Diabetes associated with hypertension exacerbated oxidative stress-mediated inflammation, apoptosis and autophagy leading to erectile dysfunction in rats

3-Hydroxy-3-methylglutaryl-CoA synthase 2 facilitates erectile dysfunction via inhibiting autophagy by enhancing the mammalian target of rapamycin pathway in type 1 diabetic mellitus rats

BACKGROUND

The relationship between erectile dysfunction (ED) and type 1 diabetes mellitus (T1DM) is currently a hot topic of medical research. It has been reported that autophagy plays a crucial role in causing erectile dysfunction in T1DM. Recent research has shown that mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) is strongly linked to the development of T1DM. However, the specific mechanism by which it regulates the erectile function is not yet fully understood.

OBJECTIVES

To investigate whether HMGCS2 affects erectile function in type 1 diabetic rats by regulating autophagy in corpus cavernosum endothelial cells (CCECs).

MATERIALS AND METHODS

First, the rat model of T1DM was established. Then, the ratio of maximum penile intracavernous pressure (ICPmax) and mean arterial pressure (MAP) was detected to assess the erectile function in various groups, and the protein expression of HMGCS2, mTOR and p-mTOR was evaluated by western blot (WB) and immunohistochemistry (IHC). To explore the relationship between HMGCS2 and the mTOR signaling pathway in T1DM ED rats, we silenced the expression of HMGCS2 and activated the mTOR signaling pathway with MHY1485 in CCECs and then assessed the expression of beclin1, P62, LC3, autophagosome, endothelial nitric oxide synthase (eNOS), phosphorylation of eNOS (p-eNOS), and nitric oxide (NO) to evaluate autophagy and the erectile function by reverse transcription quantitative polymerase chain reaction and western blot.

RESULTS

The study conducted on T1DM ED rats showed that the expression of HMGCS2 was significantly increased, while the autophagy was suppressed. Additionally, the mTOR signaling pathway was highly activated. In contrast, when HMGCS2 was silenced in vitro, p-mTOR/mTOR was reduced, and autophagy was improved. These effects were accompanied by the enhanced activity of eNOS. Furthermore, when HMGCS2 was silenced and the mTOR signaling pathway was simultaneously activated, the results revealed a decrease in autophagy as well as a reduction in activity of eNOS in comparison to just silencing HMGCS2 alone.

DISCUSSION AND CONCLUSION

HMGCS2 upregulation in T1DM rats inhibited autophagy and eNOS activity by activating the mTOR pathway and led to a decrease in the erectile function.

Autophagy in erectile dysfunction: focusing on apoptosis and fibrosis

In most types of erectile dysfunction, particularly in advanced stages, typical pathological features observed are reduced parenchymal cells coupled with increased tissue fibrosis. However, the current treatment methods have shown limited success in reversing these pathologic changes. Recent research has revealed that changes in autophagy levels, along with alterations in apoptosis and fibrosis-related proteins, are linked to the progression of erectile dysfunction, suggesting a significant association. Autophagy, known to significantly affect cell fate and tissue fibrosis, is currently being explored as a potential treatment modality for erectile dysfunction. However, these present studies are still in their nascent stage, and there are limited experimental data available. This review analyzes erectile dysfunction from a pathological perspective. It provides an in-depth overview of how autophagy is involved in the apoptotic processes of smooth muscle and endothelial cells and its role in the fibrotic processes occurring in the cavernosum. This study aimed to develop a theoretical framework for the potential effectiveness of autophagy in preventing and treating erectile dysfunction, thus encouraging further investigation among researchers in this area.

Polystyrene nanoplastics exposure causes erectile dysfunction in rats

Polystyrene nanoplastics (PS-NPs), emerging and increasingly pervasive environmental contaminants, have the potential to cause persistent harm to organisms. Although previous reports have documented local accumulation and adverse effects in a variety of major organs after PS-NPs exposure, the impact of PS-NPs exposure on erectile function remains unexplored. Herein, we established a rat model of oral exposure to 100 nm PS-NPs for 28 days. To determine the best dose range of PS-NPs, we designed both low-dose and high-dose PS-NPs groups, which correspond to the minimum and maximum human intake doses, respectively. The findings indicated that PS-NPs could accumulate within the corpus cavernosum and high dose but not low dose of PS-NPs triggered erectile dysfunction. Moreover, the toxicological effects of PS-NPs on erectile function include fibrosis in the corpus cavernous, endothelial dysfunction, reduction in testosterone levels, elevated oxidative stress and apoptosis. Overall, this study revealed that PS-NPs exposure can cause erectile dysfunction via multiple ways, which provided new insights into the toxicity of PS-NPs.

