Altered expression of TPP1 in fibroblast-like synovial cells might be involved in the pathogenesis of rheumatoid arthritis

We undertook this study to determine whether the altered expression of telomeric proteins TPP1 and POT1 in fibroblast-like synovial cells (FLS) could provide insights into the pathogenesis of rheumatoid arthritis (RA). FLS were isolated from patients with RA, osteoarthritis (OA) and traumatic joint disease, and cultured in vitro. TPP1 and POT1 mRNA level of FLS were measured using real-time quantitative polymerase chain reaction (RT-qPCR) in 42 RA, 23 OA and 13 healthy cases. Immunofluorescence staining and Western blot were used to detect the expression of TPP1 and POT1 protein. Expression of TPP1 and POT1 mRNA was significantly reduced in RA cases (P < 0.001, respectively), and no significant difference was observed between OA and healthy cases (P > 0.05, respectively). Confocal microscopy images showed TPP1 and POT1 proteins mainly located in nucleus of FLS. Western blot demonstrated that TPP1 protein level was significantly reduced in RA cases (P < 0.001), and POT1 protein expression was not statistical significance among RA, OA patients and healthy cases (P > 0.05). Significant negative correlation was observed between level of TPP1 mRNA and titers of anti-CCP antibody (P < 0.001), RF (P < 0.01). Altered expression of TPP1 might contribute to persistent proliferation of FLS in RA, further study on functions of telomeric proteins in RA would be needed.     

Concurrence of malignant fibrohistiocytoma and Takayasu arteritis: a case report

Takayasu arteritis (TA) is a type of systemic large-vessel vasculitis that usually affects the aorta and its major branches. It remains unrecognized owing to delayed diagnosis (Boltin et al. in Rheumatol Int 27(10):985-987, 2007) and non-characteristic clinical features. It has been described in association with many autoimmune diseases, such as inflammatory digestive tract diseases. However, report of TA associated with tumors, especially malignant tumors, are rare. We here presented a case diagnosed by both Takayasu arteritis and malignant fibrous histiocytoma, from which we learned not only clinical lessons, but also consensus of relationships between these two diseases.     

Cord blood analysis for rapid prenatal confirmation of Hb Bart's disease using the Sebia Capillary electrophoresis system

Prenatal diagnosis of severe α-thalassemia (α-thal) diseases is usually performed by DNA analysis. To establish a simple and rapid method, we evaluated the reliability of cord blood hemoglobin (Hb) analysis using an automated capillary electrophoresis (CE) system. Our results demonstrated that analysis of fetal Hb using the Sebia CapillaryS 2 is an effective, accurate and simple alternative for prenatal diagnosis of Hb Bart's (γ4) disease.     

Simultaneous modulation of COX-2, p300, Akt, and Apaf-1 signaling by melatonin to inhibit proliferation and induce apoptosis in breast cancer cells

Melatonin exhibits anti-inflammatory and anticancer effects and could be a chemopreventive and chemotherapeutic agent against cancers, but the precise mechanisms involved remain largely unresolved. In this study, we evaluated the mechanism of action of melatonin in human MDA-MB-361 breast cancer cells. Melatonin at pharmacological concentrations (10(-3) m) significantly suppressed cell proliferation and induced apoptosis in a dose-dependent manner. The observed suppression of proliferation was accompanied by the melatonin-mediated inhibition of COX-2, p300, and NF-κB signaling. Melatonin significantly inhibited COX-2 expression and prostaglandin E(2) (PGE2) production, abrogated p300 histone acetyltransferase activity and p300-mediated NF-κB acetylation, thereby blocking NF-κB binding and p300 recruitment to COX-2 promoter. Pretreatment with a COX-2- or p300-selective inhibitor abrogated the melatonin-induced inhibition of cell proliferation, whereas PGE2 treatment or COX-2 transfection reversed the inhibition by melatonin. Moreover, melatonin markedly inhibited phosphorylation of PI3K, Akt, PRAS40, and GSK-3 proteins, thereby inactivating the PI3K/Akt signaling pathway. Pretreatment with a PI3K- or an Akt-selective inhibitor or an Akt-specific siRNA blocked the melatonin-mediated inhibition of cell proliferation. Conversely, gene delivery of a constitutively active Akt effectively reversed the inhibition by melatonin. Furthermore, melatonin induced Apaf-1 expression, triggered cytochrome C release, and stimulated caspase-3 and caspase-9 activities and cleavage, leading to an activation of the Apaf-1-dependent apoptotic pathway. Pretreatment with an Apaf-1-specific siRNA effectively attenuated the melatonin-induced apoptosis. These results therefore indicate that melatonin inhibits cell proliferation and induces apoptosis in MDA-MB-361 breast cancer cells in vitro by simultaneously suppressing the COX-2/PGE2, p300/NF-κB, and PI3K/Akt/signaling and activating the Apaf-1/caspase-dependent apoptotic pathway.     

Activation of Tetrodotoxin-Resistant Sodium Channel NaV1.9 in Rat Primary Sensory Neurons Contributes to Melittin-Induced Pain Behavior

Tetrodotoxin-resistant (TTX-R) sodium channels Na_V1.8 and Na_V1.9 in dorsal root ganglion (DRG) neurons play important roles in pathological pain. We recently reported that melittin, the major toxin of whole bee venom, induced action potential firings in DRG neurons even in the presence of a high concentration (500 nM) of TTX, indicating the contribution of TTX-R sodium channels. This hypothesis is fully investigated in the present study. After subcutaneous injection of melittin, Na_V1.8 and Na_V1.9 significantly upregulate mRNA and protein expressions, and related sodium currents also increase. Double immunohistochemical results show that Na_V1.8-positive neurons are mainly medium- and small-sized, whereas Na_V1.9-positive ones are only small-sized. Antisense oligodeoxynucleotides (AS ODNs) targeting Na_V1.8 and Na_V1.9 are used to evaluate functional significance of the increased expressions of TTX-R sodium channels. Behavioral tests demonstrate that AS ODN targeting Na_V1.9, but not Na_V1.8, reverses melittin-induced heat hypersensitivity. Neither Na_V1.8 AS ODN nor Na_V1.9 AS ODN affects melittin-induced mechanical hypersensitivity. These results provide previously unknown evidence that upregulation of Na_V1.9, but not Na_V1.8, in small-sized DRG neurons contributes to melittin-induced heat hypersensitivity. Furthermore, melittin-induced biological effect indicates a potential strategy to study properties of TTX-R sodium channels.