A small-molecule activator of mitochondrial aldehyde dehydrogenase 2 reduces the severity of cerulein-induced acute pancreatitis

Ferroptosis in Rat Lung Tissue during Severe Acute Pancreatitis-Associated Acute Lung Injury: Protection of Qingyi Decoction

Qingyi decoction (QYD) has anti-inflammatory pharmacological properties and substantial therapeutic benefits on severe acute pancreatitis (SAP) in clinical practice. However, its protective mechanism against SAP-associated acute lung injury (ALI) remains unclear. In this study, we screened the active ingredients of QYD from the perspective of network pharmacology to identify its core targets and signaling pathways against SAP-associated ALI. Rescue experiments were used to determine the relationship between QYD and ferroptosis. Then, metabolomics and 16s rDNA sequencing were used to identify differential metabolites and microbes in lung tissue. Correlation analysis was utilized to explore the relationship between core targets, signaling pathways, metabolic phenotypes, and microbial flora, sorting out the potential molecular network of QYD against SAP-associated lung ALI. Inflammatory damage was caused by SAP in the rat lung. QYD could effectively alleviate lung injury, improve respiratory function, and significantly reduce serum inflammatory factor levels in SAP rats. Network pharmacology and molecular docking identified three key targets: ALDH2, AnxA1, and ICAM-1. Mechanistically, QYD may inhibit ferroptosis by promoting the ALDH2 expression and suppress neutrophil infiltration by blocking the cleavage of intact AnxA1 and downregulating ICAM-1 expression. Ferroptosis activator counteracts the pulmonary protective effect of QYD in SAP rats. In addition, seven significant differential metabolites were identified in lung tissues. QYD relatively improved the lung microbiome's abundance in SAP rats. Further correlation analysis determined the correlation between ferroptosis, differential metabolites, and differential microbes. In this work, the network pharmacology, metabolomics, and 16s rDNA sequencing were integrated to uncover the mechanism of QYD against SAP-associated ALI. This novel integrated method may play an important role in future research on traditional Chinese medicine.

Aldehyde Dehydrogenase 2 as a Therapeutic Target in Oxidative Stress-Related Diseases: Post-Translational Modifications Deserve More Attention

Aldehyde dehydrogenase 2 (ALDH2) has both dehydrogenase and esterase activity; its dehydrogenase activity is closely related to the metabolism of aldehydes produced under oxidative stress (OS). In this review, we recapitulate the enzyme activity of ALDH2 in combination with its protein structure, summarize and show the main mechanisms of ALDH2 participating in metabolism of aldehydes in vivo as comprehensively as possible; we also integrate the key regulatory mechanisms of ALDH2 participating in a variety of physiological and pathological processes related to OS, including tissue and organ fibrosis, apoptosis, aging, and nerve injury-related diseases. On this basis, the regulatory effects and application prospects of activators, inhibitors, and protein post-translational modifications (PTMs, such as phosphorylation, acetylation, S-nitrosylation, nitration, ubiquitination, and glycosylation) on ALDH2 are discussed and prospected. Herein, we aimed to lay a foundation for further research into the mechanism of ALDH2 in oxidative stress-related disease and provide a basis for better use of the ALDH2 function in research and the clinic.

Design, Synthesis, Biological Evaluation and In Silico Study of Benzyloxybenzaldehyde Derivatives as Selective ALDH1A3 Inhibitors

