Regulatory mechanism of C4-dicarboxylates in cyclo (Phe-Pro) production.

Cyclo (Phe-Pro) (cFP), a cyclic dipeptide with notable antifungal, antibacterial, and antiviral properties, shows great promise for biological control of plant diseases. Produced as a byproduct by non-ribosomal peptide synthetases (NRPS), the regulatory mechanism of cFP biosynthesis remains unclear. In a screening test of 997 Tn5 mutants of Burkholderia seminalis strain R456, we identified eight mutants with enhanced antagonistic effects against Fusarium graminearum (Fg). Among these, mutant 88's culture filtrate contained cFP, confirmed through HPLC and LC-MS, which actively inhibited Fg. The gene disrupted in mutant 88 is part of the Dct transport system (Dct-A, -B, -D), responsible for C4-dicarboxylate transport. Knockout mutants of Dct genes exhibited higher cFP levels than the wild type, whereas complementary strains showed no significant difference. Additionally, the presence of exogenous C4-dicarboxylates reduced cFP production in wild type R456, indicating that these substrates negatively regulate cFP synthesis. Given that cFP synthesis is related to NRPS, we previously identified an NRPS cluster in R456, horizontally transferred from algae. Specifically, knocking out gene 2061 within this NRPS cluster significantly reduced cFP production. A Fur box binding site was predicted upstream of gene 2061, and yeast one-hybrid assays confirmed Fur protein binding, which increased with additional C4-dicarboxylates. Knockout of the Fur gene led to up-regulation of gene 2061 and increased cFP production, suggesting that C4-dicarboxylates suppress cFP synthesis by enhancing Fur-mediated repression of gene 2061.

Evaluating the effects of azelaic acid in the metabolism of Arabidopsis thaliana seedlings through untargeted metabolomics and ionomics approaches.

The present study demonstrates that low concentrations of azelaic acid (AZA) significantly impact the metabolism of Arabidopsis thaliana seedlings, leading to imbalances in numerous minerals and metabolites due to AZA-induced stress. Untargeted metabolomic analyses were conducted on untreated and AZA-treated seedlings at two time points: 7 and 14 days after treatment initiation. The results revealed a general accumulation of sugars (e.g., glucose, mannose, xylose), amino acids (e.g., lysine, GABA, threonine, glutamine), and organic acids (e.g., glutaric acid, shikimic acid, succinic acid) in AZA treated-seedlings, suggesting that AZA triggers stress responses in Arabidopsis. Ionomic analysis revealed that AZA induces phosphorus deficiency, which plants compensate by increasing malate content in the roots. Additionally, AZA treatment induced putrescine accumulation within the root, a metabolic biomarker of potassium deficiency and plant stress. The metabolomic profile showed elevated levels of different specialized metabolites, such as nitrogen- and sulphur-containing compounds, and altered levels of various phytohormones, including jasmonates and brassinosteroids, implicated in plant protection under biotic and/or abiotic stresses. These findings support the hypothesis that AZA's mode of action is associated with an auxin imbalance, suggesting its function as an auxinic herbicide. The observed increases in starch and jasmonates, coupled with the disruptions in potassium homeostasis, are linked to the previously reported alterations in the auxin transport, root architecture and gravitropic root response. Statistical analyses were applied, including Kruskal-Wallis tests for ionomic data, as well as multifactor analysis, Principal Component Analysis, Orthogonal Partial Least Squares-Discriminant Analysis, and enrichment pathway analysis for metabolomic data, ensuring the robustness and validity of these findings.

Human skin absorption of three plasticizers: Diisononyl-1,2-cyclohexanedicarboxylate (DINCH), di(2-ethylhexyl) terephthalate (DEHTP), and di(2-ethylhexyl) adipate (DEHA).

