Potential Regulator (potential + regulator)

Distribution by Scientific Domains


Selected Abstracts


Skeletal muscle glucose uptake during exercise: A focus on reactive oxygen species and nitric oxide signaling

IUBMB LIFE, Issue 5 2009
Troy L. Merry
Abstract Like insulin, muscle contraction (in vitro or in situ) and exercise increase glucose uptake into skeletal muscle. However, the contraction/exercise pathway of glucose uptake in skeletal muscle is an independent pathway to that of insulin. Indeed, skeletal muscle glucose uptake is normal during exercise in those who suffer from insulin resistance and diabetes. Thus, the pathway of contraction-mediated glucose uptake into skeletal muscle provides an attractive potential target for pharmaceutical treatment and prevention of such conditions, especially as skeletal muscle is the major site of impaired glucose disposal in insulin resistance. The mechanisms regulating skeletal muscle glucose uptake during contraction have not been fully elucidated. Potential regulators include Ca2+ (via CaMK's and/or CaMKK), AMPK, ROS, and NO signaling, with some redundancy likely to be evident within the system. In this review, we attempt to briefly synthesize current evidence regarding the potential mechanisms involved in regulating skeletal muscle glucose uptake during contraction, focusing on ROS and NO signaling. While reading this review, it will become clear that this is an evolving field of research and that much more work is required to elucidate the mechanism(s) regulating skeletal muscle glucose uptake during contraction. © 2009 IUBMB IUBMB Life 61(5): 479,484, 2009 [source]


A novel genetic variant of BMP2K contributes to high myopia

JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2009
Hsin-Ping Liu
Abstract Loss of eye growth regulation may cause myopia, because modulation of optic globe size is essential for the generation of normal optic power. Evidence has implied variations of BMP2 gene expression mediate ocular development and retinal tissue remodeling. Given BMP2 as a potential regulator involved in myopia development, we investigate whether gene BMP2-inducible kinase (BMP2K, BIKe), whose expression is up-regulated during BMP2-induced osteoblast differentiation, contributes to susceptibility of high myopia. Participants grouped into high myopia had a spherical equivalent greater than ,6.00 D, compared with a control group of spherical equivalent less than ,0.5 D. Genotyping of polymorphisms 1379 G/A (rs2288255) and 3171 C/G (rs12507099), corresponding with 405 Gly/Ser and 1002 Thr/Ser variation in the BMP2K gene were determined by PCR-restriction fragment length polymorphism and associative study performed by comparing high myopic subjects and healthy controls. The frequency of A allele in the BMP2K gene 1379 G/A polymorphism showed a significant difference between cases and controls (P<0.001, OR=2.99, 95% CI=1.62,5.54) and subjects with either AA or AG genotype show higher risk than GG genotype (P<0.001, OR=3.07, 95% CI=1.59,5.92), while 3171 C/G polymorphism was not significant from this survey. These data suggest that BMP2K gene 1379 G/A variant is strongly correlated with high myopia and may contribute to a genetic risk factor for high degrees of myopic pathogenesis. J. Clin. Lab. Anal. 23:362,367, 2009. © 2009 Wiley-Liss, Inc. [source]


Leukemia Inhibitory Factor: An Important Regulator of Endometrial Function

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2004
Zdzis, awa Kondera-Anasz
Problem:, Leukemia inhibitory factor (LIF) is multifunctional cytokine that displays biological activities in different cells, including endometrial cells. The aim of this study is to describe implications of LIF on a physiological function of endometrium. Method of study:, The role of LIF in the endometrial function is reviewed and summarized from the available literature. Results:, LIF plays an important role in a physiological function of endometrium. In human endometrial LIF expression depends on cellular localizations, steroid hormones, menstrual stages and a local cytokine network. Stronger LIF expression exists in an endometrial epithelium during a luteal phase of the menstrual cycle, which coincides with the time of an implantation. The impairments of the endometrial LIF expression may play a significant role in the pathological processes involving implantation and the infertility. Conclusions:, There is a substantial evidence that LIF is a potential regulator of the endometrial function and might be one of the factors that play a key role in human reproduction. [source]


Profiling microRNA expression in bovine articular cartilage and implications for mechanotransduction

