Adiponectin, Leptin, and Leptin Receptor in Obese Patients with Type 2 Diabetes Treated with Insulin Detemir

Exploring the key target molecules of angiogenesis in diabetic cardiomyopathy based on bioinformatics analysis

Backgrounds

Diabetic cardiomyopathy has a very high incidence and serious clinical consequences, making it an urgent clinical problem to be solved. Angiogenesis is a significant phenotype in the occurrence and development of diabetic cardiomyopathy, especially the damage to angiogenesis of cardiac microvessels, which is inextricably linked to the cardiac risk of diabetic patients. In the current basic and clinical research, there is still a lack of treatment methods that directly target the angiogenesis of diabetic cardiomyopathy. This study hopes to discover the key molecules related to diabetic cardiomyopathy and angiogenesis damage, to provide ideas for possible interventions.

Methods

Sequencing data of animals and cells were obtained from the GEO database, and differentially expressed genes were analyzed. Subsequently, the angiogenesis-related genes were clustered for functional and pathway analysis. Then, the microangiogenesis of the diabetic mice and the angiogenesis changes of high glucose-stimulated HUVECs were verified, and the top three genes related to diabetic cardiomyopathy and angiogenesis were verified using western blot.

Results

24 differentially expressed genes associated with angiogenesis were found in GSE241565(human) and GSE215979(mice). Among them, 11 genes showed the same trend in the two databases. Then CD31 staining of diabetic mice hearts showed that microvascular angiogenesis was impaired, high glucose-stimulated HUVECs decreased tube formation, and wound healing migration was weakened. Finally, the top 3 genes most associated with diabetic cardiomyopathy were verified, and there was no significant difference between the changes of Edn1 and Lepr. At the same time, Efnb2 was significantly increased under high glucose stimulation.

Conclusion

Combined with the sequencing data of animal and cell models of diabetic cardiomyopathy, the differential genes associated with angiogenesis were screened. These findings not only elucidate a novel molecular axis linking angiogenesis damage to diabetic cardiomyopathy but also highlight Efnb2 as a potential therapeutic target.

White adipose tissue in type 2 diabetes and the effect of antidiabetic drugs

White adipose tissue (WAT) is highly flexible and was previously considered a passive location for energy storage. Its endocrine function has been established for several years, earning it the title of an "endocrine organ" due to its ability to secrete many adipokines that regulate metabolism. WAT is one of the core tissues that influence insulin sensitivity. Its dysfunction enhances insulin resistance and type 2 diabetes (T2D) progression. However, T2D may cause WAT dysfunction, including changes in distribution, metabolism, adipocyte hypertrophy, inflammation, aging, and adipokines and free fatty acid levels, which may exacerbate insulin resistance. This review used PubMed to search WAT dysfunction in T2D and the effects of these changes on insulin resistance. Additionally, we described and discussed the effects of antidiabetic drugs, including insulin therapy, sulfonylureas, metformin, glucose-like peptide-1 receptor agonists, thiazolidinediones, and sodium-dependent glucose transporters-2 inhibitors, on WAT parameters under T2D conditions.

Increased Leptin Levels in Plasma and Serum in Patients with Metabolic Disorders: A Systematic Review and Meta-Analysis

A large number of studies have reported the relationships between leptin levels and diabetes or obesity. However, the results are still controversial, and no consensus has been reached. Therefore, the purpose of the study was to collect data from various databases to perform a meta-analysis and address the inconsistencies in these studies. A systematic literature search was conducted on PubMed, Web of Science, and EBSCO for relevant available articles. The pooled standard mean difference (SMD) with 95% confidence interval (CI) was used to estimate the association by a meta-analysis. Fifteen reports with 1,388 cases and 3,536 controls were chosen for the meta-analysis. First, an increase in leptin levels in serum (SMD 0.69; 95% CI 0.36-1.02 ng/mL) and plasma (SMD 0.46; 95% CI 0.18-0.74 ng/mL) was observed in individuals with diabetes compared to controls. This increased level was also observed by gender and population. Second, statistical analysis showed that leptin levels in serum were significantly increased in individuals with obesity (SMD 1.03; 95% CI 0.72-1.34 ng/mL). This meta-analysis analyzed leptin in individuals with diabetes or obesity and emphasized the importance of monitoring serum/plasma leptin levels in patients with these diseases. However, more comprehensive studies are necessary in order to draw firm conclusions.

