Activation of the GPR35 on ILC2 drives immunosuppression to promote lung cancer progression.

Lung cancer is the most common cancer type with poor prognosis. While G protein-coupled receptor 35 (GPR35) is a potent stimulator of tumor growth, group 2 innate lymphoid cells (ILC2) have shown dual effects in tumorigenesis. Intriguingly, inflammation induced GPR35 activation leads to an upregulation in the markers associated with ILC2. Here, we reported that GPR35 knockout mice exhibited a significantly reduced tumor growth and altered immune infiltration in tumors. Furthermore, activating GPR35 in different mouse models promoted tumor development by enhancing the production of IL-5 and IL-13, thereby facilitating the formation of the ILC2-MDSC axis. Moreover, we found that GPR35 was a poor prognostic factor in patients with lung adenocarcinoma. Together, our findings suggest the potential application of targeting GPR35 in cancer immunotherapy.

G protein-coupled receptor 35 attenuates nonalcoholic steatohepatitis by reprogramming cholesterol homeostasis in hepatocytes.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Fat accumulation "sensitizes" the liver to insult and leads to nonalcoholic steatohepatitis (NASH). G protein-coupled receptor 35 (GPR35) is involved in metabolic stresses, but its role in NAFLD is unknown. We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis. Specifically, we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose (HFCF) diet-induced steatohepatitis, whereas loss of GPR35 had the opposite effect. Administration of the GPR35 agonist kynurenic acid (Kyna) suppressed HFCF diet-induced steatohepatitis in mice. Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4 (STARD4) through the ERK1/2 signaling pathway, ultimately resulting in hepatic cholesterol esterification and bile acid synthesis (BAS). The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and CYP8B1, promoting the conversion of cholesterol to bile acid. The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice. STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice. Our findings indicate that the GPR35-STARD4 axis is a promising therapeutic target for NAFLD.

Increased GPR35 expression in human colorectal and pancreatic cancer samples: A preliminary clinical validation of a new biomarker.

BACKGROUND: G protein-coupled receptor 35 (GPR35) is involved in carcinogenesis; however, limited experimental data are available on its actual expression in patients with colorectal cancer (CRC) and pancreatic adenocarcinoma (PDAC). OBJECTIVES: We aimed to measure the relative expression of GPR35 in samples from patients with CRC or PDAC. MATERIAL AND METHODS: Using real-time polymerase chain reaction (RT-PCR), we have examined GPR35 expression in surgery samples from 40 CRC and 17 PDAC patients, and performed analysis of the results. RESULTS: The analysis of GPR35 expression in patients with CRC revealed correlations between relative GPR35 mRNA expression and several tumor characteristics, with statistical significance for higher American Joint Committee on Cancer (AJCC) stages, T stages and histological grades. GPR35 expression was significantly higher in tumor samples compared to the paired healthy samples collected from the same patient. Similar, although not statistically significant trends were found in PDAC tumor samples for sex (lower expression in women) and for samples with no nodal involvement (lower expression). Samples with higher tumor T stages and higher histological grades or considered inoperable had higher GPR35 expression. CONCLUSIONS: We have identified correlations which confirm our expectation of high GPR35 expression in CRC and PDAC. Our findings suggest the prognostic value of GPR35 testing in patients with an increased risk of CRC or PDAC development, and warrant further clinical confirmation.

G protein-coupled receptor 35 attenuates nonalcoholic steatohepatitis by reprogramming cholesterol homeostasis in hepatocytes

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Fat accumulation "sensitizes" the liver to insult and leads to nonalcoholic steatohepatitis (NASH). G protein-coupled receptor 35 (GPR35) is involved in metabolic stresses, but its role in NAFLD is unknown. We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis. Specifically, we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose (HFCF) diet-induced steatohepatitis, whereas loss of GPR35 had the opposite effect. Administration of the GPR35 agonist kynurenic acid (Kyna) suppressed HFCF diet-induced steatohepatitis in mice. Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4 (STARD4) through the ERK1/2 signaling pathway, ultimately resulting in hepatic cholesterol esterification and bile acid synthesis (BAS). The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and CYP8B1, promoting the conversion of cholesterol to bile acid. The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice. STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice. Our findings indicate that the GPR35-STARD4 axis is a promising therapeutic target for NAFLD.

