Effect of pentoxifylline on caspases expression in islet beta-cells of NOD mice

AIM: To investigate the intervention effect of pentoxifylline (PTX) on type 1 diabetes mellitus in non-obese diabetic (NOD)mice and explore its possible mechanism.METHODS: Eight-week-old NOD mice were treated with PTX to investigate the incidence of cyclophosphamide accelerating diabetes.The apoptosis of beta-cells was detected by TUNEL,the expressions of caspase-3 in islet of the NOD mice was checked by immunohistochemistry and the expressions of caspase-8 was determined by RT-PCR.RESULTS: The incidence of diabetes in PTX group was 40.63%,which was obviously lower than 69.70% in the control group (P<0.05). Apoptosis index of beta-cells was 4.80% in PTX group and was 9.04% in control group,of which the former was lower than the latter (P<0.01).The expression of caspase-3 in islet of the mice in PTX group was much lower than that in control group,and the expression of caspase-8 mRNA in pancreas in PTX group were also markedly lower than that in control group (P<0.01).CONCLUSION: PTX prevents NOD mice from developing type 1 diabetes,which may be related to the downregulation of caspase-3 and caspase-8 expressions in pancreas and then the decrease of beta-cell apoptosis.     

Mechanisms of oral tolerance and the treatment of autoimmune diseases

Oral tolerance describes the phenomenon that orally administered proteins induce sys-temic hyporesponsiveness to the protein fed. The primary mechanisms which oral tolerance is mediated include clonal deletion, clonal anergy and active Sue CALT, Low doses favor active suppression cellular suppression through gut associated lymphoid tis-mediated Th2 and Th3 cells, whereas high doses favor deletion and anergy mediated Thl and Th2 cells. Oral tolerance is an effective and specific approach without toxicity. In recent years, it has been used successfully to treat autoimmune diseases in model ani-mals and patients. The article discussed the mechanisms and advances of oral tolerance for the purpose of provid new ways of treat autoimmune diseases.     

Protective effect of pentoxifylline against spinal cord ischemia/reperfusion injury in rabbits

AIM: To investigate the protection of pentoxifylline against spinal cord ischemia/reperfusion injury.METHODS: Rabbits sustained spinal cord ischemia with 45 min cross-clamping of the infrarenal aorta. Groups were as follows: sham operation (n=8); ischemic control (n=20), receiving only vehicle; PTX A (n=20), receiving PTX before clamping and PTX B (n=20), receiving PTX at the onset of reperfusion. Rabbits were evaluated for hind-limb motor function with the Tarlov scoring system at 48 h. Serum was assayed with ELISA for TNF-α and spinal cords were harvest for MPO activity, histopathologic analysis and TUNEL staining. Immunohistochemistry was used for PECAM-1 and caspase-3 detection, and the numbers of necrosic and apoptotic neuron were counted at 12 h, 24 h, 48 h and 72 h of reperfusion. The necrotic and apoptotic neurons were also observed with transmission electron microscope.RESULTS: Improved Tarlov scores were observed in PTX-treated rabbits as compared with ischemic control rabbits at 48 h. The significant reductions of TNF-α in serum, activity of MPO, immunoreactivity of the PECAM-1 and caspase-3 were found in PTX-treated rabbits. The numbers of necrosic and apoptotic neuron were higher in PTX-treated rabbits than that in the ischemic control rabbits (P<0.05). No necrosic and apoptotic neuron were found in the sham operation group. CONCLUSION: PTX induces protection against ischemia/reperfusion injury in the spinal cord, thereby preventing both necrosis and apoptosis.     

