Journal of Stem Cells最新文献

Circulating bone marrow-derived endothelial progenitor cells (EPCs) seem to play a crucial role in both vasculogenesis and vascular homeostasis. Chronic kidney disease is a state of endothelial dysfunction, accelerated progression of atherosclerosis and high cardiovascular risk. As a consequence, cardiovascular disorders are the main cause of death in end-stage renal disease (ESRD). It has been shown that patients with advanced renal failure have decreased number of bone marrow-derived endothelial progenitor cells and impaired EPCs function. Moreover, in kidney transplant patients, renal graft function significantly correlated with EPC number. The reduced number of EPCs in patients with ESRD has been ascribed to the uremia. Therefore, therapies that improve the uremic status in dialysis patients such as nocturnal hemodialysis are associated with restoration of impaired EPCs number and migratory function. In fact, some of the common treatments for patients with chronic kidney disease such as erythropoietin, statins and angiotensin II receptor antagonist increase the number of EPCs. Nowadays, there is growing evidence indicating that, under pathophysiological conditions, stem cells (SCs) derived from bone marrow are able to migrate in the injured kidney, and they seem to play a role in glomerular and tubular regeneration. After acute tubular renal injury, surviving tubular epithelial cells and putative renal stem cells proliferate and differentiate into tubular epithelial cells to promote structural and functional repair. Moreover, bone marrow stem cells, including hematopoietic stem cells and mesenchymal stem cells can also participate in the repair process by proliferation and differentiation into renal lineages. For instance, mesenchymal SCs have been shown to decrease inflammation and enhance renal regeneration. The administration of ex vivo expanded bone marrow-derived mesenchymal SCs have been proved to be beneficial in various experimental models of acute renal failure. The mechanisms underlining this beneficial effect are still a matter of debate. Thus, therapeutic strategies aimed at correcting the regenerative potential of stem cells based on the administration of ex vivo expanded SCs or stimulating expansion and differentiation of local progenitor/SC populations are another exciting area of future research.

New combination drug treatment(s) now available to patients with HIV-1 infection allows them to live longer lives with good quality of life although they suffer from the incurable HIV-1 infection. In a previous study we found that sulfatide was efficient in lowering HIV-1 viral loads in SCID mice engrafted with human fetal liver/thymus tissues (SCID-hu). Current antiviral treatments carry an increased risk of other complications like cardiovascular disease and diabetes after long-term use. There is a need for new potent safe pharmaceutical agents. Endogenous sulfatide is a mixture of -isoforms, i.e. sulfatide molecules with different long-chain bases and fatty acid chain lengths and saturation. Sulfatide isoforms may have different physicochemical properties i.e, they are of different potency at different target cells. Other investigators have shown that incubation of cultured cells with sulfatide incorporated into the plasma membrane inhibited HIV-1 entry into the cells thereby inhibiting intracellular HIV-1 replication. We have shown that CD1d dependent stimulation by sulfatide may activate pDC antigen expressing cells that produce type I inteferons. Type I inteferons are known to reduce HIV-1 replication. This could provide a second likely explanation (after the inhibition of virus entry) for the more efficient lowering of HIV-1 viral loads in sulfatide versus AZT treated mice. This review aims to show the efficiency of sulfatide in reducing HIV-1 viral loads as compared to conventional HAART treatment. We also discuss the risks of HAART treatment and propose a clinical alternative of sulfatide in HIV-1 infection.

The two neighboring southwestern states of India, Karnataka and Maharashtra, have high incidence of HIV/AIDS and are among the six most high prevalence HIV infected states. In Karnataka state, the northern districts of Bagalkot, Belgaum and Bijapur (the three Bs) and in Maharashtra state, the southern districts of Sangli, Satara, and Solapur (the three Ss) are the areas with the highest incidence of HIV/AIDS. We have evaluated the incidence of maternal to child transmission (MTCT) of HIV-1 infection in Belgaum District which is more than 500 kilometers distance by road from the campus in greater Bangalore (Karnataka State). We have obtained the prenatal CD4 counts of HIV infected pregnant mothers. We have also screened the HIV infected children in two orphanages (rehabilitation centres for HIV infected children) in Belgaum District. The clinical conditions of these infected children were assessed for their CD4 counts, anti-retroviral therapy (ART) intake status, outpatient illnesses and body composition. We have observed that there is an influence of the age factor on the CD4 counts of the HIV infected children. Further, in view of the role of our recently found involvement of sulfatide, 3-O- galactosylceramide, in inhibition of HIV-1 replication and enhancement of hematopoiesis which is otherwise inhibited due to such infection, we have discussed the possible role of sulfatides that biologically occur in the fetal adnexa (placentatrophoblasts /amnion/chorion-umbilical cord), in containing HIV infection as a potential safer alternative to the ART regimens currently approved to be clinically practiced. Lastly, we have discussed the complementary and alternative medicine (CAM) therapies such as evidence based yoga and ayurveda as add-on to ART in potential elimination of MTCT of HIV infection. Out of a total of 150 children delivered by HIV infected mothers, 13 children were found to be positive as determined by the dried blood smear (DBS) for virological testing, giving an incidence of about 8.66% in the Belgaum district during the last two years, in spite of the prescription of currently available ART regimens. All the 13 HIV-transmitting mothers had normal vaginal deliveries. Though 12% of the total 150 deliveries required lower segment caesarean section (LSCS), none among them resulted in MTCT of HIV. Comparison of the prenatal CD4 counts between transmitting and non-transmitting mothers did not show significant differences (p=0.25) thus suggesting indirectly that HIV-1 proviral loads (undetermined / unavailable) need not necessarily determine the fate of incidence of vertical transmission. The mean age of 44 HIV infected children (14 females, 30 males) that were screened in two orphanages was 10.8±3.1 years. Out of these 44 children, 27 were taking ART (61.36%) with mean duration of consumption being 2.8±2.28 years. Fifty percent (n=22) of the children were suffering from at least one outpatient illness, out of which 13 were taking ART.