Recent advances in deorphanization of GPR35 and its functions in related diseases / 药学学报

G protein-coupled receptors (GPCRs) represent the largest family of membrane proteins and are the target of approximately half of all therapeutic drugs. There are ～300 orphan GPCRs, which have great potential in drug development. G protein-coupled receptor 35 (GPR35), a rhodopsin-like orphan GPCR, is widely involved in immune regulation, gastrointestinal disorders, cardiovascular diseases, cancer, as well as other diseases, suggesting its great potential as a therapeutic target in a variety of diseases. However, the current research on GPR35 is insufficient, including the true endogenous ligand has not been confirmed, the molecular mechanism of its role in disease is not fully understood, and there is a lack of effective intervention strategies targeting GPR35. This article summarizes the deorphatization of GPR35, GPR35-related signaling pathways and their association with various diseases, in order to provide a reference for in-depth study of GPR35 in diseases and development of drugs targeting GPR35.

GPR35, ally of the anti-ischemic ATPIF1-ATP synthase interaction.

Mitochondrial ATP synthase synthesizes ATP for cellular functions; however, under various conditions, including ischemia, it hydrolyzes ATP, primarily to re-energize the mitochondria. ATP synthase inhibitory factor 1 (ATPIF1) inhibits hydrolysis of ATP by ATP synthase. Wyant and colleagues recently demonstrated that G-protein-coupled receptor 35 (GPR35) is involved in this process. This finding provides an additional framework for the novel discovery of potential therapeutic molecules against ischemia/reperfusion (I/R) injury.

The GPR35 expression pattern is associated with overall survival in male patients with colorectal cancer.

BACKGROUND: G protein-coupled receptor 35 (GPR35) is involved in the carcinogenesis; however, limited data exist on its relevance for overall survival (OS) and disease-specific survival (DSS) in patients with cancer. METHODS: We have examined The Cancer Genome Atlas dataset to check the relations between GPR35 expression pattern and OS or DSS of patients with colorectal cancer (CRC). RESULTS: The performed analysis showed a negative association between positive GPR35 expression Z score and OS in males, which remains statistically significant in advanced stages of colon (COAD) and rectal (READ) adenocarcinoma combined. CONCLUSIONS: These findings suggest the prognostic value of early testing of GPR35 in male patients with an increased risk of CRC development and warrant further clinical confirmation.

Functional metabolomics reveal the role of AHR/GPR35 mediated kynurenic acid gradient sensing in chemotherapy-induced intestinal damage.

Intestinal toxicity induced by chemotherapeutics has become an important reason for the interruption of therapy and withdrawal of approved agents. In this study, we demonstrated that chemotherapeutics-induced intestinal damage were commonly characterized by the sharp upregulation of tryptophan (Trp)-kynurenine (KYN)-kynurenic acid (KA) axis metabolism. Mechanistically, chemotherapy-induced intestinal damage triggered the formation of an interleukin-6 (IL-6)-indoleamine 2,3-dioxygenase 1 (IDO1)-aryl hydrocarbon receptor (AHR) positive feedback loop, which accelerated kynurenine pathway metabolism in gut. Besides, AHR and G protein-coupled receptor 35 (GPR35) negative feedback regulates intestinal damage and inflammation to maintain intestinal integrity and homeostasis through gradually sensing kynurenic acid level in gut and macrophage, respectively. Moreover, based on virtual screening and biological verification, vardenafil and linagliptin as GPR35 and AHR agonists respectively were discovered from 2388 approved drugs. Importantly, the results that vardenafil and linagliptin significantly alleviated chemotherapy-induced intestinal toxicity in vivo suggests that chemotherapeutics combined with the two could be a promising therapeutic strategy for cancer patients in clinic. This work highlights GPR35 and AHR as the guardian of kynurenine pathway metabolism and core component of defense responses against intestinal damage.

