A Cholecystokinin Analogue Ameliorates Cognitive Deficits and Regulates Mitochondrial Dynamics via the AMPK/Drp1 Pathway in APP/PS1 Mice.

BACKGROUND: There are no drugs on the market that can reverse or slow Alzheimer's disease (AD) progression. A protease-resistant Cholecystokinin (CCK) analogue used in this study is based on the basic structure of CCK, which further increases the stability of the peptide fragment and prolongs its half-life in vivo. We observed a neuroprotective effect of CCK-8L in APPswe/PS1dE9 (APP/PS1) AD mice. However, its corresponding mechanisms still need to be elucidated. OBJECTIVE: This study examined CCK-8L's neuroprotective effects in enhancing cognitive impairment by regulating mitochondrial dynamics through AMPK/Drp1 pathway in the APP/PS1 AD mice. METHODS: Behavioural tests are applied to assess competence in cognitive functions. Transmission electron microscopy (TEM) was performed to observe the ultrastructure of mitochondria of hippocampal neurons, Immunofluorescent staining was employed to assay for Aß1-42, APP, Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and dynamin-related protein1 (Drp1). CRISPR/Cas9 was utilized for targeted knockout of the CCKB receptor (CCKBR) in the mouse APP/PS1 hippocampal CA1 region. A model of lentiviral vector-mediated overexpression of APP in N2a cells was constructed. RESULTS: In vivo, experiments revealed that CCK analogue and liraglutide significantly alleviated cognitive deficits in APP/PS1 mice, reduced Aß1-42 expression, and ameliorated l damage, which is associated with CCKBR activation in the hippocampal CA1 region of mice. In vitro tests showed that CCK inhibited mitochondrial fission and promoted fusion through AMPK/Drp1 pathway. CONCLUSIONS: CCK analogue ameliorates cognitive deficits and regulates mitochondrial dynamics by activating the CCKB receptor and the AMPK/Drp1 pathway in AD mice.

Long-acting CCK analogue NN9056 lowers food intake and body weight in obese Göttingen Minipigs.

BACKGROUND/OBJECTIVES: Cholecystokinin (CCK) is a regulator of appetite and energy intake in man. The aim of this study was to determine the effect of NN9056, a long-acting CCK-1 receptor-selective CCK analogue, on food intake and body weight (BW) in obese Göttingen Minipigs. SUBJECTS/METHODS: Tolerability of NN9056 and acute effects on food intake, pancreas histology, amylase and lipase levels were assessed in lean domestic pigs in doses up to 100 nmol/kg (n = 3-4). Subsequently, obese Göttingen Minipigs were treated subcutaneously (s.c.) once daily for 13 weeks with vehicle, NN9056 low dose (regulated from 5 to 2 nmol/kg) or NN9056 high dose (10 nmol/kg) (n = 7-8). Food intake was measured daily and BW twice weekly. At the end of the treatment period, an intravenous glucose tolerance test (IVGTT) and a 24-h exposure profile was obtained. Data are mean ± SD. RESULTS: The acute studies in domestic pigs showed significant and dose-dependent effect of NN9056 on food intake, acceptable tolerability and no histopathological signs of pancreatitis. Sub-chronic treatment in obese Göttingen Minipigs was also well tolerated and accumulated food intake was significantly lower in both treated groups compared to vehicle, with no significant difference between the dose levels of NN9056 (41.8 ± 12.6, 51.5 ± 13.8 and 86.5 ± 19.5 kg in high-dose, low-dose and vehicle groups, respectively, p = 0.012 and p < 0.0001 for low and high dose vs. vehicle, respectively). Accordingly, there was a weight loss in both treated groups vs. a weight gain in the vehicle group (-7.2 ± 4.6%, -2.3 ± 3.2% and 12.3 ± 3.9% in the high-dose, low-dose and vehicle groups, respectively, p < 0.0001 for both vs. vehicle). IVGTT data were not significantly different between groups. CONCLUSION: NN9056, a long-acting CCK-1 receptor-selective CCK analogue, significantly reduced food intake and BW in obese Göttingen Minipigs after once daily s.c. dosing for 13 weeks.

CCK reduces the food intake mainly through CCK1R in Siberian sturgeon (Acipenser baerii Brandt).

