Pyrrolidine Dithiocarbamate Group Research Articles

Effect of 10.6 μm laser moxibustion on inflammation in diabetic peripheral neuropathy rats.

Diabetic peripheral neuropathy (DPN) is the main cause of disability in diabetes patients but the efficacy of available drugs is poor. Moxibustion is an adjunctive treatment for DPN that can reduce symptoms. The peak value of the far infrared wavelength of 10.6 μm laser moxibustion is close to the infrared radiation spectrum of traditional moxibustion. Its effect is similar to that of moxibustion and does not cause pain, infection or produce irritating smoke. Twenty-four male SD rats were divided into control (Con), DPN, laser moxibustion (LM), and pyrrolidine dithiocarbamate (PDTC) groups (n=6/group). The DPN, LM and PDTC group rats were intraperitoneally injected with 1% streptozotocin (STZ) to induce a model of DPN. LM group rats were irradiated with a laser at bilateral ST36 acupoints for 15min, once every other day, for 14 days. PDTC group rats were intraperitoneally injected with PDTC once a day. Body weight, blood glucose, and paw withdrawal mechanical threshold (PWMT) were measured and laser speckle imaging (LSI) performed before and after modeling and at 1 and 2 weeks after intervention. Two weeks after intervention, changes in serum interleukin 1β (IL1β), interleukin 6 (IL6), tumor necrosis factor α (TNFα) and nerve growth factor (NGF) were analyzed, and the abundance of NF-κB and IκB-α proteins and levels of NF-κB and IκB-α mRNAs in the sciatic nerve were observed. The results showed that 10.6 μm laser moxibustion can relieve pain, improve microcirculation, and alleviate inflammation in DPN rats, possibly via the NF-κB inflammatory pathway.

The possible protective effect of the nuclear factor kappa B inhibitor pyrrolidine dithiocarbamate on tramadol-induced testicular damage in rats

BackgroundTramadol provokes oxidative stress that gives rise to apoptosis with alterations in the cellular structure and adversely influences male fertility. A specific inhibitor of nuclear factor kappa B (NF-κB), pyrrolidine dithiocarbamate (PDTC), has observable antioxidant and anti-inflammatory characteristics and enhances the improvement of organs damage caused by various agents. The impact of PDTC on testicular damage caused by tramadol has not been previously examined.ObjectiveThis study was designed to investigate the potential impact of pyrrolidine dithiocarbamate on testicular damage provoked by chronic tramadol usage.Materials and methodsForty healthy adult male albino rats were included in this study. Rats were randomly and equally divided into 4 groups: group (I), control group; group (II), pyrrolidine dithiocarbamate (PDTC) group; group (III), tramadol (Tr) group; and group (IV), Tr + PDTC group. This study measured serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and free testosterone levels. Testicular malondialdehyde (MDA), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPX), and caspase-8 and caspase-3 activities were also detected. Immuno-histochemical evaluation of inducible NOS (iNOS) expression in testicular tissue along with histopathological examination of testicular tissue has been studied.ResultsTramadol caused a significant reduction in serum FSH, LH and testosterone levels, epididymal sperm count, and motility, as well as testicular GPX and SOD activities. On the other hand, a significant elevation of testicular MDA, IL-1β, IL-6, and TNF-α levels and caspase-8 and caspase-3 activities were found. However, PDTC administration with tramadol showed significantly increased sperm production and motility and alleviated tramadol-induced disturbance in other measured parameters in the Tr + PDTC group compared to the Tr group. Moreover, co-administration of PDTC with tramadol significantly alleviated the histopathological structure of testicular tissue and the increased iNOS expressions noticed in the tramadol-treated group.ConclusionConsidering the protective effects of PDTC against the reproductive toxicity induced by tramadol, this compound can be used as a possible protective and treating target for tramadol-induced reproductive toxicity.

Hypobaric Hypoxia Aggravates Renal Injury by Inducing the Formation of Neutrophil Extracellular Traps through the NF-κB Signaling Pathway

The hypersensitivity of the kidney makes it susceptible to hypoxia injury. The involvement of neutrophil extracellular traps (NETs) in renal injury resulting from hypobaric hypoxia (HH) has not been reported. In this study, we aimed to investigate the expression of NETs in renal injury induced by HH and the possible underlying mechanism. A total of 24 SD male rats were divided into three groups (n=8 each): normal control group, hypoxia group and hypoxia+pyrrolidine dithiocarbamate (PDTC) group. Rats in hypoxia group and hypoxia+PDTC group were placed in animal chambers with HH which was caused by simulating the altitude at 7000 meters (oxygen partial pressure about 6.9 kPa) for 7 days. PDTC was administered at a dose of 100 mg/kg intraperitoneally once daily for 7 days. Pathological changes of the rat renal tissues were observed under a light microscope; the levels of serum creatinine (SCr), blood urea nitrogen (BUN), cell-free DNA (cf-DNA) and reactive oxygen species (ROS) were measured; the expression levels of myeloperoxidase (MPO), citrullinated histone H3 (cit-H3), B-cell lymphoma 2 (Bcl-2), Bax, nuclear factor kappa B (NF-κB) p65 and phospho-NF-κB p65 (p-NF-κB p65) in rat renal tissues were detected by qRT-qPCR and Western blotting; the localization of NF-κB p65 expression in rat renal tissues was observed by immunofluorescence staining and the expression changes of NETs in rat renal tissues were detected by multiplex fluorescence immunohistochemical staining. After hypoxia, the expression of NF-κB protein in renal tissues was significantly increased, the levels of SCr, BUN, cf-DNA and ROS in serum were significantly increased, the formation of NETs in renal tissues was significantly increased, and a large number of tubular dilatation and lymphocyte infiltration were observed in renal tissues. When PDTC was used to inhibit NF-κB activation, NETs formation in renal tissue was significantly decreased, the expression level of Bcl-2 in renal tissues was significantly increased, the expression level of Bax was significantly decreased, and renal injury was significantly alleviated. HH induces the formation of NETs through the NF-κB signaling pathway, and it promotes apoptosis and aggravates renal injury by decreasing Bcl-2 and increasing Bax expression.

