A gut-derived hormone regulates cholesterol metabolism.

The reciprocal coordination between cholesterol absorption in the intestine and de novo cholesterol synthesis in the liver is essential for maintaining cholesterol homeostasis, yet the mechanisms governing the opposing regulation of these processes remain poorly understood. Here, we identify a hormone, Cholesin, which is capable of inhibiting cholesterol synthesis in the liver, leading to a reduction in circulating cholesterol levels. Cholesin is encoded by a gene with a previously unknown function (C7orf50 in humans; 3110082I17Rik in mice). It is secreted from the intestine in response to cholesterol absorption and binds to GPR146, an orphan G-protein-coupled receptor, exerting antagonistic downstream effects by inhibiting PKA signaling and thereby suppressing SREBP2-controlled cholesterol synthesis in the liver. Therefore, our results demonstrate that the Cholesin-GPR146 axis mediates the inhibitory effect of intestinal cholesterol absorption on hepatic cholesterol synthesis. This discovered hormone, Cholesin, holds promise as an effective agent in combating hypercholesterolemia and atherosclerosis.

Combined Molecular and Morphological Imaging of CTCs for HER2-Targeted Chemotherapy Guidance.

Since biomolecules change dynamically with tumor evolution and drug treatment, it is necessary to confirm target molecule expression in real time for effective guidance of subsequent chemotherapy treatment. However, current methods to confirm target proteins require complex processing steps and invasive tissue biopsies, limiting their clinical utility for targeted treatment monitoring. Here, CTCs, as a promising liquid biopsy source, were used to molecularly characterize the target protein HER2. To accurately identify CTCs, we specifically proposed a combined molecular and morphological imaging method, rather than using specific biomarker alone or morphology analysis, we identified CTCs as CK19+/CD45-/HE+. On the basis of the accurate identification of CTCs, we further analyzed the target protein HER2 in clinical patients at the single-CTC level. Comparative analysis of the clinical results of patient pathological tissue and paired blood samples showed that CTCs had a heterogeneous HER2 expression at the single-cell level and showed results inconsistent with the immunohistochemistry results in some cases. CTC-based analysis could help clinicians have a more comprehensive understanding of patient target protein expression. We believe that CTC-based target protein studies are of great significance for the precise management of targeted therapy.

The CREB coactivator CRTC2 controls hepatic lipid metabolism by regulating SREBP1.

Abnormal accumulation of triglycerides in the liver, caused in part by increased de novo lipogenesis, results in non-alcoholic fatty liver disease and insulin resistance. Sterol regulatory element-binding protein 1 (SREBP1), an important transcriptional regulator of lipogenesis, is synthesized as an inactive precursor that binds to the endoplasmic reticulum (ER). In response to insulin signalling, SREBP1 is transported from the ER to the Golgi in a COPII-dependent manner, processed by proteases in the Golgi, and then shuttled to the nucleus to induce lipogenic gene expression; however, the mechanisms underlying enhanced SREBP1 activity in insulin-resistant obesity and diabetes remain unclear. Here we show in mice that CREB regulated transcription coactivator 2 (CRTC2) functions as a mediator of mTOR signalling to modulate COPII-dependent SREBP1 processing. CRTC2 competes with Sec23A, a subunit of the COPII complex, to interact with Sec31A, another COPII subunit, thus disrupting SREBP1 transport. During feeding, mTOR phosphorylates CRTC2 and attenuates its inhibitory effect on COPII-dependent SREBP1 maturation. As hepatic overexpression of an mTOR-defective CRTC2 mutant in obese mice improved the lipogenic program and insulin sensitivity, these results demonstrate how the transcriptional coactivator CRTC2 regulates mTOR-mediated lipid homeostasis in the fed state and in obesity.

Consecutive Sorting and Phenotypic Counting of CTCs by an Optofluidic Flow Cytometer.

Circulating tumor cell (CTC) analysis has been approved for cancer diagnosis and monitoring. However, efficient sorting and high-through phenotypic counting of CTCs from peripheral blood is still a challenge. In this manuscript, we propose an optofluidic flow cytometer (OFCM), which integrates a multistage microfluidic chip and a four-color fluorescence detection system. The OFCM can automatically complete CTC separation, 3D focusing in the microchannel, single-cell phenotypic analysis, and counting at 1.2 mL of whole blood/hour. A high recovery greater than 95% was obtained. Using the OFCM, we analyzed the epithelial-to-mesenchymal transition (EMT) phenotype of CTCs in patients with breast cancer and patients with nonsmall cell lung cancer, which proved that the OFCM is adaptable for phenotypic counting of various CTCs based on the fluorescence labeling of varied biomarkers. We believe that this OFCM will provide a convenient and efficient device for clinical liquid biopsy of tumors.