To explore the effect of CCK on food intake in Siberian sturgeon, cck cDNA sequence of 1005 bp was obtained, and cck mRNA possessed the highest expression in brain. The expressions of cck were significantly increased after feeding 1 and 3 h, while displaying significant decrease after fasting within 15 days in brain and duodenum. Re-feeding for 3 days induced cck level returned to basic level. Acute i.p. injection experiment showed 100 and 200 ng/g BW CCK8 inhibited the food intake in 0-1 h together with the cumulative food intake within 3 h. 7 days chronic i.p. injection of 100 and 200 ng/g BW CCK8, both daily food intake and cumulative food intake were significantly decreased. In addition, chronic i.p injection of CCK8 induced the expression of feeding related factors changes including cck, ucn3, cart, apelin, pyy and npy in respective organization. Moreover, as revealed by the results, Lorglumide, the CCK1R selective antagonist, effectively reversed the inhibitory effects of CCK8 on food intake and the levels of feeding related factors. On the other hand, LY 225910, the CCK2R selective antagonist, partially reversed these effects. These results indicate CCK is a satiety factor inhibits the feeding of Siberian sturgeon primarily through CCK1R.

Alendronate Attenuates Spinal Microglial Activation and Neuropathic Pain.

UNLABELLED: Many derivatives of bisphosphonates, which are inhibitors of bone resorption, have been developed as promising agents for painful pathologies in patients with bone resorption-related diseases. The mechanism for pain relief by bisphosphonates remains uncertain. Studies have reported that bisphosphonates could reduce central neurochemical changes involved in the generation and maintenance of bone cancer pain. In this study, we hypothesized that bisphosphonates would inhibit spinal microglial activation and prevent the development of hyperalgesia caused by peripheral tissue injury. We investigated the effects of alendronate (a nitrogen-containing bisphosphonate) on the development of neuropathic pain and its role in modulating microglial activation in vivo and in vitro. Intrathecal and intraperitoneal administration of alendronate relieved neuropathic pain behaviors induced by chronic constriction sciatic nerve injury. Alendronate also significantly attenuated spinal microglial activation and p38 mitogen-activated protein kinase (MAPK) phosphorylation without affecting astrocytes. In vitro, alendronate downregulated phosphorylated p38 and phosphorylated extracellular signal regulated kinase expression in lipopolysaccharide-stimulated primary microglia within 1 hour, and pretreatment with alendronate for 12 and 24 hours decreased the expression of inflammatory cytokines (tumor necrosis factor α, and interleukins 1ß and 6). These findings indicate that alendronate could effectively relieve chronic constriction sciatic nerve injury-induced neuropathic pain by at least partially inhibiting the activation of spinal microglia and the p38 MAPK signaling pathway. PERSPECTIVE: Alendronate could relieve neuropathic pain behaviors in animals by inhibiting the activation of spinal cord microglia and the p38 MAPK cell signaling pathway. Therapeutic applications of alendronate may be extended beyond bone metabolism-related disease.

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.

Intraperitoneal CCK and fourth-intraventricular Apo AIV require both peripheral and NTS CCK1R to reduce food intake in male rats.

Apolipoprotein AIV (Apo AIV) and cholecystokinin (CCK) are secreted in response to fat consumption, and both cause satiation via CCK 1 receptor (CCK-1R)-containing vagal afferent nerves to the nucleus of the solitary tract (NTS), where Apo AIV is also synthesized. Fasted male Long-Evans rats received ip CCK-8 or fourth-ventricular (i4vt) Apo AIV alone or in combination. Food intake and c-Fos proteins (a product of the c-Fos immediate-early gene) were assessed. i4vt Apo AIV and/or ip CCK at effective doses reduced food intake and activated c-Fos proteins in the NTS and hypothalamic arcuate nucleus and paraventricular nucleus. Blockade of the CCK-1R by i4vt lorglumide adjacent to the NTS attenuated the satiating and c-Fos-stimulating effects of CCK and Apo AIV, alone or in combination. Maintenance on a high-fat diet (HFD) for 10 weeks resulted in weight gain and attenuation of both the behavioral and c-Fos responses to a greater extent than occurred in low-fat diet-fed and pair-fed HFD animals. These observations suggest that NTS Apo AIV or/and peripheral CCK requires vagal CCK-1R signaling to elicit satiation and that maintenance on a HFD reduces the satiating capacity of these 2 signals.

