alexa Preconditioning with associated blocking of Ca2+ inflow alleviates hypoxia-induced damage to pancreatic β-cells.
Surgery

Surgery

Surgery: Current Research

Author(s): Ma Z, Moruzzi N, Catrina SB, Hals I, Oberholzer J,

Abstract Share this page

Abstract OBJECTIVE: Beta cells of pancreatic islets are susceptible to functional deficits and damage by hypoxia. Here we aimed to characterize such effects and to test for and pharmacological means to alleviate a negative impact of hypoxia. METHODS AND DESIGN: Rat and human pancreatic islets were subjected to 5.5 h of hypoxia after which functional and viability parameters were measured subsequent to the hypoxic period and/or following a 22 h re-oxygenation period. Preconditioning with diazoxide or other agents was usually done during a 22 h period prior to hypoxia. RESULTS: Insulin contents decreased by 23\% after 5.5 h of hypoxia and by 61\% after a re-oxygenation period. Preconditioning with diazoxide time-dependently alleviated these hypoxia effects in rat and human islets. Hypoxia reduced proinsulin biosynthesis ((3)H-leucine incorporation into proinsulin) by 35\%. Preconditioning counteracted this decrease by 91\%. Preconditioning reduced hypoxia-induced necrosis by 40\%, attenuated lowering of proteins of mitochondrial complexes I-IV and enhanced stimulation of HIF-1-alpha and phosphorylated AMPK proteins. Preconditioning by diazoxide was abolished by co-exposure to tolbutamide or elevated potassium (i.e. conditions which increase Ca(2+) inflow). Preconditioning with nifedipine, a calcium channel blocker, partly reproduced effects of diazoxide. Both diazoxide and nifedipine moderately reduced basal glucose oxidation whereas glucose-induced oxygen consumption (tested with diazoxide) was unaffected. Preconditioning with diaxoxide enhanced insulin contents in transplants of rat islets to non-diabetic rats and lowered hyperglycemia vs. non-preconditioned islets in streptozotocin-diabetic rats. Preconditioning of human islet transplants lowered hyperglycemia in streptozotocin-diabetic nude mice. CONCLUSIONS: 1) Prior blocking of Ca(2+) inflow associates with lesser hypoxia-induced damage, 2) preconditioning affects basal mitochondrial metabolism and accelerates activation of hypoxia-reactive and potentially protective factors, 3) results indicate that preconditioning by K(+)-ATP-channel openers has therapeutic potential for islet transplantations.
This article was published in PLoS One and referenced in Surgery: Current Research

Relevant Expert PPTs

Relevant Speaker PPTs

  • Li Yu-Jung
    Intra-maxillary Drug delivery and Bio-sensing via Dental Implant and its considerations
    PPT Version | PDF Version
  • Nicolae Bacalbasa
    The benefits of surgery for breast cancer liver metastases – a single center experience
    PPT Version | PDF Version
  • Sitanshu Sekhar Lahiri
    A novel oral formulation for cancer therapy, loaded in a slow release matrix for targeted delivery
    PPT Version | PDF Version
  • Li-Chun Tsou
    Drug delivery device strategy for patient centric therapies
    PDF Version
  • Dipesh Shah
    Compatibility assessment of a model monoclonal antibody formulation in glass and in blow-fi ll-seal (BFS) plastic vial delivery formats
    PPT Version | PDF Version
  • Stephanie Ramos
    Enhanced Delivery of Dna-Based Vaccines and Immunotherapeutics through Next-Generation Electroporation Devices
    PPT Version | PDF Version
  • Suzi Demirbag
    Indications and effectiveness of the open surgery in vesicoureteral refl ux
    PPT Version | PDF Version
  • Mehmet Ozler
    “Mehmet Ozler-Gulhane-Military-Medical-Academy-Ankara-Turkey-Pinealectomy-Initiates-the-Oxidative-Stress-Response-in-Brain-Tissue-of-Rats-Subject-to-Abdominal-Surgery”
    PPT Version | PDF Version
  • Nirmala Chauhan
    Modification of dietary fiber psyllium for use in oral insulin delivery
    PPT Version | PDF Version
  • Youngmi Jung
    TSG-6 induces liver regeneration by enhancing autophagy in mice with chronic liver damage
    PPT Version | PDF Version
  • Yosef Yarden
    Classically, the 3’untranslated region (3’UTR) is that region in eukaryotic protein-coding genes from the translation termination codon to the polyA signal. It is transcribed as an integral part of the mRNA encoded by the gene. However, there exists another kind of RNA, which consists of the 3’UTR alone, without all other elements in mRNA such as 5’UTR and coding region. The importance of independent 3’UTR RNA (referred as I3’UTR) was prompted by results of artificially introducing such RNA species into malignant mammalian cells. Since 1991, we found that the middle part of the 3’UTR of the human nuclear factor for interleukin-6 (NF-IL6) or C/EBP gene exerted tumor suppression effect in vivo. Our subsequent studies showed that transfection of C/EBP 3’UTR led to down-regulation of several genes favorable for malignancy and to up-regulation of some genes favorable for phenotypic reversion. Also, it was shown that the sequences near the termini of the C/EBP 3’UTR were important for its tumor suppression activity. Then, the C/EBP 3’UTR was found to directly inhibit the phosphorylation activity of protein kinase CPKC in SMMC-7721, a hepatocarcinoma cell line. Recently, an AU-rich region in the C/EBP 3’UTR was found also to be responsible for its tumor suppression. Recently we have also found evidence that the independent C/EBP 3’UTR RNA is actually exists in human tissues, such as fetal liver and heart, pregnant uterus, senescent fibroblasts etc. Through 1990’s to 2000’s, world scientists found several 3’UTR RNAs that functioned as artificial independent RNAs in cancer cells and resulted in tumor suppression. Interestingly, majority of genes for these RNAs have promoter-like structures in their 3’UTR regions, although the existence of their transcribed products as independent 3’UTR RNAs is still to be confirmed. Our studies indicate that the independent 3’UTR RNA is a novel non-coding RNA species whose function should be the regulation not of the expression of their original mRNA, but of some essential life activities of the cell as a whole.
    PPT Version | PDF Version
  • Suoqin Tang
    Survivin siRNA nano particles are capable of inhibiting liver cancer cell growth both in vitro and in vivo
    PPT Version | PDF Version
  • Arshad mahmood
    TRANSPORT OF SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM (SNEDDS) ACROSS MUCUS AND CELLULAR INTERNALIZATION
    PPT Version | PDF Version
  • Wei Duan
    Cancer stem cells targeted delivery of siRNA to overcome induced chemoresistance
    PPT Version | PDF Version
  • Yung-Chih Kuo
    “Yung-Chih Kuo-National-Chung-Cheng-University-Republic-of-China-Targeting-delivery-of-etoposide-to-inhibit-the-growth-of-human-glioblastoma-multiforme-using-lactoferrin-and-folic-acid-grafted-poly(lactide-co-glycolide)-nanoparticles”
    PPT Version | PDF Version

Recommended Conferences

  • Rheumatology and Arthritis Surgeons Meeting
    October 2-4, 2017 Las Vegas , USA
  • 3rd International Conference on Spinal Surgery
    October 16-18, 2017, Chicago, USA
  • Global surgeons meeting on Bariatric surgery
    October 30-November 1, 2017,San Antonio,USA
  • International Conference on Bariatric surgery
    March 15-16, 2018, Barcelona, Spain

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords