in the tears(Mean±SEM,17.0±1.6 ng/ml;Range 3.2–45.8 ng/ml;Median,16.3 ng/ml)compared to serum.An average of~2 fold(Mean±SEM,1.9±0.2;Range 0.4–5.8;Median,1.7)higher 25-hydroxyvitamin D was observed in tears compared to serum in the subjects.In addition,a positive correlation was observed between serum and tear 25-hydroxyvitamin D levels(r=0.5595;p<0.0001).Conclusions:A higher level of 25-hydroxyvitamin D was observed in the tear fluid compared to that of the serum.It would be beneficial to consider tear vitamin D levels to study its role with reference to ocular surface diseases.展开更多
基金supported by Natural Science Foundation of Guangdong Province(10152402301000000)Science and Technology Planning Project of Dongguan(2011108102019)Science&Technology Innovation Fund of Guangdong Medical College(STIF201104)
文摘Objective To investigate the correlation between regulatory T （Treg） cells and postmenopausal osteoporosis and the antiosteoporotic effect of 1,25-dihydroxyvitamin D3 [1,25（OH）2D3] in relation to Treg cells. Methods Fifty female BALB/c mice were randomly divided into five groups： the basal control （BAS）, Sham, ovariectomy （OVX）, OVX＋diethylstilbestrol （OVX＋DES）, and OVX＋I,2S（OH）2D3. Tibias were harvested and processed with decalcification for quantitative bone histomorphometry. Femurs were stained by immunohistochemistry to detect Foxp3 protein expression. Spleens were used to detect Treg and Foxp3 gene expression by flow cy：ometry and quantitative RT-PCR, respectively. Results In comparison with the Sham group, a significant decrease was found in the OV~ group in such indices as trabecular bone volume/tc,tal tissue area （BV/TV）, trabecular number （Tb.N） and trabecular thickness （Tb.Th）. 1,25（OH）2D3 and DES partly prevented the decrease in BV/TV, Tb.N, Tb.Th in OVX mice. Treg cell number, Foxp3 mRI~：A expression in spleen and Foxp3 protein expression in femur significantly decreased in the OVX-tr^ated group compared with those in the sham group. 1,25（OH）2D3 and DES significantly increased Treg cell number and Foxp3 expression. Treg cells and Foxp3 gene expression were related to bone histomorphometric parameters. Conclusion The decrease in Treg cell numbers is relevant to the postmenopausal osteoporosis. The antiosteoporosis of 1,25（OH）2D3 is related to regulatory T cells.
基金supported by grants from the National Natural Science Foundation of China(No.81400172 and No.81470330)
文摘Low-dose cytarabine combined with differentiating or DNA hypomethylating agents,such as vitamin D compounds,is a potential regimen to treat acute myeloid leukemia(AML)patients who are unfit for high-intensity chemotherapy.The present study aimed to determine which subset of AML would be most responsive to low-dose cytarabine with the differentiating agent 1,25-dihydroxyvitamin D3(1,25-D3).Here,firstly,c Bio Portal database was used and we found out that vitamin D receptor(VDR)was highly expressed in acute monocytic leukemia(M5)and high VDR expression was associated with a poor survival of AML patients.Then,we confirmed that 1,25-D3 at clinical available concentration could induce more significant differentiation in acute monocytic leukemia cell lines(U937,MOLM-13,THP-1)and blasts from M5 patients than in non-monocytic cell lines(KG1 a and K562)and blasts from M2 patient.Finally,it was shown that the combination of 1,25-D3 and low-dose cytarabine further increased the differentiating rate,growth inhibition and G0/G1 arrest,while mild changes were found in the apoptosis in acute monocytic leukemia cell lines.Our study demonstrates that the enhanced response of acute monocytic leukemia cells to low-dose cytarabine by 1,25-D3 might indicate a novel therapeutic direction for patients with acute monocytic leukemia,especially for elderly and frail ones.
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number 5R01AR037399the UCLA Vector Core (Emmanuelle Faure and Kip Hermann) for vector and viral preparations supported by JCCC/P30 CA016042 and CURE/P30 DK41301
文摘Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D response element-binding protein （VDRE-BP）. hnRNPC acts a tetramer of hnRNPC1 （huC1） and hnRNPC2 （huC2）, and organization of these subunits is critical to in vivo nucleic acid-binding. Overexpression of either huC1 or huC2 in human osteoblasts is sufficient to confer VDRE-BP suppression of 1,25（OH）2D-mediated transcription. However, huC1 or huC2 alone did not suppress 1,25（OH）2D-induced transcription in mouse osteoblastic cells. By contrast, overexpression of huC1 and huC2 in combination or transfection with a bone-specific polycistronic vector using a ＂self-cleaving＂ 2A peptide to co-express huC1/C2 suppressed 1,25D-mediated induction of osteoblast target gene expression. Structural diversity of hnRNPC between human/NWPs and mouse/rat/rabbit/dog was investigated by analysis of sequence variations within the hnRNP CLZ domain. The predicted loss of distal helical function in hnRNPC from lower species provides an explanation for the altered interaction between huC1/C2 and their mouse counterparts. These data provide new evidence of a role for hnRNPC1/C2 in 1,25（OH）2D-driven gene expression, and further suggest that species-specific tetramerization is a crucial determinant of its actions as a regulator of VDR-directed transactivation.