Antioxidant Properties Mediate Nephroprotective and Hepatoprotective Activity of Essential Oil and Hydro-Alcoholic Extract of the High-Altitude Plant Skimmia anquetilia

There are many high-altitude plants such as Skimmia anquetilia that are unexplored for their possible medicinal values. The present study was conducted to examine the antioxidant activities of Skimmia anquetilia (SA) using in vitro and in vivo models. The SA hydro-alcoholic extracts were investigated using LC-MS for their chemical constituents. The essential oil and hydro-alcoholic extracts of SA were evaluated for pharmacological properties. The antioxidant properties were evaluated using in vitro DPPH, reducing power, cupric reducing antioxidant power, and metal chelating assays. The anti-hemolytic activity was carried out using a human blood sample. The in vivo antioxidant activities were evaluated using CCL₄-induced hepatotoxicity and nephrotoxicity assay. The in vivo evaluation included histopathological examination, tissue biochemical evaluation such as the kidney function test, catalase activity, reduced glutathione activity, and lipid peroxidation estimation. The phytochemical investigation showed that the hydro-alcoholic extract contains multiple important active constituents such as L-carnosine, acacetin, linoleic acid, leucylleucyl tyrosine, esculin sesquihydrate, etc., similar to the components of SA essential oil reported in a previous study. The high amount of total phenolic content (TPC) and total flavonoid content (TFC) reflect (p < 0.001) a high level of reducing power, cupric reducing, and metal chelating properties. This significantly (p < 0.001) inhibited enlargement of the liver, with a significant reduction in ALT (p < 0.01) and AST (p < 0.001). Highly significant improvement in the functioning of the kidney was noted using the blood urea and creatinine (p < 0.001) levels. Tissue-based activities showed a major rise in catalase, reduced glutathione, and reduced lipid peroxidation activities. We conclude from this study that the occurrence of a high quantity of flavonoid and phenolic contents had strong antioxidant properties, leading to hepatoprotective and nephroprotective activity. Further active constituent-specific activities should be evaluated.

To do one and to get more: Part II. Diabetes and metabolic dysfunction-associated fatty liver diseases

Type 2 diabetes mellitus (DM) is characterized by inability of faulty pancreatic β-cells to secret a normal amount of insulin to maintain normal body consumption, and/or peripheral tissue has a decreased susceptibility to insulin, resulting in hyperglycemia and insulin resistance. Similar to other chronic systemic inflammatory diseases, DM is a result from dysregulated interactions between ethnic, genetic, epigenetic, immunoregulatory, hormonal, and environmental factors. Therefore, it is rational to suppose the concept as "To do one and to get more", while using antidiabetic agents (ADA), a main pharmacologic agent for the treatment of DM, can provide an extraglycemia effect on comorbidities or concomittent comorbidities to DM. In this review, based on the much strong correlation between DM and metabolic dysfunction-associated fatty liver diseases (MAFLD) shown by similar pathophysiological mechanisms and a high prevalence of DM in MAFLD and its vice versa (a high prevalence of MAFLD in DM), it is possible to use the strategy to target both diseases simultaneously. We focus on a new classification of ADA, such as glucagon-like peptide-1 receptor (GLP1R) agonist and sodium-glucose cotransporter-2 (SGLT-2) inhibitors to show the potential benefits of extraglycemic effect on MAFLD. We conclude that the management of DM patients, especially for those who need ADA as adjuvant therapy should include healthy lifestyle modification to overcome the metabolic syndrome, contributing to the urgent need of an effective weight-reduction strategy. GLP1R agonist is one of effective body weight-lowering medications, which may be a better choice for DM complicated with MAFLD or its-associated severe form as metabolic associated steatohepatitis (MASH), although the role of SGLT-2 inhibitors is also impressive. The prescription of these two classes of ADA may satisfy the concept "To do one and to get more", based on successful sugar-lowering effect for controlling DM and extraglycemia benefits of hepatoprotective activity in DM patients.

The crosstalk among autophagy, apoptosis, and pyroptosis in cardiovascular disease

In recent years, the mechanism of cell death has become a hotspot in research on the pathogenesis and treatment of cardiovascular disease (CVD). Different cell death modes, including autophagy, apoptosis, and pyroptosis, are mosaic with each other and collaboratively regulate the process of CVD. This review summarizes the interaction and crosstalk of key pathways or proteins which play a critical role in the entire process of CVD and explores the specific mechanisms. Furthermore, this paper assesses the interrelationships among these three cell deaths and reviews how they regulate the pathogenesis of CVD. By understanding how these three cell death modes go together we can learn about the pathogenesis of CVD, which will enable us to identify new targets for preventing, controlling, and treating CVD. It will not only reduce mortality but also improve the quality of life.

