Ghrelin in gastrointestinal diseases and disorders: A possible role in the pathophysiology and clinical implications (Review)El-Salhy, Magdy
doi: 10.3892/ijmm_00000285pmid: 19885611
Ghrelin is a peptide hormone, which has been isolated from the stomach. It is localized mostly in endocrine cells in the oxyntic mucosa of the stomach. Ghrelin receptors are expressed equally in all parts of the gastrointestinal tract, with a similar level of expression in the mucosal and muscle layers. This peptide hormone has several functions, the most widely known is its growth hormone (GH)-releasing effect. Ghrelin plays an important role in regulating appetite, feeding and energy metabolism. It also plays a role in mediating immune response and inflammatory processes. Ghrelin stimulates gastric motility and emptying as well as motility in the small and large intestine. Ghrelin has been reported to be affected in several gastrointestinal diseases/disorders such as inflammatory bowel disease, coeliac disease, infectious diseases, functional disorders and diabetes gastroenteropathy. This indicates that ghrelin is involved in the pathophysiology of gastrointestinal diseases/disorders. Several studies have shown that ghrelin and its antagonist are a promising tool for treatment of several gastrointestinal diseases/disorders.
Neuronal and BBB damage induced by sera from patients with secondary progressive multiple sclerosisProia, Patrizia ; Schiera, Gabriella ; Salemi, Giuseppe ; Ragonese, Paolo ; Savettieri, Giovanni ; Di Liegro, Italia
doi: 10.3892/ijmm_00000287pmid: 19885613
An important component of the pathogenic process of multiple sclerosis (MS) is the blood-brain barrier (BBB) damage. We recently set an in vitro model of BBB, based on a three-cell-type co-culture system, in which rat neurons and astrocytes synergistically induce brain capillary endothelial cells to form a monolayer with permeability properties resembling those of the physiological BBB. Herein we report that the serum from patients with secondary progressive multiple sclerosis (SPMS) has a damaging effect on isolated neurons. This finding suggests that neuronal damaging in MS could be a primary event and not only secondary to myelin damage, as generally assumed. SPMS serum affects the permeability of the BBB model, as indicated by the decrease of the transendothelial electrical resistance (TEER). Moreover, as shown by both immunofluorescence and Western blot analyses, BBB breaking is accompanied by a decrease of the synthesis as well as the peripheral localization of occludin, a structural protein of the tight junctions that are responsible for BBB properties.
Molecular characterization and quantification using state of the art solid-state adiabatic TOBSY NMR in burn traumaRighi, Valeria ; Andronesi, Ovidiu ; Mintzopoulos, Dionyssios ; Tzika, A. A.
doi: 10.3892/ijmm_00000288pmid: 19885614
We describe a novel solid-state nuclear magnetic resonance (NMR) method that maximizes the advantages of high-resolution magic-angle-spinning (HRMAS), relative conventional liquid-state NMR approaches, when applied to intact biopsies of skeletal muscle specimens collected from burn trauma patients. This novel method, termed optimized adiabatic TOtal through Bond correlation SpectroscopY (TOBSY) solid-state NMR pulse sequence for two-dimensional (2D) 1H-1H homonuclear scalar-coupling longitudinal isotropic mixing, was demonstrated to provide a 40-60% improvement in signal-to-noise ratio (SNR) relative to its liquid-state analogue TOCSY (TOtal Correlation SpectroscopY). Using 1- and 2-dimensional HRMAS NMR experiments, we identified several metabolites in burned tissues. Quantification of metabolites in burned tissues showed increased levels of lipid compounds, intracellular metabolites (e.g., taurine and phosphocreatine) and substantially decreased water-soluble metabolites (e.g., glutathione, carnosine, glucose, glutamine/ glutamate and alanine). These findings demonstrate that HRMAS NMR Spectroscopy using TOBSY is a feasible technique that reveals new insights into the pathophysiology of burn trauma. Moreover, this method has applications that facilitate the development of novel therapeutic strategies.
Human platelet 12-lipoxygenase: Naturally occurring Q261/R261 variants and N544L mutant show altered activity but unaffected substrate binding and membrane association behaviorAleem, Ansari M.; Wells, Leigh M.; Jankun, Jerzy M.; Walther, Matthias M.; Kühn, Hartmut M.; Reinartz, Jeannette M.; Skrzypczak-Jankun, Ewa M.
doi: 10.3892/ijmm_00000289pmid: 19885615
The single nucleotide polymorphism (SNP) R261Q in the human platelet 12-lipoxygenase has been correlated with several human diseases. To understand better the biological performance we have compared enzymatic properties of the recombinant enzymes: ‘wild-type’ as Q261 and R261 variants with a single Q261R mutation at the enzyme periphery and N544L mutant with an altered active site. The R261 variant does not follow the same kinetics such as WT-Q261 showing a lag phase, a slower accumulation of product, following a different time-course without reaching plateau characteristic for the Q261 variant. The N544L substitution in the active site almost eradicates enzymatic activity proving that asparagine is as important for catalysis as the conserved histidines and C-terminal isoleucine. All three enzymes have comparable substrate binding and membrane association behavior. We conclude that the naturally occurring SNP, causing single mutation at a location distant to the active site, can alter the protein-protein association of this oligomeric enzyme making impact on kinetic properties of an allosteric mechanism and molecular recognition/signaling at a submembrane frontier.
