Synergistic metabolic benefits of an exenatide analogue and cholecystokinin in diet-induced obese and leptin-deficient rodents.

AIM: To test the impact of cholecystokinin (CCK) plus either amylin or a glucagon-like peptide-1 receptor (GLP-1R) agonist on metabolic variables in diet-induced obese (DIO) rodents. METHODS: A stabilized acetylated version of CCK-8 (Ac-Y*-CCK-8), selective CCK1 receptor (CCK1R) or CCK2 receptor (CCK2R) agonists, amylin or the GLP-1R agonist and exenatide analogue AC3174 were administered in select combinations via continuous subcutaneous infusion to DIO rats for 14 days, or Lep(ob) /Lep(ob) mice for 28 days, and metabolic variables were assessed. RESULTS: Combined administration of Ac-Y*-CCK-8 with either amylin or AC3174 induced greater than additive weight loss in DIO rats, with the overall magnitude of effect being greater with AC3174 + Ac-Y*-CCK-8 treatment. Co-infusion of AC3174 with a specific CCK1R agonist, but not a CCK2R agonist, recapitulated the weight loss mediated by AC3174 + Ac-Y*-CCK-8 in DIO rats, suggesting that synergy is mediated by CCK1R activation. In a 4 × 4 full-factorial response surface methodology study in DIO rats, a synergistic interaction between AC3174 and the CCK1R-selective agonist on body weight and food intake was noted. Co-administration of AC3174 and the CCK1R-selective agonist to obese diabetic Lep(ob) /Lep(ob) mice elicited a significantly greater reduction in percentage of glycated haemoglobin and food intake relative to the sum effects of monotherapy groups. CONCLUSIONS: The anti-obesity and antidiabetic potential of combined GLP-1R and CCK1R agonism is an approach that warrants further investigation.

Clinical and microbiological characteristics of Klebsiella pneumoniae from community-acquired recurrent urinary tract infections.

Understanding the pathogenesis of recurrent urinary tract infection (RUTI) and whether it is attributable to reinfection with a new strain or relapse with the primary infecting strain is of considerable importance. Because previous studies regarding community-acquired Klebsiella pneumoniae RUTI are inconclusive, we undertook this study to evaluate the characteristics of the host and the bacterial agent K. pneumoniae in RUTI. A prospective study was designed, using consecutive patients diagnosed with community-acquired K. pneumoniae-related UTI from January 2007 to December 2009. Of the total 468 consecutive episodes, we found 7 patients with RUTI. All the patients with RUTI were elderly (median, 74 years), with diabetes (100 %, 7 out of 7). Clinical K. pneumoniae isolates derived from the same patients with RUTI revealed identical genomic fingerprints, indicating that K. pneumoniae UTI relapsed despite appropriate antibiotic therapy. The antimicrobial resistance, growth curve and biofilm formation of the recurrent isolates did not change. K. pneumoniae strains causing RUTI had more adhesion and invasiveness than the colonization strains (p < 0.01). When we compared the recurrent strains with the community-acquired UTI strains, the prevalence of diabetes mellitus was significant (100 % vs 53.7 %, p = 0.03) in the RUTI group. Our data suggest that K. pneumoniae strains might be able to persist within the urinary tract despite appropriate antibiotic treatment, and the greater adhesion and invasiveness in the recurrent strains may play an important role in recurrent infections.

HAI-2 suppresses the invasive growth and metastasis of prostate cancer through regulation of matriptase.

Dysregulation of cell surface proteolysis has been strongly implicated in tumorigenicity and metastasis. In this study, we delineated the role of hepatocyte growth factor activator inhibitor-2 (HAI-2) in prostate cancer (PCa) cell migration, invasion, tumorigenicity and metastasis using a human PCa progression model (103E, N1, and N2 cells) and xenograft models. N1 and N2 cells were established through serial intraprostatic propagation of 103E human PCa cells and isolation of the metastatic cells from nearby lymph nodes. The invasion capability of these cells was revealed to gradually increase throughout the serial isolations (103E

Role of K1 capsule antigen in cirrhotic patients with Escherichia coli spontaneous bacterial peritonitis in southern Taiwan.

