mTOR inhibitor INK128 attenuates systemic lupus erythematosus by regulating inflammation-induced CD11b+Gr1+ cells.

Systemic lupus erythematosus (SLE) is an autoimmune disease, characterized by systemic chronic inflammation that can affect multiple major organ systems. Although the etiology of SLE is known to involve a variety of factors such as the environment, random factors and genetic susceptibility, the exact role of CD11b+Gr1+ myeloid cells in lupus progression is not fully understood. Myeloid-derived CD11b+Gr1+ cells are thought to be a heterogeneous group of immature myeloid cells with immune function. Some studies have reported that CD11b+Gr1+ cells and the activation of mTOR pathway are involved in the pathogenesis of systemic lupus erythematosus (SLE). However, it is still not clarified about the mechanism of influence of lupus microenvironment and mTOR signaling on CD11b+Gr1+ cells. In the present study, we found that the percentage of CD11b+Gr1+ cells increased prior to the abnormal changes of Th17, Treg, T and B cells during lupus development. TLR7 and IFN-α signaling synergized to promote CD11b+Gr1+ cell accumulation in an mTOR-dependent manner. Moreover, compared to a traditional mTOR inhibitor, INK128 inhibited more effectively the disease activity via regulating CD11b+Gr1+ cell expansion and functions. Furthermore, TLR7/IFN-α-modified CD11b+Gr1+ cells promoted unbalance of Th17/Tregs and were inclined to differentiate into macrophages via the mTOR pathway. In conclusion, CD11b+Gr1+ cells increased in the early stages of the lupus progression and mTOR pathway was critical for CD11b+Gr1+ cells in lupus development, suggesting the changes of inflammation-induced CD11b+Gr1+ cells initate lupus development. We also provide evidence for the first time that INK128, a second generation mTOR inhibitor, has a good therapeutic action on lupus development by regulating CD11b+Gr1+ cells.

Orexin-1 receptors in the rostral ventromedial medulla are involved in the modulation of capsaicin evoked pulpal nociception and impairment of learning and memory.

AIM: To investigate the role of rostral ventromedial medulla orexin-1 receptors in the modulation of orofacial nociception as well as nociception-induced learning and memory impairment in adult male rats. METHODOLOGY: Pulpal nociception was induced by intradental application of capsaicin (100 µg) into the incisors of rats. Orexin-1 receptors agonist (orexin-A, 10, 25 and 50 pmol L-1  rat-1 ) and antagonist (SB-334867-A, 40 and 80 nmol L-1  rat-1 ) were microinjected into the rostral ventromedial medulla prior to capsaicin administration. Total time spent on nocifensive behaviour was recorded by direct visualization of freely moving rats whilst learning and memory were evaluated by the Morris water maze test. One-way analysis of variance and repeated-measures were used for the statistical analysis. RESULTS: Capsaicin-treated rats had a significant increase of nocifensive behaviours (P < 0.001), as well as learning and memory impairment (P < 0.001). However, intraventromedial medulla prior micro-injection of orexin-A (50 pmol L-1  rat-1 ) significantly reduced the nociceptive behaviour (P < 0.001). This effect was blocked by pre-treatment with SB334867-A (80 nmol L-1  rat-1 ). Orexin-A (50 pmol L-1  rat-1 ) also inhibited nociception-induced learning and memory deficits. Moreover, administration of SB-334867-A (80 nmol L-1  rat-1 ) plus orexin-A (50 pmol L-1  rat-1 ) had no effect on learning and memory deficits induced by capsaicin. CONCLUSIONS: The data suggest that rostral ventromedial medulla orexin-A receptors are involved in pulpal nociceptive modulation and improvement of learning and memory deficits induced by intradental application of capsaicin.

Effects of KRC-108 on the Aurora A activity and growth of colorectal cancer cells.

Aurora A is involved in regulating multiple steps of mitosis. Over-expression of Aurora A is related to tumorigenesis and poor prognosis. KRC-108 is a novel multi-kinase inhibitor which has anti-tumor activity in vivo. In this study, we identified the inhibitory effects of KRC-108 on Aurora A kinase and growth-inhibitory characteristics of KRC-108. The in vitro kinase activity assay, immunoblot, and immunofluorescence analyses demonstrated that KRC-108 inhibited Aurora A activity. KRC-108 exhibited cytotoxicity against human colorectal cancer cell line HT-29. Colony formation assays showed that KRC-108 reduced the colony growth of HT-29 cells. KRC-108 also inhibited migration of HT-29 cells. The expression levels of cyclin B1 and CDC2 were decreased by KRC-108 in HT-29 cells. Cell cycle analysis and flow cytometry indicated that the inhibitory effects of KRC-108 on cell growth are due to induction of G2/M arrest and apoptosis by inhibition of Aurora A. KRC-108 induces cell-cycle arrest and apoptosis in colorectal cancer cell line by Aurora A inhibition. The reported in vivo anti-tumor effects of KRC-108 might partly be due to anti-Aurora A effects. This study suggests that KRC-108 has potential for development as an anti-tumor agent, although further studies are needed.

Influence of alpha-chloralose on muscle relaxant effect of chlorzoxazone in rats and pharmacodynamic analysis.

The Pharmacological response intensity of chlorzoxazone (CZX) was measured by the crossed extensor reflex (CER) method in anesthetized rats. The appropriate dose of alpha-chloralose (ACH) was examined to bring about a quantitative effect of CZX. The pharmacodynamics of CZX was also characterized in the anesthetized rats at three different doses of CZX. When rats were anesthetized with ACH at three different doses (80, 110, and 150 mg/kg i.p.), the CER response caused by CZX at the doses of 25, 50, and 75 mg/kg p.o. was depressed dose-dependently. Among these three different doses of ACH, 80 and 110 mg/kg gave similar results in describing the pharmacological response induced by CZX with time, whereas a dose of 150 mg/kg of ACH elicited a stronger and longer CZX response than the other two doses. The area under the intensity-time curve also showed the same tendency. These findings suggested that the dose size ranging from 80 to 110 mg/kg of ACH for surgical anesthesia was appropriate to evaluate the quantitative pharmacological response of CZX. Pharmacodynamic analysis offered the results that the dose-normalized biophase levels of CZX were coincident with each other when CZX was given at three different doses under ACH anesthesia at the dose of 80 mg/kg. This suggested that the disposition of CZX in rats obeyed linear kinetics and the theoretical values of CZX-induced response would be predictable. This implied that pharmacological response intensity of CZX was reasonably related to the relative biophase CZX level via Hill's equation.