The role of mammalian target of rapamycin pathway in the pathogenesis of pauci-immune glomerulonephritis.

Background: The characteristic lesion of pauci-immune glomerulonephritis is focal necrotizing and crescentic glomerulonephritis. The underlying mechanisms in the formation or progression of crescent formation need further investigations. Therefore, we aimed to evaluate the role of mammalian target of rapamycin (mTOR), which might be a potential therapeutic target, in kidney biopsies of patients with pauci-immune glomerulonephritis. Methods: The patients diagnosed as pauci-immune glomerulonephritis at an outpatient nephrology clinic were retrospectively reviewed and those patients who had a kidney biopsy before receiving an immunosuppressive treatment were included in the study. Kidney biopsy specimens were immunohistochemically stained with mTOR, antibodies of phosphatase and tensin homolog (PTEN) and transforming growth factor-ß (TGF-ß) and scored by an experienced renal pathologist. Results: In total, 54 patients with pauci-immune glomerulonephritis (28 [52%] female) were included. According to the histopathologic examination, 22% of our cases were classified as focal, 33% crescentic, 22% mixed, and 22% as sclerotic. The mTOR was expressed in substantial percentages of glomeruli of patients with pauci-immune glomerulonephritis. However, we observed PTEN expression in all samples and mTOR in all tubulointerstitial areas. mTOR expression was found to be related with the presence of crescentic and sclerotic changes observed in glomeruli and the degree of fibrosis in interstitial areas. Serum creatinine level or response to treatment was not found to be associated with mTOR pathway expression. Conclusion: Our results suggest that mTOR pathway may play role in the pathogenesis of pauci-immune glomerulonephritis, besides targeting this signaling may be an alternative option for those patients.

Paroxysmal Nocturnal Hemoglobinuria in the Differential Diagnosis of Thrombocytopenia.

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease which diagnosis may be delayed due to variable clinical findings. We describe herein a case of PNH in a 21 year old woman who admitted with complaints of chronic weakness, intermittent spontaneous ecchymoses, and an intermittent abdominal pain. On laboratory tests thrombocytopenia and iron deficiency anemia without any clinical findings were found. Flow cytometric evaluations showed a PNH clone of 15% for erythrocytes, 64% for monocytes, and 60% for granulocytes. The patient was diagnosed with PNH and an eculizumab therapy was initiated. Following initiation of eculizumab therapy, the frequency of abdominal pain attacks decreased, hemoglobin level normalized, and platelet values increased slightly. In patients submitting with a triad of symptoms such as thrombocytopenia, iron deficiency anemia, and abdominal pain attacks of unknown etiology we suggest considering PNH. We also encourage physicians to share their similar observations in order to raise the knowledge on infrequent presentations of PNH.

Effect of insulin on the mRNA expression of procollagen N-proteinases in chondrosarcoma OUMS-27 cells.

Chondrosarcoma is one of the most common bone tumors, and at present, there is no non-invasive treatment option for this cancer. The chondrosarcoma OUMS-27 cell line produces proteoglycan and type II, IX, and XI collagens, which constitutes cartilage tissue. A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) proteases are a group of secreted proteases, which include the procollagen N-proteinases ADAMTS-2, -3 and -14. These procollagen N-proteinases perform a role in the processing of procollagens to collagen and the maturation of type I collagen. The present study aimed to improve the understanding of the causes of metastasis, local invasion and resistance to chemo- and radiotherapy in chondrosarcoma, as well as the effect of insulin on cancer cells. The present study was designed to reveal the effects of insulin on procollagen N-proteinases in chondrosarcoma OUMS-27 cells. The cells were cultured in Dulbecco's modified Eagle's medium (DMEM) alone or in DMEM containing 10 µg/ml insulin. The medium was changed every other day for 11 days. The cells were harvested on days 1, 3, 7 and 11, and total RNA isolation was performed immediately following harvesting. The expression levels of ADAMTS2, ADAMTS3 and ADAMTS14 mRNA were estimated by reverse transcription-quantitative polymerase chain reaction using appropriate primers. ADAMTS2 mRNA expression was found to be decreased on day 7 (P=0.028) and increased at day 11 compared with the control group (P=0.016). The increase in mRNA concentration at day 11 was significantly different compared to the concentrations on days 3 (P=0.047) and 7 (P=0.008). The expression of ADAMTS3 mRNA decreased immediately subsequent to insulin induction on day 1 compared with the control group (P=0.008). The most evident decrease in mRNA concentration was seen at day 7 subsequent to insulin induction (P=0.008). The present results demonstrated that ADAMTS2 and ADAMTS3 may perform a role in the invasion and metastasis of tumors, and may also possess proteolytic activity that results in the breakdown of the extracellular matrix (ECM). Insulin itself can modulate the biosynthesis of ECM macromolecules that are altered in diabetes through various pathways.

The Investigation of ADAMTS16 in Insulin-Induced Human Chondrosarcoma Cells.