Anxiolytic activity of dipeptide GB-115 after oral administration.

The anxiolytic effects of GB-115, a retroanalogue of cholecystokinin-4, administered orally to outbred and inbred animals with different level of emotionality, were studied in the open field test and elevated plus-maze test. The anxiolytic effect of talanax was observed in outbred mice (0.1-0.5 mg/kg) and in inbred BALB/c mice (0.1 and 5.0 mg/kg) in the open field test. GB-115 increased the time of entries into open arms in outbred rats (0.5-0.7 mg/kg) and in BALB/c mice (0.1 mg/kg). These data confirmed the dependence of GB-115 effect on the phenotype of emotional stress response and demonstrated a shift of anxiolytic doses of the preparation from 0.006-0.100 mg/kg in intraperitoneal administration to 0.1-5.0 mg/kg in oral treatment.

Apamin attenuated cerulein-induced acute pancreatitis by inhibition of JNK pathway in mice.

BACKGROUND/AIM: We have previously reported that bee venom (BV) has a protective role against acute pancreatitis (AP). However, the effects of apamin, the major compound of BV, on AP have not been determined. The aim of this study was to evaluate the effects of apamin on cerulein-induced AP. METHODS: AP was induced via intraperitoneal injection of supramaximal concentrations of the stable cholecystokinin analogue cerulein (50 µg/kg) every hour for 6 times. In the apamin treatment group, apamin was administered subcutaneously (10, 50, or 100 µg/kg) at both 18 and 1 h before the first cerulein injection. The mice were sacrificed at 6 h after the final cerulein injection. Blood samples were obtained to determine serum amylase and lipase levels, as well as cytokine production. The pancreas and lung were rapidly removed for morphologic and histological examination, myeloperoxidase (MPO) assay, and real-time reverse transcription-polymerase chain reaction. Furthermore, we isolated the pancreatic acinar cells to specify the role of apamin in AP. RESULTS: Pre-treatment with apamin inhibited histological damage, pancreatic weight/body weight ratio, serum level of amylase and lipase, MPO activity, and cytokine production. In addition, apamin treatment significantly inhibited cerulein-induced pancreatic acinar cell death. Furthermore, apamin treatment inhibited the cerulein-induced activation of c-Jun NH2-terminal kinases (JNK). CONCLUSIONS: These results could suggest that apamin could protect against AP by inhibition of JNK activation.

Synthesis and evaluation of cholecystokinin trimers: a multivalent approach to pancreatic cancer detection and treatment.

In the quest for novel tools for early detection and treatment of cancer, we propose the use of multimers targeting overexpressed receptors at the cancer cell surface. Indeed, multimers are prone to create multivalent interactions, more potent and specific than their corresponding monovalent versions, thus enabling the potential for early detection. There is a lack of tools for early detection of pancreatic cancer, one of the deadliest forms of cancer, but CCK2-R overexpression on pancreatic cancer cells makes CCK based multimers potential markers for these cells. In this Letter, we describe the synthesis and evaluation of CCK trimers targeting overexpressed CCK2-R.

Rationale for the use of radiolabelled peptides in diagnosis and therapy.

Nuclear medicine techniques are becoming more important in imaging oncological and infectious diseases. For metabolic imaging of these diseases, antibody and peptide imaging are currently used. In recent years peptide imaging has become important, therefore the rationale for the use of peptide imaging is described in this article. Criteria for a successful peptide tracer are a high target specificity, a high binding affinity, a long metabolic stability and a high target-to-background ratio. Tracer internalization is also beneficial. For oncological imaging, many tracers are available, most originating from regulatory peptides, but penetrating peptides are also being developed. Peptides for imaging inflammatory and infectious diseases include regulatory peptides, antimicrobial peptides and others. In conclusion, for the imaging of oncological, imflammatory and infectious diseases, many promising peptides are being developed. The ideal peptide probe is characterized by rapid and specific target localization and binding with a high tumour-to-background ratio.

Ligand-induced internalization of the type 1 cholecystokinin receptor independent of recognized signaling activity.

