健康体检人群幽门螺杆菌感染的影响因素分析及对糖脂代谢和血清PGⅠ、PGⅡ和G-17的影响

摘要 目的：分析健康体检人群幽门螺杆菌（Hp）感染的影响因素,并探讨Hp感染对糖脂代谢和血清胃蛋白酶原Ⅰ（PGⅠ）、胃蛋白酶原Ⅱ（PGⅡ）和胃泌素17（G-17）的影响。方法：选择2017年1月~2019年12月期间在我院进行Hp检查的117例健康体检者进行问卷调查,分析其Hp感染情况,并应用多因素Logistic回归分析健康体检人群Hp感染的影响因素。将体检者分为Hp阳性组和Hp阴性组,对比两组血糖、血脂指标以及血清PGⅠ、PGⅡ、G-17水平。结果：117例受试体检者中Hp阳性49例,阳性率为41.88%,其中男性感染率为50.85%（30/59）,显著高于女性感染率的32.76%（19/58）（x²=10.537,P=0.001）。不同年龄体检者Hp阳性率比较差异无统计学意义（P>0.05）。不同学历体检者Hp阳性率比较差异无统计学意义（P>0.05）。多因素Logistic回归分析结果显示,饮酒、经常喝生水、经常在外就餐、经常吃辛辣食物、有家人Hp感染史是健康体检人群Hp感染的危险因素（P＜0.05）。Hp阳性组的空腹血糖（FPG）、甘油三脂（TG）、总胆固醇（TC）、低密度脂蛋白（LDL-C）水平均高于Hp阴性组,而高密度脂蛋白（HDL-C）水平则低于Hp阴性组（P＜0.05）。Hp阳性组的血清PGⅠ、PGⅡ、G-17水平均高于Hp阴性组（P＜0.05）。结论：饮酒、经常喝生水、经常在外就餐、经常吃辛辣食物、有家人Hp感染史是健康体检人群Hp感染的危险因素,糖脂代谢及血清PGⅠ、PGⅡ、G-17水平变化与Hp感染有关。     

Conformational analysis in solution of gastrin releasing peptide

Gastrin releasing peptide (GRP) is the first peptide isolated from porcine gastric and intestinal tissues and is homologous to the carboxyl terminus of bombesin (Bn) isolated from the skin of the frog Bombina bombina. It is a member of the Bn-like peptides, which are important in numerous biological and pathological processes. The Bn-like peptides show high sequence homology in their C-terminal regions, but they have different selectivity for their receptors. In particular, GRP selectively binds to the GRP receptor (GRPR). However, the molecular basis for this selectivity remains largely unknown. Here, we report the three-dimensional structure of GRP. Hopefully, it could be helpful in a better understanding of the binding selectivity between GRP and GRPR.     

CCK1 and CCK2 Receptors Are Expressed on Pancreatic Stellate Cells and Induce Collagen Production

The gastrointestinal hormone cholecystokinin (CCK) can induce acute pancreatitis in rodents through its action on acinar cells. Treatment with CCK, in combination with other agents, represents the most commonly used model to induce experimental chronic pancreatitis. Pancreatic stellate cells (PSC) are responsible for pancreatic fibrosis and therefore play a predominant role in the genesis of chronic pancreatitis. However, it is not known whether PSC express CCK receptors. Using real time PCR techniques, we demonstrate that CCK1 and CCK2 receptors are expressed on rat PSC. Interestingly both CCK and gastrin significantly induced type I collagen synthesis. Moreover, both inhibit proliferation. These effects are comparable with TGF-β-stimulated PSC. Furthermore, the natural agonists CCK and gastrin induce activation of pro-fibrogenic pathways Akt, ERK, and Src. Using specific CCK1 and CCK2 receptor (CCK2R) inhibitors, we found that Akt activation is mainly mediated by CCK2R. Akt activation by CCK and gastrin could be inhibited by the PI3K inhibitor wortmannin. Activation of ERK and the downstream target Elk-1 could be inhibited by the MEK inhibitor U0126. These data suggest that CCK and gastrin have direct activating effects on PSC, are able to induce collagen synthesis in these cells, and therefore appear to be important regulators of pancreatic fibrogenesis. Furthermore, similar to TGF-β, both CCK and gastrin inhibit proliferation in PSC.     