Adipokine receptor expression in mast cells is altered by specific ligands and proinflammatory cytokines

Adipokines play essential roles in regulating a range of biological processes, but growing evidence indicates that they are also fundamental in immunological mechanisms and, primarily, inflammatory responses. Adipokines mediate their actions through specific receptors. However, although adipokine receptors are widely distributed in many cell and tissue types, limited data are available on their expression in mast cells (MCs) and, consequently, adipokine's significance in the modulation of MC activity within the tissues. In this study, we demonstrate that rat peritoneal MCs constitutively express the leptin receptor (i.e. LEPR), adiponectin receptors (i.e. ADIPOR1 and ADIPOR2) and the chemerin receptor (i.e. CMKLR1). We also found that LEPR, ADIPOR1, ADIPOR2 and CMKLR1 expression in MCs changes in response to stimulation by their specific ligands and some cytokines with potent proinflammatory properties. Furthermore, the involvement of intracellular signaling molecules in leptin-, adiponectin- and chemerin-induced MC response was analyzed. Overall, our findings suggest that adipokines leptin, adiponectin and chemerin can significantly affect the activity of MCs in various processes, especially during inflammation. These observations may contribute significantly to understanding the relationship between adipokines, immune mechanisms and diseases or conditions with an inflammatory component.

Effect of metformin on Wnt5a in individuals new-onset type 2 diabetes with different body mass indexes: The evidences from the real word research

Aim

Metformin is a first-line therapy for the treatment of Type 2 diabetes mellitus (T2DM), due to its inhibition of hepatic gluconeogenesis. Wingless family member 5a (Wnt5a) was significantly decreased in newly diagnosed T2DM patients and regulates secretion of β cells through the Wnt/calcium signalling cascades. This study aims to investigate how metformin works on glucose-lowering effects in diabetes and whether the mechanism underlying it is associated with Wnt5a.

Methods

A total of 144 participants were enrolled in this study. Serum Wnt5a levels were measured by an enzyme-linked immunosorbent assay (ELISA). The demographic and clinical parameters were evaluated in normal weight, overweight and obese new-onset T2DM subjects grouped.

Results

Wnt5a was increased in overweight T2DM patients and obese T2DM patients compared with the levels in normal Body Mass Index (BMI) T2DM. The level of Wnt5a gradually increased after 3 and 6 months of metformin treatment. Among the three groups, the most significant improvement in blood glucose was observed in the obese type 2 diabetic patients, and the improvement showed a significant correlation with Wnt5a protein after patients received metformin treatment. Pearson correlation showed that there was a significant relationship between △2hOGTT and Wnt5a. After further adjusting for sex and age, a significant association existed only between Wnt5a and 2-h oral glucose tolerance test(2hOGTT), and this association was negative.

Conclusion

Our results indicate that Wnt5a may play a role in the mechanism by which metformin improves blood glucose in patients with type 2 diabetes.

Urinary sulphated glycosaminoglycans excretion in obese patients with type 2 diabetes mellitus treated with metformin

OBJECTIVE

The pattern of urinary excretion of total sulphated glycosaminoglycans (GAGs) and their particular types: chondroitin sulphate/dermatan sulphate (CS/DS) and heparan sulphate (HS) was analysed in obese patients with type 2 diabetes mellitus (T2DM) treated with metformin in monotherapy for the period of six months.

METHODS

The urinary sulphated glycosaminoglycans were quantitated using standardised dye (1.9-dimethylmethylene blue)-binding method and normalised to creatinine level.

