Cholecystokinin octapeptide inhibits immunoglobulin G1 production of lipopolysaccharide-activated B cells

Irisin inhibits CCK-8-induced TNF-α production via integrin αVβ5-NF-κB signaling pathways in Nile tilapia (Oreochromis niloticus)

Irisin, a secreted myokine generated by fibronectin type III domain-containing protein 5, has recently shown the potential to alleviate inflammation. Cholecystokinin-octapeptide (CCK-8) is closely associated with the inflammatory factor TNF-α, a central cytokine in inflammatory reactions. However, the interactions between irisin and CCK-8 in regulating TNF-α production and the underlying mechanism have not yet been elucidated. In the present study, irisin treatment inhibited the basal and the CCK-8-induced TNF-α production in vivo. Additionally, neutralizing circulating irisin using an irisin antiserum significantly augmented the CCK-8-induced stimulation of TNF-α levels. Moreover, the incubation of head kidney cells with irisin or CCK-8 has opposite effects on TNF-α secretion. Notably, irisin treatment inhibited basal and CCK-8-stimulated TNF-α release and gene transcription in head kidney cells. Mechanistically, the inhibitory actions of irisin on basal and CCK-8-induced TNF-α production could be negated by co-administered with the selective integrin αVβ5 inhibitor cilengitide. In addition, the inhibitory effect of irisin on basal and CCK-8-triggered TNF-α production could be abolished by the inhibition of the nuclear factor-kappa B (NF-κB) signaling pathway. Furthermore, irisin impeded CCK-8-induced phosphorylation and degradation of IκBα, simultaneously inhibiting NF-κB phosphorylation, preventing its translocation into the nucleus, and suppressing its DNA-binding activity induced by CCK-8. Collectively, these results suggest that the inhibitory effect of irisin on TNF-α production caused by CCK-8 is mediated via the integrin αVβ5-NF-κB signaling pathways in tilapia.

XBP1 impacts lung adenocarcinoma progression by promoting plasma cell adaptation to the tumor microenvironment

Background: The activation of X-box binding protein 1 (XBP1) plays an essential role in the unfolded protein response (UPR) of the endoplasmic reticulum (ER). XBP1 is commonly expressed in various tumors and is closely related to tumorigenesis and progression. However, the role of XBP1 in lung adenocarcinoma (LUAD), especially the prognostic value of its alternative splicing isoforms, remains largely unknown.

Methods: The LUAD datasets were retrieved from the The Cancer Genome Atlas, ArrayExpress and Gene Expression Omnibus. GEPIA2 and meta-analysis were employed to explore the prognostic value, and bioinformatics analysis with the TIMER2.0 database was used to investigate immune cell infiltration. We performed single-cell analyses to identify cell types with high XBP1 expression. In addition, polymerase chain reaction (PCR) and DNA sequencing were performed to verify the authenticity of the new spliceosome.

Results: In this study, we found that high expression of XBP1 was significantly associated with a good prognosis, and XBP1 expression was significantly positively correlated with B cell infiltration in LUAD. In addition, we found that high-level expression of a novel splicing isoform, XBP1 (XBP1-003), improved the prognosis of LUAD. Protein structural analysis demonstrated that XBP1-003 has several specific protein domains that are different from those of other XBP1 isoforms, indicating a unique function of this isoform in LUAD.

Conclusion: All these results suggest that XBP1 plays an antitumorigenic role in LUAD through alternative splicing, which may be related to the adaptation of plasma cells. This sheds new light on the potential strategy for LUAD prognosis evaluation and immunotherapy.

Cholecystokinin Downregulates Psoriatic Inflammation by Its Possible Self-Regulatory Effect on Epidermal Keratinocytes

