Association between Iron Intake and Diabetic Peripheral Neuropathy in Type 2 Diabetes: Significance of Iron Intake and the Ratio between Iron Intake and Polyunsaturated Fatty Acids Intake

Human mesenchymal stem cells derived exosomes improve ovarian function in chemotherapy-induced premature ovarian insufficiency mice by inhibiting ferroptosis through Nrf2/GPX4 pathway

BACKGROUND

Chemotherapy exposure has become a main cause of premature ovarian insufficiency (POI). This study aimed to evaluate the role and molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes (hUMSC-Exos) in ovarian function protection after chemotherapy.

METHODS

hUMSC-Exos were applied to cyclophosphamide-induced premature ovarian insufficiency mice and human ovarian granulosa tumor cells (KGN) to determine their effects on follicular development and granulosa cell apoptosis. Evaluation was done for iron ion and reactive oxygen species (ROS) production, lipid peroxidation levels, and changes in iron death-related molecules (nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Glutathione Peroxidase enzyme 4 (GPX4), and Solute carrier family 7 member 11 cystine glutamate transporter (SLC7A11; xCT)). Furthermore, rescue experiments using an Nrf2 inhibitor were performed to assess the therapeutic effects of hUMSC-Exos on granulosa cells.

RESULTS

hUMSC-Exos promoted ovarian hormone levels and primary follicle development in POI mice and reduced granulosa cell apoptosis. After hUMSC-Exos treatment, the ROS production, free iron ions and lipid peroxidation levels of granulosa cells decreased, and the iron death marker proteins Nrf2, xCT and GPX4 also decreased. Furthermore, the Nrf2 inhibitor ML385 significantly attenuated the effects of hUMSC-Exos on granulosa cells.

CONCLUSION

hUMSC-Exos inhibit ferroptosis and protect against CTX-induced ovarian damage and granulosa cell apoptosis through the Nrf2/GPX4 signaling pathway, revealing a novel mechanism of hUMSC-Exos in POI therapy.

Natural compounds efficacy in complicated diabetes: A new twist impacting ferroptosis

Ferroptosis, as a way of cell death, participates in the body's normal physiological and pathological regulation. Recent studies have shown that ferroptosis may damage glucose-stimulated islets β Insulin secretion and programmed cell death of T2DM target organs are involved in the pathogenesis of T2DM and its complications. Targeting suppression of ferroptosis with specific inhibitors may provide new therapeutic opportunities for previously untreated T2DM and its target organs. Current studies suggest that natural bioactive compounds, which are abundantly available in drugs, foods, and medicinal plants for the treatment of T2DM and its target organs, have recently received significant attention for their various biological activities and minimal toxicity, and that many natural compounds appear to have a significant role in the regulation of ferroptosis in T2DM and its target organs. Therefore, this review summarized the potential treatment strategies of natural compounds as ferroptosis inhibitors to treat T2DM and its complications, providing potential lead compounds and natural phytochemical molecular nuclei for future drug research and development to intervene in ferroptosis in T2DM.

Serum uric acid is associated with chronic kidney disease in elderly Chinese patients with diabetes

BACKGROUND

The relationship between hyperuricemia and chronic kidney disease (CKD) has been investigated extensively. However, studies on elderly individuals are still limited. Moreover, there is no consensus on whether hyperuricemia or elevated serum uric acid (SUA) within the normal range is correlated with the new onset of CKD and whether there are differences between males and females.

METHODS

We included 39039 elderly diabetic patients without CKD at baseline from a community-based cohort in Wuhan, China. The outcome event was the new onset of CKD (defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2). Multivariate Cox models were used to assess the adjusted hazard ratio (HR).

RESULTS

During the 2-year follow-up period, 3162 (8.10%) patients with diabetes developed new-onset CKD. The optimal cutoff value of SUA for incident CKD was 347.4 μmol/L. The adjusted HRs of hyperuricemia for new-onset CKD were 1.925 (1.724-2.150) and 1.676 (1.520-1.848) for males and females, respectively. The risk of developing CKD increased across the Q4 group up to 2.242 times for their counterparts in the lowest SUA quartile, independent of age, sex, diabetes duration, obesity, hypertension, systolic blood pressure, diastolic blood pressure, smoking, drinking, dyslipidemia, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and fasting plasma glucose.