RESULTS

Urinary total GAGs, CS/DS and HS levels were significantly higher in untreated diabetic patients in comparison to healthy subjects. Moreover, it was observed that urinary total GAGs, CS/DS and HS levels in diabetic patients after six-month metformin therapy were significantly decreased versus pre-treatment situation.

CONCLUSIONS

The obtained results suggest that the six-month treatment with metformin in obese patients with T2DM has a regulating influence on the systemic changes in proteoglycans/glycosaminoglycans, resulting in a decrease in the urinary excretion of total GAGs, CS/DS and HS.

Expression of leptin mRNA as non-invasive biomarker in type 2 diabetes mellitus

CONTEXT

Leptin, an adipocyte-derived signalling molecule that plays important role in the regulation of energy balance, body weight and glucose metabolism.

OBJECTIVE

To evaluate leptin mRNA expression as a predictive biomarker in type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

To detect the expression patterns of leptin mRNA, a quantitative real-time polymerase chain reaction was performed on samples collected from 71 T2DM patients and 32 non-diabetic controls. The receiver operating characteristic curve (ROC) was utilised to assess the discriminatory power of leptin mRNA.

RESULTS

Leptin mRNA levels were reduced significantly in diabetic patients compared with non-diabetic controls (P ≤ .0001). The ROC curve analysis showed a significant association between leptin mRNA levels and T2DM (P ≤ .0001), with a high area under the ROC curve (AUC) of 0.95 (95% CI: 0.89-0.98). The analysis also showed that fasting blood glucose and glycosylated haemoglobin had high AUC values of 0.88 and 0.97 with (95% CI: 0.80-0.93 and 0.92-0.99), respectively.

CONCLUSION

This study shows that the reduced leptin mRNA expression level is significantly associated with T2DM and could be used as a predictive and diagnostic biomarker for T2DM.

Distribution of subcutaneous and intermuscular fatty tissue of the mid-thigh measured by MRI-A putative indicator of serum adiponectin level and individual factors of cardio-metabolic risk

Obesity and metabolic syndrome (MetS) are associated with hypoadiponectinemia. On the contrary, studies revealed correlations between the amount of subcutaneous adipose tissue (SAT) and higher serum adiponectin levels. Furthermore, independent association of intermuscular adipose tissue (IMAT) deposit in the thigh with cardiometabolic risk factors (including total blood cholesterol, low-density lipoprotein (LDL), and triglycerides), and decreased insulin sensitivity, as MetS components, are sufficiently described. The combined relationship of thigh IMAT and SAT with serum adiponectin, leptin levels, and cardiometabolic risk factors have not been investigated till date. Since both SAT and IMAT play a role in fat metabolism, we hypothesized that the distribution pattern of SAT and IMAT in the mid-thigh might be related to adiponectin, leptin levels, and serum lipid parameters. We performed adipose tissue quantification using magnetic resonance imaging (MRI) of the mid-thigh in 156 healthy volunteers (78 male/78 female). Laboratory measurements of lipid panel, serum adiponectin, and leptin levels were conducted. Total serum adiponectin level showed a significant correlation with the percentage of SAT of the total thigh adipose tissue (SAT/ (IMAT+SAT)) for the whole study population and in sex-specific analysis. Additionally, SAT/(IMAT+SAT) was negatively correlated with known cardiometabolic risk factors such as elevated total blood cholesterol, LDL, and triglycerides; but positively correlated with serum high-density lipoprotein. In multiple linear regression analysis, (SAT/(IMAT+SAT)) was the most strongly associated variable with adiponectin. Interestingly, leptin levels did not show a significant correlation with this ratio. Adipose tissue distribution in the mid-thigh is not only associated to serum adiponectin levels, independent of sex. This proposed quantitative parameter for adipose tissue distribution could be an indicator for individual factors of a person`s cardiometabolic risk and serve as additional non-invasive imaging marker to ensure the success of lifestyle interventions.