AIMS65评分联合血清GAS、PGE2、BAR对急性非静脉曲张性上消化道出血患者预后的评估价值

摘要 目的：探讨AIMS65评分联合血清胃泌素（GAS）、前列腺素E₂（PGE₂）、血尿素氮/白蛋白比值（BAR）对急性非静脉曲张性上消化道出血（ANVUGIB）患者内镜下止血治疗后预后的评估价值。方法：选取2020年5月～2022年5月北京市和平里医院消化内科收治的108例的ANVUGIB患者,根据患者住院28 d内的预后分为预后不良组和预后良好组。收集患者临床资料,检测血清GAS、PGE₂水平和计算AIMS65评分、BAR。采用单因素和多因素Logistic回归分析ANVUGIB患者内镜下止血治疗后预后不良的影响因素,受试者工作特征（ROC）曲线分析AIMS65评分、GAS、PGE₂和BAR对ANVUGIB患者内镜下止血治疗后预后不良的评估价值。结果：108例ANVUGIB患者预后不良发生率为37.96％（41/108）。单因素分析显示,预后不良组年龄大于预后良好组,心率、休克指数、AIMS65评分、GAS、BAR高于预后良好组,PGE₂水平低于预后良好组（P均＜0.05）。多因素Logistic回归分析显示,年龄增加和休克指数、AIMS65评分、GAS、BAR升高为ANVUGIB患者内镜下止血治疗后预后不良的独立危险因素,PGE₂升高为其独立保护因素（P均＜0.05）。ROC曲线分析显示,AIMS65评分联合GAS、PGE₂和BAR评估ANVUGIB患者内镜下止血治疗后预后不良的曲线下面积大于AIMS65评分、GAS、PGE₂和BAR单独评估。结论：预后不良的ANVUGIB患者AIMS65评分、GAS、BAR均高于预后良好的患者,AIMS65评分联合GAS、PGE₂和BAR评估ANVUGIB患者内镜下止血治疗后预后的价值较高。     

Localisation of somatostatin- and gastrin-like immunoreactivity in the gastrointestinal tract of Ciona intestinalis L.

Summary Somatostatin- and gastrin-like immunoreactivity has been found by immunofluorescence in cells of the stomach and intestinal epithelia of Ciona intestinalis L. The cells containing the peptide immunoreactive to mammalian anti-gastrin can be restained with the Grimelius' technique for argyrophilia.     

Comparison of enkephalin and atropine in the inhibition of vagally stimulated gastric and pancreatic secretion and gastrin and pancreatic polypeptide release in dogs

Enkephalins have been detected in vagal nerves and myenteric plexus neurons but no study has been performed to determine their action on vagally stimulated gastric and pancreatic secretion. In this study we infused IV methionine-enkephalin (Met-enk) alone, naloxone (a pure opiate antagonist) alone, or their combination before, during and after vagal stimulation in 4 dogs with esophageal, gastric and pancreatic fistulas. For the comparison, atropine was given before, during and after vagal stimulation in the same animals. Vagal stimulation was obtained by 15 min sham-feeding, which produced an increase in gastric H⁺ output to a peak of about 75% of the maximal response to pentagastrin and pancreatic protein secretion amounting to about 71% of the maximal response to caerulein. It was accompanied by a significant rise in serum gastrin and pancreatic polypeptide (PP) levels. Met-enk inhibited significantly both gastric H⁺ and pancreatic protein secretion and reduced plasma PP but not gastrin levels. Similar effects were obtained after the administration of atropine. The effects of Met-enk were partly reversed by the addition of naloxone. We conclude that (1) enkephalin suppresses vagally stimulated gastric and pancreatic secretion and plasma PP release; (2) these secretory effects of enkephalin seem to be mediated by opiate receptors and could be explained by its inhibitory action on acetylcholine release (“anticholinergic” action) in the stomach and the pancreas.     

Cultured gastrointestinal smooth muscle cells: cell response to contractile agonists depends on their phenotypic state

In the digestive tract, the transit of ingested food induces a local contraction-relaxation reflex of which the smooth muscle cell (SMC) represents the functional unit. Although freshly isolated SMCs have been extensively used for in vitro studies, in specific cases cultured cells appear necessary. Because conventionally cultured SMCs lose their contractile properties, we have developed: (1) differentiated, contractile rabbit gastric SMCs (D-stim cells), cultured in a medium supplemented with insulin, and (2) proliferative, dedifferentiated rabbit gastric SMCs (P-stim cells), cultured in a medium supplemented with insulin, fetal serum, EGF and b-FGF. The proliferative index was 5±4% and 82±10%, respectively, for D-stim and P-stim cells. Expression of SM-myosin heavy chain was observed in 90% of D-stim cells, whereas it was progressively lost in P-stim cells. Carbachol (1–100 nM), glicentin (2 nM) and gastrin-17 (100 nM) induced contraction of D-stim cells cultured for 3 or 6 days, whereas they did not induce the contraction of P-stim cells; in contrast, gastrin-17 (10 nM) was able to stimulate DNA synthesis (1.86±0.09-fold increase) in P-stim cells. The coupling of muscarinic receptors to intracellular transduction pathways was evaluated in D-stim cells: at day 3, carbachol (100 nM) induced a twofold increase in the production of inositol tri-tetra-phosphates; in parallel, a phosphorylation of ERK MAP kinases occurred within 1 min of carbachol stimulation. In conclusion, cultured functional myocytes derived from mature tissue may be used for long-term studies concerning the events coupled either to proliferation or to motility regulation of differentiated SMCs due to the activation of G-protein-coupled receptors.This study was supported in part by grants from the AFM (Association Française contre les Myopathies).     

