1.Intestinal Dopamine Receptor D2 is Required for Neuroprotection Against 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Dopaminergic Neurodegeneration.
Hairong PENG ; Shui YU ; Yukai ZHANG ; Yanqing YIN ; Jiawei ZHOU
Neuroscience Bulletin 2022;38(8):871-886
A wealth of evidence has suggested that gastrointestinal dysfunction is associated with the onset and progression of Parkinson's disease (PD). However, the mechanisms underlying these links remain to be defined. Here, we investigated the impact of deregulation of intestinal dopamine D2 receptor (DRD2) signaling in response to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurodegeneration. Dopamine/dopamine signaling in the mouse colon decreased with ageing. Selective ablation of Drd2, but not Drd4, in the intestinal epithelium, caused a more severe loss of dopaminergic neurons in the substantia nigra following MPTP challenge, and this was accompanied by a reduced abundance of succinate-producing Alleoprevotella in the gut microbiota. Administration of succinate markedly attenuated dopaminergic neuronal loss in MPTP-treated mice by elevating the mitochondrial membrane potential. This study suggests that intestinal epithelial DRD2 activity and succinate from the gut microbiome contribute to the maintenance of nigral DA neuron survival. These findings provide a potential strategy targeting neuroinflammation-related neurological disorders such as PD.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/adverse effects*
;
Animals
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Disease Models, Animal
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Dopamine
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Dopaminergic Neurons/metabolism*
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Gastrointestinal Microbiome
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Mice
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Mice, Inbred C57BL
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Neuroprotection
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Parkinson Disease
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Pyrrolidines
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Receptors, Dopamine D2/metabolism*
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Substantia Nigra
;
Succinates
2.Effectiveness, safety and tolerability of vildagliptin and vildagliptin+metformin in real-world setting in the Philippines--Results from the GUARD study.
Rosales Reynaldo ; Domingo Francis ; Javier Joselito
Philippine Journal of Internal Medicine 2016;54(4):1-7
INTRODUCTION: GUARD (vildaGliptin clinical Use in reAl woRlD) was a multinational, prospective, observational study that assessed the effectiveness,safety and tolerability of vildagliptin and vildagliptin+metformin in patients with type 2 diabetes mellitus (T2DM) under real-world conditions across four geographical regions (Asia, the Middle East, Central America and Africa). The current paper discusses the results of patients with T2DM enrolled in the Philippines.
METHODS: Patients with T2DM who were prescribed vildagliptin or vildagliptin+metformin combination therapy were enrolled and followed as per routine clinical practice for 24 ± six weeks. Primary endpoint was the change in HbA1c from baseline to study end (week 24±6). Key secondary endpoints included proportion of patients reaching target HbA1c ?7.0%, incidence of hypoglycemic events, adverse events (AEs) and serious AEs (SAEs).
RESULTS: A total of 1,117 patients were included in the final analysis, 280 on vildagliptin (of these, eight patients received additional oral antidiabetes medications) and 837 on vildagliptin+metformin. At baseline, the mean (±SD) age of the enrolled population was 54.1±11.5 years, BMI 26.3±4.7 kg/m2, HbA1c 8.0±1.2% and T2DM duration 2.3±4.0 years.At study end, significant mean (±SE) reductions in HbA1c of -1.2±0.1% (p<0.0001) and -1.5±0.1% (p<0.0001) from a baseline of 7.6±1.1% and 8.1±1.2% were observed for the vildagliptin and vildagliptin+metformin group, respectively.A similar proportion of patients achieved HbA1c ?7.0% in the vildagliptin (66.1%) and vildagliptin+metformin group(62.7%). Changes in body weight and BMI from baseline to week 24±6 were statistically significant (p<0.0001) in both the vildagliptin (-1.5±0.3 kg; -0.6±0.1 kg/m2) and the vildagliptin+metformin group (-1.4±0.2 kg; -0.5±0.1 kg/m2).The incidence of hypoglycemia was low--six patients reported hypoglycemia in the vildaglipti metformin group and none in the vildagliptin group. Incidence of adverse events was also low in both the groups (vildagliptin, 8.6% and vildagliptin+metformin, 5.3%).