Circular RNA expression profile in transgenic diabetic mouse kidneys

Background

Diabetic nephropathy is one of the most important complications in patients with diabetes. The etiology and pathogenesis of diabetic nephropathy remain unclear. Several studies have indicated that circular RNAs (circRNAs) play crucial regulatory roles in numerous human diseases and normal physiology; however, to date, no study has focused on the comprehensive expression profile of circRNAs in the kidneys of diabetic mice. Therefore, we aimed to identify differentially expressed circRNAs in diabetic mouse kidneys to explore the possible roles of dysregulated circRNAs in diabetic nephropathy development.

Results

Diabetic BKS-Lepr^em2Cd479/Nju (BKS-DB/Nju) mice and their nondiabetic wild-type littermates of C57BL/KsJ wild-type (WT) mice were used as experimental animals. Among all circRNAs identified by high-throughput RNA sequencing, four circRNAs were upregulated and ten were downregulated in diabetic mouse kidneys compared to those in nondiabetic mouse kidneys. After verification using quantitative reverse transcriptase polymerase chain reaction assays, we found that circR_1084, circR_182, circR_4, circR_50, circR_596, circR_897, and circR_203 were downregulated, whereas circR_627, circR_628, circR_735, and circR_801 were upregulated in the renal tissues of 8- and 16-week-old BKS-DB/Nju mice compared to those in WT mice.

Conclusion

We studied the circRNA expression profile in the kidneys of diabetic mice. Differentially expressed circRNAs may be useful as candidate biomarkers for diabetic nephropathy. Collectively, our results provide a novel theoretical basis for further investigation of the regulatory roles of circRNA in the etiology and pathogenesis of diabetic nephropathy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-021-00270-z.

Association between Single Nucleotide Polymorphism rs9891119 of STAT3 Gene and the Genetic Susceptibility to Type 2 Diabetes in Chinese Han Population from Guangdong

Background

The aim of this study was to investigate the association between single nucleotide polymorphism (SNP) rs9891119 of the signal transducer and activator of the transcription 3 (STAT3) gene and genetic susceptibility to type 2 diabetes in Chinese Han population from the Guangdong province.

Objective

The aim of the present study was to explore the relationship between single nucleotide polymorphism rs9891119 of STAT3 gene and type 2 diabetes mellitus (T2DM), which provides a basis for molecular genetic research on the pathogenesis of T2DM in Chinese Han population.

Methods

In our case-control study, the SNP rs9891119 was picked out from the STAT3 gene and the SNP genotyping was performed by using the SNPscan^™ kit in 1092 patients with type 2 diabetes as cases and 1092 normal persons as controls. The distributions of genotype and allele frequencies in two groups were analyzed by SPSS 20.0 software.

Results

Our results showed that the alleles of A and C of rs9891119 of the STAT3 gene were 54.3 and 45.7% in patients with type 2 diabetes, while 55.5% and 44.5% in the normal persons, which have no statistical significance (P > 0.05). There were also no significant differences in AA, AC, and CC genotype frequencies between type 2 diabetes patients and normal persons. There were no significant differences in codominant, dominant, recessive, and overdominant genetic models of SNP rs9891119 before and after adjusting the covariant factors (P > 0.05).

Conclusions

Therefore, genetic susceptibility to type 2 diabetes may be not associated with SNP rs9891119 of the STAT3 gene in Chinese Han population from the Guangdong province.

Effect of Ileal Transposition (IT) on Angiopoietin-Like Protein-8 (ANGPTL8) and Pentraxin (PTX3) Plasma Level in Sprague-Dawley Rats Fed High-Fat Diet (HFD)

BACKGROUND

Metabolic surgery procedures are designed not only for sustained weight loss but also for achieving positive metabolic changes, including improved glucose tolerance and insulin sensitivity, along with an increase in energy expenditure. Based on recent findings, the present study focuses on the relationship between the effects of ileal transposition (IT), high-fat diet (HFD), and selected markers of lipid metabolism and inflammation.

