Short-term high-fat diet exacerbates insulin resistance and glycolipid metabolism disorders in young obese men with hyperlipidemia, as determined by metabolomics analysis using ultra-HPLC-quadrupole time-of-flight mass spectrometry

Analysis of bone metabolic alterations linked with osteoporosis progression in type 2 diabetic db/db mice

Type 2 diabetes (T2D) is a common chronic disease, characterized by persistent hyperglycemia and insulin resistance. This disorder is associated with decreased bone quality and an elevated risk of bone fractures. However, evidence on the relationship between systemic metabolic change and the development of type 2 diabetic osteoporosis (T2DOP) remains elusive. Herein, we investigate the changes of bone metabolites with bone loss in db/db mice (an animal model of T2DOP exhibited bone loss with age progression), and explore the potential metabolic mechanism underlying type 2 diabetes and osteoporosis. C57BKS male mice were distributed in four groups, consisting six mice in each group: 8w m/m, 24w m/m, 8w db/db and 24w db/db. Bone morphometric and biomechanical parameters of db/db mice were analyzed by micro-CT and materials tester, it was found that 24w db/db mice showed severe bone loss and decreased bone tissue hardness compared with misty/misty littermates. The tibia of misty/misty mice (8 weeks, 24 weeks) and db/db mice (8 weeks, 24 weeks) were screened for differential metabolites by UPLC-Orbitrap MS. Ninety-eight metabolites were identified (35 and 63 metabolites are associated with early staged and late staged, respectively), consisting of amino acids, fatty acyls, and nucleotides. Notably, fatty acyls (such as 18-HEPE, 16(17)-EpDPE, arachidonic acid) and glycerophospholipids (such as phosphocholines (PC) (O-10:1(9E)/0:0), PC (O-16:1(9E)/0:0) [U] and phosphatidylethanolamines (PE) (P-16:0/0:0)) were significantly increased, and metabolites of amino acid pathway (such as l-glutamine, proline, phenylalanine) showed a downregulation trend. Dysregulation of lipid and glutathione pathways is the major contributor to progression of T2DOP in C57BKS mice.

Based on Plasma Metabonomics and Network Pharmacology Exploring the Therapeutic Mechanism of Gynura procumbens on Type 2 Diabetes

Gynura procumbens (GP) is a perennial herbal medicine and food homologous plant, which has been reported to have a good hypoglycemic effect. However, its active components and underlying mechanism of action are not clear. Here, we aimed to confirm the effects of GP on type 2 diabetes (T2DM) from several different aspects. We used UPLC/Q-TOF MS to analyze the metabolic patterns, which included blood samples of clinical subjects and db/db mice to screen for serum metabolic markers and metabolic pathways. We also used network pharmacology to study GP targets in the treatment of T2DM. Data from endogenous metabolites in plasma showed that two common pathways, including glycerol phosphate metabolism and retinol metabolism, were identified in plasma samples of the groups. Finally, Western blot analysis was used to verify the expression of proteins in the PI3K/AKT and AGE–RAGE signaling pathways. The protein expression of AKT, eNOS, iNS, and MAPK was significantly upregulated, and the expression of caspase-8 and caspase-3 was significantly downregulated. Thus, our findings indicated that GP could alleviate insulin resistance by regulating biometabolic markers and key proteins in the PI3K/AKT and AGE–RAGE signaling pathways to treat T2DM.

Excess mortality at Christmas due to cardiovascular disease in the HUNT study prospective population-based cohort in Norway

Background

Although it is known that winter inclusive of the Christmas holiday period is associated with an increased risk of dying compared to other times of the year, very few studies have specifically examined this phenomenon within a population cohort subject to baseline profiling and prospective follow-up. In such a cohort, we sought to determine the specific characteristics of mortality occuring during the Christmas holidays.