CONCLUSIONS

Hyperuricemia is an independent predictor of incident CKD. Elevated SUA was linearly correlated with CKD in elderly patients with diabetes, showing a relatively higher intensity among males compared with that among females. The optimal cutoff value of SUA for the risk of new-onset CKD in elderly patients with diabetes was 347.4 μmol/L.

Ferroptosis: new insight into the mechanisms of diabetic nephropathy and retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are the most serious and common diabetes-associated complications. DN and DR are all highly prevalent and dangerous global diseases, but the underlying mechanism remains to be elucidated. Ferroptosis, a relatively recently described type of cell death, has been confirmed to be involved in the occurrence and development of various diabetic complications. The disturbance of cellular iron metabolism directly triggers ferroptosis, and abnormal iron metabolism is closely related to diabetes. However, the molecular mechanism underlying the role of ferroptosis in DN and DR is still unclear, and needs further study. In this review article, we summarize and evaluate the mechanism of ferroptosis and its role and progress in DN and DR, it provides new ideas for the diagnosis and treatment of DN and DR.

The role of ferroptosis in metabolic diseases

The annual incidence of metabolic diseases such as diabetes, non-alcoholic fatty liver disease (NAFLD), osteoporosis, and atherosclerosis (AS) is increasing, resulting in a heavy burden on human health and the social economy. Ferroptosis is a novel form of programmed cell death driven by iron-dependent lipid peroxidation, which was discovered in recent years. Emerging evidence has suggested that ferroptosis contributes to the development of metabolic diseases. Here, we summarize the mechanisms and molecular signaling pathways involved in ferroptosis. Then we discuss the role of ferroptosis in metabolic diseases. Finally, we analyze the potential of targeting ferroptosis as a promising therapeutic approach for metabolic diseases.

Association between dietary theobromine with depression: a population-based study

OBJECTIVE

The purpose of this study is to investigate the possible link between dietary theobromine intake and symptoms of depression.

MATERIALS AND METHODS

These results are based on the responses of 3637 people who took part in the National Health and Nutrition Examination Survey in 2017-2018. Participants' daily theobromine intake was determined using a 24-h food questionnaire from the 2017-2018 cycle. Presence of depression was defined as a score of 5 or above on the Patient Health Questionnaire. Association between theobromine intake and depression was examined using a multivariate logistic regression adjusting for several relevant sociodemographic, lifestyle and health-related factors.

RESULTS

A total of 6903 participants were included in the study. The results of multivariate logistic regression showed a correlation between depressive symptoms and theobromine intake (OR:1.17, 95%CI:1.02-1.34).

CONCLUSIONS

Our cross-sectional population based study suggests that increased theobromine intake is associated with increased risk for depression. Nevertheless, more investigations are needed to confirm our findings.

The association of healthy eating index with periodontitis in National Health and Nutrition Examination Study 2011–2012

Aim

Periodontitis is a chronic inflammatory disorder caused by periodontopathic bacteria that causes inflammation of the supporting tissues around teeth. Previous studies have found that daily dietary nutritional intake can influence the development of periodontal disease. However, research on the Healthy Eating Index’s involvement in periodontitis is limited. The purpose of this study was to look at the link between the Healthy Eating Index and periodontitis.

Methods and design

We examined data from the National Health and Nutrition Examination Study (NHANES), a nationally representative survey that was performed in 2-year cycles from 2011 to 2012. As part of our investigation, we used multivariate logistic regression models to investigate the independent relationship between the Healthy Eating Index and periodontitis. We used odds ratios (OR) with 95% confidence intervals to assess the significance of the connection (95% CI).

Results

Individuals with a lower total healthy eating index were more likely to have periodontitis. A higher healthy diet index was associated with a lower prevalence of periodontitis (OR = 0.69; 95%CI: 0.49–0.97), according to adjusted multivariate regression models. The restricted cubic spline (RCS) analysis revealed that the non-linear relationship between HEI-2015 and periodontitis was statistically significant and that high HEI-2015 reduced periodontitis prevalence.

Conclusion

The study’s findings revealed that dietary structure was linked to the prevalence of periodontitis. Patients with a higher Healthy Eating Index were less likely to have periodontitis. There is a need for future prospective longitudinal studies to confirm causality.