Analysis of Chemical Components of Anti-allergic Asthma Active Fractions in Alkaloids-free Part of Ephedrae Herba / 中国药房

OBJECTIVE：To provide reference for elucidating the anti-allergic asthma constituents in alkaloids-free part of Ephedrae Herba. METHODS ：Ephedrae Herba was extracted with 85％ ethanol and n-heptane，and then subjected to solid-phase extraction（filler AC 18）for pretreatment to enrich alkaloids-free part from the extract of Ephedrae Herba. HPLC method was adopted，and alkaloids-free fractions of Ephedrae Herba were performed on Unitary C 18 column and Eclipse XDB-C 18 column. Using high expression G protein coupled-receptor 35（GPR35 receptor）in HT- 29 cell as target ，GPR35 receptor agonist zaprinast （1 μmol/L）as positive control ，DMR response value as the detection index ，the agonistic and desensitizing activity of each fraction（100 μg/mL）on GPR 35 receptor was screened by label-free integrated pharmacological method ，so as to screen active anti-allergic asthma fraction. HPLC-Q-TOF-MS method was used to identify the chemical composition of the selected active fractions. RESULTS ：The alkaloids-free part of Ephedrae Herba was divided into two parts ，involving the precipitated part before solid phase extraction and the 95％ methanol elution part ；from them ，20 fractions were screened. Among them ，the precipitated fraction F 1.5-F1.10 and 95％ methanol eluted fraction F 2.5-F2.10 had a strong agonistic activity on GPR 35 receptor；at the same time，GPR35 receptor agonist zaprinast showed a relatively strong desensitization activity. The signal intensity of DMR induced by F1.5-F1.10 in the precipitated part of HT- 29 cells was even higher than that of reference drug zaprinast. By HPLC-Q-TOF-MS analysis，24 chemical components were identified from active fractions ，involving 14 flavonoids，2 volatile oils ，7 organic carboxylic acids ，1 anthraquinones. CONCLUSIONS ：The alkaloid-free part of Ephedrae Herba is mainly flavonoids and has anti-allergic asthma activity.

Isolation and bioactive evaluation of flavonoid glycosides from Lobelia chinensis Lour using two-dimensional liquid chromatography combined with label-free cell phenotypic assays.

Flavonoid glycosides are widespread in herbs and often used as medicines and nutraceuticals because of good bioactivities and low toxicities. However, due to their structural complexity and diversity, isolation of flavonoid glycosides and evaluation of their bioactivities are still highly challenging. To solve this problem, a new method for separation and preparation of novel flavonoid glycosides from Lobelia chinensis Lour (L. chinensis) was developed. To avoid the interference of non-flavonoids, a solid phase extraction method was used to selectively enrich the flavonoids from the total extract. Based on hydrophilic and hydrophobic properties of the flavonoid chemical structure consisting of sugar residue and diphenylpropane (C6C3C6) skeleton, a structure-guided method development strategy was employed to design a 2D-HILIC × RPLC system in the first time. After optimization of chromatographic conditions, high selectivity and symmetric peaks of flavonoids were obtained on a zwitterionic Click XIon column and a polar-modified Atlantis T3 column. Based on these two columns, a 2 D-HILIC × RPLC system was constructed and successfully enlarged from the analytical level to the preparative level. In the first dimension, 20 fractions were obtained with good peak shapes at high sample loading. In the second-dimensional preparation, nine compounds were isolated and identified. Seven of them were novel flavonoid glycosides, lobelitin A-G, and two other known compounds were linatin and diosmin, respectively. Their target activities were evaluated via label-free cell phenotypic assays. Four novel flavonoid glycosides lobelitin A-D were found to have agonistic activities at G protein-coupled receptor 35 (GPR35). These results demonstrated that this method was effective to orthogonally separate flavonoids at the preparative level, especially for novel active flavonoid glycosides. The discovery of flavonoid glycosides with novel agonistic activity on GPR35 also sheds light on the mechanisms of action of L. chinensis relevant to its clinical application.

The presence and distribution of G protein-coupled receptor 35 (GPR35) in the human cornea - Evidences from in silico gene expression analysis and immunodetection.