Spontaneous bacterial peritonitis (SBP) is one of the most serious complications in patients with cirrhosis. This study aimed to investigate the prevalence of SBP caused by Escherichia coli isolates with or without the K1 capsule antigen in cirrhotic patients and the outcome. From January 2004 to January 2012, a total of 54 and 41 E. coli strains derived from patients with SBP and intestinal perforation (IP), respectively, were included for comparison in this study. Bacterial characteristics including phylogenetic groups, K1 capsule antigen, and 14 virulence factor genetic determinants, as well as data regarding patient characteristics, clinical manifestations, and in-hospital deaths, were collected and analyzed. The prevalence of the K1 capsule antigen gene neuA was more common in SBP isolates compared to IP isolates (28 % vs. 10 %, p = 0.0385). Phylogenetic groups B2 and group D were dominant in E. coli isolates with and without the K1 capsule antigen, respectively. The prevalence of virulence factors genes papG II, ompT, and usp was higher in E. coli K1 strains. There were 26 deaths (48 %) during hospitalization. Presence of the K1 capsule antigen in E. coli isolates was significantly associated with in-hospital death in cirrhotic patients with SBP (42 % vs. 14 %, p = 0.0331). This study demonstrates a higher prevalence of the K1 capsule antigen in E. coli SBP compared to E. coli peritonitis caused by IP. There were significant associations between the K1 capsule antigen and in-hospital mortality and bacterial virulence in cirrhotic patients with E. coli SBP.

Pharmacokinetics/genotype associations for major cytochrome P450 enzymes in native and first- and third-generation Japanese populations: comparison with Korean, Chinese, and Caucasian populations.

Application of foreign clinical data across geographic regions can accelerate drug development. Drug disposition can be variable, and identification of factors influencing responsible pharmacokinetic/pharmacogenomic approaches could facilitate the universal application of foreign data and reduce the total amount of phase III clinical trials evaluating risks in different populations. Our objective was to establish and compare genotype (major cytochrome P450 (CYP) enzymes)/phenotype associations for Japanese (native and first- and third-generation Japanese living abroad), Caucasian, Chinese, and Korean populations using a standard drug panel. The mean metabolic ratios (MRs) for the four ethnic groups were similar except for a lower activity of CYP2D6 in Caucasians and CYP2C19 in Asians. Genotype, not ethnicity, impacted the MR for CYP2C9, CYP2C19, and CYP2D6; neither affected CYP1A2, CYP2E1, and CYP3A4/5 activities. We conclude that equivalent plasma drug concentrations and metabolic profiles can be expected for native Japanese, first- and third-generation Japanese, Koreans, and Chinese for compounds handled through these six CYP enzymes.

Pituitary adenylate cyclase-activating polypeptide acts synergistically with relaxin in modulating ovarian cell function in rats.