A Role for Fatty Acids in Peripheral Neuropathy Associated with Type 2 Diabetes and Prediabetes

Significance: As the global prevalence of diabetes rises, diabetic complications are also increasing at an alarming rate. Peripheral neuropathy (PN) is the most prevalent complication of diabetes and prediabetes, and is characterized by progressive sensory loss resulting from nerve damage. While hyperglycemia is the major risk factor for PN in type 1 diabetes (T1D), the metabolic syndrome (MetS) underlies the onset and progression of PN in type 2 diabetes (T2D) and prediabetes. Recent Advances: Recent reports show that dyslipidemia, a MetS component, is strongly associated with PN in T2D and prediabetes. Dyslipidemia is characterized by an abnormal plasma lipid profile with uncontrolled lipid levels, and both clinical and preclinical studies implicate a role for dietary fatty acids (FAs) in PN pathogenesis. Molecular studies further show that saturated and unsaturated FAs differentially regulate the nerve lipid profile and nerve function. Critical Issues: We first review the properties of FAs and the neuroanatomy of the peripheral nervous system (PNS). Second, we discuss clinical and preclinical studies that implicate the involvement of FAs in PN. Third, we summarize the potential effects of FAs on nerve function and lipid metabolism within the peripheral nerves, sensory neurons, and Schwann cells. Future Directions: Future directions will focus on identifying molecular pathways in T2D and prediabetes that are modulated by FAs in PN. Determining pathophysiological mechanisms that underlie the injurious effects of saturated FAs and beneficial properties of unsaturated FAs will provide mechanistic targets for developing new targeted therapies to treat PN associated with T2D and prediabetes. Antioxid. Redox Signal. 37, 560-577.

The association of healthy eating index with periodontitis in NHANES 2013-2014

Background

Periodontal disease is very common worldwide and is one of the main causes of tooth loss in adults. Periodontal disease is characterized by chronic inflammation that can destroy adjacent alveolar bone and lead to a loss of periodontal ligaments. Although previous studies have found that a daily diet can influence the development of periodontal disease (e.g., a diet low in carbohydrates and rich in vitamins C and D and fiber can have a protective effect). Periodontal disease may present as gingivitis or periodontitis. However, studies on the role of healthy eating index in periodontitis are lacking. The purpose of this study was to assess the association between healthy eating index and periodontitis.

Methods

We analyzed data collected from participants in the National Health and Nutrition Examination Survey (NHANES), a nationally representative survey conducted in 2-year cycles from 2013 to 2014. As part of our analysis, we developed multivariate logistic regression models to examine the independent association between the healthy eating index and periodontitis. We evaluated the significance of association using odds ratios (OR) with 95% confidence intervals (95%CI).

Results

Individuals with a lower total healthy eating index had a higher prevalence of periodontitis. Adjusted multivariate regression models showed that a higher healthy diet index was associated with a lower prevalence of periodontitis (OR = 0.69, 95% CI: 0.55-0.86, P < 0.05).

Conclusion

The results of the study showed that dietary structure was associated with the prevalence of periodontitis. Patients with a higher healthy eating index had a lower prevalence of periodontitis. These findings will need to be confirmed by longitudinal, prospective studies in the future.

Dietary magnesium intake is protective in patients with periodontitis

Background

Periodontitis is a chronic inflammatory disease of the oral cavity characterized by inflammation of the periodontal tissue and resorption of the alveolar bone, which has a high incidence and is the main cause of tooth loss in adults. In addition to its role in promoting osteogenesis, magnesium also has a role in regulating the inflammatory response, both systemically and locally. There is growing evidence that magnesium is an important factor in maintaining the normal functioning of the body's immune system. Hypomagnesaemia can lead to a variety of chronic inflammatory diseases throughout the body, including periodontitis. Two-thirds of the US population suffers from magnesium deficiency. The connection between dietary magnesium and periodontitis is unknown. As a result, we set out to investigate the link between dietary magnesium intake and periodontitis.

Methods

In this study, we collected data from the National Health and Nutrition Examination Survey (NHANES) database from 2013 to 2014. Through 24-h dietary recalls, information about food consumption was collected. We examined the association between the dietary magnesium and periodontitis using multivariable logistic regression model. Based on odds ratios (OR) and 95% confidence intervals (CIs), a strong association was detected.

Results

Multivariable logistic regression analysis showed that the OR for periodontitis comparing the highest to the lowest quintile of dietary magnesium intake was 0.69 (95% CIs = 0.52~0.92). The restricted cubic spline (RCS) analysis showed that the non-linear association between dietary magnesium and periodontitis was statistically significant and that dietary magnesium supplementation reduced the prevalence of periodontitis.