Alternative plasticizers such as diisononyl-1,2-cyclohexanedicarboxylate (DINCH), di(2-ethylhexyl) terephthalate (DEHTP), and di(2-ethylhexyl) adipate (DEHA) are progressively replacing phthalates in many consumer and professional products because of adverse effects on reproduction associated with some phthalates. Human exposures to these phthalate substitutes can occur through ingestion, skin absorption and inhalation. Skin uptake can lead to greater concentration at the target organs compared to ingestion because the skin exposure route bypasses the first-pass effect. Skin absorption studies are almost absent for these alternative plasticizers. We therefore wanted first, to characterize skin absorption of a mixture containing DINCH, DEHA and DEHTP in vitro using a flow-through diffusion cell system with ex vivo human skin, quantifying their respective monoester metabolites (mono-isononyl-cyclohexane-1,2-dicarboxylate (MINCH), mono-2-ethylhexyl adipate (MEHA), mono-2-ethylhexyl terephthalate (MEHTP), respectively); second, to validate these results by exposing five human volunteers to this mixture on their forearm and quantifying the corresponding urinary metabolites (including the monoesters and their oxidation products). Our study showed that two of these alternative plasticizers, DEHTP and DINCH, did not permeate skin showing as quantifiable metabolite levels in vitro and only traces of DEHA were quantified as its monoester metabolite, MEHA. Permeation coefficient (Kp) 0.06 and 55.8*10-7 cm/h for neat and emulsified DEHA, respectively, while the permeation rate (J) remained low for both (0.005 and 0.001 µg/cm2/h, respectively). Participants exposed to a mixture of these three plasticizers did not have noteworthy urinary concentrations of their respective metabolites after 24 hours post-application. However, the alternative plasticizer mixture was completely absorbed after six hours post-application on the forearms of the human volunteers, and the urinary elimination curves showed a slight increase after 24 hours post-application. Further studies on skin absorption of these substances should follow the urinary elimination kinetics of these metabolites more than 24 hours post-application. We also recommend quantifying the parent compounds in the in vitro diffusion experiments.

Recent Advances in the Biosynthesis of Mid- and Long-Chain Dicarboxylic Acids Using Terminally Oxidizing Unconventional Yeasts.

As high-performance monomers for the manufacture of polyamide materials, mid- and long-chain dicarboxylic acids (DCAi, i ≥ 6) have received extensive attention from researchers. Biosynthesis is gradually replacing chemical synthesis due to its outstanding advantages in the industrial production of mid- and long-chain dicarboxylic acids, which is mostly achieved by using the strong terminal oxidation ability of nonmodel microorganisms such as Candida tropicalis to oxidize hydrophobic substrates such as alkanes. Here, we first summarize the metabolic pathways of oxidative alkane conversion into dicarboxylic acid by terminally oxidizing unconventional yeasts and the corresponding metabolic engineering strategies. Then, we summarize the research progress on new dicarboxylic acid production processes. Finally, the future development directions in the biosynthesis of mid- and long-chain dicarboxylic acids are prospected from synthetic biology and bioprocess engineering, which can also provide a reference for the synthesis of other biobased chemicals and biomaterials.

The Off-Treatment Effects of Olpasiran on Lipoprotein(a) Lowering: OCEAN(a)-DOSE Extension Period Results.

BACKGROUND: Olpasiran, a small interfering RNA (siRNA), blocks lipoprotein(a) (Lp(a)) production by preventing translation of apolipoprotein(a) mRNA. In phase 2, higher doses of olpasiran every 12 weeks (Q12W) reduced circulating Lp(a) by >95%. OBJECTIVES: This study sought to assess the timing of return of Lp(a) to baseline after discontinuation of olpasiran, as well as longer-term safety. METHODS: OCEAN(a)-DOSE (Olpasiran Trials of Cardiovascular Events And LipoproteiN[a] Reduction-DOSE Finding Study) was a phase 2, dose-finding trial that enrolled 281 participants with atherosclerotic cardiovascular disease and Lp(a) >150 nmol/L to 1 of 4 active doses of olpasiran vs placebo (10 mg, 75 mg, 225 mg Q12W, or an exploratory dose of 225 mg Q24W given subcutaneously). The last dose of olpasiran was administered at week 36; after week 48, there was an extended off-treatment follow-up period for a minimum of 24 weeks. RESULTS: A total of 276 (98.2%) participants entered the off-treatment follow-up period. The median study exposure (treatment combined with off-treatment phases) was 86 weeks (Q1-Q3: 79-99 weeks). For the 75 mg Q12W dose, the off-treatment placebo-adjusted mean percent change from baseline in Lp(a) was -76.2%, -53.0%, -44.0%, and -27.9% at 60, 72, 84, and 96 weeks, respectively (all P < 0.001). The respective off-treatment changes in Lp(a) for the 225 mg Q12W dose were -84.4%, -61.6%, -52.2%, and -36.4% (all P < 0.001). During the extension follow-up phase, no new safety concerns were identified. CONCLUSIONS: Olpasiran is a potent siRNA with prolonged effects on Lp(a) lowering. Participants receiving doses ≥75 mg Q12W sustained a ∼40% to 50% reduction in Lp(a) levels close to 1 year after the last dose. (Olpasiran Trials of Cardiovascular Events And LipoproteiN[a] Reduction-DOSE Finding Study [OCEAN(a)-DOSE]; NCT04270760).