METHODS

Forty-eight male rats were divided into two groups: HFD and control diet (CD) fed rats. After eight weeks, animals in each group were randomly assigned to two types of surgery: IT and SHAM. Thereafter, fifty percent of the animals in the HFD and CD groups had their diets changed, while the remaining half maintained their presurgery diets. Eight weeks after surgery, plasma levels of ANGPTL8, PTX3, leptin, and adiponectin were assessed.

RESULTS

The IT group pre- and postoperatively maintained on the HFD showed higher ANGPTL8 level compared to SHAM operated animals (p=0.0041). The effect of IT on PTX3 level in the group pre- and postoperatively maintained on a CD was not significant, and there were no differences compared to SHAM. Only the postoperative diet change to HFD increased PTX3 level in the IT operated animals (p=0.0002). The IT group had increased plasma adiponectin (p=0.026) and leptin (p=0.0027) levels after dietary change to HFD compared to IT rats fed CD.

CONCLUSIONS

This study indicates that the outcomes of metabolic surgery can be greatly modified by HFD. The effects of the IT procedure in this experiment are ambiguous and do not provide a clear answer as to whether or not they are beneficial.

Comparison of Insulin Glargine and Detemir Effects on Hormones of Appetite and Metabolic Control in Patients with Type 1 Diabetes: A Randomized Clinical Trial

The aim of this study was to compare the insulin glargine and detemir effects on hormons affecting appetite and metabolic control of patients with type 1 diabetes. This single-blind randomized clinical trial was conducted on patients aged 2 to 18 years with type 1 diabetes who were referred to the endocrinology department of Ali-Asghar Children Hospital in Tehran, from April to September 2019. Patients were randomly allocated to receive insulin Glargine or insulin Detemir. Before starting treatment, blood samples were obtained for routine biochemical tests and factors affecting appetite, including Leptin, Ghrelin, Aguti-Related Peptide (AGRP), and Peptide-YY3-36 (PYY 3-36). Patients were evaluated monthly and insulin dose was adjusted based on target glucose and carbohydrate counting. At the end of three months, the anthropometric values , HbA1C and factors that influence appetite were measured again in both groups, and the results were compared. A total of 40 children with a new onset of type 1 diabetes under 18 years who were hospitalized in Ali Asghar Children Hospital were randomly assigned into two groups as Glargine (n = 20) and Detemir (n = 20). The mean age of patients in the Glargine group was 11.07 ±4.18 years and in the Detemir group was 8.06 ± 3.56. In Glargine group HbA1C, Cholesterol, LDL, AGRP significantly decreased and leptin increased after treatment., while the change of BMI Z-score was not significant. There was a significant decrease of HbA1C in the Detemir group after treatment but there was no significant change of other variables. There was no significant difference for all the variables between two groups after treatment. There was no significant difference for BMI, metabolic control and appetite hormones between Glargine and Detemir groups. BMI-z score did not change in Glargine group while leptin increased and AGRP decreased after treatment. HbA1C decreased significantly after treatment in both groups.

Novel Targets in Glucose Homeostasis and Obesity-Lesson from Rare Mutations

PURPOSE OF REVIEW

Obesity and diabetes have already become the second largest risk factor for cardiovascular disease. During the last decade, remarkable advances have been made in understanding the human genome's contribution to glucose homeostasis disorders and obesity. A few studies on rare mutations of candidate genes provide potential genetic targets for the treatment of diabetes and obesity. In this review, we discussed the detailed findings of these studies and the possible causalities between specific genetic variations and dysfunctions in energy or glucose homeostasis. We are optimistic that novel therapeutic strategies targeting these specific mutants for treating and preventing diabetes and obesity will be developed in the near future.