Cholecystokinin (CCK) is a peptide hormone that functions in digestive organs and the CNS. We previously showed that CCK downregulates peripheral pruritus by suppressing degranulation of mast cells. In this study, we demonstrated that CCK octapeptide (CCK8) was constitutively expressed in the epidermis of normal skin, whereas its expression was lost in acanthotic lesions of psoriasis. In contrast, CCKA receptor (CCKAR), a high-affinity receptor for CCK, was constitutively expressed in the epidermis of psoriatic skin lesions. Expression of CCK was also reduced in skin lesions of an imiquimod (IMQ)-induced psoriatic mouse model. Notably, the expression level of CCK inversely correlated with the severity of epidermal inflammation, raising the possibility that CCK from epidermal keratinocytes suppresses the psoriatic inflammation. To verify this hypothesis, we investigated the effects of sulfated CCK octapeptide (CCK8S) on the development of IMQ-induced psoriatic inflammation. i.p. injection of CCK8S suppressed the IMQ-induced psoriatic inflammation accompanied by reduced mRNA expression of IL-17, IL-22, and IL-6 but not of IL-23. The suppressive effect of CCK8S was completely restored by administration of CCKAR antagonist. In vitro studies showed that exogenous CCK8S suppressed IL-6 production in CCKAR-expressing cultured human keratinocytes, and blocking the endogenous CCK signaling with CCKAR antagonist markedly enhanced IL-6 production. When keratinocytes were stimulated with IL-17, the expression of endogenous CCK was significantly decreased. These findings suggest that CCK physiologically functions as a negative regulator of keratinocyte-based inflammation in an autocrine or paracrine manner, although decreased CCK may pathologically contribute to continuous and aggravated skin lesions such as psoriasis.

Screen-detected gallstone disease and autoimmune diseases - A cohort study

BACKGROUND

Gallstone disease is highly prevalent and is associated with systemic inflammation.

AIMS

To determine whether screen-detected gallstones or cholecystectomy are associated with the occurrence of autoimmune and autoinflammatory diseases and the most common subgroups thereof.

METHODS

A cohort study of three randomly selected general population samples from Copenhagen was performed. Participants (n = 5928) were examined in the period 1982-1992, underwent abdominal ultrasound examination to detect gallstone disease, and followed through national registers until December 2014 (median 24.7 years) for occurrence of immunological diseases. Multivariable Cox regression analyses were performed.

RESULTS

Gallstone disease was identified in 10% (591/5928) of participants, of whom 6.8% had gallstones and 3.2% had cholecystectomy at baseline. Gallstone disease was associated with incidence of autoimmune diseases (12.9% versus 7.92%; hazard ratio 1.46; 95% confidence interval [CI], [1.11;1.91]), diabetes mellitus type 1 (5.95% versus 3.67%; 1.53; [1.02;2.30]), and autoimmune thyroid disease (3.70% versus 1.59%; 2.06; [1.26;3.38]). Rheumatoid arthritis, autoinflammatory diseases, or any subgroups thereof were not associated.

CONCLUSIONS

In a large general population sample, screen-detected gallstone disease was associated with the development of autoimmune diseases during long-term follow-up. Future research efforts are needed to further explore common disease mechanisms.

Cholecystokinin octapeptide inhibits the inflammatory response and improves neurological outcome in a porcine model of cardiopulmonary resuscitation

Previous studies have demonstrated that cholecystokinin octapeptide (CCK8) induces hypothermia and inhibits the systemic inflammatory response in septic shock in rat and murine models. The present study aimed to ascertain whether CCK8 induced hypothermia and improved the neurological outcomes in a porcine model of cardiopulmonary resuscitation (CPR). Ventricular fibrillation was induced and left untreated for 10 min in 12 male Bama miniature pigs. Defibrillation was attempted after 5 min of CPR. At 5 min following resuscitation, the pigs were randomized and equally assigned into the CCK8 or the control group. CCK8 was continuously infused for 1 h at a dose of 44.4 µg/kg/h and a rate of 20 ml/h in the CCK8 group. Body temperature, hemodynamic measurements and post-resuscitation myocardial function were monitored in the first 4 h following CPR. Neuron specific enzyme (NSE), S100B protein, tumor necrosis factor (TNF)-α and interleukin (IL)-6 were measured at baseline and 4, 12 and 24 h following resuscitation. The neurological deficient score (NDS) was recorded and cerebral samples were collected for terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling assay and integrated optical density (IOD) analysis at 24 h following CPR. The results revealed that hypothermia was not induced by CCK8; however, post-resuscitation NSE, S100B, IL-6 and TNF-α were significantly decreased, and NDS and IOD were significantly improved in the CCK8 group compared with the control group (P<0.05). The present study revealed that in a porcine model of CPR, CCK8 does not induce hypothermia, but inhibits the inflammatory response and significantly improves neurological outcomes.