The interactive effects of pituitary adenylate cyclase-activating polypeptide (PACAP) and relaxin on the secretion of gelatinases, involved in matrix remodeling, in ovarian theca-interstitial cells and granulosa cells, were investigated in gonadotropin-primed immature rats. The gelatinases secreted from cultured cells were analyzed using gelatin zymography and scanning densitometry. We have previously shown that relaxin stimulated the secretion of a 71 kDa gelatinase, identified as a type IV collagenase (matrix metalloproteinase 2), in rat theca-interstitial cells. This study has demonstrated that PACAP27 and PACAP38, with similar potency, dose-dependently enhanced relaxin-induced secretion of 71 kDa gelatinase, whereas PACAP alone had no effect. In rat granulosa cells, both PACAP27 and PACAP38 alone dose-dependently increased the secretion of a 63 kDa gelatinase. In addition, this study has shown that cAMP signaling pathway mediators act similarly to that of PACAP on gelatinase secretion in rat ovarian cells. Cholera toxin, forskolin and 8-bromoadenosine cAMP augmented relaxin-induced secretion of 71 kDa gelatinase in theca-interstitial cells, and alone they had no effect. These mediators also increased the secretion of 63 kDa gelatinase in granulosa cells. It is well known that the increase in cellular cAMP level is associated with the morphological rounding-up phenomenon in granulosa cells. This study has shown that PACAP and cAMP pathway mediators, but not relaxin, could cause such changes in cell shape in granulosa cells as well as in theca-interstitial cells. In conclusion, this study provides original findings that PACAP acts synergistically with relaxin in stimulating the secretion of gelatinases in rat ovarian theca-interstitial cells and granulosa cells. This supports the idea that relaxin and PACAP may serve as ovarian physiological mediators of gonadotropin function in facilitating the ovulatory process. In addition, PACAP appears to act through the cAMP signaling pathway to affect biological functions in ovarian cells, whereas relaxin does not.

Cell cycle modulation by a multitargeted antifolate, LY231514, increases the cytotoxicity and antitumor activity of gemcitabine in HT29 colon carcinoma.

The proliferation rate of HT29 colon carcinoma cells was decreased by the multitargeted antifolate (MTA), LY231514. This effect correlated with a buildup of cells near the G1-S interface after 24 h of incubation, and a synchronized progression of the population through S phase during the next 24 h. MTA treatment (0.03-3 microM) was minimally cytotoxic (20-30%) to HT29 cells after a 24-h exposure, and no dose response was observed. In contrast, the nucleoside analogue gemcitabine (GEM) was cytotoxic (IC50, 0.071 +/- 0.011 microM; IC90, 0.648 +/- 0.229 microM) after a 24-h exposure. We hypothesized that pretreatment of these cells with MTA would increase the potency of GEM by synchronizing the population for DNA synthesis. The cytotoxicity of GEM increased 2-7-fold when MTA was administered 24 h before GEM (IC50, 0.032 +/- 0.009 microM; IC90, 0.094 +/- 0.019 microM). In addition, an increase in cell kill for the combination compared with GEM alone (IC99, 12 microM for GEM alone; IC99, 0.331 microM for combination) was observed. No increase in potency or cell kill was observed when the two compounds were added simultaneously. MTA pretreatment also potentiated the cytotoxicity of a 1-h exposure to GEM. These cell-based observations were extended to evaluate the schedule-dependent interaction of these two agents in vivo using a nude mouse HT29 xenograft tumor model. At the doses tested, MTA alone (100 mg/kg) had a marginal effect on tumor growth delay, whereas GEM (80 mg/kg) produced a statistically significant tumor growth delay. In combination, the increase in tumor growth delay was greatest when MTA was administered before GEM, compared with simultaneous drug administration or the reverse sequence, e.g., GEM followed by MTA. The effect of sequential administration of MTA followed by GEM was greater than additive, indicating synergistic interaction of these agents. Thus, in vitro, MTA induced cell cycle effects on HT29 cells that resulted in potentiation of the cytotoxicity of GEM. In vivo, combination of these two drugs also demonstrated a schedule-dependent synergy that was optimal when MTA treatment preceded GEM.

Protective action of capsaicin and chilli on haemorrhagic shock-induced gastric mucosal injury in the rat.