RECENT FINDINGS

Studies on rare genetic mutation-caused obesity or diabetes have identified potential genetic targets to decrease body weight or reduce the risk of diabetes. Rare mutations observed in lipodystrophy, obese, or diabetic human patients are promising targets in the treatment of diabetes and obesity.

More than an Anti-diabetic Bariatric Surgery, Metabolic Surgery Alleviates Systemic and Local Inflammation in Obesity

Obesity, associated with increased risk of type 2 diabetes (T2D), cardiovascular disease, and hepatic steatosis et al., has become a major global health problem. Recently, obesity has been proven to be under a status of low-grade, chronic inflammation, which contributes to insulin resistance and T2D. Bariatric surgery is currently an effective treatment for the control of morbid obesity and T2D, which impels ongoing efforts to clarify physiological and molecular mechanisms mediating these benefits. The correlation between obesity, inflammation, and T2D has been revealed to a certain extent, and studies have shed light on the effect of bariatric surgery on inflammatory status of subjects with obesity. Based on recent findings, this review focuses on the relationship between inflammation, obesity, and bariatric surgery.

Associations of leptin and leptin receptor genetic variants with coronary artery disease: a meta-analysis

Background: Some pilot studies already tried to investigate potential associations of leptin (LEP) and LEP receptor (LEPR) variants with coronary artery disease (CAD). However, the results of these studies were not consistent. Thus, we performed the present meta-analysis to explore associations between LEP/LEPR variants and CAD in a larger pooled population.

Methods: Systematic literature research of PubMed, Web of Science, Embase and CNKI was performed to identify eligible case–control studies on associations between LEP/LEPR variants and CAD. The initial search was conducted in September 2018 and the latest update was performed in December 2018. Q test and I² statistic were employed to assess between-study heterogeneities. If probability value(P-value) of Q test was less than 0.1 or I² was greater than 50%, random-effect models (REMs) would be used to pool the data. Otherwise, fixed-effect models (FEMs) would be applied for synthetic analyses.

Results: A total of ten studies published between 2006 and 2018 were eligible for analyses (1989 cases and 2601 controls). Pooled analyses suggested that LEP rs7799039 variant was significantly associated with CAD under over-dominant model (P=0.0007, odds ratio (OR) = 1.36, 95% confidence interval (CI): 1.14–1.63, I² = 41%, FEM) in overall population, and this significant finding was further confirmed in East Asians in subsequent subgroup analyses. However, no positive findings were observed for LEPR rs1137100 and rs1137101 variants in overall and subgroup analyses.

Conclusions: Our meta-analysis suggested that LEP rs7799039 variant might affect individual susceptibility to CAD.

Serum leptin and leptin resistance correlations with NAFLD in patients with type 2 diabetes

AIMS

Leptin/leptin resistance has been suggested to play a role in nonalcoholic fatty liver disease (NAFLD), and therefore we investigated the correlation of leptin/leptin-receptor system with markers of hepatic steatosis (HS) and fibrosis (HF) in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In 159 T2D subjects with disease duration of 6.0 (0.0-27.0) years, HS was evaluated by semi-quantitative ultrasonographic scores and by clinical/biochemical variables: Fatty liver index and Hepatic steatosis index. HF was evaluated by NAFLD fibrosis score (NAFLD-FS). Serum leptin and leptin receptor (sObR) concentrations were measured and leptin resistance estimated by Free Leptin Index (FLpI). Both simple and multiple correlations between the HS and HF with the three parameters of interest were examined.

RESULTS

Leptin levels and FLpI correlated with diabetes duration (0.25 [95%CI: 0.09-0.39] and 0.24 [95%CI: 0.08-0.39]; P < 0.01 for both). 76.1% of T2D patients had HS and 29% had HF. The univariate analysis indicated positive correlations of HS indexes with serum leptin, FLpI, and negative correlations with serum sObR (P < 0.0001 for all). In the multiple regression analysis leptin, sObR, FLpI, waist-to-hip ratio, HbA1c, lipids, and HOMA-IR correlated independently with HS (P < 0.0001 for all). Although the univariate analyses indicated weak correlations of NAFLD-FS with leptin, sObR, and FLpI, in the multiple regression analyses, only age and waist independently predicted HF.

