Strong intensification of mouse hepatic tamoxifen DNA adduct formation by pretreatment with the sulfotransferase inhibitor and ubiquitous environmental pollutant pentachlorophenol

Although negative in assays for mutagenicity, the clinicallyimportant antiestrogen tamoxifen induces hepakic DNA adductformation in mice, rats and hamsters, as indicated by ³²P-postlabeling,and is a potent hepatocardnogen in rats. Both phenolic and alcoholicmetabolites of tamoxifen have been reported. As these metabolitesare potential candidates for sulfate coqjugation, we examinedwhether the sulfe transferase inhibitor pentachlorophenol, aubiquitous environmental contaminant, modulates hepatic tamoxifenadduct formation in vivo. Female ICR mice were given tamoxifen(45 mg/kg) daily per os for up to 4 days, with and without i.p.pretreatment with pentachloropheno1 (20 mg/kg) 1 h before dosingwith tamoxifen. At days 1,2 and 4, liver DNA wm analyzed 5 hafter tamoxifen administration by a modified monophosphate versionof the ³²P-postlabeling assay. At day 4, patachrophenol pretreatmentled to a large increase (13- to 17-fold) of the levels of fourtamoxifen adduct fractions, while two adducts appeared unaffected,resulting in an     

Inhibition of monocyte/macrophage migration to a spinal cord injury site by an antibody to the integrin alphaD: a potential new anti-inflammatory treatment

The inflammatory response that ensues during the initial 48 to 72 h after spinal cord injury causes considerable secondary damage to neurons and glia. Infiltration of proinflammatory-activated neutrophils and monocytes/macrophages into the cord contributes to spinal cord injury-associated secondary damage. beta2 integrins play an essential role in leukocyte trafficking and activation and arbitrate cell-cell interactions during inflammation. The beta2 integrin, alphaDbeta2, is expressed on monocytes/macrophages and neutrophils and binds to vascular adhesion molecule-1 (VCAM-1). The increased expression of VCAM-1 during central nervous system (CNS) inflammation likely contributes to leukocyte extravasation into the CNS. Accordingly, blocking the interaction between alphaDbeta2 and VCAM-1 may attenuate the inflammatory response at the SCI site. We investigated whether the administration of monoclonal antibodies (mAbs) specific for the rat alphaD subunit would reduce the inflammatory response after a spinal cord transection injury in rats. At a 1 mg/kg dose two of three anti-alphaD mAbs caused a significant ( approximately 65%) reduction in the number of macrophages at the injury site and one anti-alphaD mAb led to a approximately 43% reduction in the number of neutrophils at the SCI site. Thus, our results support the concept that the alphaDbeta2 integrins play an important role in the trafficking of leukocytes to a site of central nervous system inflammation. This study also offers preliminary evidence that anti-alphaD mAbs can reduce the extravasation of macrophages and, to a lesser extent, neutrophils, to the SCI site.     

LX4211, a dual SGLT1/SGLT2 inhibitor, improved glycemic control in patients with type 2 diabetes in a randomized, placebo-controlled trial

Thirty-six patients with type 2 diabetes mellitus (T2DM) were randomized 1:1:1 to receive a once-daily oral dose of placebo or 150 or 300 mg of the dual SGLT1/SGLT2 inhibitor LX4211 for 28 days. Relative to placebo, LX4211 enhanced urinary glucose excretion by inhibiting SGLT2-mediated renal glucose reabsorption; markedly and significantly improved multiple measures of glycemic control, including fasting plasma glucose, oral glucose tolerance, and HbA(1c); and significantly lowered serum triglycerides. LX4211 also mediated trends for lower weight, lower blood pressure, and higher glucagon-like peptide-1 levels. In a follow-up single-dose study in 12 patients with T2DM, LX4211 (300 mg) significantly increased glucagon-like peptide-1 and peptide YY levels relative to pretreatment values, probably by delaying SGLT1-mediated intestinal glucose absorption. In both studies, LX4211 was well tolerated without evidence of increased gastrointestinal side effects. These data support further study of LX4211-mediated dual SGLT1/SGLT2 inhibition as a novel mechanism of action in the treatment of T2DM.     

Cyclosporin A reduces the inflammatory response to a multi-mutant herpes simplex virus type-1 leading to improved transgene expression in sympathetic preganglionic neurons in hamsters.

Herpes simplex virus type 1 (HSV-1) based vectors hold great promise for gene transfer to CNS neurons. Problems such as loss of transgene expression, vector-associated cytotoxicity and the immune response to the vector or encoded transgene still remain obstacles to success. We used a replication-defective, HSV-1 vector (14Hdelta3vhsZ) that was engineered to have reduced cytotoxicity and express recombinant beta-galactosidase. A previous study in our laboratory showed no evidence for cytotoxicity in infected neurons although an inflammatory infiltrate occurred around infected cells and transgene expression was lost between 5 and 8 days. The immune response consisted of a primary response at the site of inoculation (adrenal gland), and a secondary immune response in the spinal cord around infected adrenal sympathetic preganglionic neurons due to retrograde transport of the vector. We tested whether conventional immunosuppressants could reduce the secondary immune response, leading to improved transgene expression at the secondary CNS site. 14Hdelta3vhsZ was injected into the adrenal gland in hamsters 1 day after immunosuppressant treatment began. Non-drug treated, 14Hdelta3vhzZ-infected hamsters were used as controls. Cyclosporin A administration led to the most persistent beta-galactosidase activity in neurons at 5 and 8 days. Methylprednisolone treatment resulted in the greatest reduction in the inflammatory cell infiltrate but the numbers of infected neurons did not increase concomitantly. This suggested no direct relationship between extent of the inflammatory cell infiltrate and level of transgene expression. These data demonstrate the potential of cyclosporin A as an immunosuppressant adjunct treatment for HSV-1 vector-mediated gene transfer from a peripheral site to neurons in the spinal cord.