Methods

Baseline profiling and outcome data were derived from a prospective population-based cohort with longitudinal follow-up in Central Norway - the Trøndelag Health (HUNT) Study. From 1984 to 1986, 88% of the target population comprising 39,273 men and 40,353 women aged 48 ± 18 and 50 ± 18 years, respectively, were profiled. We examined the long-term pattern of mortality to determine the number of excess (all-cause and cause-specific) deaths that occurred during winter overall and, more specifically, the Christmas holidays.

Results

During 33.5 (IQR 17.1–34.4) years follow-up, 19,879 (50.7%) men and 19,316 (49.3%) women died at age-adjusted rate of 5.3 and 4.6 deaths per 1000/annum, respectively. Overall, 1540 (95% CI 43–45 deaths/season) more all-cause deaths occurred in winter (December to February) versus summer (June to August), with 735 (95% CI 20–22 deaths per season) of these cardiovascular-related. December 25th–27th was the deadliest 3-day period of the year; being associated with 138 (95% CI 96–147) and 102 (95% CI 72–132) excess all-cause and cardiovascular-related deaths, respectively. Accordingly, compared to 1st–21st December (equivalent winter conditions), the incidence rate ratio of all-cause mortality increased to 1.22 (95% CI 1.16–1.27) and 1.17 (95% 1.11–1.22) in men and women, respectively, during the next 21 days (Christmas/New Year holidays). All observed differences were highly significant (P < 0.001). A less pronounced pattern of mortality due to respiratory illnesses (but not cancer) was also observed.

Conclusion

Beyond a broader pattern of seasonally-linked mortality characterised by excess winter deaths, the deadliest time of year in Central Norway coincides with the Christmas holidays. During this time, the pattern and frequency of cardiovascular-related mortality changes markedly; contrasting with a more stable pattern of cancer-related mortality. Pending confirmation in other populations and climates, further research to determine if these excess deaths are preventable is warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10503-7.

Metabolomic analysis of plasma from normal-weight adults with hypo-HDL cholesterolemia by UPLC-QTOF MS

High-density lipoprotein cholesterol (HDL-C) is negatively correlated with atherosclerotic cardiovascular disease. The prevalence of hypo-HDL cholesterolemia is as high as 33.9%. The plasma metabolomic differences between hypo-HDL cholesterolemia populations and normal controls were investigated using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Participants with hypo-HDL cholesterolemia and normal controls were clearly discriminated from each other on the orthogonal partial least squares-discriminant analysis score plot and a total of 90 differential metabolites were identified, including down-regulated phosphatidylserine [18:0/20:3(8Z,11Z,14Z)], phosphatidylcholine [19:0/18:3(6Z,9Z,12Z)], phosphatidylserine, phosphatidylethanolamine [18:0/20:4(5Z,8Z,11Z,13E) (15Ke)], etc., and up-regulated triglyceride [15:0/18:1(9Z)/18:3(9Z,12Z,15Z)][iso6], 13-methyl-1-tritriacontene, tridodecylamine, etc. Most of the changed metabolites were lipids, notably, a significant part of which were odd chain fatty acid incorporated lipids. Carnitine shuttle was the most significant metabolic pathway, except for the disturbed glycerophospholipid metabolism, glycosphingolipid metabolism and sphingolipid metabolism in participants with hypo-HDL cholesterolemia. We identified the key metabolites and metabolic pathways that may be changed in hypo-HDL cholesterolemia participants, providing useful clues for studying the metabolic mechanisms and for early prevention of hypo-HDL cholesterolemia and dyslipidemia.