Conclusion

Dietary magnesium intake is associated with the prevalence of periodontitis. Dietary magnesium deficiency increases the prevalence of periodontitis.

Correlations Between Iron Status and Body Composition in Patients With Type 2 Diabetes Mellitus

Background

Our study aimed to investigate the association between iron metabolism and body composition in patients with type 2 diabetes mellitus (T2DM).

Methods

A total of 824 patients with T2DM were enrolled. Measurements of body composition were obtained by dual-energy X-ray absorptiometry. Patients were stratified into three groups according to their sex-specific ferritin levels. Basic information, laboratory results, and body composition were collected.

Results

Serum iron and transferrin saturation (TSAT) were increased significantly with increased serum ferritin (all p < 0.05). Total iron-binding capacity (TIBC) was decreased significantly with increased serum ferritin (p < 0.05). Visceral fat mass (VF), android fat/total body fat mass, android-to-gynoid fat ratio (A/G ratio), and high-sensitivity C-reactive protein were all increased significantly with increased serum ferritin (all p < 0.05). Patients with a high A/G ratio (A/G ratio ≧ 1) had significantly higher serum iron, ferritin, and TSAT, but significantly lower TIBC. In the model adjusted for age and gender, higher ferritin levels were associated with a higher VF (all p < 0.05). Serum iron was positively correlated with the occurrence of a high A/G ratio (A/G ratio ≧ 1) after the adjustment of confounding factors [an odds ratio (OR = 1.09, 95% CI, 1.02–1.19, p = 0.02)]. With receiver operating curve analysis, the cutoff value of serum iron for a high A/G ratio was 18.56, and the area under the curve was 0.771 (sensitivity 88.9%and specificity 63.9%, p = 0.01).

Conclusion

Higher serum iron and ferritin concentrations were positively associated with a higher VF. Higher serum iron concentrations were positively correlated with a high A/G ratio. This study indicates the potential relationship between iron overload and the body composition in patients with T2DM.

Curcumin Ameliorates the Experimental Diabetic Peripheral Neuropathy through Promotion of NGF Expression in Rats

Increasing evidence suggested that inhibiting the apoptosis of Schwann cells (SCs) and promoting nerve growth factor (NGF) expression in sciatic nerves play key roles in preventing the onset of diabetic peripheral neuropathy (DPN). Curcumin, a primary bioactive substance in turmeric with multiple characteristics, has been shown to have many therapeutic effects in a variety of diseases. However, curcumin is poorly studied in the DPN models. We aimed to explore the therapeutic benefits and underlying mechanism of curcumin in high fat/sugar diets joint streptozotocin (STZ)-induced DPN rat models. Sprague-Dawley (SD) rats were divided into five groups (6 rats per group), control group, DPN group, Curcumin groups (50, 100, and 150 mg/kg). Curcumin was administered intragastrically once per day for 4 continuous weeks. Body weight (BW) and fasting blood glucose (FBG) were monitored in all groups. The mechanical withdraw threshold (MWT) was measured. We also assessed neuropathic change by testing nerve conductance velocity (NCV) in sciatic nerves. TEM was applied to observe the sciatic nerves ultrastructure. The SCs apoptosis in sciatic nerves was stained using TUNEL kit. NGF contents in sciatic nerves and serum were detected using western blotting and ELISA analysis. The results showed curcumin had no obvious effect on the BW and FBG change. Curcumin (100 and 150 mg/kg) attenuated the MWT, NCV, and sciatic nerves ultrastructure in DPN rats. Curcumin (50, 100 and 150 mg/kg) reduced SCs apoptosis in sciatic nerves. In addition, curcumin at 150 mg/kg had the best efficacy in increasing protein expression of NGF in sciatic nerves and serum NGF level. Our work demonstrated that curcumin has neuroprotective effects for the treatment of DPN.

The Macrophage Iron Signature in Health and Disease

Throughout life, macrophages are located in every tissue of the body, where their main roles are to phagocytose cellular debris and recycle aging red blood cells. In the tissue niche, they promote homeostasis through trophic, regulatory, and repair functions by responding to internal and external stimuli. This in turn polarizes macrophages into a broad spectrum of functional activation states, also reflected in their iron-regulated gene profile. The fast adaptation to the environment in which they are located helps to maintain tissue homeostasis under physiological conditions.