Renoprotective effects of angiotensin receptor blocker and stem cells in acute kidney injury: Involvement of inflammatory and apoptotic markers

Cisplatin, Cis-diamminedichloroplatinum (CDDP), is a platinum-based chemotherapy drug, and its chemotherapeutic use is restricted by nephrotoxicity. Inflammatory and apoptotic mechanisms play a central role in the pathogenesis of CDDP-induced acute kidney injury (AKI). The aim of this study was to compare the therapeutic potential of candesartan, angiotensin II receptor blocker, versus bone marrow-derived mesenchymal stem cells (BM-MSCs) in a rat model of CDDP-induced nephrotoxicity. Adult male Wistar rats (n = 40) were divided into four groups; Normal control: received saline injection, CDPP group: received CDDP injection (6 mg/kg single dose), Candesartan group: received candesartan (10 mg/kg/day) for 10 days + CDDP at day 3, and Stem cells group: received CDDP + BM-MSCs intravenously one day after CDDP injection. The rats were sacrificed seven days after CDDP injection. Significant elevation in serum creatinine and urea, renal levels of tumor necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1, renal expressions of nuclear factor kappa B (NF-κB), p38-mitogen-activated protein kinase (MAPK), caspase-3 and Bcl-2-associated x protein (Bax) were found in CDDP-injected rats when compared to normal rats. Both candesartan and BM-MSCs ameliorated renal function and reduced significantly the inflammatory markers (TNF-α , NF-κB, p38-MAPK and MCP-1) and apoptotic markers (caspase-3 and Bax) in renal tissue after CDDP injection. Candesartan as well as BM-MSCs have anti-inflammatory and anti-apoptotic actions and they can be used as nephroprotective agents against CDDP-induced nephrotoxicity. BM-MSCs is more effective than candesartan in amelioration of AKI induced by CDDP.     

Upregulation of IL-17A/F from human lung tissue explants with cigarette smoke exposure: implications for COPD

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder marked by relative resistance to steroids. The IL-17 superfamily, which mediates cross-talk between the adaptive and innate immune systems, has been associated with diminished responses to steroids. Increasing evidence supports elevated IL-17 expression in the lung of COPD subjects. However, whether cells of the immune system (systemic) and/or local lung cells are contributing to the elevated IL-17 remains unclear. To address this issue, we utilized a human parenchymal lung tissue explant culture system with cigarette smoke exposure to investigate the expression of IL-17 and the mechanisms involved.

Methods

Parenchymal lung tissue removed from 10 non-COPD and 8 COPD patients was sectioned and cultured with different concentrations of cigarette smoke extract (CSE) for 3 or 6 hours. Tissue viability was evaluated by LDH (lactate dehydrogenase) in culture supernatants. Western blot and real-time PCR were performed to evaluate IL-17A/F expression. To investigate the mechanisms, pharmacological inhibitors for MAPK p38, ERK1/2, NF-κB and PI3K pathways were added into the culture media.

Results

No tissue damage was observed after the cigarette smoke exposure for 3 h or 6 h compared with the control media. At the protein level, the expression of both IL-17A (2.4 ± 0.6 fold) and IL-17 F (3.7 ± 0.7 fold) in the tissue from non-COPD subjects was significantly increased by 5% of CSE at 3 h. For COPD subjects, IL-17A/F expression were significantly increased only at 6 h with 10% of CSE (IL-17A: 4.2 ± 0.8 fold; IL-17 F: 3.3 ± 0.8 fold). The increased expression of IL-17A/F is also regulated at the mRNA level. The inhibitors for NF-κB and PI3K pathways significantly inhibited CSE-induced IL-17A/F expression from lung tissue of non-COPD subjects.

Conclusions

We found the evidence that the expression of both IL-17A and IL-17 F is increased by the cigarette smoke exposure in explants from both non-COPD and COPD subjects, supporting that local lung cells contribute IL-17 production. The elevated IL-17A/F expression is dependent on NF-κB and PI3K pathways. These observations add to the growing evidence which suggests that Th17 cytokines play a significant role in COPD.     

Gremlin in the pathogenesis of hepatocellular carcinoma complicating chronic hepatitis C: an immunohistochemical and PCR study of human liver biopsies

ABSTRACT: BACKGROUND: The possible role of secretory products of fibrous tissue in the development of hepatocellular carcinoma (HCC) complicating chronic hepatitis C was investigated. Our hypothesis was that gremlin, secreted by fibroblasts, inhibited bone morphogenic protein (BMP), which mediates stem cell maturation into adult functioning hepatocytes, and thus, arrest stem cell maturation and promoted their proliferation in an immature state possibly culminating into development of HCCs. RESULTS: Protein expression of cytokeratin 19 (CK19) and fibroblast growth factor 2 (FGF-2), and mRNA expression of gremlin and BMP-7 were studied in 35 cases of chronic hepatitis, cirrhosis and HCC complicating chronic hepatitis C. CK19 expression was higher in cases of cirrhosis (0.004), which correlated with the grade (r=0.64, p=0.009) and stage (r=0.71, p=0.001). All HCCs were negative for CK19. Stem cell niche activation (as indicated as a ductular reaction) was highest in cases of cirrhosis (p=0.001) and correlated with CK19 expression (r=0.42, p=0.012), the grade(r=0.56, p=0.024) and stage (0.66, p=0.006). FGF-2 expression was highest in HCCs and correlated with the grade (r=0.6, p=0.013), stage (0.72, p=0.002), CK19 expression (r=0.71, p=002) and ductular reaction (0.68, p=0.004) in hepatitis cases. Higher numbers of cirrhosis cases and HCCs (p=0.009) showed gremlin expression, which correlated with the stage (r=0.7, p=0.002). Gremlin expression correlated with that of CK19 (r=0.699, p=0.003) and FGF2 (r=0.75, p=0.001) in hepatitis cases. CONCLUSIONS: Fibrosis promotes carcinogenesis by fibroblast-secreted gremlin that blocks BMP function and promotes stem cell activation and proliferation as well as possibly HCC development.     