Single-Cell Phenotypic Profiling of CTCs in Whole Blood Using an Integrated Microfluidic Device.

Single-cell phenotypic profiling of circulating tumor cells (CTCs) in the blood of cancer patients can reveal vital tumor biology information. Even though various approaches have been provided to enrich and detect CTCs, it remains challenging for consecutive CTC sorting, enumeration, and single-cell characterizations. Here, we report an integrated microfluidic device (IMD) for single-cell phenotypic profiling of CTCs that enables automated CTCs sorting from whole blood following continuous single-cell phenotypic analysis while satisfying the requirements of both high purity (92 ± 3%) of cell sorting and high-throughput processing capacity (5 mL whole blood/3 h). Using this new technique we test the phenotypes of individual CTCs collected from xenograft tumor-bearing mice and colorectal (CRC) patients at different tumor stages. We obtained a correlation between CTC characterization and clinical tumor stage and treatment response. The developed IMD offers a high-throughput, convenient, and rapid strategy to study individual CTCs toward minimally invasive cancer therapy prediction and disease monitoring and has the potential to be translated to clinic for liquid biopsy.

1-Deoxynojirimycin modulates glucose homeostasis by regulating the combination of IR-GlUT4 and ADIPO-GLUT4 pathways in 3T3-L1 adipocytes.

1-Deoxynojirimycin (DNJ), the main alkaloid in mulberry leaves, was recognized to treat patients with type 2 diabetes mellitus (T2DM). However, the regulatory mechanism of DNJ on glucose homeostasis was still unclear. In the present study, a safe concentration of 0.1-10 µmol/L for DNJ was incubated with mature 3T3-L1 adipocytes. The results demonstrated that the genes/proteins expression of insulin receptor (IR), phosphatidylinositol-3-kinase (PI3K), protein kinase B (AKt/PkB), and adiponectin (ADIPO) increased with the increasing of DNJ concentration from 0.1-10 µmol/L. However the mRNA expression of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), glucose transporter 4 (GLUT4) and glucose absorption increased to the maximum at concentration of 5 µmol/L then decreased with further increase of DNJ concentration to 10 µmol/L. Both IR and ADIPO signaling pathways simultaneously affect the glucose homeostasis regulation effect of DNJ, whereas the key response target located in AMPK and its effect on subsequent GLUT4 mRNA expression.

Inositol-1,4,5-trisphosphate receptor regulates hepatic gluconeogenesis in fasting and diabetes.

In the fasted state, increases in circulating glucagon promote hepatic glucose production through induction of the gluconeogenic program. Triggering of the cyclic AMP pathway increases gluconeogenic gene expression via the de-phosphorylation of the CREB co-activator CRTC2 (ref. 1). Glucagon promotes CRTC2 dephosphorylation in part through the protein kinase A (PKA)-mediated inhibition of the CRTC2 kinase SIK2. A number of Ser/Thr phosphatases seem to be capable of dephosphorylating CRTC2 (refs 2, 3), but the mechanisms by which hormonal cues regulate these enzymes remain unclear. Here we show in mice that glucagon stimulates CRTC2 dephosphorylation in hepatocytes by mobilizing intracellular calcium stores and activating the calcium/calmodulin-dependent Ser/Thr-phosphatase calcineurin (also known as PP3CA). Glucagon increased cytosolic calcium concentration through the PKA-mediated phosphorylation of inositol-1,4,5-trisphosphate receptors (InsP(3)Rs), which associate with CRTC2. After their activation, InsP(3)Rs enhanced gluconeogenic gene expression by promoting the calcineurin-mediated dephosphorylation of CRTC2. During feeding, increases in insulin signalling reduced CRTC2 activity via the AKT-mediated inactivation of InsP(3)Rs. InsP(3)R activity was increased in diabetes, leading to upregulation of the gluconeogenic program. As hepatic downregulation of InsP(3)Rs and calcineurin improved circulating glucose levels in insulin resistance, these results demonstrate how interactions between cAMP and calcium pathways at the level of the InsP(3)R modulate hepatic glucose production under fasting conditions and in diabetes.