文摘目的:1,25-二羟维生素D3[1,25-(OH)2D3]对连续多次小剂量链脲菌素(the mu ltip le low dose streptozotoc in,MLDS)诱导的自身免疫性糖尿病小鼠的预防作用及其机制初探。方法:小鼠分为三组。正常对照组:连续5天腹腔注射与糖尿病组等容量柠檬酸盐缓冲液;糖尿病组:连续5天腹腔注射STZ(40mg.kg-1),以血糖水平持续高于16.7mmol/L为成模标准;预防组:先隔日腹腔注射1,25-(OH)2D3(5μg.kg-1),共15次,然后再连续5天腹腔注射STZ(40mg.kg-1)。实验结束后各组动物处死收集血清并采集胰腺检测诱导型一氧化氮合酶(iNOS)活性及血清胰岛素水平。结果:MLDS诱发的自身免疫性糖尿病模型在第四周基本建成。MLDS使小鼠血糖、血清及胰腺iNOS活性升高,血清胰岛素水平下调;预防组小鼠注射STZ前给予1,25-(OH)2D3有明显降血糖和上调血清胰岛素水平作用,同时抑制血清及胰腺iNOS活性,与糖尿病组比较有显著性差异(P<0.05)。结论:1,25-(OH)2D3可有效预防MLDS诱导的自身免疫性糖尿病的发生。该效应可能与1,25-(OH)2D3抑制iNOS活性有关。
基金supported by Natural Science Foundation of Guangdong Province:gd291823
文摘Objective:To explore the effect of 1,25-dihydroxyvitamin D3 on the mast cell tryptase(MCT) in asthmatic guinea pigs.Methods:A total of 60 male or female healthy guinea pigs were randomly divided into control group(group A),asthmatic group(group B).and 1,25-dihydroxyvitamin D3 group(group C),with 20 cases in each group.To establish asthmatic guinea pig models,1ml peanut oil was tilled into stomach in the morning in group A and group B.and 1 ml peanut oil with 1,25-dihydroxyvitamin D3 was filled into stomach in group C.Airway resistance(Re) of asthmatic guinea pigs was detected,and the bronchoalveolar lavage fluid(BALF) cells were counted.Lung tissue with HE and MCT immunohistochemical staining were used to observe the pathological changes in lung tissue and the distribution of MCT.Results:After injection of different concentration of acetylcholine chloride,the Re in group B and group C were increased significantly compared with group A(P<0.05):compared with group B.the Re in group C were decreased significantly(t=-5.385.-5.761.-6.184.-13.574.P<0.05):the total number of BALF cells and eosinophils were increased significantly in group B and C(t=19.618.9.598.10.854.5.388.P<0.05);compared with group B.the total number of BALF cells and eosinophils in group C was decreased significantly(t=-5.555.-5.392.P<0.05):the number of tryptase positive cells in group B was increased significantly than that in group A(t=21.312,P<0.05),and in addition to the alveolar septum and submucosa,the cells were also distributed around blood vessels and outside the cells:the number of tryptase positive cells in group C was decreased significantly compared with group B.and the difference was statistically significant(t=5.043.P<0.05).Conclusions:After the asthmatic guinea pigs arc treated with 1,25-dihydroxyvitamin D3,their BALF.Re.infiltration degree of inflammatory cells in the trachea and lung tissue and airway inflammatory reaction are reduced significantly.1,25-dihydroxyvitamin D3 has a certain inhibiting effect on the activation of mast cells and the release of MCT granules.
基金This work was supported by research Funds from the Ministerio de Ciencia e Innovación(SAF2009-12671).
文摘In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.
基金supported by grants from the National Natural Science Foundation of China (81773800 and 81471070)the CAMS Innovation Fund for Medical Sciences (CIFMS, 2016I2M-1-010 to Xiao-wei Zhang and 2016-I2M-1-012 to Wen Jin)
文摘Vitamin D_3 has been found to produce therapeutic effects on obesity-associated insulin resistance and dyslipidemia through its potent anti-inflammatory activity, but the precise immunomodulatory mechanism remains poorly understood. In the present study we found that 1,25-dihydroxyvitamin D_3[1,25(OH)_2D_3], the biologically active form of vitamin D_3, significantly attenuated monosodium glutamate(MSG)-induced obesity and insulin resistance as indicated by body weight reduction, oral glucose tolerance improvement, and a glucose infusion rate increase as detected with hyperinsulinemiceuglycemic clamp. Moreover, 1,25(OH)_2D_3 not only restored pancreatic islet functions but also improved lipid metabolism in insulin-targeted tissues. The protective effects of 1,25(OH)_2D_3 on glycolipid metabolism were attributed to its ability to inhibit an obesity-activated inflammatory response in insulin secretory and targeted tissues, as indicated by reduced infiltration of macrophages in pancreas islets and adipose tissue while enhancing the expression of Tgf-β1 in liver tissue, which was accompanied byincreased infiltration of Treg cells in immune organs such as spleen and lymph node as well as in insulintargeted tissues such as liver, adipose, and muscle. Together, our findings suggest that 1,25(OH)_2D_3 serves as a beneficial immunomodulator for the prevention and treatment of obesity or metabolic syndrome through its anti-inflammatory effects.