Glucose-6-phosphate dehydrogenase deficiency and sulfadimidin acetylation phenotypes in Egyptian oases

Screening of 1315 males from two Egyptian oases for glucose-6-phosphate dehydrogenase deficiency (G-6PD) found an incidence of 5.9%. The rate of acetylation of sulfadimidin was also studied, and a bimodal distribution was found with 73% rapid acetylators. There is a correlation between high frequency of G-6PD deficiency and high frequency of slow acetylation rate. This work was supported by a grant from the International Center of Agricultural Research in the Dry Areas (ICARDA), Nile Valley project of faba beans.     

Comparative studies of endonuclease I from cold-adapted Vibrio salmonicida and mesophilic Vibrio cholerae

Endonuclease I is a periplasmic or extracellular enzyme present in many different Proteobacteria. The endA gene encoding endonuclease I from the psychrophilic and mildly halophilic bacterium Vibrio salmonicida and from the mesophilic brackish water bacterium Vibrio cholerae have been cloned, over-expressed in Escherichia coli, and purified. A comparison of the enzymatic properties shows large differences in NaCl requirements, optimum pH, temperature stability and catalytic efficiency of the two proteins. The V. salmonicida EndA shows typical cold-adapted features such as lower unfolding temperature, lower temperature optimum for activity, and higher specific activity than V. cholerae EndA. The thermodynamic activation parameters confirm the psychrophilic nature of V. salmonicida EndA with a much lower activation enthalpy. The optimal conditions for enzymatic activity coincide well with the corresponding optimal requirements for growth of the organisms, and the enzymes function predominantly as DNases at physiological concentrations of NaCl. The periplasmic or extracellular localization of the enzymes, which renders them constantly exposed to the outer environment of the cell, may explain this fine-tuning of biochemical properties.     

Thermal unfolding studies of cold adapted uracil-DNA N-glycosylase (UNG) from Atlantic cod (Gadus morhua). A comparative study with human UNG

Uracil-DNA N-glycosylase (UNG; EC 3.2.2.27) from Atlantic cod (cUNG) possesses cold adapted features like increased catalytic efficiency and reduced temperature optimum for activity compared to its warm-adapted homologue human UNG (hUNG). Here, we present the first thermal stability analysis of cUNG and hUNG by differential scanning calorimetry (DSC), and the results showed that cUNG is less stable than hUNG and unfolds at a melting temperature (T_m) 9° lower than its warm-adapted homologue. In addition, an ion-pair (D183-K302) suggested to be crucial for global stability of hUNG was investigated by biochemical characterization and DSC of four mutants (cUNG G183D and cUNG G183D-R302K, hUNG D183G and hUNG D183G-K302R). The hUNG mutants with an expected disruption of the ion-pair showed a slight increase in stability with concomitant reduction in the enzyme activity, while the apparent introduction of the ion-pair in cUNG caused a reduction in the enzyme activity but no increase in stability. Because the mutants did not behave as expected, the phenomenon was further investigated by crystal structure determination. Indeed, the crystal structure of the hUNG D183G-K302R mutant revealed that compensating interactions for the loss of the ion-pair were generated close to and in regions distant from the mutation site. In conclusion, the reduced stability of cUNG supports the suggested requirement of a flexible structure for improved activity at low temperatures. Furthermore, the lack of a direct correlation between enzyme activity and global stability of the mutants supports the significance of distributing locally flexible and/or rigid regions for modulation of enzyme activity.     

Gulf War Agent Exposure Causes Impairment of Long-Term Memory Formation and Neuropathological Changes in a Mouse Model of Gulf War Illness

Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component such as memory deficits, neurological, and musculoskeletal problems. There are ample data that demonstrate that exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and pesticides such as permethrin (PER), were key contributors to the etiology of GWI post deployment to the Persian GW. In the current study, we examined the consequences of acute (10 days) exposure to PB and PER in C57BL6 mice. Learning and memory tests were performed at 18 days and at 5 months post-exposure. We investigated the relationship between the cognitive phenotype and neuropathological changes at short and long-term time points post-exposure. No cognitive deficits were observed at the short-term time point, and only minor neuropathological changes were detected. However, cognitive deficits emerged at the later time point and were associated with increased astrogliosis and reduction of synaptophysin staining in the hippocampi and cerebral cortices of exposed mice, 5 months post exposure. In summary, our findings in this mouse model of GW agent exposure are consistent with some GWI symptom manifestations, including delayed onset of symptoms and CNS disturbances observed in GWI veterans.     

A Novel Approach for the Synthesis of seco C-Nucleoside Analogues

Abstract

The synthesis of 4-amino-3-(D-gluco- or D-galacto-pentitol-1.yl)-5-mercapto-1,2,4-triazoles and their conversion to the respective 6-methyl-3-(1,2,3,4,5-penta-O-acetyl-pentitol-1-yl)1,2,4-triazolo[3,4-b]1,3,4-thiadiazoles have been achieved. The vicinal coupling constants were used to deduce the favored conformations.