Irisin Alleviates Inflammatory Injury in Diabetic Cardiomyopathy by Regulating NF-κB Pathway

To investigate the protective effect of irisin in diabetic cardiomyopathy (DCM) and its mechanism. A mouse model of DCM was established by high-fat diet combined with the injection of streptozotocin. The mice were assigned to a control group, a DCM group, a DCM+low-dose irisin group, a DCM+high-dose irisin group, and a DCM+pyrrolidine dithiocarbamate (PDTC) (nuclear factor [NF]-κB inhibitor) group. Then, the mice received irisin intervention for 3 weeks after successful modeling. Myocardial morphologic changes were observed by hematoxylin and eosin (HE) staining and Masson staining. The levels of serum creatine kinase (CK) and creatine kinase isoenzyme CK-MB were examined by automatic biochemical analyzer. H9c2 cells were divided into the control group, high glucose and high lipid (HG/HL) group, HG/HL+low-dose irisin group, HG/HL+high-dose irisin group, and HG/HL+PDTC group. CCK-8 assay was conducted to determine cell viability. The expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 in the myocardial tissue and the cells were determined by ELISA. In addition, nuclear translocation of NF-κB p65 protein and the protein expression level of NF-κB inhibitor protein α (IκBα) in the myocardial tissue and the cells were determined by Western blot. According to the results of animal experiment, low and high doses of irisin could alleviate the pathological injury and fibrosis of myocardial tissue to varying degrees. Irisin inhibited the levels of CK, CK-MB, and inflammatory factors, up-regulated IκB protein expression, and diminished NF-κB nuclear translocation. According to the results of cell experiment, low and high doses of irisin could enhance H9c2 cell viability to varying degrees, increase the level of intracellular IκB proteins, and inhibit NF-κB p65 nuclear translocation and inflammatory factor expression. The changes in these aspects in the DCM+low-dose irisin group and the DCM+high-dose irisin group were similar to those in the DCM+PDTC group. Through inhibiting NF-κB p65 nuclear translocation, irisin may reduce the inflammatory response in the myocardial tissue of DCM mice and H9c2 cells of myocardial injury induced by high glucose and high fat, thereby exerting a protective effect on myocardium.

Mechanism of Xiaoqinglong Decoction and Qingqi Huatan Pills in improving pathological airway mucus based on nuclear factor-κB/microRNA-494 signaling regulation of mucin 5AC and cystic fibrosis transmembrane conductance regulator

To observe the effects of Xiaoqinglong Decoction and Qingqi Huatan Pills on interleukin-1β (IL-1β)-induced mucushypersecretion model of human airway epithelial H292 cellsand related molecules of nuclear factor-κB/microRNA-494(NF-κB/miR-494) signaling pathway, and to explore the mechanism of the two medicines in improving pathological airway mucus. Methyl thiazolyl tetrazolium (MTT) colorimetric method was used to detect the effects of different concentrations of Xiaoqinglong Decoction and Qingqi Huatan Pills on the activity of H292 cellsinduced by IL-1β, and the appropriate concentration was selected for subsequent experiments. Cells were randomly divided into blank group, IL-1β model group (5 μg/L IL-1β), NF-κB inhibitor pyrrolidinedithiocarbamate (PDTC) group (5 μg/L IL-1β+100 μmol/L PDTC), Xiaoqinglong Decoction (5 μg/L IL-1β+1 000 mg/L Xiaoqinglong Decoction) and Qingqi Huatan Pill group (5 μg/L IL-1β+1 000 mg/L Qingqi Huatan Pills). 5 μg/L IL-1β was used to induce H292 cells for 24 hours to establish a model of airway epithelial mucus hypersecretion. Enzyme linked immunosorbent assay (ELISA) method was used to detect the levels of mucin 5AC (MUC5AC), tumor necrosis factor-α (TNF-α) and IL-8 and the synthesis of intracellular MUC5AC and cystic fibrosis transmembrane conductance regulator (CFTR). Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of MUC5AC mRNA, CFTR mRNA, miR-494. Western blotting was used to detect protein expression of key proteins (p65) and NF-κB inhibitors (IκB) in NF-κB signaling pathway. Xiaoqinglong Decoction and Qingqi Huatan Pills with the concentration of 1 000 mg/L were selected for the follow-up experiment. Compared with the blank group, the levels of MUC5AC, TNF-α and IL-8 were significantly increased in the model group, intracellular MUC5AC protein content and mRNA expression were also significantly increased, intracellular CFTR protein content and mRNA expression were significantly decreased, and intracellular p65 protein expression was significantly up-regulated, the expression of IκB protein was significantly down-regulated, and the expression of miR-494 was significantly increased. Compared with the model group, the levels of MUC5AC, TNF-α and IL-8 were significantly reduced in PDTC group, Xiaoqinglong Decoction group and Qingqi Huatan Pill group, intracellular MUC5AC protein content and mRNA expression were also significantly decreased, and intracellular p65 protein expression was significantly down-regulated, and IκB protein expression was significantly up-regulated, miR-494 expression was significantly reduced. Intracellular CFTR protein content and mRNA expression were significantly increased in both PDTC group and Qingqi Huatan Pill group. Compared with the PDTC group, the level of TNF-α in the Xiaoqinglong Decoction group was significantly increased (ng/L: 22.77±3.14 vs. 11.09±3.37, P < 0.05),the content and mRNA expression of CFTR and IκB protein expression was significantly decreased [CFTR protein (ng/L): 97.38±6.62 vs. 227.04±19.48, CFTR mRNA (2-ΔΔCt): 0.99±0.08 vs. 1.21±0.08, IκB/β-actin: 1.69±0.11 vs. 2.00±0.18, all P < 0.05], the level of TNF-α in Qingqi Huatan Pill group was significantly higher (ng/L: 19.08±3.71 vs. 11.09±3.37, P < 0.05). Compared with Xiaoqinglong Decoction group, the protein content and mRNA expression of CFTR and IκB protein expression in Qingqi Huatan Pill group were significantly increased [CFTR protein (ng/L): 235.01±22.71 vs. 97.38±6.62, CFTR mRNA (2-ΔΔCt): 1.32±0.15 vs. 0.99±0.08, IκB/β-actin: 1.94±0.16 vs. 1.69±0.11, all P < 0.05]. The effect of Xiaoqinglong Decoctionin improving the hypersecretion of mucus in the airway epithelium may be related to the inhibition of NF-κB/miR-494 inflammatory signal-mediated MUC5AC hypersecretion, while the effect of Qingqi Huatan Pills may be related to the inhibition of NF-κB/miR-494 inflammatory signal-mediated MUC5AC hypersecretion and CFTR dysfunction. Therefore, the difference in the mechanism of the two treatments of airway pathological mucus is mainly in the regulation of CFTR mRNA and protein.