ARTHRITIS & RHEUMATISM, Issue 8 2009
Walter Dunn
Objective Articular cartilage is an avascular tissue with precise polarity and organization comprising 3 distinct functional zones: the surface, middle, and deep zones. Each zone has a different gene expression pattern that plays a specific role in articular cartilage development and maintenance. MicroRNA (miRNA) are small noncoding gene products that play an important regulatory role in determining cell differentiation and function. The purpose of this study was to test our hypothesis that miRNA expression profiles in the different articular cartilage zones as well as between regions subjected to different levels of weight-bearing stresses are unique. Methods Using an miRNA microarray approach in conjunction with quantitative reverse transcription,polymerase chain reaction, we identified miRNA in bovine articular cartilage that were differentially expressed in the different functional zones and in the anterior weight-bearing and posterior non,weight-bearing regions of the medial femoral condyle (M1 and M4, respectively). Results We identified miRNA-221 and miR-222 as part of a subset of differentially expressed miRNA that were up-regulated in articular cartilage in the anterior, M1, greater weight-bearing location. Additionally, miR-126, miR-145, and miR-335 were down-regulated in monolayers of tissue-cultured chondrocytes as compared with levels determined directly from intact native cartilage. Conclusion In conclusion, miR-222 expression patterns in articular cartilage are higher in the weight-bearing anterior medial condyle as compared with the posterior non,weight-bearing medial condyle. Thus, miR-222 might be a potential regulator of an articular cartilage mechanotransduction pathway. These data implicate miRNA in the maintenance of articular cartilage homeostasis and are therefore targets for articular cartilage tissue engineering and regenerative medicine. [source]


Trophic control of grassland production and biomass by pathogens

ECOLOGY LETTERS, Issue 2 2003
Charles E. Mitchell
Abstract Current theories of trophic regulation of ecosystem net primary production and plant biomass incorporate herbivores, but not plant pathogens. Obstacles to the incorporation of pathogens include a lack of data on pathogen effects on primary production, especially outside agricultural and forest ecosystems, and an apparent inability to quantify pathogen biomass. Here, I report the results of an experiment factorially excluding foliar fungal pathogens and insect herbivores from an intact grassland ecosystem. At peak in control plots, 8.9% of community leaf area was infected by pathogens. Disease reduction treatment dramatically increased root production and biomass by increasing leaf longevity and photosynthetic capacity. In contrast, herbivory reduction had no detectable effects at the ecosystem or leaf scale. Additionally, biomass of foliar fungal pathogens in the ecosystem was comparable with that of insect herbivores. These results identify pathogens as potential regulators of ecosystem processes and promote the incorporation of pathogens into trophic theory. [source]


Adiponectin and visfatin concentrations in children treated with valproic acid

EPILEPSIA, Issue 2 2008
Markus Rauchenzauner
Summary Chronic antiepileptic therapy with valproic acid (VPA) is associated with increased body weight and insulin resistance in adults and children. Attempts to determine the underlying pathophysiologic mechanisms have failed. Adipocytokines have recently been defined as a link between glucose and fat metabolism. We herein demonstrate that VPA-associated overweight is accompanied by lower adiponectin and higher leptin concentrations in children. The absence of any relationship with visfatin concentration does not suggest a role of this novel insulin-mimetic hormone in VPA-associated metabolic alterations. Therefore, adiponectin and leptin but not visfatin may be considered as potential regulators of glucose and fat metabolism during VPA-therapy. [source]


The role of neurotrophins in muscle under physiological and pathological conditions

MUSCLE AND NERVE, Issue 4 2006
Guillaume Chevrel MD
Abstract This review summarizes the various effects of neurotrophins in skeletal muscle and how these proteins act as potential regulators of development, maintenance, function, and regeneration of skeletal muscle fibers. Increasing evidence suggests that this family of neurotrophic factors not only modulates survival and function of innervating motoneurons and proprioceptive neurons but also development and differentiation of myoblasts and muscle fibers. Neurotrophins and neurotrophin receptors play a role in the coordination of muscle innervation and functional differentiation of neuromuscular junctions. However, neurotrophin receptors are also expressed in differentiating muscle cells, in particular at early developmental stages in myoblasts before they fuse. In adults with pathological conditions such as human degenerative and inflammatory muscle disorders, variations of neurotrophin expression are found, but the role of neurotrophins under such conditions is still not clear. The goal of this review is to provide a basis for a better understanding and future studies on the role of these factors under such pathological conditions and for treatment of human muscle diseases. Muscle Nerve, 2005 [source]