Medicine and Health Sciences Commons^™

Unique Regulation Of Enterocyte Brush Border Membrane Na-Glutamine And Na-Alanine Co-Transport By Peroxynitrite During Chronic Intestinal Inflammation, Subha Arthur, Palanikumar Manoharan, Shanmuga Sundaram, M. M. Rahman, Balasubramanian Palaniappan, Uma Sundaram

Clinical & Translational Sciences

Na-amino acid co-transporters (NaAAcT) are uniquely affected in rabbit intestinal villus cell brush border membrane (BBM) during chronic intestinal inflammation. Specifically, Na-alanine co-transport (ASCT1) is inhibited secondary to a reduction in the affinity of the co-transporter for alanine, whereas Na-glutamine co-transport (B0AT1) is inhibited secondary to a reduction in BBM co-transporter numbers. During chronic intestinal inflammation, there is abundant production of the potent oxidant peroxynitrite (OONO). However, whether OONO mediates the unique alteration in NaAAcT in intestinal epithelial cells during chronic intestinal inflammation is unknown. In this study, ASCT1 and B0AT1 were inhibited by OONO in vitro. The mechanism of …

Lactobacillus Acidophilus Alleviates Platelet-Activating Factor-Induced Inflammatory Responses In Human Intestinal Epithelial Cells, Alip Borthakur, Sumit Bhattacharyya, Anoop Kumar, Arivarasu Natarajan Anbazhagan, Joanne K. Tobacman, Pradeep K. Dudeja

Clinical & Translational Sciences

Probiotics have been used as alternative prevention and therapy modalities in intestinal inflammatory disorders including inflammatory bowel diseases (IBD) and necrotizing enterocolitis (NEC). Pathophysiology of IBD and NEC includes the production of diverse lipid mediators, including platelet-activating factor (PAF) that mediate inflammatory responses in the disease. PAF is known to activate NF-kB, however, the mechanisms of PAF-induced inflammation are not fully defined. We have recently described a novel PAF-triggered pathway of NF-κB activation and IL-8 production in intestinal epithelial cells (IECs), requiring the pivotal role of the adaptor protein Bcl10 and its interactions with CARMA3 and MALT1. The current studies …

Prolongation Of Carrageenan-Induced Inflammation In Human Colonic Epithelial Cells By Activation Of An Nfκb-Bcl10 Loop, Alip Borthakur, Sumit Bhattacharyya, Arivarasu N. Anbazhagan, Anoop Kumar, Pradeep K. Dudeja, Joanne K. Tobacman

Clinical & Translational Sciences

Carrageenan, a sulfated polysaccharide that is widely used as a food additive, induces inflammatory responses in animal models and human cells. The carrageenan-induced inflammatory cascades involve tolllike receptor (TLR)4- and B-cell leukemia/lymphoma (BCL)10-dependent activation of NF-κB, leading to increased IL-8 production. Translocations involving BCL10 in the mucosa-associated lymphoid tissue (MALT) lymphomas are associated with constitutive activation of NF-κB. This report presents a mechanism by which carrageenan exposure leads to prolonged activation of both BCL10 and NF-κB in human colonic epithelial cells. Study findings demonstrate that nuclear RelA and RelB bind to an NF-κB binding motif in the BCL10 promoter in …

The P53-Induced Siva-1 Plays A Significant Role In Cisplatin-Mediated Apoptosis, John L. Barkinge, Radhika Gudi, Hawkins Sarah, Fei Chu, Alip Borthakur, Bellur S. Prabhakar

Clinical & Translational Sciences

Background: The pro-apoptotic protein Siva-1 functions in both extrinsic and intrinsic cell death signaling; however, the exact contribution of the endogenous Siva-1 to DNA damage-induced apoptosis is unclear. Using cisplatin, a chemotherapeutic drug, to induce DNA damage and cell death, we determined the role of Siva-1.

Methods: Cisplatin treated HCT116 colorectal carcinoma cells (p53+/+ and -/-) were used in the study. With the help of recombinant lentivirus that can express siSiva (siRNA that specifi cally targets Siva-1), we also generated Siva-1 knockdown HCT116 cells. Apoptosis was determined by tetramethyl rhodamine methyl ester (TMRM) staining and propidium iodide (PI) staining.

Results: …

Siva-1 Binds To And Inhibits Bcl-Xl-Mediated Protection Against Uv Radiation-Induced Apoptosis, Li Xue, Fei Chu, Yuan Cheng, Xiangjie Sun, Alip Borthakur, Manjunath Ramarao, Pramod Pandey, Mei Wu, Stuart F. Schlossman, Kanteti V. S. Prasad

Clinical & Translational Sciences

We previously cloned Siva-1 by using the cytoplasmic tail of CD27, a member of the tumor necrosis factor receptor family, as the bait in the yeast two-hybrid system. The Siva gene is organized into four exons that code for the predominant full-length Siva-1 transcript, whereas its alternate splice form, Siva-2, lacks exon 2 coding sequence. Various groups have demonstrated a role for Siva-1 in several apoptotic pathways. Interestingly, the proapoptotic properties of Siva-1 are lacking in Siva-2. The fact that Siva-1 is partly localized to mitochondria despite the absence of any mitochondrial targeting signal, it harbors a 20-aa-long putative amphipathic …