A regulatory circuit comprising GATA1/2 switch and microRNA-27a/24 promotes erythropoiesis.

Transcriptional networks orchestrate complex developmental processes, and such networks are commonly instigated by master regulators for development. By now, considerable progress has been made in elucidating GATA factor-dependent genetic networks that control red blood cell development. Here we reported that GATA-1 and GATA-2 co-regulated the expression of two microRNA genes, microRNA-27a and microRNA-24, with critical roles in regulating erythroid differentiation. In general, GATA-2 occupied the miR-27a≈24 promoter and repressed their transcription in immature erythroid progenitor cells. As erythropoiesis proceeded, GATA-1 directly activated miR-27a≈24 transcription, and this involved a GATA-1-mediated displacement of GATA-2 from chromatin, a process termed 'GATA switch'. Furthermore, the mature miR-27a and miR-24 cooperatively inhibited GATA-2 translation and favoured the occupancy switch from GATA-2 to GATA-1, thus completing a positive feedback loop to promote erythroid maturation. In line with the essential role of GATA factors, ectopic expression of miR-27a or miR-24 promoted erythropoiesis in human primary CD34+ haematopoietic progenitor cells and mice, whereas attenuated miR-27 or miR-24 level led to impaired erythroid phenotypes in haematopoietic progenitor cells and zebrafish. Taken together, these data integrated micro RNA expression and function into GATA factor coordinated networks and provided mechanistic insight into a regulatory circuit that comprised GATA1/2 switch and miR-27a/24 in erythropoiesis.

A comprehensive analysis of GATA-1-regulated miRNAs reveals miR-23a to be a positive modulator of erythropoiesis.

miRNAs play important roles in many biological processes, including erythropoiesis. Although several miRNAs regulate erythroid differentiation, how the key erythroid regulator, GATA-1, directly orchestrates differentiation through miRNA pathways remains unclear. In this study, we identified miR-23a as a key regulator of erythropoiesis, which was upregulated both during erythroid differentiation and in GATA-1 gain-of-function experiments, as determined by miRNA expression profile analysis. In primary human CD34+ hematopoietic progenitor cells, miR-23a increased in a GATA-1-dependent manner during erythroid differentiation. Gain- or loss-of-function analysis of miR-23a in mice or zebrafish demonstrated that it was essential for normal morphology in terminally differentiated erythroid cells. Furthermore, a protein tyrosine phosphatase, SHP2, was identified as a downstream target of miR-23a that mediated its regulation of erythropoiesis. Taken together, our data identify a key GATA-1-miRNA axis in erythroid differentiation.

Changes of bile acids and resting energy expenditure after laparoscopic cholecystectomy in type 2 diabetes patients: a prospective study.

BACKGROUND: We aimed to investigate changes of bile acids and resting energy expenditure (REE) in patients with type 2 diabetes mellitus (T2DM) after laparoscopic cholecystectomy (LC) and the role in metabolic homeostasis. METHODS: From December 2019 to December 2021, a total of 77 T2DM patients with gallbladder polyps were included in our study. Among them, 40 patients who underwent LC were enrolled into the cholecystectomy group, and 37 patients who did not undergo LC were enrolled into the control group. Preoperative and 6-months postoperative demographic data, body weight, food intake, effects on diabetes control, and biomedical variables were recorded and compared. RESULTS: The mean level of total bile acids (TBA) was higher than that in the control group (P = 0.033) and increased significantly after LC compared to baseline (P = 0.029). The REE level in the cholecystectomy group was higher than that in the control group (P = 0.032) and increased compared to the baseline (P = 0.011). The utilization of carbohydrates increased significantly after LC (P < 0.001) while the utilization of fat decreased (P < 0.001). The mean level of fasting plasma glucose (P = 0.004), hemoglobin A1C (P < 0.001), and homeostasis model assessment-insulin resistance (P = 0.045) decreased after LC. The mean level of total cholesterol (P = 0.003) and low-density lipoprotein cholesterol significantly decreased (P = 0.021), whereas the level of high-density lipoprotein cholesterol increased (P < 0.001). CONCLUSIONS: The level of REE and TBA increased after LC in patients with T2DM, and the glucose and lipid metabolism improved. Trial registration This study was registered in the Chinese Clinical Trial Registry on November 30, 2018, registered number: ChiCTR1900027823.