CONCLUSION: Vildagliptin and vildagliptin+metformin significantly reduced HbA1c with good weight control and low incidence of hypoglycemia in patients with T2DM under real-world conditions in Philippines
Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Metformin ; Vildagliptin ; Diabetes Mellitus, Type 2 ; Adamantane ; Pyrrolidines ; Hypoglycemic Agents ; Nitriles ; Hypoglycemia ; Body Weight ; Asia ; Africa ; Central America
3.Pyrrolidine Dithiocarbamate Inhibits Nuclear Factor kappaB and Toll-Like Receptor 4 Expression in Rats with Acute Necrotizing Pancreatitis.
Min XU ; Kun Ning WANG ; Kai WU ; Xing Peng WANG
Gut and Liver 2015;9(3):411-416
BACKGROUND/AIMS: To investigate the expression of Toll-like receptor 4 (TLR4) in the pancreases of rats with acute necrotizing pancreatitis (ANP) and any changes upon treatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear factor kappaB (NF-kappaB), as well as to determine the relationship between TLR4 and NF-kappaB in ANP pathogenesis. METHODS: A total of 72 SD rats were randomly divided into three groups, namely, the control (sham-operation), ANP, and ANP with PDTC pretreatment groups. The PDTC-pretreated group was intraperitoneally injected with PDTC at a dose of 100 mg/kg 1 hour before the induction of ANP. The expressions of TLR4 and NF-kappaB in pancreatic tissue were evaluated by immunohistochemistry and Western blot analysis. The mRNA levels of cytokines tumor necrosis factor alpha, interleukin (IL)-1beta, and IL-6 were measured by reverse transcription polymerase chain reaction. RESULTS: The expressions of TLR4, NF-kappaB, and cytokine (NF-kappaB target) genes in the pancreatic tissue increased more significantly in the ANP groups than in the sham-operation group at 3, 6, and 12 hours. Pretreatment with PDTC alleviated the inflammatory activation in the pancreas with ANP, causing a significant decrease in the expressions of TLR4, NF-kappaB, and cytokine genes in the pancreatic tissue. CONCLUSIONS: The expressions of TLR4 and NF-kappaB were increased in the pancreases of rats with ANP. PDTC not only inhibits NF-kappaB but also suppresses the expression of TLR4 and downregulates the expression of the related cytokine genes.
Animals
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Antioxidants/*pharmacology
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Interleukin-1beta/genetics/metabolism
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Interleukin-6/genetics/metabolism
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Male
;
NF-kappa B/*drug effects/metabolism
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Pancreas/metabolism/pathology
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Pancreatitis, Acute Necrotizing/chemically induced/*drug therapy
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Pyrrolidines/*pharmacology
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RNA, Messenger/metabolism
;
Random Allocation
;
Rats
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Rats, Sprague-Dawley
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Thiocarbamates/*pharmacology
;
Toll-Like Receptor 4/*drug effects/metabolism
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Tumor Necrosis Factor-alpha/genetics/metabolism
4.Pyrrolidine Dithiocarbamate Inhibits Nuclear Factor kappaB and Toll-Like Receptor 4 Expression in Rats with Acute Necrotizing Pancreatitis.
Min XU ; Kun Ning WANG ; Kai WU ; Xing Peng WANG
Gut and Liver 2015;9(3):411-416
BACKGROUND/AIMS: To investigate the expression of Toll-like receptor 4 (TLR4) in the pancreases of rats with acute necrotizing pancreatitis (ANP) and any changes upon treatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear factor kappaB (NF-kappaB), as well as to determine the relationship between TLR4 and NF-kappaB in ANP pathogenesis. METHODS: A total of 72 SD rats were randomly divided into three groups, namely, the control (sham-operation), ANP, and ANP with PDTC pretreatment groups. The PDTC-pretreated group was intraperitoneally injected with PDTC at a dose of 100 mg/kg 1 hour before the induction of ANP. The expressions of TLR4 and NF-kappaB in pancreatic tissue were evaluated by immunohistochemistry and Western blot analysis. The mRNA levels of cytokines tumor necrosis factor alpha, interleukin (IL)-1beta, and IL-6 were measured by reverse transcription polymerase chain reaction. RESULTS: The expressions of TLR4, NF-kappaB, and cytokine (NF-kappaB target) genes in the pancreatic tissue increased more significantly in the ANP groups than in the sham-operation group at 3, 6, and 12 hours. Pretreatment with PDTC alleviated the inflammatory activation in the pancreas with ANP, causing a significant decrease in the expressions of TLR4, NF-kappaB, and cytokine genes in the pancreatic tissue. CONCLUSIONS: The expressions of TLR4 and NF-kappaB were increased in the pancreases of rats with ANP. PDTC not only inhibits NF-kappaB but also suppresses the expression of TLR4 and downregulates the expression of the related cytokine genes.