We provide the evidence for G protein-coupled receptor 35 (GPR35) presence and distribution in the human cornea. The initial data on GPR35 gene expression were retrieved from microarray repositories and were further confirmed by western blotting and immunohistochemical analysis. Immunoblotting suggested that GPR35 exists predominantly as a dimer in corneal tissue. Moreover, corneal tissues were significantly richer in GPR35 compared to the adjacent sclera. Immunoreactivity for GPR35 was detected in normal corneas, keratoconus and Fuchs' dystrophy, mainly in the corneal epithelium and endothelium. In corneas with Fuchs' dystrophy, less intensive immunoreactivity for GPR35 in endothelium was revealed. The physiological relevance of this phenomenon requires further investigation.

Molecular mechanism of aortic dissection induced by GPR35 / 解放军医学杂志

Objective To investigate the function of G-protein-coupled receptor 35 (GPR35) in aortic dissection (AD) and its mechanism. Methods Thirty wild-type (WT) male mice were randomly divided into the WT+Sham group and WT+AD group (15 each), and 15 GPR35 knockout mice (GPR35-/-) were set as GPR35-/-+AD group. Mice in WT+AD group and GPR35-/-+AD group were back-subcutaneously implanted with angiotensin II [4.5 mg/(kg·24 h)] by miniosmotic pump, while in WT+Sham group received equivalent saline. Mice were sacrificed and the aortas were removed on the 14th postoperative day for further experiments. The mice aortic vascular smooth muscle cell lines (MOVAS) were divided into control group, aortic dissection group (AD group), GPR35 inhibitor group (CID group). The expressions of GPR35 in aorta and MOVAS were determined by q-PCR and Western blotting. The aortas were stained with HE and VVG to detect the formation of aortic dissection and elastic fiber structure. The infiltration of monocyte macrophage (CD68 positive cell) and expression of inflammatory factors (IL)-6 and (TNF)-α in aorta were detected with immunohistochemistry and q-PCR. The apoptosis of aortic smooth muscle was measured by TUNEL staining and flow cytometer. Results Compared with the WT+Sham group, the expression of GPR35 mRNA increased by (1.88±0.07) times and of GPR35 protein increased by (1.34±0.05) times in WT+AD group (P<0.05), and similar results were obtained in cell model; Compared with the WT+AD group, the incidence of AD decreased obviously in GPR35-/-+AD group (53.3% vs. 13.3%, P<0.05), meanwhile the aortic dilatation, media thickness and elastic fiber structure were attenuated evidently; Furthermore, the mononuclear macrophage infiltration (CD68 positive cells) were elevated in WT+AD group than in WT+Sham group and GPR35-/-+ AD group [(32.8±1.1)% vs. (5.1±0.9)% vs. (16.0±1.1)%] with statistical significance (P<0.05). The expression levels of IL-6 and TNF-α mRNA were higher in WT+AD group (2.6±0.1, 1.8±0.1) than in WT+Sham group (both 1.00±0.06) and GPR35-/-+ AD group (1.6±0.1, 1.4±0.1) with statistical significance (P<0.05); The number of apoptotic aortic smooth muscle cells in WT+AD group [(24.0±0.7)%] was more than that in WT+Sham group and GPR35-/-+AD group [(6.6±0.5)% and (11.2±0.9)%] with statistical significance (P<0.05). Meanwhile, the apoptosis rate of MOVAS was also significantly higher in AD group [(11.6±0.5)%] than in control group and CID group [(4.7±0.4)% and (7.6±0.4)%, P<0.05]. Conclusion Inhibition of GPR35 can protect aortic dissection by preventing aortic inflammation and smooth muscle apoptosis.

Disruption of GPR35 Exacerbates Dextran Sulfate Sodium-Induced Colitis in Mice.