Pyrrolidine Dithiocarbamate Might Mitigate Radiation-Induced Heart Damage at an Early Stage in Rats.

Objective: Radiation-induced heart damage (RIHD) is becoming an increasing concern due to offsetting clinical benefits of radiotherapy to a certain extent. Pyrrolidine dithiocarbamate (PDTC) as an antioxidant has been implicated in cardioprotective effects. We aimed to investigate whether pyrrolidine dithiocarbamate could attenuate heart damage at an early stage post-irradiation and unveil the potential mechanisms. Methods: A total of 15 adult male Sprague–Dawley rats were randomized into the control, irradiation (IR), and PDTC plus irradiation (PDTC + IR) groups. Hearts were irradiated with a single fraction of 20.0 Gy. Rats received daily intraperitoneal injection of PDTC for 14 days. At the 14th day post-irradiation, echocardiography was performed, and rats were killed. Morphological damage was examined by hematoxylin–eosin (HE) stain and Masson’s trichrome stain. The collagen volume fraction (CVF) was applied for semi-quantitative analysis. The protein levels were analyzed by Western blot and mRNA levels by quantitative real-time PCR. Results: No significant damage to systolic function of left ventricular was induced at an early stage post-irradiation. HE staining of cardiac tissue showed that the disordered arrangement of myocardial cells and abnormal cell infiltration were alleviated in the PDTC + IR group. The increased CVF in the irradiation group was inhibited in the PDTC + IR group (22.05 ± 2.64% vs. 9.99 ± 1.65%, p < 0.05). The protein levels of nuclear factor-kappa B (NF-κB), hypoxia-inducible factor-1α (HIF-1α), and COL-1 were downregulated after treatment with PDTC (p < 0.05), and there was a declining trend in the protein of the connective tissue growth factor (CTGF). The mRNA expression of NF-κB and HIF-1α in the PDTC plus irradiation group was lower than that in the irradiation group (p < 0.05), and there was a declining trend in the mRNA expression of the connective tissue growth factor and COL-1. Conclusion: PDTC alleviates myocardial cell disordered arrangement, abnormal cell infiltration, and pro-fibrotic change at an early stage in rats with radiation-induced heart damage. Such a protective effect is closely associated with the downregulation of NF-κB.

Protective effect of pyrrolidine dithiocarbamate against methotrexate-induced testicular damage.

The aim of the study was to investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) against methotrexate (MTX)-induced testicular damage in rats. Forty Wistar albino male rats were divided into equally four groups: Control group (saline solution, IP), PDTC group (100mg/kg PDTC,IP, 10days), MTX group (20mg/kg MTX, IP, single dose, on the 6thday) and MTX + PDTC group (100mg/kg PDTC, IP, 10days and 20mg/kg MTX, IP, single dose, on the 6thday). After 10days, testicular tissues were excised for morphometric, histological and immunohistochemical evaluations. Serum testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH) and prokineticin 2 (PK2) levels were determined. Body and testicular weights were measured. Testicular damage was assessed by histological evaluation. Nuclear factor kappa B (NFkB), nuclear factor erythroid 2 related factor 2 (Nrf2) and PK2 immunoreactivities were evaluated by HSCORE. Body and testicular weights, serum FSH, LH, testosterone levels, seminiferous tubule diameter and germinal epithelial thickness were significantly decreased in the MTX group. However, serum PK2 level, histologically damaged seminiferous tubules and interstitial field width were significantly increased. Additionally, there was an increase in NFkB and PK2 immunoreactivity, whereas there was a significant decrease in Nrf2 immunoreactivity. PDTC significantly improved hormonal, morphometric, histological and immunohistochemical findings. Taken together, we conclude that PDTC may reduce MTX-induced testicular damage via NFkB, Nrf2 and PK2 signaling pathways.

Pathogenic role of innate immunity in a model of chronic NO inhibition associated with salt overload.

