Effects of selective LDL apheresis on plasma concentrations of ICAM-1, VCAM-1 and P-selectin in diabetic patients with arteriosclerosis obliterans and receiving maintenance hemodialysis

BACKGROUND: Arteriosclerosis obliterans (ASO) is a serious complication in patients with end-stage renal disease (ESRD) caused by diabetic nephropathy. Adsorption of low-density lipoprotein (LDL) has been performed to treat ASO. While efficacy of this treatment has been reported in limb ischemia, the mechanism underlying the benefit remains unclear. We investigated how LDL adsorption affected soluble adhesion molecules; P-selectin, an endothelial and platelet activation marker; inflammatory cytokines such as interleukin (IL)-1beta, IL-6 and tissue necrosis factor (TNF)-alpha; and lipids in serum. METHODS: Selective LDL adsorption by dextran sulfate columns (LDL apheresis) was performed weekly for 10 weeks to treat eight hemodialysis patients with ASO, ESRD, and type 2 diabetes mellitus. Serum was sampled before and immediately after apheresis. RESULTS: LDL apheresis was performed safely. After LDL apheresis lipid concentrations were significantly reduced and clinical findings, such as Fontaine's classification and ankle brachial pressure index values, were improved. Pretreatment concentrations of soluble intercellular and vascular cell adhesion molecules (sICAM-1 and sVCAM-1) and also P-selectin were higher in patients than healthy controls. After apheresis these decreased, especially P-selectin. IL-1beta, IL-6, and TNF-alpha concentrations before apheresis were similar to those in controls and were unaffected by treatment. CONCLUSION: Effectiveness of LDL apheresis against ASO may involve decreased endothelial cell and platelet activation.     

Functional differences between wild‐type and mutant‐type BRCA1‐associated protein 1 tumor suppressor against malignant mesothelioma cells

Malignant mesothelioma (MM) shows inactivation of the BRCA1‐associated protein 1 (BAP1) gene. In this study, we found BAP1 mutations in 5 (26%) of the 19 cell lines that we established from Japanese MM patients, and examined functional differences between the WT and mutant BAP1. First, we studied the subcellular localization of BAP1, demonstrating that the WT primarily resides in the nucleus and that the mutant BAP1 is found in the cytoplasm of the cells. Transduction of the WT BAP1 vector into MM cells with homozygous deletion at the BAP1 3′ side resulted in both inhibition of cell proliferation and anchorage‐independent cell growth, whereas BAP1 mutants of a missense or C‐terminal truncated form showed impaired growth inhibitory effects. Next, we studied how BAP1 is involved in MM cell survival after irradiation (IR), which causes DNA damage. After IR, we found that both WT and mutant BAP1 were similarly phosphorylated and phospho‐BAP1 localized mainly in the nucleus. Interestingly, BRCA1 proteins were decreased in the MM cells with BAP1 deletion, and transduction of the mutants as well as WT BAP1 increased BRCA1 proteins, suggesting that BAP1 may promote DNA repair partly through stabilizing BRCA1. Furthermore, using the MM cells with BAP1 deletion, we found that WT BAP1, and even a missense mutant, conferred a higher survival rate after IR compared to the control vector. Our results suggested that, whereas WT BAP1 suppresses MM cell proliferation and restores cell survival after IR damage, some mutant BAP1 may also moderately retain these functions.     

Efficacy of the polo-like kinase inhibitor rigosertib,alone or in combination with Abelson tyrosine kinase inhibitors,against break point cluster region-c-Abelson-positive leukemia cells

The potency of Abelson (ABL) tyrosine kinase inhibitors (TKIs) against chronic myeloid leukemia (CML) has been demonstrated. However, ABL TKI resistance can develop. In this study, we investigated the efficacy of a combination therapy including rigosertib (ON 01910.Na), a polo-like kinase (PLK) and phosphoinositide 3-kinase (PI3K) inhibitor, and ABL TKIs. A 72-h rigosertib treatment was found to inhibit cell growth, induce apoptosis, reduce phosphorylation of the breakpoint cluster region-c (BCR)-ABL and its substrate Crk-L, and increase the activities of caspase 3 and poly (ADP-ribose) polymerase (PARP). This combination therapy also exerted a synergistic inhibitory effect on Philadelphia chromosome (Ph)-positive cell proliferation and reduced the phosphorylation of BCR-ABL and Crk-L while increasing that of cleaved PARP and the H2A.X histone. Rigosertib also potently inhibited the growth of ABL TKI-resistant cells, and cotreatment with ABL TKIs and rigosertib induced higher cytotoxicity. These results indicate that rigosertib treatment may be a powerful strategy against ABL TKI-resistant cells and could enhance the cytotoxic effects of ABL TKIs.     

Ultrasonic vocalization impairment of Foxp2 (R552H) knockin mice related to speech-language disorder and abnormality of Purkinje cells

Previous studies have demonstrated that mutation in the forkhead domain of the forkhead box P2 (FOXP2) protein (R553H) causes speech-language disorders. To further analyze FOXP2 function in speech learning, we generated a knockin (KI) mouse for Foxp2 (R552H) [Foxp2 (R552H)-KI], corresponding to the human FOXP2 (R553H) mutation, by homologous recombination. Homozygous Foxp2 (R552H)-KI mice showed reduced weight, immature development of the cerebellum with incompletely folded folia, Purkinje cells with poor dendritic arbors and less synaptophysin immunoreactivity, and achieved crisis stage for survival 3 weeks after birth. At postnatal day 10, these mice also showed severe ultrasonic vocalization (USV) and motor impairment, whereas the heterozygous Foxp2 (R552H)-KI mice exhibited modest impairments. Similar to the wild-type protein, Foxp2 (R552H) localized in the nuclei of the Purkinje cells and the thalamus, striatum, cortex, and hippocampus (CA1) neurons of the homozygous Foxp2 (R552H)-KI mice (postnatal day 10), and some of the neurons showed nuclear aggregates of Foxp2 (R552H). In addition to the immature development of the cerebellum, Foxp2 (R552H) nuclear aggregates may further compromise the function of the Purkinje cells and cerebral neurons of the homozygous mice, resulting in their death. In contrast, heterozygous Foxp2 (R552H)-KI mice, which showed modest impairment of USVs with different USV qualities and which did not exhibit nuclear aggregates, should provide insights into the common molecular mechanisms between the mouse USV and human speech learning and the relationship between the USV and motor neural systems.     

Alogliptin

Alogliptin, a dipeptidyl peptidase-4(DPP-4) inhibitor, is launched in Japan in advance of other countries in the world. Alogliptin has high-selectivity to inhibit DPP-4 activity compared to other DPP-4 inhibitors due to its unique formula of chemical structure. Clinical studies provided evidences that alogliptin monotherapy with daily doses of 12.5 and 25 mg decreased the HbAlc level approximately 0.4-0.8% accompanied with an elevation of active glucagon-like peptide(GLP)-1 level. Neither body weight change nor apparent adverse events was observed. In type 2 diabetic patients who already treated with pioglitazone or voglibose, addition of alogliptin further decreased HbAlc by 0.9% from basal level during 12-week study period. Here, we entirely reviewed pharmacological and clinical profiles of alogliptin by introducing preclinical and clinical studies conducted inside and outside of Japan.