Glucagon-CREB/CRTC2 signaling cascade regulates hepatic BMAL1 protein.

Energy metabolism follows a diurnal pattern responding to the cycles of light and food exposures. Although food availability is a potent synchronizer of peripheral circadian clock in mammals, the underlying mechanism remains elusive. Here, we found that the temporal signals of fasting and refeeding hormones regulate the transcription of Bmal1, a key transcription activator of molecular clock, in the liver. During fasting, glucagon, a major fasting hormone, activates CREB/CRTC2 transcriptional complex that is recruited to Bmal1 promoter to induce its expression. Furthermore, we showed that CRTC2 is required for basal transcriptional regulation of Bmal1 by experiments using either adenovirus-mediated CRTC2 RNAi knockdown or primary Crtc2 null hepatocytes. On the other hand, insulin suppresses fasting-induced Bmal1 expression by inhibiting CRTC2 activity after refeeding. Taken together, our results indicate CRTC2 as a key component of the circadian oscillator that integrates the mammalian clock and energy metabolism.

The CREB coactivator CRTC2 links hepatic ER stress and fasting gluconeogenesis.

In fasted mammals, circulating pancreatic glucagon stimulates hepatic gluconeogenesis in part through the CREB regulated transcription coactivator 2 (CRTC2, also referred to as TORC2). Hepatic glucose production is increased in obesity, reflecting chronic increases in endoplasmic reticulum (ER) stress that promote insulin resistance. Whether ER stress also modulates the gluconeogenic program directly, however, is unclear. Here we show that CRTC2 functions as a dual sensor for ER stress and fasting signals. Acute increases in ER stress triggered the dephosphorylation and nuclear entry of CRTC2, which in turn promoted the expression of ER quality control genes through an association with activating transcription factor 6 alpha (ATF6alpha, also known as ATF6)--an integral branch of the unfolded protein response. In addition to mediating CRTC2 recruitment to ER stress inducible promoters, ATF6alpha also reduced hepatic glucose output by disrupting the CREB-CRTC2 interaction and thereby inhibiting CRTC2 occupancy over gluconeogenic genes. Conversely, hepatic glucose output was upregulated when hepatic ATF6alpha protein amounts were reduced, either by RNA interference (RNAi)-mediated knockdown or as a result of persistent stress in obesity. Because ATF6alpha overexpression in the livers of obese mice reversed CRTC2 effects on the gluconeogenic program and lowered hepatic glucose output, our results demonstrate how cross-talk between ER stress and fasting pathways at the level of a transcriptional coactivator contributes to glucose homeostasis.

Evaluation indexes for symptom changes in Chinese medicine.

OBJECTIVE: To screen and summarize evaluation indexes for symptom changes in Chinese medicine (CM). METHODS: A case database was established based on information from subsequent patient visits from the case records of famous doctors since 1866. Symptom change descriptions in the database were regarded as research materials. The evaluation indexes of the symptom changes were screened and summarized. RESULTS: In total, 243 evaluation indexes for 256 symptoms were summarized. Among them, common symptoms were frequency, quantity, degree, mobility, color, and correlation with fatigue. CONCLUSION: There are many aspects to evaluating the changes in a symptom. Some symptoms occur with other simultaneous symptoms. The alleviation or aggravation of simultaneous symptoms could reflect the corresponding changes in a symptom. The changes of inducing factors are important to judging changes in symptoms.

Effect of recombinant Hepatitis B virus on human glomerular mesangial cell apoptosis.

The aim of this study was to investigate the expression of recombinant Hepatitis B virus (HBV) in normal human glomerular mesangial cells (NHMC) and its effect on cell apoptosis. Cell transfection was conducted by the liposome method. The levels of HBsAg and HBeAg in the culture supernatant were detected by electrochemiluminescence. Morphological changes were observed by light and fluorescence microscopy. Cell proliferation was analysed by the methyl thiazole tetrazolium (MTT) assay and cell apoptosis, by flow cytometry. The expression level of Bax and Bcl-2 mRNA was measured by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR). Caspase-3 activity was detected by a Caspase-3 activity detection kit. The results showed high expression levels of HBsAg and HBeAg in NHMC cells transfected with recombinant full-length C genotype HBV (PHY106-CHBV). Typical apoptotic morphology was observed at 48 h after PHY106-CHBV transfection. Cell proliferation was inhibited. The percentage of apoptotic cells and the expression level of Bax mRNA were significantly higher in the PHY106-CHBV group than those in the blank control group and the PHY106 group. There was no significant difference in the expression level of Bcl-2 mRNA among the three groups. Caspase-3 was significantly activated after PHY106-CHBV transfection. The results demonstrate that recombinant HBV can be expressed in NHMC and its expression induces NHMC apoptosis.