Nitric oxide inhibition with Nω-nitro-l-arginine methyl ester (l-NAME), along with salt overload, leads to hypertension, albuminuria, glomerulosclerosis, glomerular ischemia, and interstitial fibrosis, characterizing a chronic kidney disease (CKD) model. Previous findings of this laboratory and elsewhere have suggested that activation of at least two pathways of innate immunity, Toll-like receptor 4 (TLR4)/NF-κB and nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 (NLRP3) inflammasome/IL-1β, occurs in several experimental models of CKD and that progression of renal injury can be slowed with inhibition of these pathways. In the present study, we investigated whether activation of innate immunity, through either the TLR4/NF-κB or NLRP3/IL-1β pathway, is involved in the pathogenesis of renal injury in chronic nitric oxide inhibition with the salt-overload model. Adult male Munich-Wistar rats that received l-NAME in drinking water with salt overload (HS + N group) were treated with allopurinol (ALLO) as an NLRP3 inhibitor (HS + N + ALLO group) or pyrrolidine dithiocarbamate (PDTC) as an NF-κB inhibitor (HS + N + PDTC group). After 4 wk, HS + N rats developed hypertension, albuminuria, and renal injury along with renal inflammation, oxidative stress, and activation of both the NLRP3/IL-1β and TLR4/NF-κB pathways. ALLO lowered renal uric acid and inhibited the NLRP3 pathway. These effects were associated with amelioration of hypertension, albuminuria, and interstitial inflammation/fibrosis but not glomerular injury. PDTC inhibited the renal NF-κB system and lowered the number of interstitial cells staining positively for NLRP3. PDTC also reduced renal xanthine oxidase activity and uric acid. Overall, PDTC promoted a more efficient anti-inflammatory and nephroprotective effect than ALLO. The NLRP3/IL-1β and TLR4/NF-κB pathways act in parallel to promote renal injury/inflammation and must be simultaneously inhibited for best nephroprotection.

The roles of NF-kB in the development of lung injury after one-lung ventilation.

To explore the roles of NF-kB in the development of lung injury after one-lung ventilation. Eighteen Sprague-Dawley (SD) rats were randomly divided into 3 groups including control group, one-lung ventilation (OL) group and NF-kB inhibitor pyrrolidine dithiocarbamate (PDTC) group, with 6 rats in each group. Rats in OL and PDTC groups were used to establish one-lung ventilation model, and rats in PDTC group were subjected to intravenous injection of NF-kB specific inhibitor PDTC at 30 min before model construction. One-lung ventilation was performed for 3 h, and arterial blood gas analyzer was used for blood gas analysis. The hemodynamics and respiratory mechanics parameters were detected. The respiratory index (RI) and oxygenation index (OI) were calculated. The pathological changes of lung tissue were observed by HE staining. The levels of TNF-α, IL-1β, IL-6, and IL-8 in lung tissue were detected by ELISA. The expression levels of p65, p-p65, p-IκBα and IκBα and the activity of NF-Kβ in lung tissue were detected by Western Blot. Compared with OL group, HR, RI and W/D were significantly reduced and MAP and OI were significantly increased in PDTC group (p<0.05). Compared with OL group, alveolar fluid exudation, pulmonary interstitial thickening and inflammatory cell infiltration were significantly improved in PDTC group. The levels of TNF-α, IL-1β, IL-6 and IL-8 in PDTC group were significantly lower than in OL group (p<0.05). The ratios of p-p65/p65 and p-IκBα/IκBα and the activity of NF-kB in OL group were significantly reduced than in PDTC group (p<0.05). NF-kB can promote lung injury after one-lung ventilation, and the inhibition of NF-kB may be a new way for the treatment of this disease.

Inhibition of NF-κB by Pyrrolidine Dithiocarbamate Prevents the Inflammatory Response in a Ligature-Induced Peri-Implantitis Model: A Canine Study

Background/Aims: The roles of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) in peri-implantitis are unclear. Here, we used a canine model of peri-implantitis to explore the effects of inhibiting NF-κB with pyrrolidine dithiocarbamate (PDTC) on the inflammatory response in ligature-induced peri-implantitis. Methods: After successfully establishing the peri-implantitis model, beagles were randomly assigned to normal, model or PDTC groups. ELISA tests were used to determine the levels of interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). Immunohistochemistry was employed to assess the expression of NF-κB p65. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine the mRNA levels of TLR4 and NF-κB p65, and western blot analysis was used to measure the protein levels of TLR4 in periodontal tissues from each group. Periodontal ligament fibroblasts (PDLFs) were cultured and subsequently classified into PDLF normal, PDLF model, PDLF LPS, PDLF PDTC, and PDLF LPS + PDTC groups. An immunofluorescence assay was used to measure the expression level of NF-κB p65. The CCK-8 assay and flow cytometry were performed to evaluate cell proliferation and apoptosis. Results: The in vitro results indicated that NF-κB p65 and TLR4 were upregulated in canine periodontal tissues, and PDTC could suppress the expression levels of NF-κB p65 and TLR4. Inflammation could increase TLR4 protein expression in canine periodontal tissue, and PDTC could inhibit the inflammation-induced increase in TLR4 protein expression. These results revealed that PDTC could reverse the LPS-induced increases in the levels of IL-1, IL-6, IL-8 and TNF-α. In vivo, the results demonstrated that PDTC inhibited the LPS-induced NF-κB p65 upregulation, and PDTC could reverse the inhibitory effect of the PDLF model + LPS on the proliferation of periodontal fibroblasts. The results also showed that in the PDLF model, LPS promoted PDLF apoptosis by inducing implant periodontitis in canines, but PDTC inhibited the PDLF apoptosis and relieved implant periodontitis in canines. Conclusion: Based on our results, we concluded that PDTC can inhibit the expression of NF-κB and alleviate the inflammatory response induced by LPS, thereby preventing periodontal inflammation and reducing the development of peri-implantitis.