Stability Indicating Method Development and Validation for the Estimation of Bempedoic Acid by RP-HPLC.

BACKGROUND: Bempedoic acid (BEM) belongs to a category of drugs known as Adenosine triphosphate-citrate Lyase (ACL) inhibitors. It is a prodrug with intracellular activation that is administered orally. Bempedoic acid is used to treat existing atherosclerotic cardiovascular diseases, mainly hypercholesterolemia. METHODS: For the stability-indicating assay, the HPLC method was employed using a Kromasil 100-5-C8 column (100 mm × 4.6 mm), a UV detector set at 230 nm, and a mobile phase comprising a 70:30 v/v mixture of acetonitrile and 0.1% Orthophosphoric Acid (OPA) buffer. The method was operated at an ambient temperature with a flow rate of 1 mL/min. The method developed has been statistically validated according to ICH guidelines. RESULTS: The stability-indicating method was executed using a Kromasil 100-5-C8 (100 mm × 4.6 mm) column at a 1.0 mL/min flow rate. A mixture of acetonitrile and 0.1% Orthophosphoric Acid (OPA) buffer in a 70:30 v/v ratio made up the mobile phase. BEM's retention times were discovered to be 1.88 minutes each. The temperature was kept at room temperature. 234 nm was the ideal wavelength for BEM. According to ICH criteria, the approach developed has undergone statistical validation. BEM's % RSD was discovered to be 0.6, respectively. For BEM, the % recovery was determined to be 100.0%. Regression models for bempedoic acid yielded LoD and LoQ values of 3.3 and 10.1 g/mL, respectively. The method showed good reproducibility and recovery with a % RSD less than 2. Studies on forced degradation confirmed the method's capacity to indicate stability in the presence of stress conditions, such as acid, basic, peroxide, UV, heat, and humidity. Both the retention times and the run time were shortened. CONCLUSION: In accordance with ICH Q2 (R1) guidelines, this method was successfully tested with HPLC to confirm the chemical structures of newly produced degradation products of bempedoic acid.

Exploring the Role of Bempedoic Acid in Metabolic Dysfunction Associated Steatotic Liver Disease: Actual Evidence and Future Perspectives.

Metabolic dysfunction-associated steatotic liver disease (MASLD) involves excessive lipid accumulation in hepatocytes, impacting global healthcare due to its high prevalence and risk of progression to severe liver conditions. Its pathogenesis involves genetic, metabolic, and inflammatory factors, with cardiovascular events as the leading cause of mortality. This review examines the role of lipid-lowering therapies in MASLD, with a particular focus on bempedoic acid, a recently approved cholesterol-lowering agent for hypercholesterolemia and high cardiovascular-risk patients. It explores its potential in liver disease by modulating lipid metabolism and inflammatory pathways based on the most recent studies available. Bempedoic acid inhibits ATP-citrate lyase, reducing cholesterol and fatty acid synthesis while activating AMP-activated protein kinase to suppress gluconeogenesis and lipogenesis. Animal studies indicate its efficacy in reducing hepatic steatosis, inflammation, and fibrosis. Bempedoic acid holds promise as a therapeutic for MASLD, offering dual benefits in lipid metabolism and inflammation. Further clinical trials are required to confirm its efficacy and safety in MASLD patients, potentially addressing the multifaceted nature of this disease.

New insights into azelaic acid-induced resistance against Alternaria Solani in tomato plants.

