scholarly journals Lactobacillus acidophilus upregulates intestinal NHE3 expression and function

2012 ◽  
Vol 303 (12) ◽  
pp. G1393-G1401 ◽  
Author(s):  
Varsha Singh ◽  
Geetu Raheja ◽  
Alip Borthakur ◽  
Anoop Kumar ◽  
Ravinder K. Gill ◽  
...  
Keyword(s):  
Lactobacillus Acidophilus ◽  
Molecular Mechanisms ◽  
Major Mechanism ◽  
Protein Levels ◽  
Nacl Absorption ◽  
Human Colonic Adenocarcinoma Cell ◽  
And Function ◽  
Exchange Activity

A major mechanism of electroneutral NaCl absorption in the human ileum and colon involves coupling of Na+/H+ and Cl−/HCO3− exchangers. Disturbances in these mechanisms have been implicated in diarrheal conditions. Probiotics such as Lactobacillus have been indicated to be beneficial in the management of gastrointestinal disorders, including diarrhea. However, the molecular mechanisms underlying antidiarrheal effects of probiotics have not been fully understood. We have previously demonstrated Lactobacillus acidophilus (LA) to stimulate Cl−/HCO3− exchange activity via an increase in the surface levels and expression of the Cl−/HCO3− exchanger DRA in vitro and in vivo. However, the effects of LA on NHE3, the Na+/H+ exchanger involved in the coupled electroneutral NaCl absorption, are not known. Current studies were, therefore, undertaken to investigate the effects of LA on the function and expression of NHE3 and to determine the mechanisms involved. Treatment of Caco2 cells with LA or its conditioned culture supernatant (CS) for 8–24 h resulted in a significant increase in Na+/H+ exchange activity, mRNA, and protein levels of NHE3. LA-CS upregulation of NHE3 function and expression was also observed in SK-CO15 cells, a human colonic adenocarcinoma cell line. Additionally, LA treatment increased NHE3 promoter activity, suggesting involvement of transcriptional mechanisms. In vivo, mice gavaged with live LA showed significant increase in NHE3 mRNA and protein expression in the ileum and colonic regions. In conclusion, LA-induced increase in NHE3 expression may contribute to the upregulation of intestinal electrolyte absorption and might underlie the potential antidiarrheal effects of probiotics.

FKBP51 Modulates Hippocampal Size and Function in Post-translational Regulation of Parkin

2021 ◽  
Author(s):  
Bin Qiu ◽  
Zhaohui Zhong ◽  
Shawn Righter ◽  
Yuxue Xu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Translational Regulation ◽  
Disease Onset ◽  
Fold Increase ◽  
Knock Out ◽  
Fk506 Binding Protein ◽  
Protein Levels ◽  
And Function

Abstract FK506-binding protein 51 (encoded by Fkpb51) has been associated with stress-related mental illness. To identify its function, we studied the morphological consequences of Fkbp51 deletion. Artificial Intelligence-assist morphological analysis identified that Fkbp51 knock-out (KO) mice possess more elongated CA and DG but shorter in height in coronal section when compared to WT. Primary cultured Fkbp51 KO hippocampal neurons were shown to exhibit larger dendritic outgrowth than wild-type (WT) controls, pharmacological manipulation experiments suggest that this may occur through regulation of microtubule-associated protein. Both in vitro primary culture and in vivo labeling support that FKBP51 regulates microtubule-associated protein expression. Furthermore, in the absence of differences in mRNA expression, Fkbp51 KO hippocampus exhibited decreases in βIII-tubulin, MAP2, and Tau protein levels, but a greater than 2.5-fold increase in Parkin protein. Overexpression and knock-down FKBP51 demonstrated that FKBP51 negatively regulates Parkin in a dose-dependent and ubiquitin-mediated manner. These results indicate a potential novel post-translational regulatory of Parkin by FKBP51 and significance of their interaction on disease onset.

scholarly journals HIF-1–dependent repression of equilibrative nucleoside transporter (ENT) in hypoxia