Chilli and its pungent ingredient, capsaicin, have been shown to protect against experimental gastric mucosal injury induced by various necrotizing agents such as ethanol and aspirin and stress. We investigated the effect of capsaicin and long-term ingestion of chilli on haemorrhagic shock-induced gastric mucosal injury in the rat. Anaesthetized male Sprague-Dawley rats were subjected to haemorrhagic shock by withdrawing blood to reduce the mean arterial blood pressure to 30-40 mmHg with subsequent reinfusion of shed blood. This resulted in gastric mucosal injury with readily identifiable haemorrhagic lesions. Capsaicin (5 mg) administered prior to, but not after, haemorrhagic shock, significantly reduced the gastric mucosal injury in intact animals. Sensory ablation with capsaicin pretreatment (125 mg/kg bodyweight) abolished the gastroprotective effect afforded by capsaicin. Similarly, 4 week intake of chilli powder (360 mg daily) reduced the gastric mucosal injury in intact, but not in capsaicin-desensitized rats. Capsaicin and long-term chilli intake protected against haemorrhagic shock-induced gastric mucosal injury and the protection may be mediated by capsaicin-sensitive afferent neurons. Our studies are of potential significance in the context of stress ulcer disease in the human.

Role of capsaicin sensitive nerves in epidermal growth factor effects on gastric mucosal injury and blood flow.

BACKGROUND: Epidermal growth factor (EGF) and capsaicin protect against experimental gastric mucosal injury. Capsaicin exerts its gastroprotective effect by stimulating afferent neurones leading to release of calcitonin gene related peptide (CGRP) which causes gastric hyperaemia. EGF also causes gastric hyperaemia but whether it acts via capsaicin sensitive neurones is unknown. AIMS: To assess the influence of: (1) capsaicin desensitisation on EGF effects on gastric mucosal injury and gastric mucosal blood flow: and (2) close arterial infusion of hCGRP8-379, a CGRP antagonist, on EGF effects on gastric mucosal blood flow. METHODS: The absolute ethanol induced gastric mucosal injury model in the rat was used. Gastric mucosal damage was assessed by planimetry and light microscopy. Gastric mucosal blood flow was measured by laser Doppler flowmetry in a gastric chamber preparation. RESULTS: Capsaicin desensitisation abolished the gastroprotective and gastric hyperaemic effects of EGF. Close arterial infusion of hCGRP8-37 antagonised the hyperaemic effect of both capsaicin and EGF. CONCLUSION: Results show that EGF may exert its gastroprotective and gastric hyperaemic effects via capsaicin sensitive afferent neurones.

Relaxin modulates the ovulatory process and increases secretion of different gelatinases from granulosa and theca-interstitial cells in rats.

There were two related objectives in this study. The first was to determine the influence of endogenous relaxin on ovulation in rats. The second was to investigate the effect of relaxin on the secretion of gelatinases involved in extracellular matrix remodeling from rat ovarian cells. Immature rats were primed s.c. with 10 IU eCG; 51 to 52 h later, a monoclonal antibody specific for rat relaxin (MCAR), a control antibody against fluorescein (MCAF), or PBS vehicle was administered via intraovarian bursal injection under anesthesia, and 15 IU hCG was injected i.p. immediately thereafter. Rats were killed 26 h later, and oviducts were isolated and examined under the microscope to determine the number of ovulated oocytes. MCAR (0.25 and 2.5 micrograms/ovary) partially suppressed gonadotropin-induced ovulation as compared to the value for PBS controls. There was no significant difference in the number of ovulated oocytes between animals treated with MCAF and PBS controls. Also, porcine relaxin, given s.c. immediately after MCAR treatment, could reverse the inhibitory effect of MCAR on ovulation. To examine a possible mechanism for the effect of relaxin on ovulation, granulosa cells and theca-interstitial cells were obtained from ovaries of eCG-primed immature rats. The gelatinases secreted from cultured cells were analyzed using gelatin zymography and scanning densitometry. In the granulosa cell culture, relaxin increased the secretion of two major gelatinases of about 92 and 63 kDa in a dose-and time-dependent manner within 24 h of treatment. In the theca-interstitial cell culture, relaxin induced dose- and time-dependent increases in the secretion of two other major gelatinases of about 76 and 71 kDa. These gelatinases were characterized as metalloproteinases but not serine/cysteine proteinases. Furthermore, an immunoblot study demonstrated that relaxin stimulated the secretion of a 72-kDa type IV collagenase-like substance from cultured theca-interstitial cells but not from granulosa cells. This study demonstrates several original findings. First, endogenous relaxin may facilitate the ovulatory process in rats. Second, exogenous relaxin exhibits a biological effect on cultured rat theca-interstitial cells in addition to granulosa cells. Third, exogenous relaxin regulates the secretion of different major forms of gelantinases from cultured rat granulosa cells and theca-interstitial cells. The study supports the idea that relaxin may play an autocrine/paracrine role that is involved in modulating ovarian function.