BACKGROUND: The effect of azelaic acid (Aza) on the response of tomato plants to Alternaria solani was investigated in this study. After being treated with Aza, tomato plants were infected with A. solani, and their antioxidant, biochemical, and molecular responses were analyzed. RESULTS: The results demonstrated that H2O2 and MDA accumulation increased in control plants after pathogen infection. Aza-treated plants exhibited a remarkable rise in peroxidase (POD) and catalase (CAT) activities during the initial stages of A. solani infection. Gene expression analysis revealed that both Aza treatment and pathogen infection altered the expression patterns of the SlNPR1, SlERF2, SlPR1, and SlPDF1.2 genes. The expression of SlPDF1.2, a marker gene for the jasmonic acid/ethylene (JA/ET) signaling pathway, showed a remarkable increase of 4.2-fold upon pathogen infection. In contrast, for the SlNPR1, a key gene in salicylic acid (SA) pathway, this increased expression was recorded with a delay at 96 hpi. Also, the phytohormone analysis showed significantly increased SA accumulation in plant tissues with disease development. It was also revealed that tissue accumulation of JA in Aza-treated plants was increased following pathogen infection, while it was not increased in plants without pathogen inoculation. CONCLUSION: The results suggest that the resistance induced by Aza is mainly a result of modulations in both SA and JA pathways following complex antioxidant and molecular defense responses in tomato plants during A. solani infection. These findings provide novel information regarding inducing mechanisms of azelaic acid which would add to the current body of knowledge of SAR induction in plants as result of Aza application.

Novel Therapies for the Treatment of Cardiovascular Disease.

Over the last decade, randomized clinical trials of several pharmacologic agents have demonstrated a reduction in cardiovascular mortality and other important secondary outcomes. Angiotensin-Neprilysin Inhibitors and Sodium-Glucose Co-transporter 2 inhibitors have now become pillars in the treatment of heart failure. Ivabradine is a negative chronotropic agent used as an adjunctive therapy in patients with heart failure. Two new hypertension therapies, zilebresiran and aprocitentan, are currently in investigational stages. Finally, mavacamten has emerged as a pharmacologic treatment for hypertrophic obstructive cardiomyopathy. Practitioners must be familiar with the indications and side effects of newer therapies as they are now frequently prescribed.

Comparative Cardiovascular Benefits of Bempedoic Acid and Statin Drugs.

BACKGROUND: In the CLEAR (Cholesterol Lowering via Bempedoic Acid, an ACL-Inhibiting Regimen) Outcomes trial, treatment of statin-intolerant patients with bempedoic acid produced a 21% decrease in low-density lipoprotein cholesterol (LDL-C) relative to placebo and a 13% relative reduction in the risk of major adverse cardiovascular events. OBJECTIVES: This study sought to determine whether the relationship between LDL-C lowering and cardiovascular benefit achieved with bempedoic acid resembles that observed with statins when standardized per unit change in LDL-C. METHODS: To compare the treatment effect of bempedoic acid with statins, the methodology of the Cholesterol Treatment Trialists' Collaboration (CTTC) was applied to outcomes among the 13,970 patients enrolled in the CLEAR Outcomes trial. The CTTC endpoint of "major vascular event" was a composite of coronary heart disease death, nonfatal myocardial infarction, fatal or nonfatal stroke, or coronary revascularization. HRs for CTTC-defined endpoints were normalized to 1 mmol/L differences in LDL-C levels between bempedoic acid and placebo groups. RESULTS: A first major vascular event occurred in 703 (10.1%) patients in the bempedoic acid group and 816 (11.7%) patients in the placebo group (HR: 0.85; 95% CI: 0.77-0.94). When normalized per 1 mmol/L reduction in LDL-C, the HR was 0.75 (95% CI: 0.63-0.90), comparable to the rate ratio of 0.78 reported for statins in the CTTC meta-analysis. Normalized risk reductions were similar for bempedoic acid and statins for the endpoints of major coronary events, nonfatal myocardial infarction, and coronary revascularization. CONCLUSIONS: Cardiovascular risk reduction with bempedoic acid is similar to that achieved with statins for a given absolute magnitude of LDL-C lowering. (Evaluation of Major Adverse Cardiovascular Events in Participants With, or at High Risk for, Cardiovascular Disease Who Are Statin Intolerant Treated with Bempedoic Acid [ETC-1002] or Placebo [CLEAR Outcomes]; NCT02993406).