Receptor ligands, identified as antagonists, based on the absence of stimulation of signaling, can rarely stimulate receptor internalization. d-Tyr-Gly-[(Nle(28,31),d-Trp(30))CCK-26-32]-2-phenylethyl ester (d-Trp-OPE) is such a ligand that binds to the cholecystokinin (CCK) receptor and stimulates internalization. Here, the molecular basis of this trafficking event is explored, with the assumption that ligand binding initiates conformational change, exposing an epitope to direct endocytosis. Ligand-stimulated internalization was studied morphologically using fluorescent CCK and d-Trp-OPE. d-Trp-OPE occupation of Chinese hamster ovary cell receptors stimulated internalization into the same region as CCK. Arrestin-biased action was ruled out using morphological translocation of fluorescent arrestin 2 and arrestin 3, moving to the membrane in response to CCK, but not d-Trp-OPE. Possible roles of the carboxyl terminus were studied using truncated receptor constructs, eliminating the proline-rich distal tail, the serine/threonine-rich midregion, and the remainder to the vicinal cysteines. None of these constructs disrupted d-Trp-OPE-stimulated internalization. Possible contributions of transmembrane segments were studied using competitive inhibition with peptides that also had no effect. Intracellular regions were studied with a similar strategy using coexpressing cell lines. Peptides corresponding to ends of each loop region were studied, with only the peptide at the carboxyl end of the third loop inhibiting d-Trp-OPE-stimulated internalization but having no effect on CCK-stimulated internalization. The region contributing to this effect was refined to peptide 309-323, located below the recognized G protein-association motif. While a receptor in which this segment was deleted did internalize in response to d-Trp-OPE, it exhibited abnormal ligand binding and did not signal in response to CCK, suggesting an abnormal conformation and possible mechanism of internalization distinct from that being studied. This interpretation was further supported by the inability of peptide 309-323 to inhibit its d-Trp-OPE-stimulated internalization. Thus the 309-323 region of the type 1 CCK receptor affects antagonist-stimulated internalization of this receptor, although its mechanism and interacting partner are not yet clear.

Relationship between vulnerability to reinforcing effects of morphine and activity of the endogenous cholecystokinin system in Lewis and Fischer rats.

A great number of studies have shown the presence of physiological interactions between brain neurotransmitter systems in behavioural responses. This is the case for opioid, cholecystokinin (CCK) and dopamine systems. However, so far the role that the CCK system may play in vulnerability to consumption of drugs of abuse is not clear. This was investigated in this study using Lewis rats that are more sensitive to the reinforcing properties of drugs of abuse than Fischer rats. The extraneuronal CCK(8) levels and brain CCK(2) receptors were found higher in Fischer than in Lewis rats in the nucleus accumbens, one of the most important structures involved in drug consumption. Moreover, pharmacological modulation of the CCK system by administration of a selective CCK(2) agonist blocked, in the conditioned place preference, the reinforcing effects of morphine in Lewis rats, whereas a selective CCK(2) antagonist revealed reinforcing effects of the alkaloid in Fischer rats. These results obtained following systemic administrations of the CCK ligands were confirmed following microinjection into the nucleus accumbens. Thus, a low level of CCK efflux in the nucleus accumbens could be one of the many factors involved in drug reinforcing effects, whereas a high level of CCK efflux could attenuate it.

CCK stimulation of GLP-1 neurons involves α1-adrenoceptor-mediated increase in glutamatergic synaptic inputs.

OBJECTIVE: Glucagon-like peptide 1 (GLP-1) is involved in the central regulation of food intake. It is produced within the brain by preproglucagon (PPG) neurons, which are located primarily within the brain stem. These neurons project widely throughout the brain, including to the appetite centers in the hypothalamus, and are believed to convey signals related to satiety. Previous work demonstrated that they are directly activated by leptin and electrical activity of the afferent vagus. Another satiety hormone, cholecystokinin (CCK), has also been linked to activation of brain stem neurons, suggesting that it might act partially via centrally projecting neurons from the nucleus tractus solitarius (NTS). The aim of this study was to investigate the neuronal circuitry linking CCK to the population of NTS-PPG neurons. RESEARCH DESIGN AND METHODS: Transgenic mice expressing yellow fluorescent protein (Venus) under the control of the PPG promoter were used to identify PPG neurons in vitro and to record their electrical and pharmacological profile. RESULTS: PPG neurons in the NTS were excited by CCK and epinephrine, but not by the melanocortin receptor agonist melanotan II. Both CCK and epinephrine acted to increase glutamatergic transmission to the PPG neurons, and this involved activation of α(1)-adrenergic receptors. Inhibition of adrenergic signaling abolished the excitatory action of CCK. CONCLUSIONS: CCK activates NTS-PPG cells by a circuit involving adrenergic and glutamatergic neurons. NTS-PPG neurons integrate a variety of peripheral signals that indicate both long-term energy balance and short-term nutritional and digestional status to produce an output signal to feeding and autonomic circuits.