The effect of NF-κB on NLRP3 of lung tissue in rats with acute lung injury induced by phosgene

Objective To observe the effect of signal transduction pathway of nuclear factor-kappa B (NF-κB) on Nod-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome and pyroptosis in rats with acute lung injury induced (ALI) by phosgene. Methods The rats were randomly(random number) divided into 3 groups: air exposure control group, phosgene exposure group and PDTC group with phosgene exposure after 100 mg/kg pyrrolidine dithiocarbamate (PDTC) administration. The specimens of serum, bronchoalveolar lavage fluid (BALF) and lung tissue were collected 6 h after exposure. Morphological changes were observed by HE staining. The expression of NLRP3 in the lung of three groups was detected by immunohistochemistry. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expressions of NF-κB p65,NLRP3, ASC and caspase-1 mRNA in the lung tissue. NF-κB p65, NLRP3, ASC and caspase-1 protein levels in the lung tissue were quantified by Western blot. The concentrations of IL-1β, IL-18 and IL-33 in the serum and BALF were measured by enzyme-linked immunosorbent assay (ELISA). Pyroptosis was observed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). Results The model of phosgene-induced ALI was successfully established in rats. Morphological changes with inflammatory cell infiltration were observed in the lung tissues of phosgene group, in which NLRP3 positive cells also could be observed by immunohistochemical staining. The mRNA expressions and protein levels of NF-κB p65, NLRP3 and caspase-1 in lung tissues were significantly increased (P<0.05) in phosgene group, compared with air control group. The mRNA expressions and protein levels of NF-κB p65, NLRP3 and caspase-1 in lung tissues were significantly decreased (P<0.05) in PDTC group, compared with phosgene group. The IL-1β, IL-18 and IL-33 protein levels in serum and BALF were significantly increased (P<0.05) in phosgene group, compared with air control group. The IL-1β, IL-18 and IL-33 protein levels in serum and BALF were significantly decreased (P<0.05) in PDTC group, compared with phosgene group. TUNEL results showed that pyroptosis in the lung tissue obviously increased in phosgene group, while decreased in PDTC group. Conclusions NLRP3 inflammasome and lung cell pyroptosis were induced through NF-κB signal transduction pathway in rats with acute lung injury caused by phosgene inhalation. Blockade of NF-κB can alleviate acute lung injury by down-regulating the expression of NLRP3 inflammasome to inhibit pyroptosis. Key words: Nuclear factor-kappa B (NF-κB); Phosgene; acute lung injury; Pyrin domain-containing 3 (NLRP3) innammasome; Inhalation; pyroptosis; Inflammation; Pyrrolidinedithiocarbamic acid (PDTC)

Effect of pyrrolidine dithiocarbamate on oxidative stress and mitochondrial function of lung tissue in mice with acute lung injury

To investigate the effects of pyrrolidine dithiocarbamate (PDTC) on oxidative stress and mitochondrial function of lung tissue in mice with acute lung injury (ALI) induced by lipopolysaccharide (LPS). Forty female Balb/c mice were randomly divided into normal saline (NS) control group, LPS model group, PDTC group, and PDTC+LPS group, with 10 mice in each group. The model of mice with ALI was reproduced by intraperitoneal injection of 15 mg/kg LPS. PDTC was administered intraperitoneally with 50 mg/kg PDTC 1 hour before LPS treatment in the PDTC+LPS group. The mice in NS control group was given intraperitoneal injection of 0.1 mL NS only, and those in PDTC group was given intraperitoneal injection of 50 mg/kg PDTC only. The mice were sacrificed at 24 hours after model reproduction, and the lung tissues were harvested. The total antioxidant capacity (T-AOC) of lung tissue was measured by spectrophotometric kits. The content of malondialdehyde (MDA) was determined by thiobarbituric acid reactive substances assay. The protein expressions of superoxide dismutases (SOD1, SOD2) and catalase (CAT) in lung tissue were determined by Western Blot. Mitochondria from mouse lungs were isolated, and adenosine triphosphate (ATP) synthesis was measured with a luciferase/luciferin-based approach. The mitochondrial membrane potential (ΔΨm) was estimated by using Rhodamine. The mRNA expressions of mitochondrial uncoupling proteins (UCPs) were determined by reverse transcription-polymerase chain reaction (RT-PCR). LPS stimulation could significantly increase oxidative stress in lung tissue of mice and lead to mitochondrial dysfunction. The results showed that the protein expressions of T-AOC and SOD1 were decreased, the level of MDA was increased, the ATP synthesis was decreased in the mitochondrial, the ΔΨm was decreased, and the mRNA expression of UCP2 was decreased. However, there was no significant change in the expressions of SOD2, CAT in lung tissue and UCP1, UCP3 in the mitochondria. Pretreatment with PDTC could obviously alleviate the increase in LPS-induced oxidative stress in lung tissue and mitigate mitochondrial dysfunction. Compared with the LPS model group, T-AOC in lung tissue of PDTC+LPS group was significantly increased (U/g: 0.35±0.08 vs. 0.31±0.07), the level of MDA was significantly decreased (μmol/mg: 13.29±1.13 vs. 17.54±1.72), the protein expression of SOD1 was significantly upregulated (SOD1 protein: 1.13±0.11 vs. 0.71±0.09), ATP synthesis was significantly increased in the mitochondrial (μmol/mg: 49.23±5.42 vs. 36.92±2.21), ΔΨm was significantly increased (mV: 226.03±11.69 vs. 194.86±7.79), and the mRNA expression of UCP2 was significantly increased (2-ΔΔCt: 0.88±0.06 vs. 0.73±0.04). The differences were statistically significant (all P < 0.05). In lung tissue of normal mice, PDTC treatment also had the effect of anti-oxidizing, reducing oxidative stress and promoting ATP synthesis in the mitochondrial. Compared with the NS control group, the level of T-AOC (U/g: 0.49±0.09 vs. 0.43±0.06) and the protein expressions of SOD2 and CAT (SOD2 protein: 1.33±0.08 vs. 1.00±0.11, CAT protein: 1.39±0.08 vs. 1.00±0.11), and ATP synthesis in the mitochondrial of PDTC group was significantly increased (μmol/mg: 61.53±4.92 vs. 53.33±3.20), MDA was significantly decreased (μmol/mg: 10.27±1.25 vs. 12.27±1.36), with statistical differences, but had no effect on the protein expression of SOD1 in lung tissue and ΔΨm and UCPs mRNA expressions in mitochondrion. LPS can induce ALI in mice, increased oxidative stress in lung tissue, and induce mitochondrial dysfunction by inhibiting ATP synthesis. PDTC pretreatment has anti-oxidative effect on LPS-induced ALI, and can mitigate mitochondrial dysfunction.