Dicarboxylic acids counteract the metabolic effects of a Western diet by boosting energy expenditure.

Obesity has reached pandemic proportion not only in the West but also in other countries around the world; it is now one of the leading causes of death worldwide. A Western diet is rich in saturated fats and provides more calories than necessary, contributing to the rise of the obesity rate. It also promotes the development of liver steatosis, insulin resistance, hyperglycemia, and hyperlipidemia. In this issue of the JCI, Goetzman and colleagues describe the effects of consuming dicarboxylic acids (DAs) as an alternative source of dietary fat. The 12-carbon dicarboxylic acid (DC12) was administered to mice at 20% of their daily caloric intake for nine weeks in place of triglycerides. Notably, the change in diet increased the metabolic rate, reduced body fat, reduced liver fat, and improved glucose tolerance. These findings highlight DAs as useful energy nutrients for combatting obesity and treating various metabolic disorders.

1H-Pyrrole-2,5-dicarboxylic acid, a quorum sensing inhibitor from one endophytic fungus in Areca catechu L., acts as antibiotic accelerant against Pseudomonas aeruginosa.

Pseudomonas aeruginosa has already been stipulated as a "critical" pathogen, emphasizing the urgent need for researching and developing novel antibacterial agents due to multidrug resistance. Bacterial biofilm formation facilitates cystic fibrosis development and restricts the antibacterial potential of many current antibiotics. The capacity of P. aeruginosa to form biofilms and resist antibiotics is closely correlated with quorum sensing (QS). Bacterial QS is being contemplated as a promising target for developing novel antibacterial agents. QS inhibitors are a promising strategy for treating chronic infections. This study reported that the active compound PT22 (1H-pyrrole-2,5-dicarboxylic acid) isolated from Perenniporia tephropora FF2, one endophytic fungus from Areca catechu L., presents QS inhibitory activity against P. aeruginosa. Combined with gentamycin or piperacillin, PT22 functions as a novel antibiotic accelerant against P. aeruginosa. PT22 (0.50 mg/mL, 0.75 mg/mL, and 1.00 mg/mL) reduces the production of QS-related virulence factors, such as pyocyanin and rhamnolipid, and inhibits biofilm formation of P. aeruginosa PAO1 instead of affecting its growth. The architectural disruption of the biofilms was confirmed by visualization through scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Real-time quantitative PCR (RT-qPCR) indicated that PT22 significantly attenuated the expression of QS-related genes followed by docking analysis of molecules against QS activator proteins. PT22 dramatically increased the survival rate of Galleria mellonella. PT22 combined with gentamycin or piperacillin presents significant inhibition of biofilm formation and eradication of mature biofilm compared to monotherapy, which was also confirmed by visualization through SEM and CLSM. After being treated with PT22 combined with gentamycin or piperacillin, the survival rates of G. mellonella were significantly increased compared to those of monotherapy. PT22 significantly enhanced the susceptibility of gentamycin and piperacillin against P. aeruginosa PAO1. Our results suggest that PT22 from P. tephropora FF2 as a potent QS inhibitor is a candidate antibiotic accelerant to combat the antibiotic resistance of P. aeruginosa.

Analytical method development and validation for simultaneous estimation of Bempedoic acid and Ezetimibe in pure and its pharmaceutical dosage form by RP-HPLC.

A simple, accurate and precise method was developed for the simultaneous estimation of the bempedoic acid and ezetimibe in pure and tablet dosage form. The developed method was validated as per International Conference on Harmonization guidelines. The chromatographic separation was achieved isocratically on a Waters- C18, 250 × 4.6 mm, 5 µm column. Mobile phase containing K2HPO4-methanol in the ratio 60:40 in buffer at pH 4.3 was pumped through column at a flow rate of 1.0 ml/min. The temperature was maintained at 25°C. The optimized wavelength selected was 242 nm. The separation of bempedoic acid and ezetimibe showed retention times of 3.090 and 4.268 min respectively. The RSD values of the bempedoic acid and ezetimibe were 0.34 and 0.08 respectively. The accuracy of method was determined at three levels (50,100 and 150%). The percentage recovery was obtained as 100.0 and 100.0% for bempedoic acid and ezetimibe, respectively. The limits of determination and quantitation obtained from regression equations of bempedoic acid and ezetimibe were 1.065, 3.550 and 0.203, 0.677, respectively. The regression equation of bempedoic acid is y = 20,795x + 24,168, and it is y = 6,885.7x + 11,000 for ezetimibe. The retention times were decreased and the run time was decreased, so that the method developed is simple and economical that can be adopted for regular quality control tests in industry.

