OBJECTIVES: Helicobacter pylori infection induces selective reduction of the number of antral D-cells and results in abnormal regulation of serum gastrin secretion. The purpose of this study was to investigate the relationship between H. pylori infection and the numbers of G-cells and D-cells. METHODS: The numbers of antral G-cells and D-cells, the ratio of G-cells to D-cells and fasting serum gastrin concentrations were compared between 37 patients with (29 with duodenal ulcers and 8 with gastric ulcers) and 33 without H. pylori infection (22 with duodenal ulcers and 11 with gastric ulcers). Serum gastrin concentrations were measured using the radioimmunoassay technique. Antral mucosal biopsy specimens were examined using immunohistochemical staining with antibodies specific for gastrin and somatostatin and the numbers of G-cells and D-cells per gastric gland were counted. RESULTS: Fasting serum gastrin concentrations were significantly higher in patients with H. pylori infection compared to patients without infection (80.3 +/- 23.5 vs 47.6 +/- 14.1 pg/ml, p < 0.001). The number of G-cells per gastric gland was similar in infected and uninfected patients (7.1 +/- 3.1 vs 7.3 +/- 3.9, respectively, p > 0.5). The number of D-cells was significantly lower in patients with H. pylori infection than in uninfected patients in both duodenal and gastric ulcer patients (1.3 +/- 0.4 vs 2.5 +/- 1.6, respectively, p < 0.001). The ratio of G-cells to D-cells was also significantly higher in infected patients compared with uninfected patients for both gastric and duodenal ulcers (5.7 +/- 2.7 vs 3.5 +/- 1.9, respectively, p < 0.001). CONCLUSIONS: These results strongly suggest that Helicobacter pylori infection induces reduction of the number of antral D-cells. The resulting relative hypofunction of the inhibitory action of D-cells against G-cells may be responsible for increased serum gastrin secretion.
Case-Control Studies ; D Cells/pathology ; D Cells/metabolism ; G Cells/pathology ; G Cells/metabolism ; Gastrins/metabolism ; Gastrins/blood ; Gastritis/pathology ; Gastritis/metabolism* ; Helicobacter Infections/pathology ; Helicobacter Infections/metabolism* ; Helicobacter pylori* ; Human ; Somatostatin/metabolism

Calcium is one of the most versatile intracellular second messengers, which plays crucial roles in many intracellular signaling pathways. Researches on intracellular calcium distribution, regulation and function are important for our understanding of cellular physiology. In this mini-review, the regulation of intracellular calcium signal in retinal horizontal cells and the relevant physiological functions were introduced based on the experiments carried out in our laboratory. Intracellular calcium dynamics following the activation of AMPA and NMDA receptors were introduced based on our experiments performed on carp retinal horizontal cells using calcium imaging technique and computational methods. An initial peak response was observed in both cases, which indicated an active participation of intracellular calcium store during the calcium dynamics initiated by AMPA/NMDA receptor activation. Intracellular recording experiments indicated that calcium signaling was crucial for the gradual enhancement of the retinal horizontal cell's responsiveness in exposure to repetitive red flashes. Possible roles of intracellular calcium signaling in the regulation of GABA transporter activity were also introduced based on our whole-cell recording experiments performed on isolated carp retinal horizontal cells.
Animals ; Calcium ; metabolism ; Calcium Signaling ; Carps ; Cells, Cultured ; Patch-Clamp Techniques ; Receptors, AMPA ; metabolism ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Retinal Horizontal Cells ; physiology

AIMAccumulated evidence suggest that the development of vascular calcification is similar to osteogenesis. Here we want to elucidate the effect of the common used osteo-regulatory factor 1,25(OH)2D3 on vascular calcification.

METHODS AND RESULTSAdding 10(-9) mol/L to the culture media 1,25(OH)2D3 time dependently increased the calcium deposition on the in vitro calcification of bovine vascular smooth muscle cells (BVSMCs) induced by beta-GP. It also increased cellular alkaline phosphatase activity by 301.1% during the calcified process. Osteocalcin, one of the osteogenic specific metric proteins, was dramatically elevated by 58.3% during the calcified processes, which indicate the transformation of BVSMCs to osteoblastic cell. 1,25(OH)2D3 had no such effect on non-calcified BVSMCs.