2005 ◽  
Vol 202 (11) ◽  
pp. 1493-1505 ◽  
Author(s):  
Holger K. Eltzschig ◽  
Parween Abdulla ◽  
Edgar Hoffman ◽  
Kathryn E. Hamilton ◽  
Dionne Daniels ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Nucleoside Transporter ◽  
In Vivo Models ◽  
Equilibrative Nucleoside Transporter ◽  
Hypoxia Inducible Factor 1 ◽  
And Function

Extracellular adenosine (Ado) has been implicated as central signaling molecule during conditions of limited oxygen availability (hypoxia), regulating physiologic outcomes as diverse as vascular leak, leukocyte activation, and accumulation. Presently, the molecular mechanisms that elevate extracellular Ado during hypoxia are unclear. In the present study, we pursued the hypothesis that diminished uptake of Ado effectively enhances extracellular Ado signaling. Initial studies indicated that the half-life of Ado was increased by as much as fivefold after exposure of endothelia to hypoxia. Examination of expressional levels of the equilibrative nucleoside transporter (ENT)1 and ENT2 revealed a transcriptionally dependent decrease in mRNA, protein, and function in endothelia and epithelia. Examination of the ENT1 promoter identified a hypoxia inducible factor 1 (HIF-1)–dependent repression of ENT1 during hypoxia. Using in vitro and in vivo models of Ado signaling, we revealed that decreased Ado uptake promotes vascular barrier and dampens neutrophil tissue accumulation during hypoxia. Moreover, epithelial Hif1α mutant animals displayed increased epithelial ENT1 expression. Together, these results identify transcriptional repression of ENT as an innate mechanism to elevate extracellular Ado during hypoxia.

scholarly journals IL-2 administration increases CD4+CD25hi Foxp3+ regulatory T cells in cancer patients

Blood ◽  
2006 ◽  
Vol 107 (6) ◽  
pp. 2409-2414 ◽  
Author(s):  
Mojgan Ahmadzadeh ◽  
Steven A. Rosenberg
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Interleukin 2 ◽  
Selective Inhibition ◽  
High Dose ◽  
Protein Levels ◽  
And Function ◽  
The Impact

Abstract Interleukin-2 (IL-2) is historically known as a T-cell growth factor. Accumulating evidence from knockout mice suggests that IL-2 is crucial for the homeostasis and function of CD4+CD25+ regulatory T cells in vivo. However, the impact of administered IL-2 in an immune intact host has not been studied in rodents or humans. Here, we studied the impact of IL-2 administration on the frequency and function of human CD4+CD25hi T cells in immune intact patients with melanoma or renal cancer. We found that the frequency of CD4+CD25hi T cells was significantly increased after IL-2 treatment, and these cells expressed phenotypic markers associated with regulatory T cells. In addition, both transcript and protein levels of Foxp3, a transcription factor exclusively expressed on regulatory T cells, were consistently increased in CD4 T cells following IL-2 treatment. Functional analysis of the increased number of CD4+CD25hi T cells revealed that this population exhibited potent suppressive activity in vitro. Collectively, our results demonstrate that administration of high-dose IL-2 increased the frequency of circulating CD4+CD25hi Foxp3+ regulatory T cells. Our findings suggest that selective inhibition of IL-2-mediated enhancement of regulatory T cells may improve the therapeutic effectiveness of IL-2 administration. (Blood. 2006;107:2409-2414)

scholarly journals Mesenchymal Stem Cells with Enhanced Bcl-2 Expression Promote Liver Recovery in a Rat Model of Hepatic Cirrhosis

2016 ◽  
Vol 40 (5) ◽  
pp. 1117-1128 ◽  
Author(s):  
Shizhu Jin ◽  
Hulun Li ◽  
Mingzi Han ◽  
Mengting Ruan ◽  
Zishuai Liu ◽  
...  
Keyword(s):  
Liver Function ◽  
Hepatic Cirrhosis ◽  
Post Transplantation ◽  
Experimental Cirrhosis ◽  
Adeno Associated Virus ◽  
Protein Levels ◽  
Histological Sign ◽  
And Function