NLRP3 inflammasome in pathogenesis of MS/EAE and its targeted therapy

Inflammasomes, the important component of innate immune system, play an important role in inflammatory diseases. NLRP3, the most studied inflammasome, is activated after recognizing danger-associated molecular patterns and pathogen-associated molecular patterns. The activated NLRP3 inflammasome promotes inflammation by maturation and release of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. Involvement of the NLRP3 inflammasome in the development of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) was suggested in a number of studies. Therefore, targeting on NLRP3 inflammasome is one of the promising methods for treatment of related diseases. In this review, we summarize the main ways by which the NLRP3 inflammasome is activated in the cytosol. We also discuss the development and treatment of NLRP3 inflammasome in MS and EAE, and expect to provide reference for the treatment of MS.     

Effects of atorvastatin on the experimental autoimmune myocarditis in Lewis rats

AIM:To test the hypothesis that atorvastatin affects T cell-mediated autoimmunity through modulating the balance of Th1/Th2 and reduces the severity of EAM. METHODS:Myocarditis was induced in Lewis rats by injection of porcine cardiac myosin. High-dose (10 mg·kg^-1·d^-1) or low-dose (1 mg·kg^-1·d^-1) atorvastatin or vehicle was administered orally for 3 weeks. On day 21, echocardiography was examined and the severity of myocarditis was detected by histopathological evaluation. Levels of serum IFN-γ, IL-2, IL-4 and IL-10 were measured by ELISA. RESULTS:Cardiac function and histological severity of myocarditis were improved in the two atorvastatin-treated groups. Treatment with atorvastatin decreased the levels of Th1 cytokine (IFN-γ, IL-2) and increased the levels of Th2 cytokine (IL-4, IL-10). CONCLUSION:These results suggest that HMG-CoA reductase blockade may be a promising new strategy for the treatment of autoimmune myocarditis.     

Research progress in association between angiopoietin-like protein 2 and inflammation-related diseases

Chronic low-grade inflammatory diseases are a subclinical process caused by innate system disorders. In recent years, with the study of chronic low-grade inflammatory diseases, inflammation has become a hot topic of major human diseases, including obesity, diabetes, cardiovascular diseases, cancer and autoimmune diseases. Angiopoietin-like protein 2 (ANGPTL2) is one of the emerging angiogenesis-related factors. Studies show that ANGPTL2 induces vascular inflammation, insulin resistance and other characteristics. The article reviews the research progress in association between angiopoietin-like protein 2 and inflammation-related diseases.     

Role of Th17/IL-17A in chronic inflammatory airway diseases

The idea has been popular for a long time that Th1/Th2 imbalance is the major cause of many diseases. However, the Th1/Th2 paradigm has encountered increasing challenge since the discovery of a novel subset of Th cells, Th17. Th17 cells secrete a series of cytokines (IL-17A~F, IL-21 and IL-22), which is quite different from those produced by Th1 and Th2 cells. It is now generally accepted that Th17/IL-17A plays a pivotal role in autoimmune and host defense. Although first discovered in autoimmune diseases, emerging studies begin to explore the way in which Th17/IL-17A acts in chronic inflammatory airway diseases, such as asthma and chronic obstructive pulmanary disease. In this review, we will summarize the differentiation and function of Th17, and introduce the progress in the correlation between Th17/IL-17A and chronic inflammatory airway diseases. Further elucidating the mechanism of Th17/IL-17A-related pathophysiological changes will contribute to prevention and treatment of chronic inflammatory airway diseases.     

Study on cobra venomfactor

Cobra venom factor (CVF), separated from the cobra venoms, is an acidic glucoprotein with anticomplementory activity. The combination of CVF with factor B in the blood produces a stable C3 and C5 converterase resulting in complement depletion by activating complement continually. There are many studies on it, such as inflammation, autoimmune disease, xenotransplantation, anti-tumor, etc. CVF is also an important tool drug for the study of complement role in the pathophysiological development of diseases.     