基金Supported by the National Natural Science Foundation of China(31872530)。
文摘T-2 toxin is the most widespread mycotoxin in crops,feed and food,which poses a serious threat to body health.Bone is the main target tissue for T-2 toxin accumulation.Ingestion of food contaminated by T-2 toxin is the main cause of Kashin-Beck disease.However,the specific mechanism of bone damage caused by T-2 toxin is still unclear.In this study,a total of 40 male C57BL/6N mice were divided into four groups and orally treated with 0,0.5,1.0 and 2.0 mg·kg^(-1) body weight T-2 toxin for 28 days.The results showed that exposure to T-2 toxin led to weight loss,bone mineral density reduction and femoral structural damage of mice.In addition,osteoblast-mediated bone formation was inhibited,and osteoclast-mediated bone resorption was enhanced.Meanwhile,the levels of bone metabolism-related hormones including parathyroid hormone,calcitonin and 1,25-dihydroxyvitamin D3 were reduced.More importantly,it was found that the level of neuropeptide Y(a neurohormone)was decreased.These results provided a new perspetive for understanding the osteotoxicity of T-2 toxin.
文摘Objective:Vitiligo is a chronic autoimmune depigmenting skin disorder.In this disease,the destruction of functional melanocytes can lead to reduced or absent pigmentation of the skin.Vitamin D deficiency has been reported in some autoimmune diseases.The association of eosinophils and basophils with autoimmune diseases has also been recently examined.The present study was performed to evaluate the serum vitamin D concentration and blood eosinophil and basophil counts in patients with vitiligo.Methods:Data from 30 patients aged 20 to 40 years with vitiligo and 30 healthy people were collected.Blood samples were obtained to evaluate the serum vitamin D concentration,and eosinophil and basophil counts.The serum vitamin D concentration was measured by enzyme-linked immunosorbent assay.Independent t-test was used to compare the quantitative variables between the groups.Results:This descriptive cross-sectional study involved 30 patients with vitiligo.The average serum vitamin D concentration was significantly lower in the case group than in the control group(P=0.01).Furthermore,the mean serum vitamin D concentration was significantly lower in women than in men(P=0.03).The average eosinophil and basophil counts were not significantly different between the case and control groups.Discussion:The results of this study showed that the serum vitamin D concentration is low in patients with vitiligo.However,whether this reduction is a factor in the promotion of vitiligo or occurs after the onset of vitiligo remains unknown.Further studies on the serum vitamin D concentration in patients with vitiligo are needed to clarity this issue and develop effective treatments.
基金The study was supported by the Narayana Nethralaya Foundation,Bangalore,India.
文摘Background:Vitamin D deficiency is associated with a range of systemic diseases including ocular disorders.The objective of this study is to measure tear vitamin D levels and investigate the correlation between serum and tear vitamin D levels.Methods:A total of 48 healthy volunteers without any systemic and ocular disease were recruited for this observational cohort study.Serum was collected using clot activator coated Vacutainer®Plus tubes.Tear fluid was collected using Schirmer’s strips.Serum and tear total 25-hydroxyvitamin D levels were measured by competitive chemiluminescent ELISA and the correlation between the levels were studied.Results:The measured serum 25-hydroxyvitamin D level ranged between 3.3 and 27.5 ng/ml(Mean±SEM,9.4±0.7 ng/ml;Median 8.4 ng/ml).Significantly(p<0.0001)higher level of 25-hydroxyvitamin D was detected in the tears(Mean±SEM,17.0±1.6 ng/ml;Range 3.2–45.8 ng/ml;Median,16.3 ng/ml)compared to serum.An average of~2 fold(Mean±SEM,1.9±0.2;Range 0.4–5.8;Median,1.7)higher 25-hydroxyvitamin D was observed in tears compared to serum in the subjects.In addition,a positive correlation was observed between serum and tear 25-hydroxyvitamin D levels(r=0.5595;p<0.0001).Conclusions:A higher level of 25-hydroxyvitamin D was observed in the tear fluid compared to that of the serum.It would be beneficial to consider tear vitamin D levels to study its role with reference to ocular surface diseases.