Background/Aims: Mesenchymal stem cell (MSC) transplantation has emerged as an option for the treatment of chronic hepatic cirrhosis, while its therapeutic efficacy could be improved. The bcl-2 gene is anti-apoptotic and can help cell survival and proliferation. Therefore, we explored whether transplanted MSCs with enhanced bcl-2 expression may be beneficial in the treatment of experimental cirrhosis in rats. Methods: MSCs were isolated from rat bone marrow, expanded in vitro and transfected with adeno-associated virus (AAV) engineered the bcl-2 gene (AAV-bcl-2). Rats with cirrhosis induced by carbon tetrachloride (CCl4) were treated with AAV-bcl-2 infected BMSCs-AAV-bcl-2, with the cells traced in vivo post transplantation. Liver pathology and function were evaluated 7, 14, 21, and 28 days post transplantation, respectively. Results: On day 7 post transplantation, the infused AAV-bcl-2 had integrated into the hepatocyte-like cells (HLCs) that expressed albumin (ALB), Cytokeratin 18 (CK18), and hepatocytes nuclear factor 4a (HNF4a). On day 28 post transplantation, rats in the cirrhosis + BMSCs-AAV-bcl-2 group showed the most dense HLCs, highest mRNA and protein levels of ALB, CK18, and HNF4a, compared to the other groups. Their liver function recovered most rapidly in 4 week observation, while histological sign of cirrhosis remained at the end of this period. Conclusion: BMSCs over expressing bcl-2 gene showed better survival, and enhanced the differentiation into hepatocytes-like cells, and appeared to promote the recovery of liver function in rats with experimental cirrhosis.

scholarly journals Building neuromuscular junctions in vitro

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev193920
Author(s):  
Susie Barbeau ◽  
Julie Tahraoui-Bories ◽  
Claire Legay ◽  
Cécile Martinat
Keyword(s):  
Human Disease ◽  
Molecular Mechanisms ◽  
Neuromuscular Junctions ◽  
Ex Vivo ◽  
Culture Methods ◽  
Recent Developments ◽  
Chemical Synapses ◽  
And Function

ABSTRACTThe neuromuscular junction (NMJ) has been the model of choice to understand the principles of communication at chemical synapses. Following groundbreaking experiments carried out over 60 years ago, many studies have focused on the molecular mechanisms underlying the development and physiology of these synapses. This Review summarizes the progress made to date towards obtaining faithful models of NMJs in vitro. We provide a historical approach discussing initial experiments investigating NMJ development and function from Xenopus to mice, the creation of chimeric co-cultures, in vivo approaches and co-culture methods from ex vivo and in vitro derived cells, as well as the most recent developments to generate human NMJs. We discuss the benefits of these techniques and the challenges to be addressed in the future for promoting our understanding of development and human disease.

scholarly journals Lactobacillus acidophilus attenuates downregulation of DRA function and expression in inflammatory models

2014 ◽  
Vol 307 (6) ◽  
pp. G623-G631 ◽  
Author(s):  
Varsha Singh ◽  
Anoop Kumar ◽  
Geetu Raheja ◽  
Arivarasu N. Anbazhagan ◽  
Shubha Priyamvada ◽  
...  
Keyword(s):  
Lactobacillus Acidophilus ◽  
Therapeutic Potential ◽  
Experimental Models ◽  
In Vivo Model ◽  
Inhibitory Effects ◽  
Inflammatory Models ◽  
Ifn Γ ◽  
Exchange Activity

Probiotics, including Lactobacilli, are commensal bacteria that have been used in clinical trials and experimental models for the prevention and treatment of diarrheal disorders. Our previous studies have shown that Lactobacillus acidophilus (LA) and its culture supernatant (CS) stimulated Cl−/HCO3− exchange activity, acutely via an increase in the surface levels of downregulated in adenoma (DRA, SLC26A3) and in long-term treatments via increasing its expression involving transcriptional mechanisms. However, the role of LA in modulating DRA activity under inflammatory conditions is not known. Current in vitro studies using human intestinal epithelial Caco-2 cells examined the efficacy of LA or its CS in counteracting the inhibitory effects of interferon-γ (IFN-γ) on Cl−/HCO3− exchange activity. Pretreatment of cells with LA or LA-CS for 1 h followed by coincubation with IFN-γ significantly alleviated the inhibitory effects of IFN-γ on Cl−/HCO3− exchange activity. In the in vivo model of dextran sulfate sodium-induced experimental colitis (3% in drinking water for 7 days) in C57BL/6J mice, administration of live LA (3 × 109 colony-forming units) via oral gavage attenuated colonic inflammation. LA administration also counteracted the colitis-induced decrease in DRA mRNA and protein levels. Efficacy of LA or its secreted soluble factors in alleviating inflammation and inflammation-associated dysregulation of DRA activity could justify their therapeutic potential in inflammatory diarrheal diseases.

