Carsten Alt

Nociceptin/orphanin FQ inhibition with SB612111 ameliorates dextran sodium sulfate-induced colitis.

Inflammatory bowel diseases, primarily Crohns disease and ulcerative colitis, are chronic inflammatory disorders of the gastrointestinal tract with unknown etiology. The majority of current therapeutic agents focus on controlling proinflammatory molecules. The neuropeptide nociceptin/orphanin FQ (N/OFQ) has been described as a potential immunomodulator for inflammatory bowel diseases. In this study, we asked whether the small molecule N/OFQ antagonist (-)-cis-1-methyl-7-[[4-(2,6-dichlorophenyl)piperidin-1-yl]methyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol (SB612111) would inhibit the development of dextran sodium sulfate-induced colitis in C57BL/6 mice. Inhibition of the N/OFQ receptor (NOP) by SB612111 significantly ameliorated the clinical disease course in these animals, as indicated by reduced fecal bleeding, improved recovery from diarrhea and weight loss, and a reduction in histopathological alterations. In addition, the inflammatory response in the colon was diminished, as demonstrated by reduced cytokine protein and messenger RNA expression for CXCL1/keratinocyte-derived chemokine, interferon-γ, interleukin-1β, interleukin-6, and tumor necrosis factor-α, some of which are known targets for the treatment of this devastating disease. Our results strongly support a role for the receptor-ligand pair NOP-N/OFQ in the pathogenesis of colitis. We conclude that inhibition of NOP receptors with small molecule inhibitors may constitute a novel, urgently needed approach for the treatment of inflammatory bowel diseases.

DARC shuttles inflammatory chemokines across the blood-brain barrier during autoimmune central nervous system inflammation.

Trafficking of T cells into the CNS is a pathophysiological hallmark of multiple sclerosis. Using an in vitro model of the blood-brain barrier, Minten et al. reveal that the atypical chemokine receptor DARC shuttles inflammatory chemokines across the barrier, where they contribute to immune cell trafficking into the brain.

L-Selectin-deficient SJL and C57BL/6 mice are not resistant to experimental autoimmune encephalomyelitis.

L‐selectin has been suggested to play a role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Here we demonstrate that L‐selectin–/– SJL mice are susceptible to proteolipid protein (PLP)‐induced EAE because the compromised antigen‐specific T cell proliferation in peripheral lymph nodes is fully compensated by the T cell response raised in their spleen. Transfer of PLP‐specific T cells into syngeneic recipients induced EAE independent of the presence or absence of L‐selectin on PLP‐specific T cells or in the recipient. Leukocyte infiltration into the central nervous system parenchyma was detectable independent of the mode of disease induction and the presence or absence of L‐selectin. In addition, we found L‐selectin–/– C57BL/6 mice to be susceptible to myelin oligodendrocyte glycoprotein‐induced EAE. Taken together, we demonstrate that in SJL and C57BL/6 mice L‐selectin is not required for EAE pathogenesis. The apparent discrepancy of our present observation to previous findings, demonstrating a role of L‐selectin in EAE pathogenesis in C57BL/6 mice or myelin‐basic protein (MBP)‐specific TCR‐transgenic B10.PL mice, may be attributed to background genes rather than L‐selectin and to a unique role of L‐selectin in EAE pathogenesis in MBP‐TCR‐transgenic mice.

Increased CCL2 Expression and Macrophage/Monocyte Migration During Microbicide-Induced Vaginal Irritation

Despite availability of successful prevention strategies, HIV continues to spread at alarming rates, especially among women in developing countries. Vaginal microbicides offer a promising approach for blocking transmission of HIV when condom use cannot be negotiated with male partners. A major problem in the development of vaginal microbicides is chemically induced vaginal irritation, which can enhance the risk of HIV transmission. Evaluation of vaginal irritation prior to clinical trials typically uses an expensive and animal-intensive rabbit vaginal irritation model, which could be supplemented by measuring additional inflammatory biomarkers. We studied several immunological parameters as potential biomarkers of vaginal irritation, using the spermicides nonoxynol-9 and benzalkonium chloride as test microbicides. We measured amounts of cytokines, as well as inflammatory cells, in vaginal tissue lysates and on the vaginal surface. We observed that treatment with the selected microbicides increases quantities of the inflammatory cytokines interleukin-1beta, CXCL8, and CCL2 in the vaginal tissue parenchyma, and of CCL2 on the vaginal surface. This observation was correlated with increases in macrophages in the vaginal parenchyma. We suggest that measurements of CCL2 and macrophages can serve as new inflammatory biomarkers to evaluate the safety of promising novel microbicides for prevention of HIV.