Effect of capsaicin and cimetidine on the healing of acetic acid induced gastric ulceration in the rat.

BACKGROUND: Capsaicin protects the gastric mucosa against experimental injury while capsaicin desensitisation reduces the rate of gastric ulcer healing. The effect of exogenous capsaicin on gastric ulcer healing has not to date been reported. AIM/METHOD: To investigate the effect of capsaicin, cimetidine, and in combination, given intragastrically in the healing of acetic acid induced chronic gastric ulcer in the rat. Treatment started immediately after ulcer induction. RESULTS: At the end of one week, capsaicin, cimetidine, and in combination increased ulcer healing but the effect of combined treatment was less than that of capsaicin alone. In an in vivo gastric chamber preparation, capsaicin increased, while cimetidine decreased, gastric mucosal blood flow measured by laser Doppler flowmetry. A dose response effect in reduction of gastric mucosal blood flow could be demonstrated for cimetidine. The gastric hyperaemic effect of capsaicin was blunted by prior administration of cimetidine. In contrast, capsaicin had no effect on gastric acid secretion and its addition to cimetidine did not affect the acid suppressant effect of the latter. CONCLUSIONS: Capsaicin promotes the healing of acetic acid induced gastric ulcer, probably by its gastric hyperaemic effect. Although cimetidine also promotes ulcer healing due to its inhibitory effect on acid secretion it may have an antagonistic effect on the gastric ulcer healing effect of capsaicin by virtue of inhibition of gastric hyperaemia.

Effect of capsaicin and chilli on ethanol induced gastric mucosal injury in the rat.

Capsaicin, the pungent ingredient of chilli, is gastroprotective against experimental gastric injury when given intragastrically. Epidemiological and clinical data suggest that chilli ingestion may have a beneficial effect on human peptic ulcer disease. This study showed a gastroprotective effect of intragastric capsaicin, in doses of 2 and 5 mg, on ethanol induced gastric mucosal injury using macroscopic, histological, scanning electron microscopic, and biochemical indices. Subcutaneous administration of 2 mg of capsaicin had the same gastroprotective effect as intragastric administration. Acute intragastric administration and chronic ingestion of chilli powder in doses comparable with that consumed in humans (up to 200 mg in single doses or 200 mg daily for four weeks) likewise protected the gastric mucosa. Both the mucosa and gastric juice had higher mucus contents when capsaicin or chilli rather than saline or solvent was used before ethanol challenge. In control animals capsaicin also increased gastric juice mucus content although the mucosal content was unaffected. Increased gastric mucus production may therefore be one mechanism by which capsaicin and chilli exert their gastroprotective effect although an alternative explanation is that the reduction in mucosal mucus depletion is secondary to the protective effect of capsaicin and chilli.

Chili protects against aspirin-induced gastroduodenal mucosal injury in humans.

Capsaicin, the pungent ingredient of chili, has a gastroprotective effect against experimental gastric mucosal injury in animals. Such an effect has not, however, been documented in humans to date. Eighteen healthy volunteers with normal index endoscopies underwent two studies four weeks apart. Each subject took 20 g chili orally with 200 ml water in one study and 200 ml water in another study. In each case this was followed half an hour later by 600 mg aspirin BP with 200 ml water. Endoscopy was repeated 6 hr later. Gastroduodenal mucosal damage was assessed by a previously validated scoring system. The median gastric injury score after chili was 1.5 compared to 4 in the control group (P < 0.05), demonstrating a gastroprotective effect of chili in human subjects.