scholarly journals UBAC2 promotes bladder cancer proliferation through BCRC-3/miRNA-182-5p/p27 axis

2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Chaohui Gu ◽  
Keyuan Zhao ◽  
Naichun Zhou ◽  
Feng Liu ◽  
Fei Xie ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Posttranscriptional Regulation ◽  
Molecular Mechanisms ◽  
Malignant Tumors ◽  
Circular Rna ◽  
Cancer Proliferation ◽  
Lower Survival Rate ◽  
Protein Levels

Abstract Emerging evidences have demonstrated that ubiquitin-associated domain-containing protein 2 (UBAC2) is closely related to the occurrence and development of malignant tumors. However, the functions and underlying molecular mechanisms of UBAC2 in bladder cancer (BC) development have not been defined. In this study, we found that both UBAC2 mRNA and protein levels were upregulated in BC tissues and cell lines, and knockdown of UBAC2 inhibited BC cells proliferation both in vitro and in vivo. Meanwhile, Kaplan–Meier survival plots of 406 BC cases from TCGA database showed that higher expression of UBAC2 in BC patients was associated with lower survival rate. Mechanistic studies revealed that knockdown of UBAC2 increased the expression of p27 by posttranscriptional regulation. Our previous study indicated that circular RNA BCRC-3 (BCRC-3) promoted the expression of p27 through interacting with miR-182-5p, and reversed miR-182-5p-induced inhibition of p27 3′UTR activity. In the present study, we found that UBAC2 could bind to BCRC-3, and subsequently affected the interaction of BCRC-3 with miR-182-5p to inhibit the expression of p27. Furthermore, knockdown of BCRC-3 partly reversed the upregulation of p27 expression induced by knockdown of UBAC2. Our findings highlight a novel mechanism of UBAC2 in regulating p27 through affecting the function of BCRC-3, and provide a research basis for the diagnostic and therapeutic application of BC.

scholarly journals Lactobacillus acidophilus stimulates the expression of SLC26A3 via a transcriptional mechanism

2010 ◽  
Vol 298 (3) ◽  
pp. G395-G401 ◽  
Author(s):  
Geetu Raheja ◽  
Varsha Singh ◽  
Ke Ma ◽  
Redouane Boumendjel ◽  
Alip Borthakur ◽  
...  
Keyword(s):  
Western Blot ◽  
Lactobacillus Acidophilus ◽  
Promoter Activity ◽  
In Vivo Studies ◽  
Mrna Levels ◽  
Long Term Effects ◽  
Exchange Activity

Clinical efficacy of probiotics in treating various forms of diarrhea has been clearly established. However, mechanisms underlying antidiarrheal effects of probiotics are not completely defined. Diarrhea is caused either by decreased absorption or increased secretion of electrolytes and solutes in the intestine. In this regard, the electroneutral absorption of two major electrolytes, Na+ and Cl−, occurs mainly through the coupled operation of Na+/H+ exchangers and Cl−/OH− exchangers. Previous studies from our laboratory have shown that Lactobacillus acidophilus (LA) acutely stimulated Cl−/OH− exchange activity via an increase in the surface levels of the apical anion exchanger SLC26A3 (DRA). However, whether probiotics influence SLC26A3 expression and promoter activity has not been examined. The present studies were, therefore, undertaken to investigate the long-term effects of LA on SLC26A3 expression and promoter activity. Treatment of Caco-2 cells with LA for 6–24 h resulted in a significant increase in Cl−/OH− exchange activity. DRA mRNA levels were also significantly elevated in response to LA treatment starting as early as 8 h. Additionally, the promoter activity of DRA was increased by more than twofold following 8 h LA treatment of Caco-2 cells. Similar to the in vitro studies, in vivo studies using mice gavaged with LA also showed significantly increased DRA mRNA (∼4-fold) and protein expression in the colonic regions as assessed by Western blot analysis and immunofluorescence. In conclusion, increase in DRA promoter activity and expression may contribute to the upregulation of intestinal electrolyte absorption and might underlie the potential antidiarrheal effects of LA.