Animals
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Antioxidants/*pharmacology
;
Interleukin-1beta/genetics/metabolism
;
Interleukin-6/genetics/metabolism
;
Male
;
NF-kappa B/*drug effects/metabolism
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Pancreas/metabolism/pathology
;
Pancreatitis, Acute Necrotizing/chemically induced/*drug therapy
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Pyrrolidines/*pharmacology
;
RNA, Messenger/metabolism
;
Random Allocation
;
Rats
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Rats, Sprague-Dawley
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Thiocarbamates/*pharmacology
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Toll-Like Receptor 4/*drug effects/metabolism
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Tumor Necrosis Factor-alpha/genetics/metabolism
5.Effect of reactive oxygen species induced by paraquat on neutrophil apoptosis.
Kai-xiu QIN ; Chun-wen LI ; Yan FANG ; Lei YU ; Xiao-long WANG
Chinese Journal of Applied Physiology 2015;31(2):111-114
OBJECTIVETo investigate the effect of paraquat (PQ) on reactive oxygen species (ROS) and neutrophil apoptosis and its possible signal transduction pathways.
METHODSCultured neutrophils were treated with different concentrations of PQ for 6-24 h. The apoptosis rate of neutrophils and ROS content were determined by flow cytometry. The exoressions of nuclear factor kappa B (NF-κB) and Caspase 3 were detected by Western blot. These parameters were checked again after NF-κB and Caspase 3 antagonist were applied.
RESULTSPQ could boost ROS generation and depress neutrophil apoptosis significantly. At the same time PQ could enhance the expression of NF-κB and inhibit the expression of Caspase 3. These effects could be reversed by ROS inhibitor diphenyleneiodonium (DPI) and NF-κB inhibitor pyrrolidinedithiocarbamate (PDTC).
CONCLUSIONPQ is a potent inducer of ROS and can inhibit neutrophil apoptosis by activating NF-κB and surpressing Caspase 3 activity.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cells, Cultured ; NF-kappa B ; antagonists & inhibitors ; metabolism ; Neutrophils ; cytology ; drug effects ; Paraquat ; toxicity ; Pyrrolidines ; pharmacology ; Reactive Oxygen Species ; metabolism ; Signal Transduction ; Thiocarbamates ; pharmacology
6.Therapeutic effect of vildagliptin and insulin aspart injection in elderly patients with type 2 diabetes.
Ling XU ; Kai LIN ; Haiou DENG ; Yinglan LI ; Ximei ZHI ; Weijie ZHANG ; Wen WU
Journal of Southern Medical University 2014;34(10):1511-1518
OBJECTIVETo observe the therapeutic effect and safety of vildagliptin combined with insulin aspart injection in elderly patients with type 2 diabetes.
METHODSSixty-six elderly patients with type 2 diabetes who had poor blood glucose control with insulin aspart injection were divided into two groups to have additional Vildagliptin (50 mg, twice daily, n=36, observation group) or Acarbose (50 mg, three times a day, n=30, control group). Blood glucose (including FBG and 2hPG), HbA1C, fasting c-peptide, postprandial c-peptide, BMI and GFR were observed after 12 weeks.
RESULTSIn the observation group, FBG, 2hPG and HbA1C decreased significantly (P<0.05), fasting and postprandial c-peptide increased (P<0.05), and BMI and GFR showed no obvious changes (P>0.05). In the control group, 2hPG and HbA1C were significant lowered (P<0.05) but FBG, fasting and postprandial c-peptide, BMI or GFR showed no changes (P>0.05). Compared with those in the control group, FBG in the observation group showed a significant reduction (P<0.05), but no significant differences were found in 2hPG, HbA1C, BMI or GFR (P>0.05). No hypoglycemia occurred in the two groups during the treatment.
