Development of Small Molecule MEIS Inhibitors that modulate HSC activity.

Meis1, which belongs to TALE-type class of homeobox gene family, appeared as one of the key regulators of hematopoietic stem cell (HSC) self-renewal and a potential therapeutical target. However, small molecule inhibitors of MEIS1 remained unknown. This led us to develop inhibitors of MEIS1 that could modulate HSC activity. To this end, we have established a library of relevant homeobox family inhibitors and developed a high-throughput in silico screening strategy against homeodomain of MEIS proteins using the AutoDock Vina and PaDEL-ADV platform. We have screened over a million druggable small molecules in silico and selected putative MEIS inhibitors (MEISi) with no predicted cytotoxicity or cardiotoxicity. This was followed by in vitro validation of putative MEIS inhibitors using MEIS dependent luciferase reporter assays and analysis in the ex vivo HSC assays. We have shown that small molecules named MEISi-1 and MEISi-2 significantly inhibit MEIS-luciferase reporters in vitro and induce murine (LSKCD34l°w cells) and human (CD34+, CD133+, and ALDHhi cells) HSC self-renewal ex vivo. In addition, inhibition of MEIS proteins results in downregulation of Meis1 and MEIS1 target gene expression including Hif-1α, Hif-2α and HSC quiescence modulators. MEIS inhibitors are effective in vivo as evident by induced HSC content in the murine bone marrow and downregulation of expression of MEIS target genes. These studies warrant identification of first-in-class MEIS inhibitors as potential pharmaceuticals to be utilized in modulation of HSC activity and bone marrow transplantation studies.

Effects of single-agent bortezomib as post-transplant consolidation therapy on multiple myeloma-related bone disease: a randomized phase II study.

This phase II study explored the effects of bortezomib consolidation versus observation on myeloma-related bone disease in patients who had a partial response or better after frontline high-dose therapy and autologous stem cell transplantation. Patients were randomized to receive four 35-day cycles of bortezomib 1·6 mg/m2 intravenously on days 1, 8, 15 and 22, or an equivalent observation period, and followed up for disease status/survival. The modified intent-to-treat population included 104 patients (51 bortezomib, 53 observation). There were no meaningful differences in the primary endpoint of change from baseline to end of treatment in bone mineral density (BMD). End-of-treatment rates (bortezomib versus observation) of complete response/stringent complete response were 22% vs. 11% (P = 0·19), very good partial response or better of 80% vs. 68% (P = 0·17), and progressive disease of 8% vs. 23% (P = 0·06); median progression-free survival was 44·9 months vs. 21·8 months (P = 0·22). Adverse events observed ≥15% more frequently with bortezomib versus observation were diarrhoea (37% vs. 0), peripheral sensory neuropathy (20% vs. 4%), nausea (18% vs. 0) and vomiting (16% vs. 0). Compared with observation, bortezomib appeared to have little impact on bone metabolism/health, but was associated with trends for improved myeloma response and survival.

Role of glutamine administration on cellular immunity after total parenteral nutrition enriched with glutamine in patients with systemic inflammatory response syndrome.

Glutamine is an important substrate for enterocyte and other rapidly proliferating cells. Low plasma and tissue levels present in glutamine in critically ill patients suggest that demand may exceed endogenous supply. Because commercially available amino acid solutions do not contain glutamine because of its instability in aqueous solution, conventional total parenteral nutrition (TPN) does not prevent stress-induced glutamine depletion. In this study, we administered intravenous glutamine-supplemented TPN to patients with systemic inflammatory response syndrome (SIRS) to investigate the effect of glutamine supplementation on immune states. This study is a prospective, randomized clinical trial. All patients received TPN given continuously for 6 days. Thirty patients with SIRS were allocated to either a glutamine group (l-glutamine 0.4g/[kg d]) (n = 15) or a control group (n = 15). Blood samples were collected on day 1 and day 6 after admission for C-reactive protein, immunoglobulin (Ig) M, IgG, IgA, C(3), C4, and lymphocyte analysis. The Acute Physiologic and Chronic Health Evaluation II score and the Simplified Acute Physiologic II (SAPS II) score were used to evaluate the patients after admission. Although there was a tendency for decreased T cytotoxic cells and natural killer cells in the control group, no significant difference was observed between the 2 groups. However, an increase in lymphocyte and lymphocyte subgroups in the glutamine group was observed; but there was no difference between the groups. A low SAPS II score was observed on the sixth day in the glutamine group, whereas no difference in SAPS II and Acute Physiologic and Chronic Health Evaluation II scores was observed between the 2 groups. There was no difference in IgM, IgG, IgA, C(3), and C4 levels and numbers of B-lymphocytes between the groups. Glutamine-added TPN significantly decreases leukocyte and natural killer cell count and therefore suppresses inflammation. Furthermore, total lymphocyte count, B- and T-lymphocytes, and their subgroups (helper T-lymphocytes, cytotoxic T-lymphocytes) are increased; although not statistically significant, these increases might be playing a role in improving the immune system.

The effects of natural pollen exposure on inflammatory cytokines and their relationship with nonspecific bronchial hyperresponsiveness in seasonal allergic rhinitis.

The exact mechanism of bronchial hyperresponsiveness (BHR) is not clear in allergic rhinitis (AR); an increase of BHR in pollen season suggests that natural pollen exposure causes airway inflammation in seasonal AR (SAR). This study was designed to investigate the effects of natural pollen exposure on inflammatory cytokines and their relationship with BHR. Sixty-six SAR patients with grass pollen sensitivity and 26 nonallergic rhinitis (NAR) patients were included. Peripheral blood samples for cytokine levels were taken and a nonspecific bronchial provocation test was performed during pollen season between May and August. The same measurements were repeated off-season between November and February. These measurements were done in NAR patients once. During the pollen season, SAR patients had significantly more increased levels of IL-13 than NAR patients (11.45 +/- 12.54 versus 5.19 +/- 4.02; p = 0.005). Blood eosinophil numbers were higher in those patients with BHR during pollen season than those without BHR (399.0 +/- 255.8 versus 278.9 +/- 193.2 mm(-3); p = 0.046). Blood eosinophil numbers during off-season were not different in those with and without BHR (respectively, 261.4 +/- 202.3 mm(-3) versus 205.9 +/- 116.9 mm(-3); p = 0.53). IL-10 levels were higher in the patients without BHR (n = 28) than those patients with BHR (n = 22) during off-season (8.12 +/- 13.1 versus 3.28 +/- 0.37; p = 0.04). Having higher levels of IL-10 than threshold value was more frequent in SAR patients without BHR than those patients with BHR during off-season (7/28 versus 1/22; chi(2) = 4.34; p = 0.04). IL-10 has a role in the continuation of BHR during off-season in SAR patients.