OBJECTIVES: A disintegrin-like metalloproteinase with thrombospondin motifs (ADAMTS) is a group of proteins that have enzymatic activity secreted by cells to the outside extracellular matrix. Insulin induces proteoglycan biosynthesis in chondrosarcoma chondrocytes. The purpose of the present in vitro study is to assess the time course effects of insulin on ADAMTS16 expression in OUMS-27 (human chondrosarcoma) cell line to examine whether insulin regulates ADAMTS16 expression as well as proteoglycan biosynthesis with multifaceted properties or not. METHODS: Chondrosarcoma cells were cultured in Dulbecco's modified Eagle's medium having either 10 µg/mL insulin or not. While the experiment was going on, the medium containing insulin had been changed every other day. Cells were harvested at 1st, 3rd, 7th, and 11th days; subsequently, RNA and proteins were isolated in every experimental group according to their time interval. RNA expression of ADAMTS was estimated by quantitative real-time polymerase chain reaction (qRT-PCR) by using primers. Immunoreactive protein levels were encountered by the western blot protein detection technique by using proper anti-ADAMTS16 antibodies. RESULTS: ADAMTS16 mRNA expression level of chondrosarcoma cells was found to be insignificantly decreased in chondrosarcoma cells induced by insulin detected by the qRT-PCR instrument. On the other hand, there was a gradual decrease in immune-reactant ADAMTS16 protein amount by the time course in insulin-treated cell groups when compared with control cells. CONCLUSION: It has been suggested that insulin might possibly regulate ADAMTS16 levels/activities in OUMS-27 chondrosarcoma cells taking a role in extracellular matrix turnover.

Future opportunities in preventing ototoxicity: Caffeic acid phenethyl ester may be a candidate (Review).

Caffeic acid phenethyl ester (CAPE) is an important active component of propolis, which is derived from honeybee hives. It has received increasing attention in a variety of medical and pharmaceutical research, due to its anti­oxidant, antiproliferative, anti­inflammatory, antiviral and antifungal activity, in addition to its antineoplastic properties. Besides the use of CAPE as an antioxidant and anti­inflammatory agent in a number of in vivo studies of ear disease, its beneficial effects have been reported in the treatment of cancer, arthritis, allergies, heart disease, diabetes, kidney disease, liver disease and neurological disease. CAPE influences a number of biochemical pathways, as well as several targets involved in ear diseases, in particular, in ototoxicity. The protective effects of CAPE in ototoxicity, which may be induced by a number factors, including lipopolysaccharides, hydrogen peroxide and streptomycin, are evaluated and discussed in the present review.

Interleukin-1ß induced nuclear factor-κB binds to a disintegrin-like and metalloproteinase with thrombospondin type 1 motif 9 promoter in human chondrosarcoma cells.

Nuclear factor-κB (NF-κB) is involved in the regulation of inflammation­associated genes. NF-κB forms dimers which bind with sequences referred to as NF-κB sites (9-11 bp). A disintegrin-like and metalloproteinase with thrombospondin type 1 motif 9 (ADAMTS9) is a type of proteoglycanase, which proteolytically cleaves versican and aggrecan. ADAMTS9 is a cytokine-inducible gene that contains binding sites for NF-κB within its promoter region. Interleukin-1ß (IL-1ß) affects cartilage metabolism and is involved in the NF-κB pathway. It is therefore hypothesized that NF-κB binding with ADAMTS9 promoters may activate IL-1ß, thereby promoting chondrocytic cell growth. In the present study, the OUMS-27 chondrocytic human chondrosarcoma cell line was treated with IL-1ß with or without inhibitors of NF-κB signaling pathways. Chromatin immunoprecipitation (ChIP) and electromobility shift assays (EMSA) were conducted order to analyze the binding of NF-κB with the ADAMTS9 promoter region. NF-κB-p65 subunit phosphorylation was promoted in IL-1ß-treated cells, which were not treated with inhibitors of NF-κB signaling pathways. By contrast, NF-κB-p65 subunit phosphorylation was inhibited in cells that had been treated with BAY-117085, an NF-κB pathway inhibitor. ChIP and EMSA assays demonstrated that, following treatment with IL-1ß, NF-κB­p65 bound to elements located at -1177 and -1335 in the ADAMTS9 promoter region, in contrast to the untreated samples. The results of the present study suggested that NF-κB may be involved in IL-1ß-induced activation of ADAMTS9 in human chondrocytes.

Caffeic acid phenethyl ester: its protective role against certain major eye diseases.

As an effective compound found mainly in the honeybee product propolis, caffeic acid phenethyl ester (CAPE) has been commonly utilized as a medicine and remedial agent, in a number of countries. Specifically, it might inhibit nuclear factor kappa B at micromolar concentrations and demonstrate antioxidant, antineoplastic, antiproliferative, cytostatic, antiviral, antibacterial, antifungal, and anti-inflammatory features. This review article summarizes the recent progress regarding the favorable effects of CAPE on a number of eye disease models, including cataract and posterior capsule opacification, corneal diseases, retina and optic nerve-related diseases, ischemia/reperfusion injury of retina, inflammation and infection-related diseases. CAPE has been found to exhibit promising efficacy, with minimal adverse effects, in animal and cell culture studies of several eye diseases.

Caffeic acid phenethyl ester as a protective agent against nephrotoxicity and/or oxidative kidney damage: a detailed systematic review.

Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been attracting the attention of different medical and pharmaceutical disciplines in recent years because of its antioxidant, anti-inflammatory, antiproliferative, cytotoxic, antiviral, antifungal, and antineoplastic properties. One of the most studied organs for the effects of CAPE is the kidney, particularly in the capacity of this ester to decrease the nephrotoxicity induced by several drugs and the oxidative injury after ischemia/reperfusion (I/R). In this review, we summarized and critically evaluated the current knowledge regarding the protective effect of CAPE in nephrotoxicity induced by several special medicines such as cisplatin, doxorubicin, cyclosporine, gentamycin, methotrexate, and other causes leading to oxidative renal injury, namely, I/R models and senility.