Associations between in vivo neuroimaging and postmortem brain cytokine markers in a rodent model of Wernicke's encephalopathy

Thiamine (vitamin B1) deficiency, associated with a variety of conditions, including chronic alcoholism and bariatric surgery for morbid obesity, can result in the neurological disorder Wernickes encephalopathy (WE). Recent work building upon early observations in animal models of thiamine deficiency has demonstrated an inflammatory component to the neuropathology observed in thiamine deficiency. The present, multilevel study including in vivo magnetic resonance imaging (MRI) and spectroscopy (MRS) and postmortem quantification of chemokine and cytokine proteins sought to determine whether a combination of these in vivo neuroimaging tools could be used to characterize an in vivo MR signature for neuroinflammation. Thiamine deficiency for 12days was used to model neuroinflammation; glucose loading in thiamine deficiency was used to accelerate neurodegeneration. Among 38 animals with regional brain tissue assayed postmortem for cytokine/chemokine protein levels, three groups of rats (controls+glucose, n=6; pyrithiamine+saline, n=5; pyrithiamine+glucose, n=13) underwent MRI/MRS at baseline (time 1), after 12days of treatment (time 2), and 3h after challenge (glucose or saline, time 3). In the thalamus of glucose-challenged, thiamine deficient animals, correlations between in vivo measures of pathology (lower levels of N-acetyle aspartate and higher levels of lactate) and postmortem levels of monocyte chemotactic protein-1 (MCP-1, also known as chemokine ligand 2, CCL2) support a role for this chemokine in thiamine deficiency-related neurodegeneration, but do not provide a unique in vivo signature for neuroinflammation.

Abstract 3532: Antitumor activity of SR16388 on multiple myeloma targets factors needed for adaptation to bone marrow microenvironment

Multiple myeloma (MM) is a B-cell malignancy that is characterized by accumulation of clonal plasma cells in the bone marrow. The bone marrow microenvironment plays a critical role in MM cell pathogenesis and progression. In the bone marrow milieu, MM cells adhere to the bone marrow stromal cells and trigger the secretion of growth factors such as vascular endothelial growth factor (VEGF). VEGF in turn upregulates the secretion of interleukin-6 (IL-6), the major cytokine that mediates MM cell growth and survival in part through the activation of Janus kinase (Jak)/signal transducers and activators of transcription 3 (STAT3). VEGF also stimulates the proliferation of endothelial and stromal cells and induces angiogenesis via its receptors. Thus, targeting both myeloma cells and bone marrow microenvironment is a valid approach for the development of therapeutic agents for MM. At SRI International, we have developed an antiestrogen, SR16388, that binds to ER-α, ER-β and ERR-α with potent antitumor and antiangiogenic properties. We have previously reported that SR16388 inhibited MM cell proliferation in vitro and MM tumors in vivo. In the current study, we are presenting data to show that the inhibitory effect of SR16388 on MM cell proliferation was achieved by inducing apoptosis, and arresting cells at the G2 phase. Furthermore, at nanomolar concentrations SR16388 inhibited IL-6-induced cell proliferation and blocked the activation of STAT3 induced by IL-6 in RPMI-8226 human MM cells. In human endothelial cells, SR16388 inhibited VEGF-induced cell proliferation and VEGF-induced phosphorylation of STAT3. In a RPIM-8226 tumor xenograft model, the microvessel density in the tumor tissue was markedly reduced by treatment with SR16388. We are currently investigating the effect of SR16388 in combination with known therapeutic agents on the growth of MM tumors in vivo. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3532. doi:10.1158/1538-7445.AM2011-3532

Immune Responses in HIV Infection, Alcoholism, and Aging: A Neuroimaging Perspective

Biological changes that accrue during normal, healthy aging contribute to behavioral (cognitive and motor) decline attributable to structural and metabolic alterations in the brain. Superimposed on the pattern of the healthy aging brain are the consequences of frequent concomitants of aging such as hypertension and hormone deficiency. Even more complex are the brain modifications that can occur in the presence of comorbidities such as infection with the human immunodeficiency virus (HIV) and alcohol dependence, each of which has independent deleterious effects on selective brain systems. Highly active antiretroviral therapy (HAART) has extended the average life span of individuals infected with HIV [1–3]. Accompanying longevity and improved health with treatment are increased opportunity to initiate or resume high-risk activities such as unsafe drinking (estimates of alcoholism among HIV patients range from 8 to 63 %) [4–9], necessitating the consideration of the cumulative interactions of these disease processes on the aging brain [10].