BACKGROUND: G protein-coupled receptor 35 (GPR35) is an orphan receptor and is vastly expressed in immune cells and gastrointestinal cells, suggesting the potential physiological importance of GPR35 in these cells. Here, we tested the hypothesis that the lack of GPR35 expression in the colon mucosa exacerbates the severity of dextran sulfate sodium (DSS)-induced experimental colitis in mice. METHODS: Colitis was induced in GPR35 wild-type (GPR35+/+) and GPR35 knockout (GPR35-/-) mice through the administration of DSS in drinking water for 5 days followed by regular facility water for 1 day. Induction of colitis was evaluated by measuring relative body weight loss, clinical illness scores, and morphological changes in the colon. Abolition of Gpr35 gene expression in the colon mucosa of GPR35-/- mice was confirmed by quantitative real-time PCR (qPCR). Gene expressions of inflammatory and tissue remodeling cytokines were detected by qPCR. Human colorectal epithelial Caco cells were transfected with siRNA against GPR35 before treated with 1% DSS in vitro. Protein expressions were measured using Western blot. RESULTS: GPR35-/- mice receiving DSS showed a significantly worsened colitis disease with profound loss of body weight and a considerable amount of severe clinical illness compared to GPR35+/+ mice that received DSS. The histology of colon sections from GPR35-/- mice showed extensive pathological changes including submucosal edema, diffuse ulcerations, and evidence of complete loss of crypts compared to wild-type mice. The mean histopathological score was significantly higher in GPR35-/- mice as compared to GPR35+/+ mice. The qPCR data revealed significant expression of pro-inflammatory and tissue remodeling cytokines in GPR35-/- colon mucosa, including IL-1ß, CXCL1, CXCL2, CCL2, HMGB1, TGFß1, TGFß3, MMP1/9/12. The protein expressions of Zonula occludens-1, E-cadherin, Claudin1 were decreased upon knocking down GPR35 with or without 1% DSS treatment. CONCLUSIONS: Our experimental data suggest that lack of GPR35 resulted in worsened disease outcome in DSS-induced experimental colitis, indicating that GPR35 could play a crucial role in protecting from colonic inflammation and serve as a therapeutic target.

Kynurenic Acid: The Janus-Faced Role of an Immunomodulatory Tryptophan Metabolite and Its Link to Pathological Conditions.

Tryptophan metabolites are known to participate in the regulation of many cells of the immune system and are involved in various immune-mediated diseases and disorders. Kynurenic acid (KYNA) is a product of one branch of the kynurenine pathway of tryptophan metabolism. The influence of KYNA on important neurophysiological and neuropathological processes has been comprehensively documented. In recent years, the link of KYNA to the immune system, inflammation, and cancer has become more apparent. Given this connection, the anti-inflammatory and immunosuppressive functions of KYNA are of particular interest. These characteristics might allow KYNA to act as a "double-edged sword." The metabolite contributes to both the resolution of inflammation and the establishment of an immunosuppressive environment, which, for instance, allows for tumor immune escape. Our review provides a comprehensive update of the significant biological functions of KYNA and focuses on its immunomodulatory properties by signaling via G-protein-coupled receptor 35 (GPR35)- and aryl hydrocarbon receptor-mediated pathways. Furthermore, we discuss the role of KYNA-GPR35 interaction and microbiota associated KYNA metabolism for gut homeostasis.

Siblings with opposite chromosome constitutions, dup(2q)/del(7q) and del(2q)/dup(7q).

Chromosome 7q36 microdeletion syndrome is a rare genomic disorder characterized by underdevelopment of the brain, microcephaly, anomalies of the sex organs, and language problems. Developmental delay, intellectual disability, autistic spectrum disorders, BDMR syndrome, and unusual facial morphology are the key features of the chromosome 2q37 microdeletion syndrome. A genetic screening for two brothers with global developmental delay using high-resolution chromosomal analysis and subtelomeric multiplex ligation-dependent probe amplification revealed subtelomeric rearrangements on the same sites of 2q37.2 and 7q35, with reversed deletion and duplication. Both of them showed dysmorphic facial features, severe disability of physical and intellectual development, and abnormal genitalia with differential abnormalities in their phenotypes. The family did not have abnormal genetic phenotypes. According to the genetic analysis of their parents, adjacent-1 segregation from their mother's was suggested as a mechanism of their gene mutation. By comparing the phenotypes of our patients with previous reports on similar patients, we tried to obtain the information of related genes and their chromosomal locations.