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Reprogramming of somatic cells to induced pluripotent stem cells, by overexpressing certain factors referred to as the reprogramming factors, can revolutionize regenerative medicine. To provide a coherent description of induced pluripotency from the gene regulation perspective, we use 35 microarray datasets to construct a reprogramming gene regulatory network. Comprising 276 nodes and 4471 links, the resulting network is, to the best of our knowledge, the largest gene regulatory network constructed for human fibroblast reprogramming and it is the only one built using a large number of experimental datasets. To build the network, a model that relates the expression profiles of the initial (fibroblast) and final (induced pluripotent stem cell) states is proposed and the model parameters (link strengths) are fitted using the experimental data. Twenty nine additional experimental datasets are collectively used to test the model/network, and good agreement between experimental and predicted gene expression profiles is found. We show that the model in conjunction with the constructed network can make useful predictions. For example, we demonstrate that our approach can incorporate the effect of reprogramming factor stoichiometry and that its predictions are consistent with the experimentally observed trends in reprogramming efficiency when the stoichiometric ratios vary. Using our model/network, we also suggest new (not used in training of the model) candidate sets of reprogramming factors, many of which have already been experimentally verified. These results suggest our model/network can potentially be used in devising new recipes for induced pluripotency with higher efficiencies. Additionally, we classify the links of the network into three classes of different importance, prioritizing them for experimental verification. We show that many of the links in the top ranked class are experimentally known to be important in reprogramming. Finally, comparing with other methods, we show that using our model is advantageous. [ABSTRACT FROM AUTHOR]

Purpose: Ischemia-reperfusion injury (IRI) is associated with significant patient mortality and morbidity. The complex cascade of IRI is incompletely understood, but inflammation is known to be a key mediator. In addition to the predominant innate immune responses, previous research has also indicated that αβ T cells contribute to IRI in various organ models. The aim of this study was to clarify the role αβ T cells play in IRI to the gut. Methods: Adult wild-type (WT) and αβ T cell-deficient mice were subjected to acute intestinal IRI with 30min ischemia followed by 4h reperfusion. The gene expression of pro-inflammatory cytokines was measured by qPCR, and the influx of leukocyte subpopulations in the gut was assessed via flow cytometry and histology. Pro-inflammatory cytokines in the serum were measured, and transaminases were assessed as an indicator of distant organ IRI. Results: Intestinal IRI led to an increased expression of pro-inflammatory cytokines in the gut tissue and an influx of leukocytes that predominantly consisted of neutrophils and macrophages. Furthermore, intestinal IRI increased serum IL-6, TNF-α, and ALT/AST levels. The αβ T cell-deficient mice did not exhibit a more significant increase in pro-inflammatory cytokines in the gut or serum following IR than the WT mice. There was also no difference between WT- and αβ T cell-deficient mice in terms of neutrophil infiltration or macrophage activation. Furthermore, the increase in transaminases was equal in both groups indicating that the level of distant organ injury was comparable. Conclusion: An increasing body of evidence demonstrates that αβ T cells play a key role in IRI. In the gut, however, αβ T cells are not pivotal in the first hours following acute IRI as deficiency does not impact cytokine production, neutrophil recruitment, macrophage activation, or distant organ injury. Thus, αβ T cells may be considered innocent bystanders during the acute phase of intestinal IRI. [ABSTRACT FROM AUTHOR]

Mitochondria play a critical role in the generation of metabolic energy and are crucial for eukaryotic cell survival and proliferation. In most sexual eukaryotes, mitochondrial DNA (mtDNA) is inherited from only one parent in non-Mendelian inheritance in contrast to the inheritance of nuclear DNA. The model organism Saccharomyces cerevisiae is commonly used to study mitochondrial biology. It has two mating types: MATa and MATα. Previous studies have suggested that the mtDNA inheritance patterns in hybrid diploid cells depend on the genetic background of parental strains. However, the underlying mechanisms remain unclear. To elucidate the mechanisms, we examined the effects of environmental factors on the mtDNA inheritance patterns in hybrids obtained by crossing S. cerevisiae with its close relative S. paradoxus. The results demonstrated that environmental factors can influence mtDNA transmission in hybrid diploids, and that the inheritance patterns are strain dependent. The fitness competition assay results showed that the fitness differences can explain the mtDNA inheritance patterns under specific conditions. However, in this study, we found that fitness differences cannot fully be explained by mitochondrial activity in hybrids under stress conditions. [ABSTRACT FROM AUTHOR]