Aldehyde dehydrogenase 1A3 (ALDH1A3) has recently gained attention from researchers in the cancer field. Several studies have reported ALDH1A3 overexpression in different cancer types, which has been found to correlate with poor treatment recovery. Therefore, finding selective inhibitors against ALDH1A3 could result in new treatment options for cancer treatment. In this study, ALDH1A3-selective candidates were designed based on the physiological substrate resemblance, synthesized and investigated for ALDH1A1, ALDH1A3 and ALDH3A1 selectivity and cytotoxicity using ALDH-positive A549 and ALDH-negative H1299 cells. Two compounds (ABMM-15 and ABMM-16), with a benzyloxybenzaldehyde scaffold, were found to be the most potent and selective inhibitors for ALDH1A3, with IC₅₀ values of 0.23 and 1.29 µM, respectively. The results also show no significant cytotoxicity for ABMM-15 and ABMM-16 on either cell line. However, a few other candidates (ABMM-6, ABMM-24, ABMM-32) showed considerable cytotoxicity on H1299 cells, when compared to A549 cells, with IC₅₀ values of 14.0, 13.7 and 13.0 µM, respectively. The computational study supported the experimental results and suggested a good binding for ABMM-15 and ABMM-16 to the ALDH1A3 isoform. From the obtained results, it can be concluded that benzyloxybenzaldehyde might be considered a promising scaffold for further drug discovery aimed at exploiting ALDH1A3 for therapeutic intervention.

miR-9 alleviated the inflammatory response and apoptosis in caerulein-induced acute pancreatitis by regulating FGF10 and the NF-κB signaling pathway

MicroRNAs (miRs) have been implicated in the development of acute pancreatitis (AP). However, the role and potential mechanism of miR-9 in AP progression remains unclear. Caerulein-treated AR42J cells were used as a cellular model of AP. Results revealed caerulein triggered an inflammatory response by promoting the secretion of inflammatory cytokines [tumor necrosis factor-α, interleukin (IL) 1β and IL-6], as evidenced by ELISA. Furthermore, caerulein-induced apoptosis was reported by flow cytometry and western blot assays. Additionally, miR-9 expression was downregulated by caerulein treatment, as demonstrated by reverse transcription quantitative PCR. However, miR-9 overexpression reduced the inflammatory response and apoptosis in caerulein-treated AR42J cells. miR-9 knockdown resulted in opposite effects. Furthermore, fibroblast growth factor (FGF) 10 was validated to be targeted via miR-9 by luciferase, RNA immunoprecipitation and RNA pull-down assays. Results demonstrated increased FGF10 expression in caerulein-treated AR42J cells and that FGF10 overexpression exacerbated the caerulein-induced inflammatory response and apoptosis, while its knockdown had the opposite effect. Additionally, FGF10 reversed the effect of miR-9 on caerulein-induced injury in AR42J cells. Results demonstrated that miR-9 inhibited the expression of the nuclear factor κB (NF-κB) pathway-related proteins by downregulating FGF10. As a result, miR-9 decreased inflammatory response and apoptosis in caerulein-treated AR42J cells by targeting FGF10 and blocking NF-κB signaling, suggesting that miR-9 may serve as a novel target for AP treatment.

ATF4-mediated histone deacetylase HDAC1 promotes the progression of acute pancreatitis

Acute pancreatitis (AP), an acute inflammatory process, can be difficult to diagnose. Activating transcription factor 4 (ATF4) has been reported to participate in the pathogenesis of AP. Additionally, histone deacetylases (HDACs) are shown to be closely related to the development of a variety of diseases, including inflammation disease. In our study, we tried to highlight the role of ATF4 in AP through regulation of HDAC1. Firstly, we validated the effect of ATF4 on pancreatic acinar cell proliferation, apoptosis, and inflammation through in vitro experiments on cellular models of caerulein-induced AP. Next, we examined the correlation between ATF4 and HDAC1, and between HDAC1 with neutral endopeptidase (NEP) and kruppel-like factor 4 (KLF4). Finally, the regulatory role of ATF4 in AP was further assessed by determination of pathological conditions, biochemical indicators and inflammation through in vivo experiments on caerulein-induced AP mouse models. After AP induction, highly expressed ATF4 was observed, and silencing ATF4 could promote pancreatic acinar cell proliferation and inhibit apoptosis. ATF4 could bind to the HDAC1 promoter and upregulate its expression in AP. Moreover, HDAC1 could increase KLF4 expression by inhibiting NEP expression. Functionally, silencing ATF4 could suppress AP through regulation of NEP-mediated KLF4 via downregulation of HDAC1. Above all, our study uncovered the promotive role of ATF4 in AP through upregulation of HDAC1.