CONCLUSIONThese data suggest that 1,25(OH)2D3 exerts a stimulatory effect on vascular calcification through increasing the synthesis of ALP. This effect shares the same character as osteoblast cells. This effect is limited to the calcified prone vascular cell.

Animals ; Calcitriol ; metabolism ; Cattle ; Cells, Cultured ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; pathology ; Osteocalcin ; metabolism ; Vascular Calcification ; metabolism ; pathology ; Vitamin D ; analogs & derivatives ; pharmacology

OBJECTIVETo investigate the dynamic changes in the expression of clara cell protein (CC16) and surfactant protein D (SP-D) in the lung tissues and bronchoalveolar lavage fluid (BALF) of silica-treated rats.

METHODSEighty-four Wistar rats were randomly divided into control group (n = 42) and silica group (n = 42). The silica group was subsequently divided into 3, 7, 14, 21, 28, and 60 d subgroups. The silicotic model was made by instilling silica suspension directly through the trachea into rat lungs. At 3, 7, 14, 21, 28, and 60 d after silica instillation, 8 rats in each group were sacrificed and their lung tissues and BALF were collected. The expression of SP-D and CC16 in lung tissues was detected by immunohistochemistry. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of SP-D and CCl6 in BALF.

RESULTSThe immunohistochemical assay indicated that CCl6 and SP-D were expressed in lung cells. The ELISA found that in 7, 14, 21, 28, and 60 d silica subgroups, the content of CCl6 in rat BALF was 8.14±0.70, 7.15±0.66, 7.00±0.69, 6.34 ± 0.59, and 5.27±0.49 ng/L, respectively; CCl6 expression decreased gradually with the silica exposure time prolonged, indicating a negative correlation (ra = -0.953, P < 0.01). Compared with the control group, all silica subgroups had significantly decreased CCl6 levels (P < 0.05). The content of SP-D in BALF was 12.20 ± 1.57, 14.41 ± 0.65, and 12.18 ± 0.74 ng/L, respectively, in the 7, 14, and 21 d silica subgroups, significantly higher than that in the control group (P < 0.05).

CONCLUSIONThe dynamic changes in SP-D and CCl6 protein levels in the lung tissues and BALF of rats could be induced by silica exposure and are related to silica exposure time. With the extension of silica exposure, CCl6 levels are gradually reduced, while the SP-D levels first increase and then fall.

Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; Epithelial Cells ; metabolism ; Lung ; metabolism ; Pulmonary Surfactant-Associated Protein D ; metabolism ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Uteroglobin ; metabolism

The α2δ-1 protein coded by Cacna2d1 is dramatically up-regulated in dorsal root ganglion (DRG) neurons and spinal dorsal horn following sensory nerve injury in various animal models of neuropathic pain. Cacna2d1 overexpression potentiates presynaptic and postsynaptic NMDAR activity of spinal dorsal horn neurons to cause pain hypersensitivity. The α2δ-1-NMDAR interaction promotes surface trafficking and synaptic targeting of NMDARs in neuropathic pain caused by chemotherapeutic agents and peripheral nerve injury, as well as in other pathological conditions such as in the paraventricular nucleus (PVN) with neurogenic hypertension and in the brain with ischemic stroke. The lentiviral transfection method was used to construct a human embryonic kidney HEK293T cell line that could stably express α2δ-1-NMDAR complex. A stably transfected cell line was observed by florescence microscope, and identified by RT-qPCR and Western blotting. The results showed that the HEK293T cell line was successfully transfected and the genes could be stably expressed. Subsequently, the transfected cell line was successfully developed into a target drug screening system using patch clamp techniques. It provides a promising cell model for further research on the interaction mechanism of α2δ-1-NMDAR complex and drug screening for chronic pain and related diseases with low side effects.
Analgesics/therapeutic use* ; Animals ; Drug Discovery ; HEK293 Cells ; Humans ; Neuralgia/metabolism* ; Receptors, N-Methyl-D-Aspartate/genetics*

OBJECTIVETo observe the effect of electroacupuncture (EA) on phosphorylation of spinal NR2B at Tyr 1742 site in complete Freund's adjuvant (CFA) induced inflammatory pain rats. METHods Forty male Sprague Dawley rats were randomly divided into normal group (N group, n = 10), the model group (CFA group, n = 15), and the EA group (n = 15). The inflammatory pain model was established by subcutaneous injecting CFA (0.1 mL per rat) into the right hind paw. Paw withdrawal thresholds (PWTs) were measured before CFA injection (as the base), as well as at 24 h, 25 h, 3rd day, and 7th day after CFA injection. Phosphorylation of NR2B at Tyr 1742 site in the ispilateral spinal dorsal horn at the 3rd day post-injection were detected using immunohistochemical assay.