The effect of aging on glucose metabolism improvement after Roux-en-Y gastric bypass in type 2 diabetes rats.

BACKGROUND: This study aimed to investigate the effect of aging on glucose metabolism improvement after Roux-en-Y gastric bypass (RYGB) in rat models with type 2 diabetes mellitus (T2DM). METHODS: Twenty aged Goto-Kakizaki rats were randomly assigned into RYGB-A group and sham RYGB (SR-A) group, and 10 adult Goto-Kakizaki rats also accept RYGB procedures (RYGB-Y). Glucose metabolism, resting energy expenditure (REE), glucagon-like peptide-1 (GLP-1) and total bile acid level were measured. RESULTS: RYGB could significantly improve glucose metabolism in aged diabetic rats. The fasting blood glucose level in the RYGB-A group decreased from 15.8 ± 1.1 mmol/l before surgery to 12.3 ± 1.5 mmol/l 16 weeks after surgery (P < 0.01), and the AUCOGTT value decreased from 2603.9 ± 155.4 (mmol/l) min to 2299.9 ± 252.8 (mmol/l) min (P = 0.08). The decrease range of fasting blood glucose in the RYGB-A group was less than that in the RYGB-Y group (20.5% ± 6.5% vs. 40.6% ± 10.6%, P < 0.01), so is the decrease range of AUCOGTT value (11.6% ± 14.8% vs. 38.5% ± 8.3%, P < 0.01). Moreover, at the 16th postoperative week, the increase range of REE of the RYGB-A group was lower than that of the RYGB-Y group (15.3% ± 11.1% vs. 29.1% ± 12.1%, P = 0.04). The increased range of bile acid of the RYGB-A group was less than that of the RYGB-Y group (80.2 ± 59.3 % vs.212.3 ± 139.0 %, P < 0.01). The GLP-1 level of the RYGB-A group was less than that of the RYGB-Y group (12.8 ± 3.9 pmol/L vs. 18.7 ± 5.6 pmol/L, P = 0.02). There was no significant difference between the RYGB-A group and the RYGB-Y group in the level of the triiodothyronine level. CONCLUSIONS: RYGB could induce a glucose metabolism improvement in aged diabetic rats, and aging might moderate the effect of RYGB.

Biliary diversion increases resting energy expenditure leading to decreased blood glucose level in mice with type 2 diabetes.

AIMS/INTRODUCTION: Type 2 diabetes mellitus is a group of metabolism abnormalities in carbohydrates and energy. Our aim was to investigate resting energy expenditure (REE) and blood glucose changes after biliary diversion in mice with diabetes. MATERIALS AND METHODS: Male mice with diabetes were randomly divided into biliary diversion and sham groups. REE was detected by indirect calorimetry, the levels of fasting blood glucose, total bile acids and triiodothyronine were analyzed. After mice were killed, the weight amount of brown adipose tissue (BAT) and gastrocnemius was measured, and the expression level of G protein-coupled bile acid receptor and type 2 iodothyronine deiodinase in BAT and gastrocnemius were examined. RESULTS: The two groups of mice were pair-fed, the bodyweights (P < 0.001) and the fasting blood glucose level (P < 0.001) in the biliary diversion group significantly decreased 24 weeks after surgery. The intraperitoneal glucose tolerance test (P = 0.035) and oral glucose tolerance test (P = 0.027) showed improvement in glucose tolerance after surgery. The REE level significantly increased 24 weeks after surgery (P = 0.005), the levels of total bile acids (P = 0.014) and triiodothyronine (P < 0.001) increased at the 24th postoperative week. The weight ratio of BAT (P = 0.038) and gastrocnemius (P = 0.026) in the biliary diversion group were higher than that in the sham group. The expression of G protein-coupled bile acid receptor in BAT (P < 0.001) and gastrocnemius (P = 0.003) were upregulated after surgery, and the type 2 iodothyronine deiodinase expression also increased in BAT (P = 0.015) and gastrocnemius (P = 0.015). CONCLUSIONS: The REE level increased and the glucose metabolism improved in mice with diabetes after biliary diversion.

Improvement of Postprandial Lipid Metabolism After Ileal Transposition in Non-obese Diabetic Rats.