Ginsenoside Rg1 protects against hind-limb ischemia reperfusion induced lung injury via NF-κB/COX-2 signaling pathway

Background/aimsGinsenoside Rg1 is regarded as the primary bioactive ingredient in Panax notoginseng that has been well recognized for its protective effects against ischemia/reperfusion (IR) injury. However, the mechanisms still remain elusive. Our study aims to investigate the effects of Rg1 against lung injury induced by hind-limb IR in rats. MethodsTwenty-four Sprague Dawley rats were randomly submitted to sham operation (SM group), hind-limb IR (IR group), hind-limb IR + Rg1 (Rg1 group), and hind-limb IR + Pro-DTC group (PD group). All the rats except those in SM group were subjected to 3 h of ischemia followed by 6 h of reperfusion, and extra intravenous Rg1 and pyrrolidine dithiocarbamate (Pro-DTC), a selective inhibitor of nuclear factor kappa B (NF-κB), was administered intravenously before ischemia in the Rg1 and PD group, respectively. The activities of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT), as well as protein expressions of NF-κB p65 and cyclooxygenases-2 (COX-2) in lung tissue, and thromboxane B2 (TXB2) and 6-keto-ProstaglandinF1α (6-keto-PGF1α) levels in bronchoalveolar lavage (BAL) fluid were detected. Morphological changes, index of quantitative assessment of histologic lung injury (IQA), apoptosis index (AI) and lung Wet/Dry ratio were also evaluated. ResultsThe levels of Wet/Dry ratio, IQA, AI, activities of MPO and 6-keto-PGF1α/TXB2 ratio were increased, and NF-κB p65 and COX-2 protein expression were upregulated, while SOD and CAT levels were decreased in lung tissue in IR group as compared with SM group (p < 0.05), all the alterations could be significantly reversed by Rg1 or Pro-DTC pretreatment (p < 0.05). And Rg1 and Pro-DTC also significantly attenuated the pulmonary histological abnormalities induced by IR. ConclusionGinsenoside Rg1 potentially attenuated lung injury induced by hind-limb IR by regulating NF-κB/COX-2 signaling pathway.

Role of nuclear factor kappa B in cognitive decline in aged mice with sepsis

Objective To evaluate the role of nuclear factor kappa B (NF-κB) in cognitive decline in aged mice with sepsis. Methods Forty-five SPF healthy aged female C57BL/6 mice, aged 10-12 months, weighing 20-30 g, were assigned into 3 groups (n=15 each) using a random number table: control group (group C), sepsis group (group Sep)and NF-κB selective inhibitor pyrrolidine dithiocarbamate (PDTC) group (group PDTC). Lipopolysaccharide 250 μg/kg was injected intraperitoneally once a day for 7 consecutive days in Sep and PDTC groups, and in addition PDTC 50 mg/kg was injected intraperitoneally at 30 min before lipopolysaccharide injection once a day for 7 consecutive days in group PDTC.The equal volume of normal saline was given in group C. Five mice in each group were sacrificed at 2 h after the last administration, cardiac puncture was performed and blood samples were collected, and then the mice were sacrificed and hippocampi were harvested for determination of the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 in plasma and hippocampal tissues using enzyme-linked immunosorbent assay.Cognitive function was assessed using open field, elevated plus maze and Morris water maze tests at 24 h after the last administration in the other mice left in each group. Results Compared with group C, the levels of TNF-α, IL-1β and IL-6 in plasma and hippocampal tissues were significantly increased, the time of movement at the central region was shortened, the percentage of time spent in the open arms and number of entries into the open and closed arms were decreased, the escape latency was prolonged, the time of staying at the original platform quadrant was shortened, and the frequency of crossing the platform was decreased in group Sep (P<0.05). Compared with group Sep, the levels of TNF-α, IL-1β and IL-6 in plasma and hippocampal tissues were significantly decreased, the time of movement at the central region was prolonged, the percentage of time spent in the open arms and number of entries into the open and closed arms were increased, the escape latency was shortened, and the time of staying at the original platform quadrant was prolonged in group PDTC (P<0.05). Conclusion NF-κB is involved in cognitive decline in aged mice with sepsis. Key words: NF-kappa B; Sepsis; Cognition disorders; Aged

MicroRNA-106b overexpression alleviates inflammation injury of cardiac endothelial cells by targeting BLNK via the NF-κB signaling pathway.

We aim to investigate whether microRNA-106b (miR-106b) affects the inflammation injury of cardiac endothelial cells (ECs) by targeting B-cell linker (BLNK) via the NF-κB signaling pathway. Human cardiac microvascular endothelial cells (HCMECs) were assigned into the control, hypoxia/reoxygenation (H/R), negative control (NC), pyrrolidine dithiocarbamate (PDTC), miR-106b mimic, miR-106b inhibitor, and si-BLNK, and miR-106b inhibitor+si-BLNK groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were conducted for miR-106b expression and expressions of BLNK, interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, NF-κB, pIκBα, BTK, and PLC-γ2. Enzyme-linked immunosorbent assay was applied for levels of IL-6, IL-10, and TNF-α; cell counting Kit-8 assay for cell proliferation; and flow cytometry for cell cycle and ensuing apoptosis. In-vitro tube formation assay was performed for tube formation ability. Dual-luciferase reporter assay revealed that BLNK was verified as the target gene of miR-106b. Compared with the H/R and NC groups, the PDTC, miR-106b mimic, and si-BLNK groups had declined expressions of IL-6, IL-1β, TNF-α, BTK, PLC-γ2, NF-κB p105/p50, and pIκBα as well as levels of L-6 and TNF-α, but contrarily elevated levels of NF-κB p105/p50 and IL-10. The PDTC, miR-106b mimic, and si-BLNK groups had less cell number in G0 /G1 phase but higher cell count in both S and G2 phases, decreased cell apoptosis but increased proliferation and tube formation ability, while opposite trends were observed in the miR-106b inhibitor group. Our findings indicated that the overexpression of miR-106b alleviated the inflammation injury of cardiac ECs by targeting BLNK via the NF-κB signaling pathway.