Mechanism responsible for pulmonary fibrosis induced by concomitant chronic smoke exposure and pentoxifylline administration

AIM: To investigate the impact of long-term administration of pentoxifylline (PTX) on morphology and inflammation of the lung in mouse models with chronic exposure of cigarette smoke. METHODS: Male BALB/c mice were randomized into the following four study groups: smoke-exposure only, shamed smoke-exposure, smoke-exposure and PTX administration, shamed smoke-exposure and PTX administration. Animals assigned to smoke-exposure were put inside a chamber twice a day for cigarette smoke exposure. The oral dose of PTX allocated to each mouse was about 20 mg·kg-1·d-1. Animals were sacrificed anaesthetically at day 120. Slices of lung were stained with H&E for pathological analysis. Modified ashcroft pulmonary fibrosis score (mAPFS) was estimated, and IFN-γ (a Th1 cytokine), IL-4 (a Th2 cytokine) in broncho-alveolar lavage fluid (BALF) and hydroxyproline in mouse lung tissue were measured by commercial kits of ELISA assay. RESULTS: Lungs in smoke-exposure only group exhibited emphysema-like morphology, low mAPFS (median 1.50, 95%CI 1.25-3.75), lowest hydroxyproline (2.43±0.11) mg/L and lowest ratio of IL-4 to IFN-γ (20.3±25.5), whereas lungs in smoke-exposure and PTX interference group exhibited interstitial fibrosis-like morphology, highest mAPFS (4.75, 4.09-5.71), highest hydroxyproline (5.57±0.55) mg/L and highest ratio of IL-4 to IFN-γ (70.7±59.9) among the four study groups (P<0.01). CONCLUSION: Interference of pulmonary inflammation induced by chronic smoke-exposure with PTX leads to the development of pulmonary fibrosis, which may relate to the turnover of Th1 polarized inflammation into Th2 polarized inflammation of the lungs.     

Effects of pentoxifylline on ventricular remodeling and cardiac function of dilated cardiomyopathy rats

AIM: To explore the effects of pentoxifylline (PTX) on ventricular remodeling and cardiac function in dilated cardiomyopathy (DCM) rats.METHODS: Lewis rats were randomly allocated to a myocin-induced dilated cardiomyopathy (DCM) group receiving saline (n=10), a DCM group receiving PTX (PTX group; 25 mg·kg^-1·d^-1, ip, for 30 days, n=10) or healthy control group (n=10). The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-10 in the blood plasma were analyzed by ELISA. The extent of fibrosis was estimated using Massons staining and immunohistochemistry analyses. Cardiac structure and function were measured by echocardiography.RESULTS: PTX decreased plasma levels of TNF-α and IL-6, and increased IL-10 level in DCM animals compared with DCM group ［TNF-α: (7.21±0.24) μg/L vs (19.30±1.31) μg/L, P<0.01; IL-6: (119.60±36.58) ng/L vs (189.50±13.25) ng/L, P<0.05; IL-10: (41.26±3.27) μg/L vs (32.45±4.32) μg/L, P<0.05］. Collagen volume fraction (CVF), perivascular collagen area (PVCA) and collagen Ⅰ/Ⅲ ratio were lower in PTX group than those in DCM group ［CVF: (16.45±3.01)% vs (23.33±4.43)%, P<0.05; PVCA: 4.58±2.10 vs 13.74±4.29, P<0.05; Ⅰ/Ⅲ ratio: 2.84±0.67 vs 4.22±0.54, P<0.01］. Left ventricular end-diastolic dimension reduced ［(6.11±0.51) mm vs (6.46±0.28) mm, P<0.05］ and left ventricular ejection fraction elevated ［(77.29±5.20)% vs (62.73±10.11)%, P<0.01］ by PTX compared with DCM.CONCLUSION: PTX modulates plasma levels of inflammatory cytokines, delays the ventricle remodeling and improves the heart function in DCM rats.     