To do one and to get more: Part I. Diabetes and bone

Type 2 diabetes mellitus (T2DM), is a chronic metabolic disease, characterized by the presence of hyperglycemia and insulin resistance. The key treatment strategies for T2DM include modification of lifestyle, medications, and continuous glucose monitoring. DM patients often have DM-associated morbidities and comorbidities; however, disorders of musculoskeletal system are often neglected, compared to other major systems in DM patients. Based on sharing similar pathophysiology of DM and osteoporosis, it is supposed that the use of antidiabetic agents (ADAs) may not only provide the lowering glucose level effect and the maintenance of the sugar homeostasis to directly delay the tissue damage secondary to hyperglycemia but also offer the benefits, such as the prevention of developing osteoporosis and fractures. Based on the current review, evidence shows the positive correlation between DM and osteoporosis or fracture, but the effectiveness of using ADA in the prevention of osteoporosis and subsequent reduction of fracture seems to be inconclusive. Although the benefits of ADA on bone health are uncertain, the potential value of "To do one and to get more" therapeutic strategy should be always persuaded. At least, one of the key treatment strategies as an establishment of healthy lifestyle may work, because it improves the status of insulin resistance and subsequently helps DM control, prevents the DM-related micro- and macrovascular injury, and possibly strengthens the general performance of musculoskeletal system. With stronger musculoskeletal system support, the risk of "fall" may be decreased, because it is associated with fracture. Although the ADA available in the market does not satisfy the policy of "To do one and to get more" yet, we are looking forward to seeing the continuously advanced technology of drug development on diabetic control, and hope to see their extra-sugar-lowering effects.

Association between Pre-Pregnancy Overweightness/Obesity and Pregnancy Outcomes in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Polycystic ovary syndrome (PCOS) is a common metabolic problem in women of reproductive age. Evidence suggests pregnant women with PCOS may have a higher risk of the development of adverse pregnancy outcomes; however, the relationship between pre-pregnancy overweight/obesity and pregnancy outcomes in women with PCOS remains uncertain. We try to clarify the relationship between pre-pregnancy overweight/obesity and subsequent pregnancy outcomes. Therefore, we conducted this systematic review and meta-analysis. We used the databases obtained from the PubMed, Embase, Web of Science, and Cochrane databases, plus hand-searching, to examine the association between pre-pregnancy overweightness/obesity and pregnancy outcomes in women with PCOS from inception to 4 February 2022. A total of 16 cohort studies, including 14 retrospective cohort studies (n = 10,496) and another two prospective cohort studies (n = 818), contributed to a total of 11,314 women for analysis. The meta-analysis showed significantly increased odds of miscarriage rate in PCOS women whose pre-pregnancy body mass index (BMI) is above overweight (OR 1.71 [95% CI 1.38–2.11]) or obese (OR 2.00 [95% CI 1.38–2.90]) under a random effect model. The tests for subgroup difference indicated the increased risk was consistent, regardless which body mass index cut-off for overweight (24 or 25 kg/m²) or obesity (28 and 30 kg/m²) was used. With the same strategies, we found that pregnant women in the control group significantly increased live birth rate compared with those pregnant women with PCOS as well as pre-pregnancy overweight/obesity (OR 0.79 [95% CI 0.71–0.89], OR 0.78 [95% CI 0.67–0.91]). By contrast, we did not find any association between PCOS women with pre-pregnancy overweight/obesity and preterm birth. Based on the aforementioned findings, the main critical factor contributing to a worse pregnancy outcome may be an early fetal loss in these PCOS women with pre-pregnancy overweight/obesity. Since PCOS women with pre-pregnancy overweightness/obesity were associated with worse pregnancy outcomes, we supposed that weight reduction before attempting pregnancy in the PCOS women with pre-pregnancy overweightness/obesity may improve the subsequent pregnancy outcomes.

N-acetylcysteine improves diabetic associated erectile dysfunction in streptozotocin-induced diabetic mice by inhibiting oxidative stress

Oxidative stress appears to play a role in the pathogenesis of diabetes mellitus erectile dysfunction (DMED). This study aimed to investigate the effect of N‐acetylcysteine (NAC) on DMED in streptozotocin‐induced diabetic mice and to explore potential mechanisms. In the present study, we show that an erectile dysfunction is present in the streptozotocin‐induced mouse model of diabetes as indicated by decreases in intracavernous pressure responses to electro‐stimulation as well as from results of the apomorphine test of erectile function. After treatment of NAC, the intracavernous pressure was increased. In these DMED mice, oxidative stress and inflammatory responses were significantly reduced within the cavernous microenvironment, while activity of antioxidant enzymes in this cavernous tissue was enhanced after NAC treatment. These changes protected mitochondrial stress damage and a significant decreased in apoptosis within the cavernous tissue of DMED mice. This appears to involve activation of the nuclear factor erythroid 2‐like‐2 (Nrf2) signalling pathway, as well as suppression of the mitogen‐activated protein kinase (MAPK) p38/ NF‐κB pathway within cavernous tissue. In conclusion, NAC can improve erectile function through inhibiting oxidative stress via activating Nrf2 pathways and reducing apoptosis in streptozotocin‐induced diabetic mice. NAC might provide a promising therapeutic strategy for individuals with DMED.