Expression and Regulation of Cholecystokinin Receptor in the Chicken's Immune Organs and Cells

Cholecystokinin (CCK) is a neuropeptide that affects growth rate in chickens by regulating appetite. CCK peptides exert their function by binding to two identified receptors, CCKAR and CCKBR in the GI tract and the brain, respectively, as well as in other organs. In mammals, CCK/CCKAR interactions affect a number of immunological parameters, including regulation of lymphocytes and functioning of monocytes. Thus, food intake and growth can potentially be altered by infection and the resulting inflammatory immune response. It is uncertain, however, whether chicken express CCKAR in immune organs and cells, and, if so, whether CCKAR expression is regulated by pathogen derived inflammatory stimuli. Herein, we identify expression of CCKAR protein in chicken peripheral blood mononuclear cells (PBMC) including monocytes, and expression of the CCKAR gene in PBMC, thymus, bursa, and spleen, in selected commercial and pure chicken breeds. Further, stimulation with various types of E. coli heat-labile enterotoxins or lipopolysaccharide significantly regulated expression of CCKAR on monocytes in the different breeds. Ligation of CCKAR with antibodies in PBMC induced mobilization of Ca²⁺, indicating that CCKAR is signal competent. Injection with polyinosinic: polycytidylic acid (poly I:C), a synthetic analogue of double stranded viral RNA that binds Toll-Like Receptor-3 (TLR3), also regulated gene expressions of CCKAR and proinflammatory cytokines, in the different breeds. Interestingly, variations in the expression levels of proinflammatory cytokines in the different breeds were highly correlated with CCKAR expression levels. Taken together, these findings indicate that the physiological function of CCKAR in the chicken is tightly regulated in immune organs and cells by external inflammatory stimuli, which in turn regulate growth. This is the first report CCKAR expression in immune organs and cells, in any species, and the initial observation that CCKAR is regulated by inflammatory stimuli associated with bacterial and viral infection.

Cholecystokinin octapeptide regulates the differentiation and effector cytokine production of CD4(+) T cells in vitro

Cholecystokinin octapeptide (CCK-8), an immunomodulatory peptide, can promote or suppress the development or function of specific CD4(+) T cell subsets by regulating antigen-presenting cell functions. In the current study, we investigated whether CCK-8 exerts a direct effect on T cells through influencing differentiation and cytokine production of distinct CD4(+) T cell subsets in vitro. Our results showed that CCK-8 differentially affects the development and function of CD4(+) T cell populations, with a negative influence on Th1 and Th17 cells and positive regulatory effect on inducible T regulatory cells (iTreg). Notably, CCK-8 suppressed Th1 while slightly enhancing Th2 development and cytokine production. Similarly, CCK-8 inhibited the differentiation of Th17 cells and promoted Foxp3 expression. L-364,718 and LY-288,513, selective antagonists of CCK1R and CCK2R, respectively, suppressed the effects of CCK-8 on CD4(+) T cell subset-specific transcription factors. Our findings strongly indicate that CCK-8 exerts a direct effect on T cells, which is dependent on CCKRs, particularly CCK2R. The collective results aid in further clarifying the mechanism underlying the anti-inflammatory and immunoregulatory effects of CCK-8.

CCK8 negatively regulates the TLR9-induced activation of human peripheral blood pDCs by targeting TRAF6 signaling

Plasmacytoid dendritic cells (pDCs) are specialized in rapid and massive secretion of type I interferon in response to foreign nuclei acids. Combined with their antigen presentation capacity, this powerful functionality enables pDCs to orchestrate innate and adaptive immune responses. Cholecystokinin octapeptide (CCK8) is a potent immunomodulator, whose role in pDCs function is unknown. In this study, we found that two different cholecystokinin receptors, CCK1R and CCK2R, are expressed on human peripheral blood pDCs. Exogenous CCK8 was able to modulate the TLR-induced activation of pDCs, including phenotypic maturation, IFN-α synthesis and secretion, and could also regulate the potential of pDCs to induce adaptive immune responses in vitro. CCK8 inhibited TLR9-induced activation of tumor-necrosis factor receptor-associated factor 6, which is an important adapter protein in activation of interferon-regulatory factor (IRF)5 and IRF7, possibly through CCK2R, by evoking the activity of protein kinase (PK)A and reducing the activity of PKC. All these results indicate that CCK8 can inhibit the TLR9-induced phenotypic maturation and activation of pDCs, acting through CCK2R by modulating the tumor-necrosis factor receptor-associated factor 6 signaling pathways.