Lipid Metabolism is the common pathologic mechanism between Type 2 Diabetes Mellitus and Parkinson's disease

Acute hyperglycemia impedes spinal cord injury recovery via triggering excessive ferroptosis of endothelial cells

Spinal cord injury (SCI) is a serious central nervous system injury that often causes sensory and motor dysfunction in patients. Diabetes seriously destroys the blood spinal cord barrier (BSCB) and aggravates SCI. Ferroptosis is a new type of programmed cell death. The role of ferroptosis in diabetes-medicated BSCB destruction has not been clearly elucidated. Here, we built a type 1 diabetes (T1D) combined with SCI rat model and confirmed that hyperglycemia exacerbates SCI-mediated BSCB destruction. Pathological mechanism demonstrated that except for apoptosis, the excessive ferroptosis is another caused factor for endothelial cells (ECs) loss under hyperglycemic condition. More importantly, ferrostatin-1(a ferroptosis inhibitor) treatment significantly inhibited the ferroptosis of ECs, and promoted the BSCB repair in T1D combined with SCI rat. The mechanism study further revealed that hyperglycemia not only induces the elevated reactive oxygen species (ROS) via activating RAGE, but also suppresses the xCT expression in system Xc- in ECs, which decreases GPX4 expression and induces ferroptosis. Additionally, hyperglycemia also accelerated the transfer of iron ions from serum to spinal cord after SCI. In summary, our results suggest that the excessive ferroptosis of ECs is essential for the severe BSCB destruction in T1D combined with spinal cord injury rat.

Widening the Spectrum of Risk Factors, Comorbidities, and Prodromal Features of Parkinson Disease

Importance

The prodromal phase of Parkinson disease (PD) may last for more than 10 years. Recognition of the spectrum and occurrence of risk factors, comorbidities, and prodromal features of PD can increase understanding of the causes and development of the disease and help identify individuals at risk.

Objective

To identify the association of a subsequent diagnosis of PD with a range of risk factors and prodromal features, including lifestyle factors, comorbidities, and potential extracerebral manifestations of PD.

Design, Setting, and Participants

This was a case-control study using insurance claims of outpatient consultations of patients with German statutory health insurance between January 1, 2011, and December 31, 2020. Included were patients with incident diagnosis of PD without a previous diagnosis of parkinsonism or dementia and controls matched 1:2 for age, sex, region, and earliest year of outpatient encounter.

Exposures

Exposures were selected based on previous systematic reviews, case-control and cohort studies reporting on risk factors, comorbidities, and prodromal features of PD.

Main Outcomes and Measures

Previously postulated risk factors and prodromal features of PD, using the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) coding.

Results

A total of 138 345 patients with incident PD (mean [SD] age, 75.1 [9.8] years; 73 720 male [53.3%]) and 276 690 matched controls (mean [SD] age, 75.1 (9.8) years; 147 440 male [53.3%]) were identified. Study participants were followed up for a mean (SD) of 6.0 (2.0) years. Consistent with previous reports, risk factors and prodromal features associated with PD included traumatic brain injury, odds ratio (OR), 1.62; 95% CI, 1.36-1.92; alcohol misuse, OR, 1.32; 95% CI, 1.21-1.44; hypertension, OR, 1.29; 95% CI, 1.26-1.31; anosmia, OR, 2.16; 95% CI, 1.59-2.93; and parasomnias (including RBD), OR, 1.62; 95% CI, 1.42-1.84. In addition, there were associations with restless legs syndrome (OR, 4.19; 95% CI, 3.91-4.50), sleep apnea (OR, 1.45; 95% CI, 1.37-1.54), epilepsy (OR, 2.26; 95% CI, 2.07-2.46), migraine (OR, 1.21; 95% CI, 1.12-1.29), bipolar disorder (OR, 3.81; 95% CI, 3.11-4.67), and schizophrenia (OR, 4.48; 95% CI, 3.82-5.25). The following diagnoses were also found to be associated with PD: sensory impairments beyond anosmia, such as hearing loss (OR, 1.14; 95% CI, 1.09-1.20) and changes of skin sensation (OR, 1.31; 95% CI, 1.21-1.43). There were also positive associations with skin disorders (eg, seborrheic dermatitis, OR, 1.30; 95% CI, 1.15-1.46; psoriasis, OR, 1.13; 95% CI, 1.05-1.21), gastrointestinal disorders (eg, gastroesophageal reflux, OR, 1.29; 95% CI, 1.25-1.33; gastritis, OR, 1.28; 95% CI, 1.24-1.33), conditions with a potential inflammatory component (eg, seronegative osteoarthritis, OR, 1.21; 95% CI, 1.03-1.43), and diabetes types 1 (OR, 1.32; 95% CI, 1.21-1.43) and 2 (OR, 1.24; 95% CI, 1.20-1.27). Associations even 5 to 10 years before diagnosis included tremor (odds ratio [OR], 4.49; 95% CI, 3.98-5.06), restless legs syndrome (OR, 3.73; 95% CI, 3.39-4.09), bipolar disorder (OR, 3.80; 95% CI, 2.82-5.14), and schizophrenia (OR, 4.00; 95% CI, 3.31-4.85).

Conclusions and Relevance

Results of this case-control study suggest that the associations found between PD and certain risk factors, comorbidities, and prodromal symptoms in a representative population may reflect possible early extrastriatal and extracerebral pathology of PD. This may be due to shared genetic risk with PD, medication exposure, or direct causation, or represent pathophysiologically relevant factors contributing to the pathogenesis of PD.