Sample Preparation Methods for Lipidomics Approaches Used in Studies of Obesity

Obesity is associated with alterations in the composition and amounts of lipids. Lipids have over 1.7 million representatives. Most lipid groups differ in composition, properties and chemical structure. These small molecules control various metabolic pathways, determine the metabolism of other compounds and are substrates for the syntheses of different derivatives. Recently, lipidomics has become an important branch of medical/clinical sciences similar to proteomics and genomics. Due to the much higher lipid accumulation in obese patients and many alterations in the compositions of various groups of lipids, the methods used for sample preparations for lipidomic studies of samples from obese subjects sometimes have to be modified. Appropriate sample preparation methods allow for the identification of a wide range of analytes by advanced analytical methods, including mass spectrometry. This is especially the case in studies with obese subjects, as the amounts of some lipids are much higher, others are present in trace amounts, and obese subjects have some specific alterations of the lipid profile. As a result, it is best to use a method previously tested on samples from obese subjects. However, most of these methods can be also used in healthy, nonobese subjects or patients with other dyslipidemias. This review is an overview of sample preparation methods for analysis as one of the major critical steps in the overall analytical procedure.

Application of metabolomics for unveiling the therapeutic role of traditional Chinese medicine in metabolic diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicine has been practiced for thousands of years in China and some Asian countries. Traditional Chinese Medicine (TCM) is characterized as multi-component and multiple targets in disease therapy, and it is a great challenge for elucidating the mechanisms of TCM.

AIM OF THE REVIEW

Comprehensively summarize the application of metabolomics in biomarker discovery, stratification of TCM syndromes, and mechanism underlying TCM therapy on metabolic diseases.

METHODS

This review systemically searched the publications with key words such as metabolomics, traditional Chinese medicine, metabolic diseases, obesity, cardiovascular disease, diabetes mellitus in "Title OR Abstract" in major databases including PubMed, the Web of Science, Google Scholar, Science Direct, CNKI from 2010 to 2019.

RESULTS

A total of 135 papers was searched and included in this review. An overview of articles indicated that metabolic characteristics may be a hallmark of different syndromes/models of metabolic diseases, which provides a new perspective for disease diagnosis and therapeutic optimization. Moreover, TCM treatment has significantly altered the metabolic perturbations associated with metabolic diseases, which may be an important mechanism for the therapeutic effect of TCM.

CONCLUSIONS

Until now, many metabolites and differential biomarkers related to the pathogenesis of metabolic diseases and TCM therapy have been discovered through metabolomics research. Unfortunately, the biological role and mechanism of disease-related metabolites were largely unclarified so far, which warrants further investigation.

High-Fat Diet Increases Amylin Accumulation in the Hippocampus and Accelerates Brain Aging in hIAPP Transgenic Mice

The accumulation of human islet amyloid polypeptide (hIAPP) in pancreatic islets under induction by a high-fat diet plays a critical role in the development of type-2 diabetes mellitus (T2DM). T2DM is a risk factor of late-onset Alzheimer’s disease (AD). Nevertheless, whether hIAPP in combination with hyperlipidemia may lead to AD-like pathological changes in the brain remains unclear. hIAPP transgenic mice were fed with a high-fat diet for 6 or 12 months to establish the T2DM model. The accumulation of amylin, the numbers of Fluoro-Jade C (FJC)-positive and β-gal positive cells, and the deposition level of Aβ42 in the hippocampi of the transgenic mice were detected by using brain sections. Cytoplasmic and membrane proteins were extracted from the hippocampi of the transgenic mice, and the ratio of membrane GLUT4 expression to cytoplasmic GLUT4 expression was measured through Western blot analysis. Changes in the cognitive functions of hIAPP transgenic mice after 12 months of feeding with a high-fat diet were evaluated. hIAPP transgenic mice fed with a high-fat diet for 6 or 12 months showed elevated blood glucose levels and insulin resistance; increased amylin accumulation, number of FJC-positive and β-gal positive cells, and Aβ42 deposition in the hippocampi; and reduced membrane GLUT4 expression levels. hIAPP transgenic mice fed with a high-fat diet for 12 months showed reductions in social cognitive ability and passive learning ability. A high-fat diet increased amylin accumulation in the hippocampi of hIAPP transgenic mice, which presented AD-like pathology and behavior characterized by neural degeneration, brain aging, Aβ42 deposition, and impaired glucose utilization and cognition.