CONCLUSIONVildagliptin with insulin aapart injection has equivalent effect with Acarbose combined with insulin aspart injection in decreasing 2hPG and HbA1C without increasing the body weight or the risk to hypoglycemia or causing lowered GFR. Vildagliptin has better effect in decreasing FBG and improving the function of the islet cells.
Adamantane ; analogs & derivatives ; therapeutic use ; Aged ; Blood Glucose ; Diabetes Mellitus, Type 2 ; drug therapy ; Glycated Hemoglobin A ; metabolism ; Humans ; Hypoglycemic Agents ; therapeutic use ; Injections ; Insulin Aspart ; therapeutic use ; Nitriles ; therapeutic use ; Pyrrolidines ; therapeutic use
7.A comparative study of the effect of vildagliptin and glimepiride on glucose variability in type 2 diabetic patients with inadequate glycemic control on metformin.
Tolentino-Wilson Odessa G. ; Litonjua Augusto D.
Philippine Journal of Internal Medicine 2014;52(4):196-201
BACKGROUND: Vildagliptin is believed to improve glucose variability by restoring the physiologic pattern of insulin secretion and improving beta and alpha cells' sensitivity to glucose but with less increase in insulin secretion compared to sulfonylureas resulting in similar glucose levels but with less risk of hypoglycemia.
OBJECTIVE: To compare the effect of vildagliptin and glimepiride on glucose variability among Type 2 diabetic patients not controlled on metformin alone.
METHODS: This investigation is a prospective, interventional, open-labeled, active control, parallel assignment, efficacy study that included patients with inadequate glycemic control on monotherapy with metformin, randomly assigned either to vildagliptin or glimeparide. For one month, one group took vildagliptin 50mg/tablet one tablet twice a day while the other group took glimepiride 1 mg/tablet one tablet once a day. Subjects were asked to monitor their capillary blood glucose at seven points throughout the day for 35 days.
RESULTS: A total of 18 patients were recruited for the study and randomly assigned to either of the two treatment arms. However, only 16 patients completed the study. The vildagliptin and glimepiride groups had comparable blood sugars at baseline and at the end of the study although the glimepiride group showed a steeper decline in the blood sugar levels. Subjects in both groups showed a downward trend in the blood glucose values from day one to the 35th day with comparable mean glucose values between treatments and across combinations of day and treatment. Likewise, mean postprandial incremental area under the curve (AUCpp)and mean amplitude of glycemic excursions (MAGE) were comparable across treatments and across combinations of day and treatment, although the Glimepiride group showed relatively higher MAGE values.
CONCLUSION: Vildaglipitin and glimepiride both improved glycemia of patients with uncontrolled blood sugar on monotherapy with metformin as both groups showed downward glucose trend, although vildagliptin showed relatively less abrupt glucose lowering effect suggesting lesser risk of hypoglycemia. Mean postprandial glucose excursions of the two groups were also comparable but the vildagliptin arm had lower MAGE and may suggest an improvement in both ?- and ?-cell function.
Human ; Male ; Female ; Aged 80 And Over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Adamantane ; Blood Glucose ; Diabetes Mellitus, Type 2 ; Glucose ; Hypoglycemia ; Insulins ; Metformin ; Nitriles ; Prospective Studies ; Pyrrolidines ; Sulfonylurea Compounds
8.Predictive Clinical Parameters and Glycemic Efficacy of Vildagliptin Treatment in Korean Subjects with Type 2 Diabetes.