Effects of Dl-3-n-butylphthalide on neurological function, hemodynamics and Hcy concentration in cerebral hemorrhage: a systematic review and meta-analysis.

Background: Dl-3-n-Butylphthalide (NBP) has emerged as a potential therapeutic agent for cerebral hemorrhage, despite not being included in current guideline recommendations. Investigating the underlying physiological and pathological mechanisms of Dl-3-n-Butylphthalide in cerebral hemorrhage treatment remains a critical area of research. Objective: This review aims to evaluate the efficacy of Dl-3-n-Butylphthalide in cerebral hemorrhage treatment and elucidate its potential biological mechanisms, thereby providing evidence to support treatment optimization. Methods: A comprehensive search of seven electronic databases (PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure, VIP, and Wanfang Database) was conducted for studies published up to September 2023. Screening and data extraction were performed by a team of researchers. The Cochrane collaboration tool was utilized for risk bias assessment, and Revman 5.3 along with Stata 17.0 were employed for statistical analysis. Outcomes: We searched 254 literature, and 19 were included in this meta-analysis. The results showed that Dl-3-n-Butylphthalide improved the clinical efficacy rate (RR = 1.25, 95% CI 1.19-1.31; p = 0.00), quality of life (MD = 13.93, 95% CI: 11.88-15.98; p = 0.000), increased cerebral blood flow and velocity, reduced cerebral edema volume, Hcy concentration, and did not have obvious adverse reactions (RR = 0.68, 95% CI: 0.39-1.18; p = 0.10). Conclusion: This meta-analysis is the first to demonstrate the potential of Dl-3-n-Butylphthalide in treating cerebral hemorrhage. It suggests that Dl-3-n-Butylphthalide may alleviate clinical symptoms by modulating neurological function and improving hemodynamics. Our findings provide robust evidence for incorporating Dl-3-n-Butylphthalide into cerebral hemorrhage treatment strategies, potentially guiding future clinical practice and research. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/ display_record.php?RecordID=355114, Identifier CRD42022355114.

DNAzyme-RCA-based colorimetric and lateral flow dipstick assays for the point-of-care testing of exosomal m5C-miRNA-21.

Methylation of microRNAs (miRNAs) is a post-transcriptional modification that affects miRNA activity by altering the specificity of miRNAs to target mRNAs. Abnormal methylation of miRNAs in cancer suggests their potential as a tumor marker. However, the traditional methylated miRNA detection mainly includes mass spectrometry, sequencing and others; complex procedures and reliance on large instruments greatly limit their application in point-of-care testing (POCT). Based on this, we developed DNAzyme-RCA-based gold nanoparticle (AuNP) colorimetric and lateral flow dipstick (LFD) assays to achieve convenient detection of exosomal 5-methylcytosine miRNA-21 (m5C-miRNA-21) for the first time. The two assays achieved specific recognition and linear amplification of m5C-miRNA-21 through the DNAzyme triggered RCA reaction and color output with low background interference through AuNP aggregation induced by base complementary pairing. The lowest concentration of m5C-miRNA-21 visible to the naked eye of the two assays can reach 1 pM and 0.1 pM, respectively. Detection of exosomal m5C-miRNA-21 in clinical blood samples showed that the expression level of m5C-miRNA-21 in colorectal cancer patients was significantly higher than that in healthy individuals. This approach not only demonstrates a new strategy for the detection of colorectal cancer but also provides a reference for the development of novel diagnostic tools for other miRNA methylation-related diseases.

Hepatocellular carcinoma that arose from primary Sjögren's syndrome.

Hepatocellular carcinoma (HCC) typically originates from HBV or HCV associated liver cirrhosis. Primary Sjögren's syndrome (pSS) is a kind of autoimmune disease. A sixty-two year old female patient with mild liver damage was diagnosed with pSS after excluding viral, alcoholic and drug-induced hepatitis according to serum immunological detection and liver biopsy. But when she was hospitalized for a second time two years later, a CT scan revealed liver neoplasm. Surgery confirmed HCC and liver cirrhosis by pathology. The elevated level of AFP recovered to normal after tumorectomy. In conclusion, HCC might be a candidate outcome in patients with pSS; it is the doctors' responsibility to keep this kind of patient under surveillance.