G蛋白调节剂对梨花粉原位萌发和花粉管生长的影响

用荧光显微镜观察了G蛋白调节剂处理柱头后对梨花粉萌发和花粉管伸长的影响,结果表明:1)G蛋白激活剂霍乱毒素(CTX)处理柱头后进行自花授粉,授粉后24h和48h,可明显促进自花花粉的萌发;而G蛋白抑制剂百日咳毒素(PTX)处理柱头后异花授粉则抑制异花花粉萌发。2)CTX处理柱头后自花授粉对自花花粉管的生长具有促进作用;而PTX处理柱头后异花授粉,表现出对异花花粉管生长的抑制作用。     

Preparation and characterization of anti-hBLyS monoclonal antibody by DNA immunization

AIM:To establish the monoclonal antibody against human B lymphocyte stimulator (hBLyS) by DNA immunization and analyse its characterization. METHODS:The 858 bp DNA fragment of hBLyS was cloned into pcDNA3 plasmids. The cloned insert was identified by both sequence analysis and double digestion of the recombinant plasmid with restriction enzymesXho Iand EcoR I. After the splenocytes from BALB/c mice immunized with the recombinant plasmid of pcDNA3/hBLyS were fused with myeloma cells SP2/0,the hybridoma which can produce monoclonal antibodies against hBLyS were obtained. The specificity of anti-BLyS monoclonal antibody from hybridoma was verified by ELISA, Western blot and flow cytometry. RESULTS:The recombinant mammalian cell expression vector of pcDNA3/hBLyS was constructed,the sequence of the insert gene was identified to be the sequence encoding hBLy S antigen. The culture supernatants of hybridoma 9c10 were tested to be the monoclonal antibody with specificity against hBLyS on human peripheral blood CD3⁺T cell activated by hIFN-γ by ELISA,Western blot and flow cytometry.CONCLUSION:The monoclonal antibodies against hBLyS with high activity and specificity have been established successfully, and will be an useful tool in the studies of relationship between hBLyS and human autoimmunity diseases.     

Recent advances in heat shock protein 60

The family of HSP60 belongs to heat shock proteins with highly species conservatism and some important biologic functions. It can help other proteins for their assembling, folding and translocating, and plays a role in protecting cells against injuries and other types of stress. In addition, HSP60 is frequently recognized by the immune system as predominant antigens during infections and the progression of certain autoimmune diseases and might provide a novel strategy for the development of immunotherapeutics. This review focuses on distribution, molecular chaperone mechanism, function and gene expression regulation of HSP60.     

Mechanism of Herceptin enhancing apoptosis and improving sensitivity to chemotherapy in Ishikawa cells

AIM: To investigate the role of Herceptin in the apoptosis and drug sensitivity of endometrial cancer Ishikawa cells.METHODS: The IC₅₀ values of Herceptin, adriamycin(ADR), cisplatin(DDP) and paclitaxel(PTX) for Ishikawa cells were detected by MTT method. Ishikawa cells were treated with single drug and combined chemotherapy for 24 h, the cell cycle and the apoptosis ratio were determined by flow cytometry.RESULTS: The IC₅₀ values of Herceptin, ADR, DDP and PTX were 57.12 mg/L, 0.572 μmol/L, 67.4 μmol/L and 719.5 nmol/L, respectively. Herceptin significantly enhanced the cytotoxicity of the chemotherapeutic drugs, and increased apoptosis ratio statistically.CONCLUSION: Herceptin enhances the apoptosis-inducing ability of the chemotherapeutic drugs and improves the chemotherapeutic sensitivity in Ishikawa cells.     

Pivotal role of microRNAs in cardiac development and heart diseases

MicroRNAs (miRNAs) are non-coding small RNAs, which bind to the 3'-UTR of target mRNAs and negatively regulate the gene expression. Accumulating evidence demonstrates that miRNAs are involved in many biological processes such as embryo development, cell proliferation, differentiation, apoptosis and tumorigenesis. Heart development and heart diseases are complex processes controlled by various signaling pathways. Recent researches indicate the importance of miRNAs in the process of cardiac development and heart diseases. In this review, the role of miRNAs in cardiac development and the pathogenesis of heart diseases are overviewed. The insight into the regulating miRNAs will significantly expand the cardiovascular therapeutic strategies beyond classical pharmacology.     