Jin Sun CHANG ; Juyoung SHIN ; Hun Sung KIM ; Kyung Hee KIM ; Jeong Ah SHIN ; Kun Ho YOON ; Bong Yun CHA ; Ho Young SON ; Jae Hyoung CHO
Diabetes & Metabolism Journal 2013;37(1):72-80
BACKGROUND: The aims of this study are to investigate the glycemic efficacy and predictive parameters of vildagliptin therapy in Korean subjects with type 2 diabetes. METHODS: In this retrospective study, we retrieved data for subjects who were on twice-daily 50 mg vildagliptin for at least 6 months, and classified the subjects into five treatment groups. In three of the groups, we added vildagliptin to their existing medication regimen; in the other two groups, we replaced one of their existing medications with vildagliptin. We then analyzed the changes in glucose parameters and clinical characteristics. RESULTS: Ultimately, 327 subjects were analyzed in this study. Vildagliptin significantly improved hemoglobin A1c (HbA1c) levels over 6 months. The changes in HbA1c levels (DeltaHbA1c) at month 6 were -2.24% (P=0.000), -0.77% (P=0.000), -0.80% (P=0.001), -0.61% (P=0.000), and -0.34% (P=0.025) for groups 1, 2, 3, 4, and 5, respectively, with significance. We also found significant decrements in fasting plasma glucose levels in groups 1, 2, 3, and 4 (P<0.05). Of the variables, initial HbA1c levels (P=0.032) and history of sulfonylurea use (P=0.026) were independently associated with responsiveness to vildagliptin treatment. CONCLUSION: Vildagliptin was effective when it was used in subjects with poor glycemic control. It controlled fasting plasma glucose levels as well as sulfonylurea treatment in Korean type 2 diabetic subjects.
Adamantane
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Diabetes Mellitus
;
Dipeptidyl Peptidase 4
;
Fasting
;
Glucose
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Hemoglobins
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Nitriles
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Plasma
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Pyrrolidines
;
Retrospective Studies
9.The Efficacy of Vildagliptin in Korean Patients with Type 2 Diabetes.
Diabetes & Metabolism Journal 2013;37(1):36-39
No abstract available.
Adamantane
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Humans
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Nitriles
;
Pyrrolidines
10.Effects of pyrrolidine dithiocarbamate on expressions of α-smooth muscle actin, integrin α5 and fibronectin in acute paraquat poisoned rats.
Min HUANG ; Hui-fang YANG ; Ping ZHANG ; Xiu-li CHANG ; Zhi-jun ZHOU
Chinese Journal of Industrial Hygiene and Occupational Diseases 2013;31(5):341-346
OBJECTIVETo observe the expressions of α-SMA, integrin α5 and fibronectin (Fn) in acute paraquat poisoned rats and the effect of PDTC. To investigate the mechanism of paraquat-induced pulmonary fibrosis.
METHODSSprague-Dawley rats were randomly divided into three experimental groups: Control group (6 rats), PQ group (36 rats) and PQ+PDTC group (36 rats). On the 1st, 3rd, the 7th, the 14th, the 28th and the 56th day after exposure, the protein expression of α smooth muscle actin (α-SMA) was evaluated by western blot. The mRNA levels of integrin α5 and fibronectin (Fn) were analyzed with real-time quantitative PCR (RT-PCR). Meanwhile, the lung pathological changes were observed and semi-quantified.
RESULTST With the time passing, the expression of α-SMA in PQ group increased gradually compared with control group (P < 0.05 or P < 0.01). The increasing extent was gently on the 3 rd, the 7 th day. While increasing extent was rapidly from the 28 th to the 56 th day. RT-PCR showed PQ significantly increased Fn mRNA level on all time points and increased integrin α5 mRNA level from the 7 rd to 56 th day compared with control group (P < 0.05 or P < 0.01). PDTC treatment significantly deceased α-SMA, Fn, and integrin α5 levels compared with PQ group in corresponding time points (P < 0.05 or P < 0.01) Noteworthy, in PQ+PDTC group, the occurrence of pathological changes were drastically attenuated and pathologic score significantly decreased (P < 0.05 or P < 0.01).
CONCLUSIONSα-SMA, integrin α5 and fibronectin could play an important role in the development of pulmonary fibrosis caused by paraquat poisoning. PDTC, asa strong NF-κB inhibitor, may inhibit NF-κB activity and further significantly decreased expressions of α-SMA, integrin α5 and fibronectin which were important part of ECM, leading to drastically attenuated pulmonary fibrosis. However, the mechanisms of PDTC intervention still remains to be explored.
Actins ; metabolism ; Animals ; Disease Models, Animal ; Fibronectins ; metabolism ; Integrin alpha5 ; metabolism ; Male ; Paraquat ; poisoning ; Pulmonary Fibrosis ; chemically induced ; metabolism ; Pyrrolidines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Thiocarbamates ; pharmacology

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