Saikosaponin A-Induced Gut Microbiota Changes Attenuate Severe Acute Pancreatitis through the Activation of Keap1/Nrf2-ARE Antioxidant Signaling

Objective

Severe acute pancreatitis (SAP) is a serious and life-threatening disease associated with multiple organ failure and a high mortality rate and is accompanied by distinct oxidative stress and inflammatory responses. Saikosaponin A has strong antioxidant properties and can affect the composition of gut microbiota. We sought to determine the effects of Saikosaponin A interventions on SAP by investigating the changes of gut microbiota and related antioxidant signaling.

Methods

A SAP model was established in Sprague-Dawley (SD) rats through the injection of sodium taurocholate into the biliopancreatic duct and confirmed by elevated levels of serum lipase and amylase. The model was fed a standard diet either with saline solution or with Saikosaponin A. Fecal microbiota transplantation (FMT) from Saikosaponin A-induced rats into the rat model was performed to test the effects of gut microbiota. The composition of gut microbiota was analyzed by using 16S rRNA gene sequencing. We measured apoptotic status, inflammatory biomarkers, and Keap1-Nrf2-ARE ((Kelch-like ECH-associated protein 1) nuclear factor erythroid 2-related factor 2-antioxidant response element) antioxidant signaling.

Results

Saikosaponin A intervention attenuated SAP lesions and reduced the levels of serum amylase and lipase, oxidative stress, and inflammatory responses by reducing pathological scores and affecting the serum level of oxidative and inflammatory factors. Meanwhile, the expression of Keap1-Nrf2-ARE was increased. Saikosaponin A intervention improved microbiota composition by increasing the relative abundance of Lactobacillus and Prevotella species. FMT resulted in similar results as those caused by the Saikosaponin A intervention, suggesting Saikosaponin A may exert its function via the improvement of gut microbiota composition.

Conclusions

Saikosaponin A-induced gut microbiota changes attenuate SAP progression in the rat model and may be a potential natural drug for adjuvant treatment of SAP. Further work is needed to clear up the points.

The Association and Interaction of Aldehyde Dehydrogenase 2 Polymorphisms with Food Group Intake and Probability of Having Non-Alcoholic Fatty Liver Disease

PURPOSE

This study investigated the association between the aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, food group intake, and the probability of having non-alcoholic fatty liver disease (NAFLD) in a Chinese population.

PATIENTS AND METHODS

A total of 3506 adults were enrolled in this study, and all underwent physical examinations and genotyping of polymorphisms with polymerase chain reaction. Participants filled out a dietary questionnaire that was used to assess the frequency and quantity of food consumption.

RESULTS

We found that milk groups were associated with a lower probability of developing NAFLD. On the contrary, meat and salted and smoked foods were associated with a higher probability of NAFLD. However, the influences of salted and smoked foods and fresh fruit and vegetables on NAFLD were obviously different in the two genotype groups. Salted and smoked foods intake was a factor associated with a higher probability of having NAFLD or nonalcoholic steatohepatitis (NASH) in the A genotype group, but there was no effect in the G genotype group. Moreover, eating salted and smoked foods several times per week was associated with a higher probability of having NAFLD than seldom consuming them. Consumption of fresh fruit and vegetables was not a factor influencing the probability of having NAFLD in the A genotype group, and there was no effect in the G genotype group. Further analysis of the interaction indicated that the GA +AA genotype showed an interaction with fresh fruit and vegetables and salted and smoked foods. Moreover, it was not obvious that meat intake increased the probability of having NAFLD or NASH among different genotypes.

CONCLUSION

Our results indicate that ALDH2 rs671 GA and AA genotypes are factors associated with increased probability of NAFLD among Chinese subjects. This could stimulate the development of novel approaches for preventing NAFLD.