Experimental study of the anti-cancer mechanism of tanshinone IIA against human breast cancerLu, Qing ; Zhang, Purong ; Zhang, Xin ; Chen, Jie
doi: 10.3892/ijmm_00000291pmid: 19885617
Tanshinone IIA is a widely used Chinese herbal medicine isolated from Danshen (Salvia miltiorrhiza). Recent studies indicate that tanshinone IIA may have anti-inflammatory and anti-oxidant properties, as well as cytotoxic activities against multiple human cancer cell lines. This study was performed to determine the anti-cancer activity of tanshinone IIA on human breast cancer cells in vitro and in vivo and to elucidate the underlying mechanism of this activity. Human breast cancer cell lines (estrogen receptor-positive and -negative) were treated with tanshinone IIA and tamoxifen. The inhibitory effects of tanshinone IIA and tamoxifen on breast cancer cell proliferation were examined using MTT assays, BrdU incorporation, immunohistochemistry and flow cytometry. Upon treatment with tanshinone IIA, breast cancer cell proliferation was significantly inhibited in a dose- and time-dependent manner (IC50 = 0.25 µg/ml) and apoptotic cell populations increased, while tamoxifen inhibited only ER-positive breast cancer cells prominently and had no effect on ER-negative cells. In addition, tamoxifen had significantly weaker inhibitory effect than tanshinone IIA on ER-positive breast cancer cells in vitro and in vivo. Furthermore, tanshinone IIA decreased the expression of P53 and bcl-2, but not of cerbB-2, in estrogen receptor-positive and negative xenografted nude mice. Our findings suggest that tanshinone IIA might have potential anti-cancer activity that is stronger than tamoxifen in both ER-positive and ER-negative breast cancers. This function could be attributed in part to its inhibition of proliferation and apoptosis induction in cancer cells via the downregulation of multiple genes involved in cell cycle regulation, cell proliferation, apoptosis and DNA synthesis.
Neuropeptide B (NPB) and neuropeptide W (NPW) system in cultured rat calvarial osteoblast-like (ROB) cells: NPW and NPB inhibit proliferative activity of ROB cellsZiolkowska, Agnieszka ; Rucinski, Marcin ; Tyczewska, Marianna ; Malendowicz, Ludwik K.
doi: 10.3892/ijmm_00000292pmid: 19885618
Neuropeptides B (NPB) and W (NPW) have been identified as endogenous ligands of two G-protein-coupled receptors, neuropeptides B/W receptor 1 (NPBWR1, formerly known as GPR7) and neuropeptides B/W receptor 2 (NPBWR2, formerly known as GPR8). In rodents where NPBWR2 is absent, its counterpart is named the similar to neuropeptides B/W receptor 2 (similar to NPBWR2, formerly GPR8-like). Both NPB and NPW play a role in the control of feeding, neuroendocrine axis functions, memory and learning processes as well as in pain regulation. The present study aimed to investigate the expression of NPB, NPW, NPBWR1 and the similar to NPBWR2 genes in cultured rat calvarial osteoblast-like (ROB) cells and the effects of both peptides on proliferative activity and osteocalcin secretion by ROB cells. Classic RT-PCR technique revealed the presence of ppNPB mRNA, ppNPW mRNA, and NPBWR1 mRNA, but not similar to NPBWR2 mRNA in ROB cells. QPCR revealed gradual (days 7, 14 and 21 of culture) increase of the ppNPB gene expression, while expression of ppNPW gene was the highest at day 14 and was comparable to that seen in freshly isolated cells. In ROB cells, expression of NPBWR1 gene was notable at day 7 of culture, lower at day 21, and negligible at day 14. Neither NPB nor NPW changed osteocalcin secretion by cultured osteoblast-like cells while both neuropeptides inhibited their proliferative activity. Results of the present study suggest that the systems of NPW, NPB and NPBWR1 directly regulate proliferative activity of cultured rat calvaria osteoblast-like cells. The physiological significance of this osteoblastic system remains unclear, and requires further investigation.
Dysfunction of Ca2+/CaM kinase IIα cascades in the amygdala in post-traumatic stress disorderXiao, Bing ; Han, Fang ; Shi, Yu-Xiu
doi: 10.3892/ijmm_00000294pmid: 19885620
Single-prolonged stress (SPS) is an established animal model for post-traumatic stress disorder (PTSD). The calcium (Ca2+)-calmodulin (CaM)-CaM kinase (K)IIα signal passage plays an important role in the plasticity of central nervous, learning and memory, mind and behavior and other types of cognitive activities. The amygdala is known to play an important role in fear, rage and emotional memory. In this study, we investigated changes in Ca2+-CaM-CaMKIIα in the basolateral amygdala of rats after SPS which may reveal part of the pathogenesis of PTSD. The intracellular free calcium level in the basolateral amygdala was examined by fluorescence spectrophotometry. CaM and CaMKIIα expression in basolateral amygdala was examined using immunohistochemistry, Western blotting and reverse transcription-polymerase chain reaction. The intracellular free calcium level in the basolateral amygdala was increased when compared to that in the control group 1 day after SPS exposure (P<0.05). CaM expression significantly increased, and CaMKIIα expression significantly decreased (P<0.05) in the basolateral amygdala after SPS. These findings suggest dysfunction of Ca2+-CaM-CaMKIIα in the basolateral amygdala of SPS rats, which may play important roles in the pathogenesis of PTSD rats.