BACKGROUND: Ileal transposition (IT) could reduce obesity and improve type 2 diabetes mellitus (T2DM). The main aim of our study was to investigate lipid metabolism changes in T2DM rats after IT without a weight reduction effect. METHODS: Thirty male diabetic rats were randomly divided into IT, sham IT (SI), and control groups. The levels of plasma cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TGs), and bile acid were measured. After sacrifice, the white adipose tissue, brown adipose tissue and liver were weighed. RESULTS: IT induced significant improvement in glucose and lipid metabolism. There were no significant differences in the levels of cholesterol (P = 0.87), HDL (P = 0.70), LDL (P = 0.96), or TGs (P = 0.97) among the groups before surgery. After IT, the levels of cholesterol (P = 0.019), LDL (P = 0.004), and TGs (P < 0.001) were lower than those in the SI and control groups, while the level of HDL was not significantly different compared to those of the other groups (P = 0.437). Higher bile acid level (P = 0.001), lower white adipose tissue/total body weight ratio (P < 0.001), and lower liver/total body weight ratio (P = 0.003) were found in the IT group. The BAT/total body weight ratio in the IT group was higher than that in the SI or control groups (P = 0.002). CONCLUSIONS: IT could improve lipid metabolism in diabetic rats.

Biliary Neuroendocrine Neoplasms: Analysis of Prognostic Factors and Development and Validation of a Nomogram.

BACKGROUND: For this study, we explored the prognostic profiles of biliary neuroendocrine neoplasms (NENs) patients and identified factors related to prognosis. Further, we developed and validated an effective nomogram to predict the overall survival (OS) of individual patients with biliary NENs. METHODS: We included a total of 446 biliary NENs patients from the SEER database. We used Kaplan-Meier curves to determine survival time. We employed univariate and multivariate Cox analyses to estimate hazard ratios to identify prognostic factors. We constructed a predictive nomogram based on the results of the multivariate analyses. In addition, we included 28 biliary NENs cases from our center as an external validation cohort. RESULTS: The median survival time of biliary NENs from the SEER database was 31 months, and the value of gallbladder NENs (23 months) was significantly shorter than that of the bile duct (45 months) and ampulla of Vater (33.5 months, p=0.023). Multivariate Cox analyses indicated that age, tumor size, pathological classification, SEER stage, and surgery were independent variables associated with survival. The constructed prognostic nomogram demonstrated good calibration and discrimination C-index values of 0.783 and 0.795 in the training and validation dataset, respectively. CONCLUSION: Age, tumor size, pathological classification, SEER stage, and surgery were predictors for the survival of biliary NENs. We developed a nomogram that could determine the 3-year and 5-year OS rates. Through validation of our central database, the novel nomogram is a useful tool for clinicians in estimating individual survival among biliary NENs patients.

Biliary Jejunostomy Might Improve Glucose in Type 2 Diabetes Patients.

PURPOSES: Biliopancreatic diversion could improve type 2 diabetes mellitus. Our aim was to investigate the effects of biliary jejunostomy on the improvement of glucose. MATERIALS AND METHODS: Twenty-seven type 2 diabetes patients underwent biliary jejunostomy between January 2013 and January 2018 in our hospital and were followed up. Demographic data, operation details, body weight, food intake, effects on diabetes control, and biomedical parameters were collected and analyzed. RESULTS: As defined previously, 3 of 27 diabetes patients were "under control," 8 patients were "in remission," and 12 patients were "improved." The fasting glucose decreased from 9.7 ± 2.1 mmol/L before surgery to 7.9 ± 1.8 mmol/L 12 months after surgery (P = 0.001). The level of hemoglobin A1c in these patients was 9.1 ± 2.3% before surgery, and it decreased to 7.2 ± 1.3% 12 months after surgery (P < 0.001). There was no significant difference in the body weight index (P = 0.78) or food intake (P = 0.18) between the time prior to surgery and 12 months afterward. The average level of total bile acids increased significantly after surgery, from 6.7 ± 2.2 µmol/L before surgery to 8.6 ± 2.9 µmol/L 12 months after surgery (P < 0.001). CONCLUSIONS: Fasting glucose in type 2 diabetes patients was improved after biliary jejunostomy. Increasing bile acids levels might play an important role in the remission of type 2 diabetes.

Changes of Resting Energy Expenditure in Type 2 Diabetes Rats After Roux-en-Y Gastric Bypass.