Depletion of PHF14, a novel histone-binding protein gene, causes neonatal lethality in mice due to respiratory failure.

The plant homeodomain (PHD) finger is identified in many chromatin-binding proteins, and functions as a 'reader' that recognizes specific epigenetic marks on histone tails, bridging transcription factors and their associated complexes to chromatin, and regulating gene expression. PHD finger-containing proteins perform many biological functions and are involved in many human diseases including cancer. PHF14 is predicted to code for a protein with multiple PHD fingers. However, its function is unidentified. The aim of this study is to characterize PHF14 and investigate its biological significance by employing multiple approaches including mouse gene-targeting knockout, and molecular cloning and characterization. Three transcripts of PHF14 in human cell lines were identified by reverse transcriptase polymerase chain reaction. Two isoforms of PHF14 (PHF14α and PHF14ß) were cloned in this study. It was found that PHF14 was ubiquitously expressed in mouse tissues and human cell lines. PHF14α, the major isoform of PHF14, was localized in the nucleus and also bound to chromatin during cell division. Interestingly, co-immunoprecipitation results suggested that PHF14α bound to histones via its PHD fingers. Strikingly, gene-targeting knockout of PHF14 in mice resulted in a neonatal lethality due to respiratory failure. Pathological analysis revealed severe disorders of tissue and cell structures in multiple organs, particularly in the lungs. These results indicated that PHF14 might be an epigenetic regulator and play an important role in the development of multiple organs in mouse.

Targeted disruption of the CREB coactivator Crtc2 increases insulin sensitivity.

Under fasting conditions, increases in circulating concentrations of pancreatic glucagon maintain glucose homeostasis through induction of gluconeogenic genes by the CREB coactivator CRTC2. Hepatic CRTC2 activity is elevated in obesity, although the extent to which this cofactor contributes to attendant increases in insulin resistance is unclear. Here we show that mice with a knockout of the CRTC2 gene have decreased circulating glucose concentrations during fasting, due to attenuation of the gluconeogenic program. CRTC2 was found to stimulate hepatic gene expression in part through an N-terminal CREB binding domain that enhanced CREB occupancy over relevant promoters in response to glucagon. Deletion of sequences encoding the CREB binding domain in CRTC2 (-/-) mice lowered circulating blood glucose concentrations and improved insulin sensitivity in the context of diet-induced obesity. Our results suggest that small molecules that attenuate the CREB-CRTC2 pathway may provide therapeutic benefit to individuals with type 2 diabetes.

Effects of NBP injection on the inflammatory response, oxidative stress response and vascular endothelial function in patients with ACI: A systematic review and meta-analysis.

BACKGROUND: Acute cerebral infarction (ACI) is a common medical emergency. This study is the first systematic review of the use of Dl-3-n-butylphthalide (NBP) injection in the treatment of ACI. The purpose of this study was to systematically evaluate the effects of NBP injection on the inflammatory response, oxidative stress response and vascular endothelial function in patients with acute ACI. The objective is to provide reference for clinical application. METHODS: From the establishment of the database until August 2022, we systematically searched EMbase, PubMed, Cochrane Library, Web of Science, CNKI, VIP, and Wanfang Database. RCTs and retrospective studies were included in this study, and the results that qualified for inclusion were screened by 2 researchers and cross-checked. After the relevant data were extracted, a meta-analysis was performed using RevMan5.3 software. RESULTS: A total of 3307 patients with ACI from 34 studies were analyzed. The meta-analysis showed that the C-reactive protein levels in the NBP combined group were effectively reduced compared with those in the control group (MD = -3.75, 95% confidence intervals [95% CI] [-4.95, -2.56], P < .00001). Based on comparison with the control group, it is evident that combination treatment with NBP is more effective than control group in reducing the oxidative stress response of ACI (MD[superoxide dismutase levels] = 22.16, 95% CI [14.20,30.11], P < .00001; MD[malondialdehyde levels] = -1.97, 95% CI [-2.62, -1.32], P < .00001). Comparison with the control group shows that combination treatment with NBP is more effective in improving vascular endothelial function in ACI patients (MD[vascular endothelial growth factor levels] = 71.44, 95% CI [41.22, 101.66], P < .00001; MD[endothelin-1 levels] = -11.47, 95% CI [-17.39, -5.55], P = .0001; MD[nitric oxide levels] = 9.54, 95% CI [8.39, 10.68], P < .00001) than control group. The NBP combined group also showed a greater reduction in cerebral infarct volume (CIV) and cerebral infarct size (CIS) of ACI (MD[CIV] = -1.52, 95% CI [-2.23, -0.81], P < .0001; MD[CIS] = -2.79, 95% CI [-3.65, -1.94], P < .00001). The NBP combined group did not show an increase in the incidence of adverse reactions compared with the control group (odds ratio = 1.06, 95% CI [0.73, 1.53], P = .77). CONCLUSION: In summary, the use of NBP in combination with control group for ACI can reduce the degree of nerve damage, reduce inflammation and oxidative stress, improve vascular endothelial function, and reduce CIS and CIV in ACI patients, without increasing the incidence of clinical adverse events.

