Shared and more specific genetic determinants and pathways underlying yeast tolerance to acetic, butyric, and octanoic acids.

BACKGROUND: The improvement of yeast tolerance to acetic, butyric, and octanoic acids is an important step for the implementation of economically and technologically sustainable bioprocesses for the bioconversion of renewable biomass resources and wastes. To guide genome engineering of promising yeast cell factories toward highly robust superior strains, it is instrumental to identify molecular targets and understand the mechanisms underlying tolerance to those monocarboxylic fatty acids. A chemogenomic analysis was performed, complemented with physiological studies, to unveil genetic tolerance determinants in the model yeast and cell factory Saccharomyces cerevisiae exposed to equivalent moderate inhibitory concentrations of acetic, butyric, or octanoic acids. RESULTS: Results indicate the existence of multiple shared genetic determinants and pathways underlying tolerance to these short- and medium-chain fatty acids, such as vacuolar acidification, intracellular trafficking, autophagy, and protein synthesis. The number of tolerance genes identified increased with the linear chain length and the datasets for butyric and octanoic acids include the highest number of genes in common suggesting the existence of more similar toxicity and tolerance mechanisms. Results of this analysis, at the systems level, point to a more marked deleterious effect of an equivalent inhibitory concentration of the more lipophilic octanoic acid, followed by butyric acid, on the cell envelope and on cellular membranes function and lipid remodeling. The importance of mitochondrial genome maintenance and functional mitochondria to obtain ATP for energy-dependent detoxification processes also emerged from this chemogenomic analysis, especially for octanoic acid. CONCLUSIONS: This study provides new biological knowledge of interest to gain further mechanistic insights into toxicity and tolerance to linear-chain monocarboxylic acids of increasing liposolubility and reports the first lists of tolerance genes, at the genome scale, for butyric and octanoic acids. These genes and biological functions are potential targets for synthetic biology approaches applied to promising yeast cell factories, toward more robust superior strains, a highly desirable phenotype to increase the economic viability of bioprocesses based on mixtures of volatiles/medium-chain fatty acids derived from low-cost biodegradable substrates or lignocellulose hydrolysates.

Sodium octanoate alleviates cardiac and cerebral injury after traumatic cardiac arrest in a porcine model.

INTRODUCTION: Traumatic cardiac arrest (TCA) is a severe condition with a high mortality rate, and patients who survive from TCA face a poor prognosis due to post-resuscitation injury, including cardiac and cerebral injury, which remains a serious challenge. Sodium octanoate has shown protective effects against various diseases. The present study aims to investigate sodium octanoate's protective effects against cardiac and cerebral injury after TCA in a porcine model. METHODS: The study included a total of 22 male domestic pigs divided into three groups: Sham group (n = 7), TCA group (n = 7), and sodium octanoate (SO) group (n = 8). Hemorrhage was initiated via the right femoral artery by a blood pump at a rate of 2 ml·kg-1·min-1 to establish TCA model. The Sham group underwent only endotracheal intubation and arteriovenous catheterization, without experiencing the blood loss/cardiac arrest/resuscitation model. At 5 min after resuscitation, the SO group received a continuous sodium octanoate infusion while the TCA group received the same volume of saline. General indicators were monitored, and blood samples were collected at baseline and at different time points after resuscitation. At 24 h after resuscitation, pigs were sacrificed, and heart and brain were obtained for cell apoptosis detection, iron deposition staining, oxidative stress detection, and the expression of ferroptosis-related proteins (ACSL4 and GPX4). RESULTS: Sodium octanoate significantly improved mean arterial pressure, cardiac output and ejection fraction induced by TCA. Serum biomarkers of cardiac and cerebral injury were found to increase at all time points after resuscitation, while sodium octanoate significantly reduced their levels. The apoptosis rates of cardiomyocytes and cerebral cortex cells in the SO group were significantly lower than in the TCA group, along with a reduced area of iron deposition staining. The sodium octanoate also reduced oxidative stress and down-regulated ferroptosis which was indicated by protein level alteration of ACSL4 and GPX4. CONCLUSION: Our study's findings suggest that early infusion of sodium octanoate significantly alleviates post-resuscitation cardiac and cerebral injury in a porcine model of TCA, possibly through inhibition of cell apoptosis and GPX4-mediated ferroptosis. Therefore, sodium octanoate could be a potential therapeutic strategy for patients with TCA.