Progress in relationship between epithelial sodium channel and related respiratory diseases

Epithelial sodium channel (ENaC) is an ion channel widely distributed in various tissues and organs of human. It is composed of 3 homologous subunits and allows the flow of sodium ion across epithelial cells, maintain?ing water-salt balance in the cells. Recent studies show that abnormal expression or dysfunction of ENaC in the respiratory system affects water-salt balance, fluid transportation and cell mobility, and causes abnormal changes of the airway surface liquid level and impaired clearance. ENaC is closely related to the development of respiratory diseases, such as cystic fibrosis, asthma and chronic obstructive pulmonary disease. This article reviews the progress in ENaC structure, function and roles in related respiratory diseases in order to provide a reference for the treatment of the diseases.     

The function of Fas,FasL and Bcl-2 in the pathogenesis of autoimmune thyroid disorders

AIM: To investigate the expression and function of apoptosis-related protein, Fas, FasL, and Bcl-2 in the pathogenesis of autoimmune thyroiditis. METHODS: Immunohistochemical staining was performed on 20 Hashimoto's thyroiditis (HT), 20 Graves' disease (GD), and 20 thyroid follicular adenoma (TFA, as control).RESULTS: All the cases expressed Fas, mainly on the cell surface and cytoplasm. FasL was found in all except 3 of the TFA. Bcl-2 in 15 of HT, 19 of GD, 17 of TFA. In TFA follicular cells expressed moderate Fas and minimal or absent FasL. In HT, follicles adjacent to infiltrating lymphocytes showed a increased levels of Fas and FasL, but infiltrating lymphocytes exhibited weaker staining of Fas and FasL than thyrocytes. In GD, thyrocytes and lymphocytes showed nearly similar Fas with HT, but rather weaker for FasL than HT. Bcl-2 was nearly similar in GD and TFA, but follicular cells in vicinity of lymphocytes and lymphocytes located in germinal centers of HT tissues exhibited significantly weaker. CONCLUSION: The expression of Fas, FasL and Bcl-2 in Hashimoto's thyroiditis and Graves' disease was nearly similar. Strong FasL expression and weak Bcl-2 expression on the follicles in HT may induce apoptosis. These results provide further proof that the functions of Fas and its ligand and Bcl-2 may play an important part in the pathogenesis of autoimmune thyroid diseases. The lymphocytes do not seem to be directly engaged in the process with their own FasL, but they may provide some cytokines that , in turn , up-regulates Fas and/or FasL leading to apoptosis.     

Altered T cell signaling events caused by anti-CD4 monoclonal antibody in suppressing experimental autoimmune cardiomyopathy

AIM:We examined the efficacy of anti-L3T4 McAb in the T cell signaling pathway in treating experimental autoimmune cardiomyopathy in BALB/c mice, as a model of the autoimmune mechanism involved in human dilated cardiomyopathy (DCM). METHODS:ADP/ATP carrier peptides were used to induce autoimmune cardiomyopathy in BALB/c mice. After 3 months, anti-L3T4 McAb was administered to deplete CD4+ T cells in the mice. Real-time PCR were used to detect the expression of intracellular signaling molecules (p56lck, p59fyn and Zap-70) and cytokine production (IFN-γ, IL-2 and IL-4) in T cells. The expression of CD45 was determined by immunohistochemistry analysis. RESULTS:Reduced expression of p56lck, p59fyn and Zap-70 and the reduced cytokine production of IFN-γ, IL-2 and IL-4 in T cells of anti-L3T4-treated DCM mice were found. Also, the expression of CD45 in spleen T cells was significantly decreased in the anti-L3T4-treated group. In contrast, immunization with irrelevant Ab did not protect the mice, the expression of T cell signaling molecules, CD45, and cytokine were not inhibited. CONCLUSION:These studies provide direct evidence that anti-L3T4 McAb can be an effective immunomodulator to T cell signal molecules and subsequent cytokine production events in ADP/ATP carrier-induced DCM in BALB/c mice.