With the expansion of the aged population, it is predicted that neurodegenerative diseases (NDDs) will become a major threat to public health worldwide. However, existing therapies can control the symptoms of the diseases at best, rather than offering a fundamental cure. As for the complex pathogenesis, clinical and preclinical researches have indicated that oxidative stress, a central role in neuronal degeneration, is a possible therapeutic target in the development of novel remedies. In this study, the motor neuron-like cell line NSC-34 was employed as an experimental model in probing the effects induced by the combination of non-invasive low intensity pulsed electric field (LIPEF) and fucoidan on the H2O2-induced neuron damage. It was found that single treatment of the LIPEF could protect the NSC-34 cells from oxidative stress, and the protective effect was enhanced by combining the LIPEF and fucoidan. Notably, it was observed that single treatment of the LIPEF obviously suppressed the H2O2-enhanced expression of ROCK protein and increased the phosphorylation of Akt in the H2O2-treated NSC-34 cells. Moreover, the LIPEF can be easily modified to concentrate on a specific area. Accordingly, this technique can be used as an advanced remedy for ROCK inhibition without the drawback of drug metabolism. Therefore, we suggest the LIPEF would be a promising strategy as a treatment for motor neurodegeneration and warrant further probe into its potential in treating other neuronal degenerations. [ABSTRACT FROM AUTHOR]

Leishmaniasis is amongst the most important neglected diseases, afflicting more than 12 million people in 88 countries. There is an urgent need for safe orally bioavailable and cost-effective drugs for the treatment of leishmaniasis. It has recently been shown that Leishmania activates host macrophage serine/threonine kinase Akt, to promote survival of both parasites and infected cells. Here, we sought to evaluate a compound, Miransertib (ARQ 092), an orally bioavailable and selective allosteric Akt inhibitor currently in clinical trials for patients with PI3K/Akt-driven tumors or Proteus syndrome. Miransertib was tested against Leishmania donovani and Leishmania amazonensis, causative agents of visceral and cutaneous leishmaniasis, respectively. Cultured promastigotes were susceptible to Miransertib. In addition, Miransertib was markedly effective against intracellular amastigotes of L. donovani or L. amazonensis-infected macrophages. Miransertib also enhanced mTOR dependent autophagy in Leishmania-infected macrophages, which may represent one mechanism of Miransertib-mediated killing of intracellular Leishmania. Whereas parasite clearance in the spleen of mice infected with L. donovani and treated with Miransertib was comparable to that when treated with miltefosine, Miransertib caused a greater reduction in the parasite load in the liver. In the cutaneous leishmaniasis infection model, lesions were reduced by 40% as compared to mock treated mice. Together, these results provide direct evidence to support the conclusion that Miransertib is an excellent lead compound for the development of a new oral drug therapy for visceral and cutaneous leishmaniasis. [ABSTRACT FROM AUTHOR]