Deep-frying oil induces cytotoxicity, inflammation and apoptosis on intestinal epithelial cells

BACKGROUND

Deep-frying oil has been found to cause inflammatory bowel disease (IBD). However, the molecular mechanism of the effect of deep-frying palm oil on IBD still remains undetermined.

RESULTS

In the present study, bioinformatics and cell biology were used to investigate the functions and signal pathway enrichments of differentially expressed genes. The bioinformatics analysis of three original microarray datasets (GSE73661, GSE75214 and GSE126124) in the NCBI-Gene Expression Omnibus database showed 17 down-regulated genes (logFC < 0) and 2 up-regulated genes (logFC > 0) existed in the enteritis tissue. Meanwhile, pathway enrichment and protein-protein interaction network analysis suggested that IBD is relevant to cytotoxicity, inflammation and apoptosis. Furthermore, Caco-2 cells were treated with the main oxidation products of deep-frying oil-total polar compounds (TPC) and its components (polymerized triglyceride, oxidized triglycerides and triglyceride degradation products) isolated from deep-frying oil. The flow cytometry experiment revealed that TPC and its components could induce apoptosis, especially for oxidized triglyceride. A quantitative polymerase chain reaction analysis demonstrated that TPC and its component could induce Caco-2 cell apoptosis through AQP8/CXCL1/TNIP3/IL-1.

CONCLUSION

The present study provides fundamental knowledge for understanding the effects of deep-frying oils on the cytotoxic and inflammatory of Caco-2 cells, in addition to clarifying the molecular function mechanism of deep-frying oil in IBD. © 2021 Society of Chemical Industry.

Sp1 transcription factor represses transcription of phosphatase and tensin homolog to aggravate lung injury in mice with type 2 diabetes mellitus-pulmonary tuberculosis

Type 2 diabetes mellitus (T2DM) can enhance the risk of mycobacterium tuberculosis (Mtb) infection and aggravate pulmonary tuberculosis (PTB). This study intended to explore the function of phosphatase and tensin homolog (PTEN) in T2DM-PTB and the molecules involved. Mice were treated with streptozotocin to induce T2DM and then infected with Mtb. The mice with T2DM had increased weight, blood glucose level, glucose intolerance and insulin resistance, and increased susceptibility to PTB after Mtb infection. PTEN was significantly downregulated in mice with T2DM-PTB and it had specific predictive value in patients. Overexpression of PTEN improved mouse survival and reduced bacterial load, inflammatory infiltration, cell apoptosis, and fibrosis in lung tissues. Sp1 transcription factor (SP1) was predicted and identified as an upstream regulator of PTEN. SP1 suppressed PTEN transcription. Silencing of SP1 enhanced mouse survival and alleviated the lung injury, and it promoted the M1 polarization of macrophages in murine lung tissues. However, further downregulation of PTEN increased protein kinase B (Akt) phosphorylation and blocked the alleviating roles of SP1 silencing in T2DM-PTB. This study demonstrates that SP1 represses PTEN transcription to promote lung injury in mice with T2DM-PTB through Akt activation.

Metabolites and Genes behind Cardiac Metabolic Remodeling in Mice with Type 1 Diabetes Mellitus

Metabolic remodeling is at the heart of diabetic cardiomyopathy. High glycemic fluctuations increase metabolic stress in the type 1 diabetes mellitus (T1DM) heart. There is a lack of understanding on how metabolites and genes affect metabolic remodeling in the T1DM heart. We hypothesize that differential expression of metabolic genes and metabolites synergistically influence metabolic remodeling preceding T1DM cardiomyopathy. To test our hypothesis, we conducted high throughput analysis of hearts from adult male hyperglycemic Ins2^+/− (Akita) and littermate normoglycemic Ins2^+/+ (WT) mice. The Akita mouse is a spontaneous, genetic model of T1DM that develops increased levels of consistent glycemic variability without the off-target cardiotoxic effects present in chemically- induced models of T1DM. After validating the presence of a T1DM phenotype, we conducted metabolomics via LC-MS analysis and genomics via next-generation sequencing in left ventricle tissue from the Akita heart. Ingenuity Pathway Analyses revealed that 108 and 30 metabolic pathways were disrupted within the metabolomics and genomics datasets, respectively. Notably, a comparison between the two analyses showed 15 commonly disrupted pathways, including ketogenesis, ketolysis, cholesterol biosynthesis, acetyl CoA hydrolysis, and fatty acid biosynthesis and beta-oxidation. These identified metabolic pathways predicted by the differential expression of metabolites and genes provide the foundation for understanding metabolic remodeling in the T1DM heart. By limited experiment, we revealed a predicted disruption in the metabolites and genes behind T1DM cardiac metabolic derangement. Future studies targeting these genes and metabolites will unravel novel therapies to prevent/improve metabolic remodeling in the T1DM heart.

Molecular dynamics revealed the effect of epoxy group on triglyceride digestion

The digestion behavior of epoxy triglyceride, the main cytotoxic product of deep-frying oil, remains unknown, which may affect its biosafety. In this study, epoxy triglyceride (EGT) and triglyceride (GT) were used to reveal the effect of epoxy group on digestion. Digestibility rate analysis showed that the free fatty acids release rate of EGT was slower. To clarify this phenomenon, binding ability with salt ions in digestive juice and particle size were also been studied. Cluster size analysis indicated that epoxy group increased triglyceride particle size, resulting in smaller contact area between EGT and lipase. Interface behaviors displayed EGT decreased binding ability with salt ions in digestive juice. Spectroscopic analysis showed EGT caused the red shift of lipase peak, indicating that epoxy group changed lipase structure. Molecular dynamics simulation suggested EGT leads to loosen lipase structure. In conclusion, this study highlights that epoxy group could weaken the triglyceride digestion.