Review of Recent Literature and Updates in Nonstatin Cholesterol Management.

The guidelines for cholesterol management have been updated over the years from treat-to-target using any drug class to emphasis on statins without treatment targets to a hybrid of the 2 approaches. The most recent guideline updates include newer nonstatin lipid-lowering therapies (LLTs), low-density lipoprotein cholesterol (LDL-C) reduction goals, and LDL-C thresholds considering secondary prevention and cardiovascular risk. Although statins have been the mainstay of LLT for years, newer pharmacological agents such as proprotein convertase subtilisin-kexin type 9 inhibitor(s) (PCSK9i) monoclonal antibodies, small interfering RNA PCSK9i, and bempedoic acid to optimize LDL-C levels may be underutilized in clinical practice. To provide an updated review for clinicians, we performed a literature search in PubMed for articles published from January 1, 2000, to August 31, 2023, that included the terms cholesterol, LLT, bempedoic acid, inclisiran, or PCSK9 inhibitor. Studies were selected for inclusion according to relatedness to cholesterol management and outcomes with novel LLT agents. Optimization of statins can improve the lipid profile and contribute to primary and secondary atherosclerotic cardiovascular disease (ASCVD) prevention. The newest guidance combines anticipated LDL-C reduction from statins and LDL-C thresholds for primary and secondary prevention. Nonstatin agents such as PCSK9i monoclonal antibodies, small interfering RNA PCSK9i, and bempedoic acid are safe and effective LLTs that can be used in addition to statin therapy for additional LDL-C lowering and prevention of ASCVD. Additionally, these nonstatin agents are reasonable to initiate in patients who have not been able to tolerate statins due to myalgias, rhabdomyolysis, or contraindications. Cost may be a barrier to initiating these agents for patients who are underinsured or uninsured. Clinicians should reference the most up-to-date guidance for LLT for primary and secondary prevention of ASCVD. Additionally, clinicians must diligently continue to optimize statin and nonstatin LLT to improve cardiovascular health outcomes.

Novel antiarthritic mechanisms of Azelaic acid against CFA-induced arthritis in rats by modulating pro- and anti-inflammatory cytokines network.

An immunologic system attacking the body's own tissues is a hallmark of autoimmune disorders, which encompass a wide range of unique conditions. Numerous essential biologic functions, including the regulation of the immune system, inflammation, cell division, and tissue repair, are carried out by cytokines. Natural compounds are an effective treatment for autoimmune illnesses by modulation of inflammatory cytokines and infiltration of leukocytes into the inflamed tissue. Here, anti-arthritic study was carried out using oral administration of Azelaic acid (AzA) for 28 days with doses (20, 40, and 80 mg/kg) in Complete Freund's Adjuvant (CFA) induced arthritis model. AzA ameliorated the adjuvant-induced arthritis by decreasing arthritic score, paw volume, improved body-weight alterations and serum levels of PGE2, 5-LOX and anti-ccp. AzA showed significant down regulation of NF-κB, COX-II, TNF-α, IL-17, IL-1ß, IL-6, and up regulation of IL4 and IL10. Hemoglobin and RBCs count remarkably increased and ESR, CRP, platelets, WBCs levels markedly reduced in post treatment. In addition, the weakened SOD (superoxide dismutase), Catalase (CAT), Glutathione (GSH) activity and the increased levels of malondialdehyde (MDA) were all reversed by AzA treatment. And showed improved radiographical and histologic alterations in the structure of the joints. Molecular docking studies targeting COX-II, iNOS, TNF-α, 5-LOX, IL4, IL10, IL-6, and IL-17 establish a correlation between theoretical and experimental results. Results showed that AzA inhibit pro-inflammatory cytokines (COX-II, TNF-α, 5-LOX, IL-17, NF-κB, IL-1ß, and IL-6) and increase anti-inflammatory cytokines, which supported the anti-arthritic and immunomodulatory potential of AzA.