[Experimental study of antidepressant effects of GB-115 dipeptide].

It was previously reported that GB-115 [Ph(CH2)5CO-Gly-D-Trp-NH2], a tryptophan-containing dipeptide analog of endogenous CCK4, exhibited pronounced anxiolytic effects in behavioral models of anxiety targeted on the "passive" phenotype of the emotional stress reaction. The aim of the present work was to study the modulator action of GB-115 (0.0125-0.1 mg/kg, i.p.) on emotional processes in both mongrel and inbred (BALB/c and C57B1/6) mice with opposite emotionality in Porsolt's test. GB-115 injected at a dose of 0.025 mg/kg led to a decrease in the immobilization time in all animals tested. The effect observed was less potent than that of amitriptyline (10 mg/kg). In contrast to the case of BALB/c mice, GB-115 increased the latent period in both C57B1/6 mice with active type of behavior and in mongrel mice. There were no changes in spontaneous locomotor activity after the acute administration of GB-115 in inbred and mongrel mice. It was found that GB-115 at an anxiolytic dose produced antidepressant-like effects independently of the genetically controlled emotional stress reaction phenotype. These results indicate that the novel dipeptide analog of CCK4 may have potential in the clinical management of concurrent anxiety and depression.

Gastrin and cholecystokinin peptide-based radiopharmaceuticals: an in vivo and in vitro comparison.

The development of suitable radioligands for targeting CCK-2 receptor expressing tumors, such as medullary thyroid carcinoma, is of great clinical interest. In the search for the best CCK-2R binding peptides, we have synthesized, evaluated and compared the CCK8 peptide (Asp-Tyr-Met-Gly-Trp-Met-Asp-PheNH(2) ) and two gastrin analogs commonly referred to as MG0 (DGlu-Glu(5)-Ala-Tyr-Gly-Trp-Met-Asp-PheNH(2) ) and MG11 (DGlu(1)-Ala-Tyr-Gly-Trp-Met-Asp-PheNH(2) ). The N-terminal portion of the three peptide sequences was derivatized by introducing the DTPAGlu or DOTA chelators to allow radiolobeling with (111) In(III) and (68) Ga(III), respectively. Saturation binding and cellular internalization experiments were performed on A431 cells overexpressing CCK2R (A431-CCK2R). All compounds showed Kd values in the nM range and were internalized with similar rates in CCK2 receptor overexpressing cells. Biodistribution experiments showed higher specific uptake of both MG0-based compounds compared to conjugates containing the CCK8 and MG11 peptide sequences. The higher retention levels of MG0-based peptides were associated with markedly elevated and undesired kidney uptake compared to the other compounds. Current indications suggest that the 5 Glu N-terminal residues while improving peptide stability and receptor-mediated tumor uptake cause unacceptably high kidney retention. Although displaying lower absolute tumor uptake values, the DOTA-coupled CCK8 peptide provided the best tumor to kidney uptake ratio and appears more suitable as lead compound for improvement of radiopharmaceutical properties.

Study of anti-inflammatory effects of GB-115, a glycine-containing retropeptide cholecystokinin analog.

Anti-inflammatory effects of GB-115 compound (N-phenylhexanoyl-glycyl-L-tryptophan amide) injected intraperitoneally in doses of 0.1, 1, and 10 mg/kg were demonstrated on the model of ConA- and carrageenan-induced inflammation. Intraperitoneal injection of GB-115 in a dose of 1 mg/kg to C57Bl/6 female mice with experimental autoimmune encephalomyelitis significantly alleviated the pathological symptoms, improved spontaneous locomotor activity, promoted recovery of thymus weight, and reduced edema and neutrophil infiltration of the perivascular space of the brain tissue. Intraperitoneal injection of GB-115 in a dose of 1 mg/kg suppressed generation of active oxygen forms by neutrophils in the chemiluminescence test.