Caprylic acid attenuates amyloid-ß proteotoxicity by supplying energy via ß-oxidation in an Alzheimer's disease model of the nematode Caenorhabditis elegans.

Computer-based analysis of motility was used as a measure of amyloid-ß (Aß) proteotoxicity in the transgenic strain GMC101, expressing human Aß1-42 in body wall muscle cells. Aß-aggregation was quantified to relate the effects of caprylic acid (CA) to the amount of the proteotoxic protein. Gene knockdowns were induced through RNA-interference (RNAi). Moreover, the estimation of adenosine triphosphate (ATP) levels, the mitochondrial membrane potential (MMP) and oxygen consumption served the evaluation of mitochondrial function. CA improved the motility of GMC101 nematodes and reduced Aß aggregation. Whereas RNAi for orthologues encoding key enzymes for α-lipoic acid and ketone bodies synthesis did not affect motility stimulation by CA, knockdown of orthologues involved in ß-oxidation of fatty acids diminished its effects. The efficient energy gain by application of CA was finally proven by the increase of ATP levels in association with increased oxygen consumption and MMP. In conclusion, CA attenuates Aß proteotoxicity by supplying energy via FAO. Since especially glucose oxidation is disturbed in Alzheimer´s disease, CA could potentially serve as an alternative energy fuel.

Discovery of sinomenine/8-Bis(benzylthio)octanoic acid hybrids as potential anti-leukemia drug candidate via mitochondrial pathway.

Traditional Chinese medicine Qingfengteng primarily acquired from the dried canes of Sinomenium acutum (Thunb.) Rehd. et Wils. var. cinereum Rehd. et Wils. and S. acutum (Thunb.) Rehd. et Wils. For the therapeutic treatment of rheumatism, acute arthritis, and rheumatoid arthritis based on Qingfengteng, sinomenine hydrochloride was recently made the principal active ingredient in various dosage forms. 8-Bis(benzylthio)octanoic acid (CPI-613) was an orphan medicine that the FDA and EMA approved orphan for the treatment of certain resistant malignancies. Its unique mode of action and minimal toxicity toward normal tissues made for an apt pharmacophore. In order to expand the field of sinomenine anticancer structures, sinomenine/8-Bis(benzylthio)octanoic acid derivatives were designed and synthesized. Among them, target hybrids e4 stood out for having notable cytotoxic effects against cancer cell lines, especially for K562 cells, with IC50 values of 2.45 µM and high safety. In-depth investigations demonstrated that e4 caused apoptosis by stopping the cell cycle at G1 phase, and doing so by altering the morphology of the nucleus and causing membrane potential of the in mitochondria to collapse. These results indicated e4 exerted an antiproliferative effect through apoptosis induction via mitochondrial pathway.

Perfluorooctanoic acid disrupts thyroid-specific genes expression and regulation via the TSH-TSHR signaling pathway in thyroid cells.

Perfluorooctanoic acid (PFOA) is a highly persistent and widespread chemical in the environment with endocrine disruption effects. Although it has been reported that PFOA can affect multiple aspects of thyroid function, the exact mechanism by which it reduces thyroxine levels has not yet been elucidated. In this study, FRTL-5 rat thyroid follicular cells were used as a model to study the toxicity of PFOA to the genes related to thyroid hormone synthesis and their regulatory network. Our results reveal that PFOA interfered with the phosphorylation of the cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB) induced by thyroid-stimulating hormone (TSH), as well as the transcription levels of paired box 8 (PAX8), thyroid transcription factor 1 (TTF1), sodium/iodide cotransporter (NIS), thyroglobulin (TG), and thyroid peroxidase (TPO). However, the above outcomes can be alleviated by enhancing cAMP production with forskolin treatment. Further investigations showed that PFOA reduced the mRNA level of TSH receptor (TSHR) and impaired its N-glycosylation, suggesting that PFOA has disrupting effects on both transcriptional regulation and post-translational regulation. In addition, PFOA increased endoplasmic reticulum (ER) stress and decreased ER mass in FRTL-5 cells. Based on these findings, it can be inferred that PFOA disrupts the TSH-activated cAMP signaling pathway by inhibiting TSHR expression and its N-glycosylation. We propose that this mechanism may contribute to the decrease in thyroid hormone levels caused by PFOA. Our study sheds light on the molecular mechanism by which PFOA can disrupt thyroid function and provides new insights and potential targets for interventions to counteract the disruptive effects of PFOA.