Isolation,identification, and synthesis of a disulfated sulfakinin from the central nervous system of an arthropods the white shrimp Litopenaeus vannamei

Two myotropic peptides displaying tyrosyl sulfation have been isolated from an extract of central nervous systems (brain, suboesophageal ganglion, thoracic ganglia, and ventral nerve cord) of the white shrimp Litopenaeus vannamei. Both peptides were identified by mass spectrometry and belong to the sulfakinin family of neuropeptides, which are characterized by the C-terminal hexapeptide Y(SO(3)H)GHMRF-NH(2) preceded by two acidic amino acid residues. Pev-SK 1 (AGGSGGVGGEY(SO(3)H)DDY(SO(3)H)GH(L/I) RF-NH(2)) has two sulfated tyrosyl residues and a unique (L/I) for M substitution in the C-terminal sequence. Pev-SK 2 (pQFDEY(SO(3)H)GHMRF-NH(2)) fully complies with the typical sulfakinin core sequence and is blocked by a pyroglutamyl residue. Synthetic analogs (sulfated and unsulfated) were synthesized and the tyrosyl sulfations were confirmed by myotropic activity studies and co-elution with the native fractions. Pev-SK 1 is the first disulfated neuropeptide elucidated in the phylum of the arthropoda, with the only other reported disulfated neuropeptide, called cionin, found in a protochordate. The similarities in amino acid sequence and posttranslational modifications of the crustacean sulfakinins and protochordate cionin provide further evidence for the hypothesis stating that gastrin/CCK, cionin, and sulfakinins originate from a common ancestral gastrin/CCK-like peptide.     

Bombesin/oligoarginine fusion peptides for gastrin releasing peptide receptor (GRPR) targeted gene delivery

The development of non-viral gene delivery systems, with the capacity to overcome most of the biological barriers facing gene delivery, is challenging. We have developed peptide-based, multicomponent, non-viral delivery systems, incorporating: a bombesin peptide ligand (BBN(6–14)), to selectively target the gastrin releasing peptide receptor (GRPR); oligoarginine peptides (hexa- (R₆) and nona-arginine (R₉)), for plasmid DNA (pDNA) condensation; and GALA, to facilitate endosome escape. The uptake and endosome escape efficiency of bombesin/oligoarginine and bombesin/oligoarginine/GALA fusion peptides for oligonucleotide delivery was evaluated in terms of their complex size, cellular uptake, endosome escape, and cellular toxicity. Complex size and cell uptake studies demonstrated that the nona-arginine/bombesin delivery system was more efficient at condensing and delivering pDNA into PC-3 prostate cancer cells compared to the hexa-arginine/bombesin delivery system. Further, competition with free bombesin peptide, and comparative uptake studies in Caco-2 cells, which express GRPR at a lower level, suggested that GRPR contributes to the targeted uptake of this system. The addition of GALA into the nona-arginine/bombesin-based system further increased the pDNA cellular uptake at all tested N/P ratios; facilitated endosomal pDNA release; and had limited effects on cell viability. In conclusion, the delivery system combining BBN(6–14) with nona-arginine and GALA had optimal characteristics for the delivery of pDNA into the GRPR overexpressing cell line PC-3.     

Secretagogue activities in cod (Gadus morhua) and shrimp (Penaeus aztecus) extracts and alcalase hydrolysates determined in AR4-2J pancreatic tumour cells

Peptides with gastrin immunoreactivity were measured in cod muscle (Gadus morhua) and shrimp heads (Penaeus aztecus) extracts and alcalase hydrolysates and separated by two chromatographic steps. Secretagogue activities present in crude extracts fractions were examined with or without specific antagonists of CCK receptors in AR4-2J cells. Several sub-fractions significantly stimulate amylase release, up to 110%. These stimulatory effects could be completely inhibited by the presence of L 365, 260 specific antagonist of CCKB receptors. After hydrolysis of the raw material, the samples were partially fractionated by two chromatographic steps and potential active fractions detected by a gastrin-CCK radioimmunoassay. The molecular masses of the active fractions were lower than for the extracts. Stimulation of amylase release was higher than with extracts, and the inhibition by L 365, 260, less pronounced. These results show that some peptides remaining after hydrolysis or extraction still exert biological activities and have to be tested in nutritional studies.