Astragaloside protects myocardial cells from apoptosis through suppression of the TLR4/NF-κB signaling pathway.

Astragaloside is a monomer isolated from Astragalus membranaceus, a flowering plant in the family Fabaceae. The aim of the present study was to investigate the anti-apoptotic affect of astragaloside on myocardial cells through the TLR4/NF-κB signaling pathway. Astragaloside, NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) and Toll-like receptor 4 (TLR4) blocking antibody solution were prepared in vitro, and myocardial cells were incubated and cultured in serum-free medium overnight. Cells were divided into five groups: the normal control group, serum-free group, astragaloside group, TLR4 blocking antibody group and NF-κB inhibitor PDTC group. The myocardial cell apoptosis in each group was detected using flow cytometry, and the expression levels of TLR4 and NF-κB were detected via western blotting. The apoptosis rate in the serum-free group was significantly higher than that in the normal control group. The apoptosis rate of myocardial cells in the TLR4 blocking antibody group and NF-κB inhibitor PDTC group was lower than that in the serum-free group. In addition, the myocardial cell apoptosis was more obviously decreased in the astragaloside group, and the protein expression levels of TLR4 and NF-κB in the serum-free group were significantly higher than those in normal control group. The protein expression levels of TLR4 and NF-κB in the astragaloside group were obviously lower than those in the serum-free group, and the protein expression levels of TLR4 and NF-κB in the TLR4 blocking antibody group and NF-κB inhibitor PDTC group were decreased. In conclusion, astragaloside reduced myocardial cell apoptosis and protected myocardial cells, which may be one of the mechanisms of a traditional Chinese medicine monomer in treating heart failure.

Effects of NF-κB inhibitor on nuclear factor-κB and intercellular adhesion moceule-1 in lung injury associated with radiation of rats

Objective: To investigate the mechanism of lung injury caused by radiation-induced lung injury by observing the change of nuclear factor (NF-κB) and intercellular adhesion moceule-1 (ICAM-1) in rats and the effects of pyrrolidine dithiocarbamate (PDTC) . Methods: 80 SD female rats were randomly classified into 4 groups: control group, radiation group, PDTC treatment group and PDTC group.The radiation induced pulmonary injury model was preformed by using 6 MV X-rays to deliver 8 Gy per day for 5 consecutive days with 40 Gy in total to the thorax of each animal.PDTC was given from 3 d before radiation to 30 d after the first radiation. Rats in control group and PDTC group received the same dose of saline. Animals were sacrificed at 8 week and 24 week after radiation, respectively. The lungs were removed and processed for HE and Masson staining, hydroxyproline content measurement, and real-time quantitative reverse transcription-polymerase chain (RT-PCR) ICAM-1mRNA and NF-κB p65mRNA were detected, Statistical analysis were carried out. Results: Compared with radiation group, there was an obvious amelioration in pathological injury of lung tissue in PDTC treatment group. The lung coefficient and the content of Hyp in PDTC treatment group were significantly lower than those in radiation group (t=3.651, 5.293, 2.348 and 4.126, respectively, allP<0.05) , while slightly higher than those in control group. The levels of ICAM-1mRNA and NF-κB p65mRNA were significantly higher in radiation group than that in PDTC treatment group (allP<0.05) , There were no significant differences in these indicators between control group and PDTC group (P>0.05) . Conclusion: The expression of ICAM-1mRNA and NF-κB p65mRNA is increased in rats with radiation-induced lung injury. Suggest that ICAM-1 and NF-κB are a key factor lead to radiation-induced lung injury. PDTC may inhibits NF-κB activity and further significantly deceases expression of ICAM-1, leading to significantly attenuated pulmonary inflammation and fibrosis, which provides a new therapeutic target for the prevention and treatment of radiation-induced lung injury.

Effects of hypoxia on the phenotype transformation of human dermal fibroblasts to myofibroblasts and the mechanism