A 2-component blend of coconut oil-derived fatty acids as an oviposition deterrent against Drosophila suzukii (Drosophilidae: Diptera).

Coconut free fatty acid (CFFA), a mixture of 8 fatty acids derived from coconut oil, is an effective repellent and deterrent against a broad array of hematophagous insects. In this study, we evaluated the oviposition deterrent activity of CFFA on spotted-wing drosophila (SWD; Drosophila suzukii), a destructive invasive pest of berries and cherries, and identified bioactive key-deterrent compounds. In laboratory 2-choice tests, CFFA deterred SWD oviposition in a dose-dependent manner with the greatest reduction (99%) observed at a 20-mg dose compared with solvent control. In a field test, raspberries treated with 20-mg CFFA received 64% fewer SWD eggs than raspberries treated with the solvent control. In subsequent laboratory bioassays, 2 of CFFA components, caprylic and capric acids, significantly reduced SWD oviposition by themselves, while 6 other components had no effect. In choice and no-choice assays, we found that a blend of caprylic acid and capric acid, at equivalent concentrations and ratio as in CFFA, was as effective as CFFA, while caprylic acid or capric acid individually were not as effective as the 2-component blend or CFFA at equivalent concentrations, indicating the 2 compounds as the key oviposition deterrent components for SWD. The blend was also as effective as CFFA for other nontarget drosophilid species in the field. Given that CFFA compounds are generally regarded as safe for humans, CFFA and its bioactive components have potential application in sustainably reducing SWD damage in commercial fruit operations, thereby reducing the sole reliance on insecticides.

Medium-chain fatty acids modify macrophage expression of metabolic and inflammatory genes in a PPAR ß/δ-dependent manner.

There is great interest on medium chain fatty acids (MCFA) for cardiovascular health. We explored the effects of MCFA on the expression of lipid metabolism and inflammatory genes in macrophages, and the extent to which they were mediated by the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPAR ß/δ). J774A.1 murine macrophages were exposed to octanoate or decanoate as MCFA, a long-chain fatty acid control (palmitate), or the PPAR ß/δ agonist GW501516, with or without lipopolysaccharide (LPS) stimulation, and with or without an siRNA-induced knockdown of PPAR ß/δ. MCFA increased the expression of Plin2, encoding a lipid-droplet associated protein with anti-inflammatory effects in macrophages, in a partially PPAR ß/δ-dependent manner. Both MCFA stimulated expression of the cholesterol efflux pump ABCA1, more pronouncedly under LPS stimulation and in the absence of PPAR ß/δ. Octanoate stimulated the expression of Pltp, encoding a phospholipid transfer protein that aids ABCA1 in cellular lipid efflux. Only palmitate increased expression of the proinflammatory genes Il6, Tnf, Nos2 and Mmp9. Non-stimulated macrophages exposed to MCFA showed less internalization of fluorescently labeled lipoproteins. MCFA influenced the transcriptional responses of macrophages favoring cholesterol efflux and a less inflammatory response compared to palmitate. These effects were partially mediated by PPAR ß/δ.

Effects of supplemental octanoate on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammation-related genes expression of large yellow croaker (Larimichthys crocea) fed with high soybean oil diet.