CONCLUSION

In patients with T2D, HS correlated positively with serum leptin and leptin resistance, and negatively with sObR, along with variables of adiposity and metabolic control, but neither of them made a significant contribution to HF.

Comparative medical characteristics of ZDF-T2DM rats during the course of development to late stage disease

BACKGROUND

There are few reports on the comparative medical characteristics of type 2 diabetes models in late stage. An analysis of comparative medical characteristics of Zucker diabetic fatty type 2 diabetes mellitus (ZDF-T2DM) rats during the course of development to late stage disease was performed.

METHODS

In this study, ZDF rats were fed with high-sugar and high-fat diets to raise the fasting blood glucose, and develop of type 2 diabetes. At the late stage of T2DM, the preliminary comparative medical characteristics of the T2DM model were analyzed through the detection of clinical indicators, histopathology, related cytokine levels, and insulin-related signaling molecule expression levels.

RESULTS

In the T2DM group, the fasting blood glucose was higher than 6.8 mmol/L, the serum insulin, leptin, and adiponectin levels were significantly decreased, and glucose intolerance and insulin resistance were measured as clinical indicators. Regarding pathological indicators, a large number of pancreatic islet cells showed the reduction of insulin secretion, resulting in damaged glycogen synthesis and liver steatosis. At the molecular level, the insulin signal transduction pathway was inhibited by decreasing the insulin receptor substrate 1 (IRS1), insulin receptor substrate 2 (IRS2), phosphatidylinositol 3 kinase (PI3K), and glycogen synthesis kinase 3β (GSK-3β) expression levels.

CONCLUSION

The results show that the ZDF/T2DM rats have typical clinical, histopathological, and molecular characteristics of human T2DM and thus can be used as an effective model for T2DM drug development and treatment of advanced T2DM.

Pectin Oligosaccharides Ameliorate Colon Cancer by Regulating Oxidative Stress- and Inflammation-Activated Signaling Pathways

Colon cancer (CC) is the third common neoplasm worldwide, and it is still a big challenge for exploring new effective medicine for treating CC. Natural product promoting human health has become a hot topic and attracted many researchers recently. Pectin, a complex polysaccharide in plant cell wall, mainly consists of four major types of polysaccharides: homogalacturonan, xylogalacturonan, rhamnogalacturonan I and II, all of which can be degraded into various pectin oligosaccharides (POS) and may provide abundant resource for exploring potential anticancer drugs. POS have been regarded as a novel class of potential functional food with multiple health-promoting properties. POS have antibacterial activities against some aggressive and recurrent bacterial infection and exert beneficial immunomodulation for controlling CC risk. However, the molecular functional role of POS in the prevention of CC risk and progression remains doubtful. The review focuses on antioxidant and anti-inflammatory roles of POS for promoting human health by regulating some potential oxidative and inflammation-activated pathways, such as ATP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor-2 (Nrf2), and nuclear factor-κB (NF-κB) pathways. The activation of these signaling pathways increases the antioxidant and antiinflammatory activities, which will result in the apoptosis of CC cells or in the prevention of CC risk and progression. Thus, POS may inhibit CC development by affecting antioxidant and antiinflammatory signaling pathways AMPK, Nrf2, and NF-κB. However, POS also can activate signal transduction and transcriptional activator 1 and 3 signaling pathway, which will reduce antioxidant and anti-inflammatory properties and promote CC progression. Specific structural and structurally modified POS may be associated with their functions and should be deeply explored in the future. The present review paper lacks the important information for the linkage between the specific structure of POS and its function. To further explore the effects of prebiotic potential of POS and their derivatives on human immunomodulation in the prevention of CC, the specific POS with a certain degree of polymerization or purified polymers are highly demanded to be performed in clinical practice.