RESULTSPWTs in the CFA group were significantly lower than those of the N group at every detective time point post-injection (P < 0.01). PWTs were obviously lower in the EA group than in the N group at 24 h post-injection (P < 0.01). It showed increasing tendency, markedly higher than those of the CFA group at 25 h and 3rd day post-injection (P < 0.01). Compared with the N group, the ratio of p-NR2B positive cells in the ispilateral spinal dorsal horn of rats in the CFA group was up-regulated. Compared with the CFA group, the ratio of p-NR2B positive cells in the ispilateral spinal dorsal horn of rats showed a decreasing tendency in the EA group.

CONCLUSIONEA might effectively inhibit CFA-induced inflammatory pain possibly associated with down-regulating phosphorylation of NR2B at Tyr 1742 site in the ispilateral spinal dorsal horn.

Adjuvants, Pharmaceutic ; pharmacology ; Animals ; Electroacupuncture ; methods ; Male ; Pain ; chemically induced ; metabolism ; Phosphorylation ; Posterior Horn Cells ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; metabolism

OBJECTIVETo study the involvement of excitatory amino acid system in astrocytes activation caused by dimethoate.

METHODSPure-cultured astrocytes were gained by three passages from primary cultured rat nerve cells, then treated with 10(-6),10(-5),10(-4) mol/L dimethoate for 48 h, 50 micromol/L and 100 micromol/L MK801, a NMDA receptor blocker, was used to intervene the effects induced by 10(-4) mol/L dimethoate. HPLC-FLD was utilized to measure the concentrations of excitatory amino acid (EAA), RT-PCR was used to detect the expression levels of NR2B, GLT-1, GLAST, GFAP and S100beta mRNA, and immunofluorescence staining method was applied to measure the expression levels of GFAP and S100beta proteins.

RESULTSThe expression levels of GLAST mRNA in all exposure groups were 67.8%, 68.6% and 76.2% of control level, respectively, which were significantly lower than that of control group (P < 0.05); The concentrations of EAA significantly decreased in 10(-4) mol/L dimethoate group, as compared with control group (P < 0.01); the expression levels of GFAP mRNA in 10(-4) mol/L dimethoate group, of S100beta mRNA in 10(-5) mol/L dimethoate group, of GFAP protein in 10(-4) mol/L and 10(-5) mol/L dimethoate groups and S100beta protein in 10(-4) mol/L dimethoate group were significantly higher than those in control group (P < 0.01). The expression levels of GLT-1 and GLAST mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01), the expression levels of NR2B mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with control group (P < 0.05 or P < 0.01); the concentration of Glu in 10(-4) mol/L dimethoate plus 100 micromol/L MK801 group increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01); the expression levels of GFAP mRNA and protein in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups decreased significantly (P < 0.01); S100beta protein expression level in 50 micromol/L MK801 intervention group was significantly higher than thatl in control group (P < 0.01).

CONCLUSIONExcitatory amino acid system involved in astrocytes activation caused by dimethoate. MK801 was useful to control astrocytes gliosis.