Cholecystokinin action on layer 6b neurons in somatosensory cortex.

Layer 6b in neocortex is a distinct sublamina at the ventral portion of layer 6. Corticothalamic projections arise from 6b neurons, but few studies have examined the functional properties of these cells. In the present study we examined the actions of cholecystokinin (CCK) on layer 6b neocortical neurons using whole-cell patch clamp recording techniques. We found that the general CCK receptor agonist CCK8S (sulfated CCK octapeptide) strongly depolarized the neurons, and this action persisted in the presence of tetrodotoxin, suggesting a postsynaptic site of action. The excitatory actions of CCK8S were mimicked by the selective CCK(B) receptor agonist CCK4, and attenuated by the selective CCK(B) receptor antagonist L365260, indicating a role for CCK(B) receptors. Voltage-clamp recordings revealed that CCK8S produced a slow inward current associated with a decreased conductance with a reversal potential near the K(+) equilibrium potential. In addition, intracellular cesium also blocked the inward current, suggesting the involvement of a K(+) conductance, likely K(leak). Our data indicate that CCK, acting via CCK(B) receptors, produces a long-lasting excitation of layer 6b neocortical neurons, and this action may play a critical role in modulation of corticothalamic circuit activity.

[Construction and expression of the fusion gene CCK39/UreB in recombinant Escherichia coli BL-21(DE3)].

The aims of this research were to construct prokaryotic expression vector containing fusion gene of Cholecystokinin 39 (CCK39) of pig and Urease subunit B (UreB) of coliform bacteria, and then to express the fusion protein in recombinant Escherichia coli BL21(DE3). The CCK39 gene was amplified by RT-PCR from the extracted total RNA of pig's duodenum, and the UreB gene was then amplified by PCR from the extracted plasmid DNA of bacillus of coliform bacteria from pig's intestinal content. Then the CCK39 and the UreB were inserted into the prokaryotic expression vector pET43a(+) to construct a recombinant fusion expression vector pET43a(+)/CCK39/UreB and then, the recombinant vector was identified by PCR, endonuclease digestion and sequence analysis. It was identified that the gene fragment of CCK39 at length of 117 bp and UreB at length of 324 bp were amplified and cloned into the vector pET43a(+) successfully. The recombinant vector was transformed into Escherichia coli BL21(DE3) and induced the expression of CCK39/UreB fusion protein with a molecular mass of approximately 80 kD by using isopropylthio-beta-D-galactoside (IPTG) as inducer. The fusion protein was mostly located in the cytoplasm and it was soluble. The soluble protein was collected and purified by Ni2+-NTA column chromatograph and then reached a purity of more than 95%. It was proved by western blotting that the fusion protein could react with rabbit anti-CCK8 antiserum and rabbit anti-UreB antiserum. Therefore, the expressed fusion protein has good antigenicity. This work established a good foundation for further study on the production of anti-CCK/Urease vaccines.

Minireview: Gut peptides: targets for antiobesity drug development?

Gut peptides play multiple roles in the controls of gastrointestinal function and in the initiation and termination of meals. Plasma levels of these peptides are differentially affected by the presence of nutrients in the digestive tract, and the patterns of peptide release are consistent with both their feeding stimulatory and inhibitory actions. A number of these peptide systems have been investigated as potential targets for antiobesity drug development. Progress has been made in developing long-acting peptide analogs and, in some cases, nonpeptide agonists and antagonists. Whether any individual approach will have significant long-term efficacy remains to be demonstrated. Approaches that target multiple systems may hold the most promise.

Peptides for tumour therapy and diagnosis: current status and future directions.

The use of peptides as targeting tools has been validated in different applications. In particular radiolabelled peptides with adequate stability, receptor-binding properties and biokinetic behaviour have been investigated as an important class of radiopharmaceuticals for cancer pathology imaging and therapy. This review focuses on recent progress in design and synthetic modifications of small biologically active peptides used in diagnosis and therapy. In particular, we report the current development and optimization of suitable peptides for targeting three relevant biological receptors (CCK, somatostatin, and integrin receptors) involved in specific tumour diseases.