BACKGROUND: This study aimed to investigate the changes of resting energy expenditure (REE) induced by Roux-en-Y gastric bypass (RYGB) in diabetic rats. METHODS: Thirty male Goto-Kakizaki rats were randomly divided into RYGB, sham RYGB (SR), and control groups. Glucose metabolism, energy expenditure, triiodothyronine, and bile acid levels were measured. Body composition in different groups was compared after sacrifice. RESULTS: RYGB induced significant diabetic improvement, with decreased maximum food intake and body weight. There was no significant difference in the REE between the groups before surgery (P = 0.74), while the REE of the RYGB group (1.15 ± 0.17 ml/h/g) was higher than that of the SR group (0.99 ± 0.13 ml/h/g) and the control group (0.97 ± 0.13 ml/h/g, P = 0.031) at the 20th postoperative week. The ratio of white adipose tissue in the RYGB group was lower (P = 0.02), and the ratio of brown adipose tissue was higher than that of the SR group and the control group (P = 0.045). Moreover, a higher bile acid level was detected in the RYGB group (6.4 ± 1.8 µmol/L) than in the SR group (4.2 ± 1.7 µmol/L) and the control group (4.0 ± 2.0 µmol/L, P = 0.025). CONCLUSIONS: RYGB induces a higher REE level in diabetic rats. The circulating bile acid level was enhanced after surgery.

DNA Methylation mediated down-regulating of MicroRNA-33b and its role in gastric cancer.

The discovery of microRNAs (miRNAs) provides a new and powerful tool for studying the mechanism, diagnosis and treatment of human cancers. Currently, down-regulation of tumor suppressive miRNAs by CpG island hypermethylation is emerging as a common hallmark of cancer. Here, we reported that the down-regulation of miR-33b was associated with pM stage of gastric cancer (GC) patients. Ectopic expression of miR-33b in HGC-27 and MGC-803 cells inhibited cell proliferation, migration and invasion, which might be due to miR-33b targeting oncogene c-Myc. Moreover, enhanced methylation level of the CpG island upstream of miR-33b in GC patients with down-regulated miR-33b was confirmed by methylation-specific PCR (MSP) amplification. Furthermore, re-introduction of miR-33b significantly suppressed tumorigenesis of GC cells in the nude mice. In conclusion, miR-33b acts as a tumor suppressor and hypermethylation of the CpG island upstream of miR-33b is responsible for its down-regulation in gastric cancer.

Association between microRNA-196a2 rs11614913, microRNA-146a rs2910164, and microRNA-423 rs6505162 polymorphisms and esophageal cancer risk: A meta-analysis.

Many observational studies have found that microRNA-196a2 rs11614913, microRNA-146a rs2910164, and microRNA-423 rs6505162 are associated with esophageal cancer risk. However, the results were mixed and inconsistent among these studies. We conducted a meta-analysis to assess the relationship between the polymorphisms of three microRNAs and esophageal cancer susceptibility. We systematically searched the PubMed and EMBASE databases to screen relevant studies. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to compute the risk of esophageal cancer. Because of the differences in ethnicities, sources of controls, and genotyping methods, the meta-analysis was conducted using a random-effect model regardless of heterogeneity. To further explore potential heterogeneity, we performed subgroup and sensitivity analyses, and publication bias was also evaluated. A total of 6 case-control studies on microRNA-196a2 rs11614913, 4 studies on microRNA-146a rs2910164, and 4 studies on microRNA-423 rs6505162 were considered eligible in the meta-analysis. No statistical association was found between microRNA-196a2 rs11614913, microRNA-146a rs2910164, and microRNA-423 rs6505162 polymorphisms and esophageal cancer susceptibility in any genetic model. Subgroup and sensitivity analyses showed similar results. In summary, based on the currently limited proof, no association exists between microRNA-196a2 rs11614913, microRNA-146a rs2910164, and microRNA-423 rs6505162 polymorphism and esophageal cancer risk. However, the result should be cautiously interpreted because of the heterogeneity among studies. Large, high quality clinical trials are required to verify our findings.

MicroRNA-10a is down-regulated by DNA methylation and functions as a tumor suppressor in gastric cancer cells.