Animals ; Astrocytes ; drug effects ; metabolism ; Cells, Cultured ; Dimethoate ; toxicity ; Dizocilpine Maleate ; pharmacology ; Excitatory Amino Acids ; metabolism ; Rats ; Receptors, N-Methyl-D-Aspartate ; antagonists & inhibitors

OBJECTIVE: To investigate the effects of N-methyl-D-aspartate receptor (NMDAR) in the spinal dorsal horn in visceral hypersensitivity in rats with colonic inflammation. METHODS: Seventy adult male Sprague-Dawley (SD) rats were randomly divided into the experimental group and the control group. Colonic inflammation was induced in the experimental rats by intraluminal administration of trinitrobenzenesulfonic acid (TNBS). Saline was administered intraluminally in the control rats. After 3, 7, 14, and 28 days of administration, abdominal contractions induced by inflation of a balloon colonically inserted were recorded in rats by implanting electrodes in the abdominal striated muscles. Immunohistochemistry method was used to study the expression of NMDAR1 and NMDAR2A/B in lumbarsacral spinal cord after inflammation. RESULTS: Colonic distension evoked a significant increase of abdominal contractions after 3, 7 and 14 days of TNBS administration. After 28 days of TNBS administration, abdominal contractions were still significantly increased in 2 TNBS-treated rats compared with the control rats. After 7 and 14 days of TNBS administration, NMDAR1 and NMDAR2A/B-immunoreactive cells were significantly increased compared with the control group (P <0.05). Twenty-eight days after TNBS administration, the number of NMDAR1-IR and NMDAR2A/B-IR neurons was still significantly increased in 4 TNBS-treated rats compared with the saline-treated rats (P < 0.05). CONCLUSION NMDAR was involved in the transmission of visceral nociceptive stimuli. After the remission of colonic inflammation, increased expression of NMDAR1 and NMDAR2A/B in the spinal dorsal horn may induce persistent neuronal hyperactivity, which results in visceral hypersensitivity.
Animals ; Colitis ; chemically induced ; metabolism ; Male ; Posterior Horn Cells ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; biosynthesis ; genetics ; Trinitrobenzenesulfonic Acid

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a key transcriptional mediator that coordinates the expression of various genes involved in tumorigenesis in response to changes in oxygen tension. The stability of HIF-1alpha protein is determined by oxygen-dependent prolyl hydroxylation, which is required for binding of the von Hippel-Lindau protein (VHL), the recognition component of an E3 ubiquitin ligase that targets HIF-1alpha for ubiquitination and degradation. Here, we demonstrate that PLD2 protein itself interacts with HIF-1alpha, prolyl hydroxylase (PHD) and VHL to promote degradation of HIF-1alpha via the proteasomal pathway independent of lipase activity. PLD2 increases PHD2-mediated hydroxylation of HIF-1alpha by increasing the interaction of HIF-1alpha with PHD2. Moreover, PLD2 promotes VHL-dependent HIF-1alpha degradation by accelerating the association between VHL and HIF-1alpha. The interaction of the pleckstrin homology domain of PLD2 with HIF-1alpha also promoted degradation of HIF-1alpha and decreased expression of its target genes. These results indicate that PLD2 negatively regulates the stability of HIF-1alpha through the dynamic assembly of HIF-1alpha, PHD2 and VHL.
Cell Line ; HEK293 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/*metabolism ; Phospholipase D/*metabolism ; Prolyl Hydroxylases/metabolism ; Proteasome Endopeptidase Complex/*metabolism ; *Protein Interaction Maps ; Proteolysis ; Ubiquitin-Protein Ligases/metabolism ; Von Hippel-Lindau Tumor Suppressor Protein/metabolism

AIM AND METHODSWhole-cell recording technique was used to observe the changes of voltage-dependent ion channels and NMDA receptor currents of rat hippocampal neurons during primary culture.

RESULTSThere was no significant difference of voltage-dependent Na+ current (I(Na)) at 7 d, 14 d and 21 d in culture. It's the same for delayed rectifier K+ current (Ik). However, voltage-dependent Ca2+ current (I(Ca)) and its density were continuously and markedly increased. Further studies showed that the increase of I(Ca) was resulted from the increase of L-type voltage-dependent Ca2+ channels (L-VDCC). NMDA receptor current was also significantly increased with time of culture.

CONCLUSIONCa2+ influx through VDCC and NMIDA receptor is the fatal factor in the aging and death of hippocampal neurons.

Animals ; Animals, Newborn ; Calcium ; metabolism ; Calcium Channels, L-Type ; metabolism ; Cell Membrane ; metabolism ; Cells, Cultured ; Cellular Senescence ; Hippocampus ; cytology ; Ion Channels ; metabolism ; Neurons ; metabolism ; Patch-Clamp Techniques ; Rats ; Rats, Wistar ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Time Factors