scholarly journals Forskolin, 8-Br-3′,5′-Cyclic Adenosine 5′-Monophosphate, and Catalytic Protein Kinase A Expression in the Nucleus Increase Radioiodide Uptake and Sodium/Iodide Symporter Protein Levels in RET/PTC1-Expressing Cells

2004 ◽  
Vol 89 (12) ◽  
pp. 6168-6172 ◽  
Author(s):  
Anjli Venkateswaran ◽  
Derek K. Marsee ◽  
Steven H. Green ◽  
Sissy M. Jhiang
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Sodium Iodide ◽  
Sodium Iodide Symporter ◽  
Thyroid Cells ◽  
Protein Levels ◽  
And Function ◽  
Kinase A

Abstract RET/PTC1, a thyroid-specific oncogene, has been reported to down-regulate sodium/iodide symporter (NIS) expression and function in vitro and in vivo. Recently, RET/PTC1 has been shown to interfere with TSH signaling at multiple levels in thyroid cells. The objective of this study was to investigate whether RET/PTC1-mediated NIS reduction can be rescued by activating cAMP-protein kinase A (PKA) pathways. We showed that both forskolin and 8-Br-cAMP increase radioiodide uptake and NIS protein in RET/PTC1-expressing cells to the same extent as the parental PC Cl 3 cells. We found that RET/PTC1 decreases nuclear localization of catalytic PKA, and forskolin treatment was able to counteract this RET/PTC1 effect. Furthermore, transient expression of catalytic PKA in the nucleus increased radioiodide uptake and NIS protein in RET/PTC1-expressing cells. Taken together, these studies suggest that RET/PTC1 down-regulates NIS expression by interrupting TSH/cAMP signaling, and this RET/PTC1 effect can be reversed by activating cAMP-PKA pathways.

P19INK4D links endomitotic arrest and megakaryocyte maturation and is regulated by AML-1

Blood ◽  
2008 ◽  
Vol 111 (8) ◽  
pp. 4081-4091 ◽  
Author(s):  
Laure Gilles ◽  
Romain Guièze ◽  
Dominique Bluteau ◽  
Véronique Cordette-Lagarde ◽  
Catherine Lacout ◽  
...  
Keyword(s):  
Ploidy Level ◽  
Molecular Mechanisms ◽  
Transcriptional Level ◽  
Moderate Increase ◽  
Protein Levels ◽  
Human Cd34 ◽  
Cd34 Cells ◽  
Ploidy Class

Abstract The molecular mechanisms that regulate megakaryocyte (MK) ploidization are poorly understood. Using MK differentiation from primary human CD34+ cells, we observed that p19INK4D expression was increased both at the mRNA and protein levels during ploidization. p19INK4D knockdown led to a moderate increase (31.7% ± 5%) in the mean ploidy of MKs suggesting a role of p19INK4D in the endomitotic arrest. This increase in ploidy was associated with a decrease in the more mature MK population (CD41highCD42high) at day 9 of culture, which was related to a delay in differentiation. Inversely, p19INK4D overexpression in CD34+ cells resulted in a decrease in mean ploidy level associated with an increase in CD41 and CD42 expression in each ploidy class. Confirming these in vitro results, bone marrow MKs from p19INK4D KO mice exhibited an increase in mean ploidy level from 18.7N (± 0.58N) to 52.7N (± 12.3N). Chromatin immunoprecipitation assays performed in human MKs revealed that AML-1 binds in vivo the p19INK4D promoter. Moreover, AML-1 inhibition led to the p19INK4D down-regulation in human MKs. These results may explain the molecular link at the transcriptional level between the arrest of endomitosis and the acceleration of MK differentiation.

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