BACKGROUND: MicroRNAs act as posttranscriptional regulators of gene expression in many biological processes. Their deregulations occur commonly in gastric cancer (GC). Although DNA methylation constitutes an important mechanism for microRNA deregulation in cancer, this field largely remains unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Total RNA was extracted from the tissues of 100 patients with GC and four gastric cancer cell lines. The expression levels of miR-10a were determined by real-time PCR with specific TaqMan probes. Moreover, a functional analysis of miR-10a in regulating cell proliferation, migration and invasion was performed. Subsequently, quantitative methylation-specific PCR (qMSP) was used to detect the DNA methylation status in the CpG islands upstream of miR-10a. In this study, we found that the expression of miR-10a in GC cells was lower than that in normal cells, which was due to the hypermethylation of the CpG islands upstream of miR-10a. We also validated the slightly lower expression of miR-10a in GC tissues than their adjacent non-neoplastic tissues in 100 GC patients and confirmed the hypermethylation of CpG islands upstream of miR-10a in some patients. Furthermore, re-introduction of miR-10a into GC cells was able to inhibit cell proliferation, migration and invasion. Bioinformatic and immunoblot analysis indicated that the tumor suppressor roles of miR-10a in GC cells were possibly through targeting HOXA1. CONCLUSIONS/SIGNIFICANCE: Our data indicate that miR-10a acts as a tumor suppressor in GC cells and is partially silenced by DNA hypermethylation in GC, suggesting that miR-10a may serve as a potential diagnostic or therapeutic target of GC.

MicroRNA-219-2-3p functions as a tumor suppressor in gastric cancer and is regulated by DNA methylation.

BACKGROUND AIMS: Gastric cancer is the most frequent gastrointestinal tumor in adults and is the most lethal form of human cancer. Despite of the improvements in treatments, the underlying mechanism of gastric carcinogenesis is not well known. To define novel modulators that regulate susceptibility to tumorgenesis, we focused on miR-219-2-3p. METHODS: Quantitative RT-PCR was employed to investigate the level of miR-219-2-3p in gastric cancer (GC) tissues (n = 113) and their matched adjacent normal tissues (n = 113). In vitro cell proliferation, apoptosis assays, cell migration, and invasion assays were performed to elucidate biological effects of miR-219-2-3p. Since silencing of miRNA by promoter CpG island methylation may be an important mechanism in tumorgenesis, GC cells were treated with 5-aza-2'-deoxycytidine and trichostatin A, and expression changes of miR-219-2-3p were subsequently examined by quantitative RT-PCR. Finally, the methylation status of CpG island upstream of miR-219-2-3p was analyzed by methylation-specific PCR in GC tissues (n = 22). RESULTS: miR-219-2-3p was down-regulated in GC and cell lines. In addition, the experiments documented the lower expression of miR-219-2-3p in GC specimens with higher grade and later stage tumors. Meanwhile, miR-219-2-3p exerted antiproliferative, proapoptotic, and antimetastatic roles and reduced levels of p-ERK1/2 in GC cells. Furthermore, 5-aza-2'-deoxycytidine and trichostatin A increased the expression (~2 fold) of miR-219-2-3p in GC cells. By methylation-specific PCR, DNA methylation in the upstream region of miR-219-2-3p was detected in both adjacent normal tissues and cancer tissues. As expected, the methylation level was considerably higher in the miR-219-2-3p down-regulated group than up-regulated group. CONCLUSIONS: miR-219-2-3p is potentially involved in gastric cancer progression and metastasis by regulating ERK1/2-related signal pathways, which may provide a novel therapeutic strategy for treatment of gastric cancer. Methylation mechanism may be involved in modulating the expression level of miR-219-2-3p in gastric cancer.

A feedback loop consisting of microRNA 23a/27a and the ß-like globin suppressors KLF3 and SP1 regulates globin gene expression.

The developmental stage-specific expression of the human ß-like globin genes has been studied for decades, and many transcriptional factors as well as other important cis elements have been identified. However, little is known about the microRNAs that potentially regulate ß-like globin gene expression directly or indirectly during erythropoiesis. In this study, we show that microRNA 23a (miR-23a) and miR-27a promote ß-like globin gene expression in K562 cells and primary erythroid cells through targeting of the transcription factors KLF3 and SP1. Intriguingly, miR-23a and miR-27a further enhance the transcription of ß-like globin genes through repression of KLF3 and SP1 binding to the ß-like globin gene locus during erythroid differentiation. Moreover, KLF3 can bind to the promoter of the miR-23a∼27a∼24-2 cluster and suppress this microRNA cluster expression. Hence, a positive feedback loop comprised of KLF3 and miR-23a promotes the expression of ß-like globin genes and the miR-23a∼27a∼24-2 cluster during erythropoiesis.