Objective: To investigate the effects of hypoxia on the phenotype transformation of human dermal fibroblasts to myofibroblasts and the mechanism. Methods: The third passage of healthy adult human dermal fibroblasts in logarithmic phase were cultured in DMEM medium containing 10% fetal bovine serum for the following five experiments. (1) In experiments 1, 2, and 3, cells were divided into normoxia group and hypoxia group according to the random number table, with 10 dishes in each group. Cells of normoxia group were cultured in incubator containing 21% oxygen, while those of hypoxia group with 1% oxygen. At post culture hour (PCH) 0 and 48, 5 dishes of cells were collected from each group, respectively. mRNA expressions of markers of myofibroblasts including alpha smooth muscle actin (α-SMA), type Ⅰ collagen, and type Ⅲ collagen of cells were determined with real time fluorescent quantitative reverse transcription polymerase chain reaction in experiment 1. Protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen of cells were determined with Western blotting in experiment 2. The protein expression of nuclear factor-kappa B (NF-κB) of cells was determined with Western blotting in experiment 3. (2) In experiment 4, cells were divided into normoxia group, hypoxia group, and hypoxia+ pyrrolidine dithiocarbamate (PDTC) group according to the random number table, with 5 dishes in each group. Cells in the former two groups were treated the same as those in experiment 1. Cells in hypoxia+ PDTC group were treated the same as those in hypoxia group plus adding 4 mL PDTC with a final molarity of 10 μmol/L in the culture medium. At PCH 48, the protein expression of NF-κB of cells was determined with Western blotting. (3) In experiment 5, cells were divided into normoxia group, hypoxia group, hypoxia+ PDTC group, and normoxia+ PDTC group according to the random number table, with 5 dishes in each group. Cells in the former three groups were treated the same as those in experiment 4. Cells in normoxia+ PDTC group were treated the same as those in normoxia group plus adding 4 mL PDTC with a final molarity of 10 μmol/L in the culture medium. At PCH 48, protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen of cells were determined with Western blotting. Data were processed with analysis of variance of factorial design, one-way analysis of variance, and LSD-t test. Results: (1) Compared with those of normoxia group at corresponding time point, mRNA expressions and protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen and the protein expression of NF-κB in fibroblasts of hypoxia group were not changed obviously at PCH 0 (with t values from -1.21 to 2.04, P values above 0.05), while mRNA expressions and protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen and the protein expression of NF-κB significantly increased at PCH 48 (with t values from -12.57 to -3.44, P values below 0.01). (2) At PCH 48, the protein expression of NF-κB in fibroblasts of hypoxia group was 0.83±0.12, significantly higher than that of normoxia group (0.17±0.06, t=-16.96, P<0.001). The protein expression of NF-κB in fibroblasts of hypoxia+ PDTC group was 0.31±0.08, significantly lower than that of hypoxia group (t=12.73, P<0.001). (3) At PCH 48, protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen in fibroblasts of hypoxia group were 0.73±0.09, 1.25±0.10, and 1.16±0.07, respectively, significantly higher than those of normoxia group (0.14±0.06, 0.87±0.08, and 0.77±0.13, respectively, with t values from 9.24 to 11.24, P values below 0.001). The protein expression of α-SMA in fibroblasts of normoxia+ PDTC group was 0.24±0.07, significantly higher than that of normoxia group (t=4.22, P<0.01). Protein expressions of type Ⅰ collagen and type Ⅲ collagen in fibroblasts of normoxia+ PDTC group were 0.25±0.06 and 0.32±0.11, respectively, significantly lower than those of normoxia group (with t values respectively -4.31 and -3.88, P values below 0.01). Protein expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen in fibroblasts of hypoxia+ PDTC group were 0.09±0.08, 0.38±0.12, and 0.47±0.08, respectively, significantly lower than those of hypoxia group (with t values from 11.78 to 22.98, P values below 0.001). Conclusions: Hypoxia can significantly up-regulate the expressions of α-SMA, type Ⅰ collagen, and type Ⅲ collagen in human dermal fibroblasts, which may promote the phenotype transformation of fibroblasts to myofibroblasts, and this is likely to be associated with the activation of NF-κB signal pathway.

Pyrrolidine dithiocarbamate alleviates the anti-tuberculosis drug-induced liver injury through JAK2/STAT3 signaling pathway: An experimental study.

To study the effect of pyrrolidine dithiocarbamate (PDTC) on the anti-tuberculosis drug-induced liver injury and the molecular mechanism. Clean male SD rats were selected as experimental animals and randomly divided into normal group, model group, PDTC group and AG490 group. Animal model of anti-tuberculosis drug-induced liver injury was established by intragastric administration isoniazid+rifampicin. PDTC group received intraperitoneal injection of PDTC, and AG490 group received intraperitoneal injection of AG490. Twenty-eight days after intervention, the rats were executed, and the liver injury indexes, inflammation indexes and oxidative stress indexes in serum as well as JAK2/STAT3 expression, liver injury indexes, inflammation indexes and oxidative stress indexes in liver tissue were determined. p-JAK2, p-STAT3, TNF-α, IL-1β, IL-6, ROS, 8-OHdG and MDA expression in liver tissue as well as TBIL, ALT, AST, γ-GT, TNF-α, IL-1β, IL-6, 8-OHdG and MDA levels in serum of model group were significantly higher than those of normal group while p-JAK2, p-STAT3, TNF-α, IL-1β, IL-6, ROS, 8-OHdG and MDA expression in liver tissue as well as TBIL, ALT, AST, γ-GT, TNF-α, IL-1β, IL-6, 8-OHdG and MDA levels in serum of PDTC group and AG490 group were significantly lower than those of model group. PDTC can inhibit the inflammation and oxidative stress mediated by JAK2/STAT3 signaling pathway to alleviate the anti-tuberculosis drug-induced liver injury.

Dexamethasone promotes regeneration of crushed inferior alveolar nerve by inhibiting NF-κB activation in adult rats

PurposeNuclear factor kappa B (NF-κB), which is closely related to inflammation, has become a topic of interest for research. The aim of this study is to investigate the effects of dexamethasone (Dex), an inhibitor of NF-κB, on inferior alveolar nerve injury in adult rats. Materials and methodsThe crushed inferior alveolar model is established in Wistar rats and they are randomly divided into three groups according to treatment: pyrrolidine dithiocarbamate (PDTC), dexamethasone (Dex), and saline (physiological saline). After treatment, the rats are respectively sacrificed at 3, 7, and 14d, and inferior alveolar nerves are extracted for histochemical and western blot analysis. ResultCompared with the PDTC and saline groups, nerve fibers in the Dex group are regularly arranged with few vacuoles, which is similar to normal inferior alveolar nerves. Immunofluorescent results show significantly decreased NF-κB expression in the Dex group. Western bolt shows higher expression of GAP-43 and lower expression of NF-κB. ConclusionTaken together, all results show that dexamethasone significantly improved the regeneration of crushed inferior alveolar nerves by inhibiting NF-κB activation in adult rats.