Exploration of 2D and 3D-QSAR analysis and docking studies for novel dihydropteridone derivatives as promising therapeutic agents targeting glioblastoma.

Background: Dihydropteridone derivatives represent a novel class of PLK1 inhibitors, exhibiting promising anticancer activity and potential as chemotherapeutic drugs for glioblastoma. Objective: The aim of this study is to develop 2D and 3D-QSAR models to validate the anticancer activity of dihydropteridone derivatives and identify optimal structural characteristics for the design of new therapeutic agents. Methods: The Heuristic method (HM) was employed to construct a 2D-linear QSAR model, while the gene expression programming (GEP) algorithm was utilized to develop a 2D-nonlinear QSAR model. Additionally, the CoMSIA approach was introduced to investigate the impact of drug structure on activity. A total of 200 novel anti-glioma dihydropteridone compounds were designed, and their activity levels were predicted using chemical descriptors and molecular field maps. The compounds with the highest activity were subjected to molecular docking to confirm their binding affinity. Results: Within the analytical purview, the coefficient of determination (R2) for the HM linear model is elucidated at 0.6682, accompanied by an R2 cv of 0.5669 and a residual sum of squares (S2) of 0.0199. The GEP nonlinear model delineates coefficients of determination for the training and validation sets at 0.79 and 0.76, respectively. Empirical modeling outcomes underscore the preeminence of the 3D-QSAR model, succeeded by the GEP nonlinear model, whilst the HM linear model manifested suboptimal efficacy. The 3D paradigm evinced an exemplary fit, characterized by formidable Q2 (0.628) and R2 (0.928) values, complemented by an impressive F-value (12.194) and a minimized standard error of estimate (SEE) at 0.160. The most significant molecular descriptor in the 2D model, which included six descriptors, was identified as "Min exchange energy for a C-N bond" (MECN). By combining the MECN descriptor with the hydrophobic field, suggestions for the creation of novel medications were generated. This led to the identification of compound 21E.153, a novel dihydropteridone derivative, which exhibited outstanding antitumor properties and docking capabilities. Conclusion: The development of 2D and 3D-QSAR models, along with the innovative integration of contour maps and molecular descriptors, offer novel concepts and techniques for the design of glioblastoma chemotherapeutic agents.

Famsin, a novel gut-secreted hormone, contributes to metabolic adaptations to fasting via binding to its receptor OLFR796.

The intestine is responsible for nutrient absorption and orchestrates metabolism in different organs during feeding, a process which is partly controlled by intestine-derived hormones. However, it is unclear whether the intestine plays an important role in metabolism during fasting. Here we have identified a novel hormone, famsin, which is secreted from the intestine and promotes metabolic adaptations to fasting. Mechanistically, famsin is shed from a single-pass transmembrane protein, Gm11437, during fasting and then binds OLFR796, an olfactory receptor, to activate intracellular calcium mobilization. This famsin-OLFR796 signaling axis promotes gluconeogenesis and ketogenesis for energy mobilization, and torpor for energy conservation during fasting. In addition, neutralization of famsin by an antibody improves blood glucose profiles in diabetic models, which identifies famsin as a potential therapeutic target for treating diabetes. Therefore, our results demonstrate that communication between the intestine and other organs by a famsin-OLFR796 signaling axis is critical for metabolic adaptations to fasting.