Quantum clusters are sub-nano sized materials mostly synthesized from noble metals with luminescence property and high quantum yield. They are important to biomedical scientists because of their excellent optical properties. Here we represent a tool for cell imaging purpose using protein stabilized gold quantum clusters. Intestinal protease Trypsin was used to develop clusters. They were conjugated to cyclic RGD peptides by EDAC coupling. Cell imaging property was checked by transfecting the RGD-conjugated quantum clusters to bone marrow stem cells. For characterization of RGD-conjugated quantum clusters UV-Vis, Fluorescence and FTIR spectroscopy was performed. DLS and Zeta potential measurement also have been done. To check the bio compatibility of the quantum clusters MTT assay, AFM and blood cell adhesion study were performed. The samples are found out to be good for cell imaging as well as bio compatible and hemo-compatible.

Acute myeloid leukemia has emerged as a paradigm for the concept of the cancer stem cell. This hypothesis presumes that the disease is maintained by a rare population of leukemia-initiating stem cells which have acquired genetic or epigenetic changes. It is most likely that a single (epi)genetic event will not be sufficient to cause leukemia, but that a number of sequential events are required. Similar to normal hematopoietic stem cells, both intrinsic as well as extrinsic factors that arise from the bone marrow niche, provide essential cues that regulate cell fate decisions such as leukemic stem cell self-renewal and differentiation. In this chapter, we will review the current understanding of genetic and epigenetic abnormalities that underlie the process of leukemic transformation, and will discuss which events potentially co-operate to induce leukemia.

Human epidemiologic studies of highly exposed occupational cohorts have demonstrated that inhalation/exposure to benzene can cause several blood disorders, like non-lymphocytic leukemia, pre leukemic stage, aplastic anemia, and other related syndromes collectively considered as bone marrow failure syndromes. Like many other agents [e.g. chemotherapeutics etc] benzene selects the bone marrow as an important target but the exact location and the mechanism of damage is yet unexplored. The present study aimed at delineating benzene induced myelodysplasia and related disorders in an experimental mouse model with a view to assessing the clinical hazards in human at a comparable event. The observations made so far documented some quantitative and qualitative changes in the bone marrow population, especially involving the hematopoietic stem cells and related microenvironment, their immune responsiveness and survival fate of the cells at that particular event. The observations furnished that benzene following occupational exposure can be hazardous by way of HSC mediated dysfunction and, the microenvironmental studies conducted in some details indicated that the damage may be in the bone marrow stem cell niche. Furthermore, some data collected showed an increased death rate of bone marrow cells and associated abnormalities in receptor expression of adhesion molecules and related growth factors. Culminating the above data the study reveals that Benzene may cause target damage in the bone marrow stem cell niche [BM SC niche] both structurally and functionally, with the resultant disease expression as in MDS.

The traditional methods of treating musculoskeletal injuries and disorders are not completely effective and have several limitations. Tissue engineering involves using the principles of biology, chemistry and engineering to design a 'neotissue' that augments a malfunctioning in vivo tissue. The main requirements for functional engineered tissue include reparative cellular components that proliferate on a scaffold grown within a bioreactor that provides specific biochemical and physical signals to regulate cell differentiation and tissue assembly. In this review we provide an overview of the biology of common musculoskeletal tissue and discuss their common pathologies. We also describe the commonly used stem cells, scaffolds and bioreactors and evaluate their role in issue engineering.

In the adult mammalian brain, bona fide neural stem cells were discovered in the subventricular zone (SVZ), the largest neurogenic niche lining the striatal wall of the lateral ventricles of the brain. In this region resides a subpopulation of astrocytes that express the glial fibrillary acidic protein (GFAP), nestin and carbohydrate Lewis X (LeX). Astonishingly, these GFAP-expressing progenitors display stem-cell-like features both in vivo and in vitro. Throughout life SVZ astrocytes give rise to interneurons and oligodendrocyte precursors, which populate the olfactory bulb and the white matter, respectively. The role of the progenies of SVZ astrocytes has not been fully elucidated, but some evidence indicates that the new neurons play a role in olfactory discrimination, whereas oligodendrocytes contribute to myelinate white matter tracts. In this chapter, we describe the astrocytic nature of adult neural stem cells, their organization into the SVZ and some of their molecular and genetic characteristics.

As our population changes osteoarthritis and cartilage defects are becoming more prevalent. The discovery of stems cells and their ability for indefinite regeneration has revolutionised the way cartilage problems are viewed. Tissue engineering has been shown to be the ideal way of repairing articular cartilage lesions, i.e. back to native tissue. The two main types of stem cells being investigated in chondrogenesis are embryological and mesenchymal stem cells. Research into embryological stem cells has been surrounded by controversy because of tumour formation and damaging embryos during the harvest of cells. We discuss the use of embryological and mesenchymal stem cells in cartilage repair and the various factors involved in the differentiation into chondrocytes.