No abstract

Cancer stem cells (CSCs) which are known to be residing deep inside the core of the tumor in its hypoxia niche is responsible for relapse of cancers. Owing to this hypoxic niche, the residing CSCs simultaneously fuel their stemness, cancerous and drug resistance properties. Attributes of CSCs are still not properly understood in its hypoxia niche. Addressing this, we sorted CSCs from Saos-2 (osteosarcoma) cell line using CD133 antibody. The CD133 CSCs exhibited quiescent cell proliferation in DNA doubling, Ca signaling and cell cycle analysis. CD133 CSCs exhibited increased production of ATP and lactate dehydrogenase (LDH) activity under hypoxia. CD133 cells exhibited decreased glucose uptake compared to ATP levels under hypoxia. Moreover, there was only negligible LDH activity in CD133 cells under normoxia which do not rely on Warburg effect. Stemness markers (such as c-Myc, SOX2, Oct4 and TERT), metastasis marker (CD44) and drug resistance marker (ABCG2) were highly expressed in CD133 cells. In summary, both CD133 cells of Saos-2 (osteosarcoma) cell line did not exhibit Warburg effect under normoxic condition. Moreover, this significantly indicates an uncoupling between stemness and Warburg effect in CD133. This work provides a novel insight into the metabolic and functional features of CSCs in a hypoxic environment which could open new avenues for therapeutic strategies aimed to target CSCs.

No abstract

BackgroundCardiosphere derived cells (CDCs) represent a valuable source in stem cell based therapy for cardiovascular diseases, yet poor differentiation rate hinders the transplantation efficiency. The aim of this study is to check the ability of 5-Azacytidine (Aza) alone and in combination with ascorbic acid (Aza+AA) in delineating CDCs to cardiomyogenesis and the underlying Wnt signaling mechanism in induced differentiation.MethodsCDCs were treated with Aza and Aza+AA for a period of 14 days to examine the expression of cardiac specific markers and Wnt downstream regulators by immunofluorescence, real time PCR and western blot.ResultsResults revealed that Aza+AA induced efficient commitment of CDCs to cardiomyogenic lineage. Immunofluorescence analysis showed significant augment for Nkx 2.5, GATA 4 and α-Sarcomeric actinin markers in Aza+AA group than control group (p = 0.0118, p = 0.009 and p = 0.0091, respectively). Relative upregulation of cardiac markers, Nkx 2.5 (p = 0.0156), GATA 4 (p = 0.0087) and down regulation of Wnt markers, β-catenin (p = 0.0107) and Cyclin D1 (p = 0. 0116) in Aza+AA group was revealed by RNA expression analysis. Moreover, the Aza+AA induced prominent expression of GATA 4, α-Sarcomeric actinin and phospho β-catenin while non phospho β-catenin and Cyclin D1 expression was significantly suppressed as displayed in protein expression analysis. Generation of spontaneous beating in Aza+AA treated CDCs further reinforced that Aza+AA accelerates the cardiomyogenic potential of CDCs.ConclusionCombined treatment of Aza along with AA implicit in inducing cardiomyogenic potential of CDCs and is associated with down regulating Wnt signaling pathway. Altogether, CDCs represent a valuable tool for the treatment of cardiovascular disorders.

<p><strong>Objective: </strong>Recombinant Human Erythropoietin (rhEPO) is strongly inferred to protect the cardiomyocytes from the reperfusion injury and our aim is to elucidate the cardioprotective effect and the exact mechanism behind the cardioprotection.</p><p><strong>Methods: </strong>Neonatal rat cardiomyocytes (NCM) exposed to Hypoxia/Reperfusion (H/R) with or without pretreatment using various concentrations of rhEPO. To determine the cell viability-MTT assay, Acridine orange and Ethidium Bromide (Ao/EtBr) staining was performed. To determine the reactive oxygen species (ROS) and mitochondrial membrane potential (<em>Δψm</em>), Dichlorofluorescein diacetate (DCF-DA) and Rhodamine-123 was used. To determine the signaling pathways Western blot analysis of pAkt, pp38 MAPK, cytochrome-c were performed.</p><p><strong>Results: </strong>rhEPO was found to reduce the cell death by stabilizing ROS significantly, Δψm, cytochrome c release, and caspase-3. rhEPO, increases the phosphorylation of p38 MAPK, Akt and BAD compared to H/R. Further myocytes blocked with Wortmannin (WT), and SB203580 showed increased caspase-3 activity.</p><p><strong>Conclusion: </strong>Hence we conclude from this study that rhEPO regulated the factors involved in reperfusion injury through modulation of Akt and p38 MAPK pathways.</p>