Defining the correlates of immune protection conferred by SIVΔnef, the most effective vaccine against SIV challenge, could enable the design of a protective vaccine against HIV infection. Here we provide a comprehensive assessment of immune responses that protect against SIV infection through detailed analyses of cellular and humoral immune responses in the blood and tissues of rhesus macaques vaccinated with SIVΔnef and then vaginally challenged with wild-type SIV. Despite the presence of robust cellular immune responses, animals at 5 weeks after vaccination displayed only transient viral suppression of challenge virus, whereas all macaques challenged at weeks 20 and 40 post-SIVΔnef vaccination were protected, as defined by either apparent sterile protection or significant suppression of viremia in infected animals. Multiple parameters of CD8 T cell function temporally correlated with maturation of protection, including polyfunctionality, phenotypic differentiation, and redistribution to gut and lymphoid tissues. Importantly, we also demonstrate the induction of a tissue-resident memory population of SIV-specific CD8 T cells in the vaginal mucosa, which was dependent on ongoing low-level antigenic stimulation. Moreover, we show that vaginal and serum antibody titers inversely correlated with post-challenge peak viral load, and we correlate the accumulation and affinity maturation of the antibody response to the duration of the vaccination period as well as to the SIVΔnef antigenic load. In conclusion, maturation of SIVΔnef-induced CD8 T cell and antibody responses, both propelled by viral persistence in the gut mucosa and secondary lymphoid tissues, results in protective immune responses that are able to interrupt viral transmission at mucosal portals of entry as well as potential sites of viral dissemination. [ABSTRACT FROM AUTHOR]

Background/Aims: Chronic myocardial infarction (MI) results in the formation of arrhythmogenic substrates, causing lethal ventricular arrhythmia (VA). We aimed to determine whether mesenchymal stem cells (MSCs) carrying a hepatocyte growth factor (HGF) gene modification (HGF-MSCs) decrease the levels of arrhythmogenic substrates and reduce the susceptibility to developing VA compared with unmodified MSCs and PBS in a swine infarction model. Methods: The left descending anterior artery was balloon-occluded to establish an MI model. Four weeks later, the randomly grouped pigs were administered MSCs, PBS or HGF-MSCs via thoracotomy. After an additional four weeks, dynamic electrocardiography was performed to assess heart rate variability, and programmed electrical stimulation was conducted to evaluate the risk for VA. Then, the pigs were euthanized for morphometric, immunofluorescence and western blot analyses. Results: The HGF-MSC group displayed the highest vessel density and Cx43 expression levels, and the lowest levels of apoptosis, and tyrosine hydroxylase (TH) and growth associated protein 43 (GAP43) expression. Moreover, the HGF-MSC group exhibited a decrease in the number of sympathetic nerve fibers, substantial decreases in the low frequency and the low-/high- frequency ratio and increases in the root mean square of successive differences (rMSSD) and the percentage of successive normal sinus R-R intervals longer than 50 ms (pNN50), compared with the other two groups. Finally, the HGF-MSC group displayed the lowest susceptibility to developing VA. Conclusion: HGF-MSCs displayed potent antiarrhythmic effects, reducing the risk for VA. [ABSTRACT FROM AUTHOR]

Latency-associated peptide (LAP) - expressing regulatory T cells (Tregs) are important for immunological self-tolerance and immune homeostasis. In order to investigate the role of LAP in human CD4+Foxp3+ Tregs, we designed a cross-sectional study that involved 42 colorectal cancer (CRC) patients. The phenotypes, cytokine-release patterns, and suppressive ability of Tregs isolated from peripheral blood and tumor tissues were analyzed. We found that the population of LAP-positive CD4+Foxp3+ Tregs significantly increased in peripheral blood and cancer tissues of CRC patients as compared to that in the peripheral blood and tissues of healthy subjects. Both LAP+ and LAP− Tregs had a similar effector/memory phenotype. However, LAP+ Tregs expressed more effector molecules, including tumor necrosis factor receptor II, granzyme B, perforin, Ki67, and CCR5, than their LAP− negative counterparts. The in vitro immunosuppressive activity of LAP+ Tregs, exerted via a transforming growth factor-β–mediated mechanism, was more potent than that of LAP− Tregs. Furthermore, the enrichment of LAP+ Treg population in peripheral blood mononuclear cells (PBMCs) of CRC patients correlated with cancer metastases. In conclusion, we found that LAP+ Foxp3+ CD4+ Treg cells represented an activated subgroup of Tregs having more potent regulatory activity in CRC patients. The increased frequency of LAP+ Tregs in PBMCs of CRC patients suggests their potential role in controlling immune response to cancer and presents LAP as a marker of tumor-specific Tregs in CRC patients. [ABSTRACT FROM AUTHOR]