Dietary high soybean oil (SO) levels might cause hepatic lipid deposition, induce oxidative stress and inflammatory response in aquatic animals, while octanoate (OCT) is beneficial to metabolism and health in mammals. However, the effect of OCT has been studied rarely in aquatic animals. In this study, a 10-week feeding trial was conducted to investigate the effect of supplemental OCT on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammatory response of large yellow croaker (Larimichthys crocea) fed with high SO levels diet. The negative control diet contained 7% fish oil (FO), while the positive control diet contained 7% SO. The other four experimental diets were supplemented with 0.7, 2.1, 6.3 and 18.9 g/kg sodium octanoate (OCT) based on the positive control diet. Results showed that OCT supplementation effectively reduced the hepatic crude lipid, triglyceride (TG), total cholesterol (TC) and non-esterified free fatty acids contents, and alleviated lipid accumulation caused by the SO diet. Meanwhile, OCT supplementation decreased the serum TG, TC, alanine transaminase, aspartate transaminase and low-density lipoprotein cholesterol levels, increased the serum high-density lipoprotein cholesterol level, improved the serum lipid profiles and alleviated hepatic injury. Furthermore, with the supplementation of OCT, the mRNA expression of genes related to lipogenesis (acc1, scd1, fas, srebp1, dgat1 and cebpα) and fatty acid (FA) transport (fabp3, fatp and cd36) were down-regulated, while the mRNA expression of genes related to lipolysis (atgl, hsl and lpl) and FA ß-oxidation (cpt1 and mcad) were up-regulated. Besides that, dietary OCT increased the total antioxidant capacity, activities of peroxidase, catalase and superoxide dismutase and the content of reduced glutathione, decreased the content of 8-hydroxy-deoxyguanosine and malondialdehyde and relieved hepatic oxidative stress. Supplementation of 0.7 and 2.1 g/kg OCT down-regulated the mRNA expression of genes related to pro-inflammatory cytokines (tnfα, il1ß and ifnγ), and suppressed hepatic inflammatory response. In conclusion, supplementation with 0.7-2.1 g/kg OCT could reduce hepatic lipid accumulation, relieve oxidative stress and regulate inflammatory response in large yellow croaker fed the diet with high SO levels, providing a new way to alleviate the hepatic fat deposition in aquatic animals.

Influence of Lipidation Pattern of the KR12 Fragment of Peptide LL-37 on Its Antibacterial and Hemolytic Activities.

Contemporary medicine has been confronted by multidrug resistance. Therefore, new antibiotics are sought to alleviate the problem. In this study, we estimated the effect of the positioning and extent of lipidation (mainly octanoic acid residue) in the KR12-NH2 molecule on antibacterial and hemolytic activities. The effect of the conjugation of benzoic acid derivatives (C6H5-X-COOH, where X: CH2, CH2-CH2, CH=CH, C≡C, and CH2-CH2-CH2) with the N-terminal part of KR12-NH2 on biological activity was also studied. All analogs were tested against planktonic cells of ESKAPE bacteria and reference strains of Staphylococcus aureus. The effect of lipidation site on the helicity of the KR12-NH2 analogs was studied using CD spectroscopy. The ability of the selected peptides to induce the aggregation of POPG liposomes was evaluated with DLS measurements. We demonstrated that both the site and extent of peptide lipidation play an essential role in the bacterial specificity of the lipopeptides. Most of the C8α-KR12-NH2 (II) analogs that were more hydrophobic than the parent compound were also more hemolytic. A similar relationship was also found between the α-helical structure content in POPC and hemolytic activity. It is worth emphasizing that in our study, the highest selectivity against S. aureus strains with an SI value of at least 21.11 exhibited peptide XII obtained by the conjugation of the octanoic acid with the N-terminus of retro-KR12-NH2. All lipidated analogs with the highest net charge (+5) were the most selective toward pathogens. Therefore, the overall charge of KR12-NH2 analogs plays pivotal role in their biological activity.

Perfluorooctanoic acid uptake in the mustard species Brassica juncea.

Perfluorooctanoic acid (PFOA), a surfactant, is a member of the perfluoroalkyl acids (PFAAs) family and is a contaminant of emerging concern for human and environmental health. Perfluorooctanoic acid is a persistent organic pollutant, but currently little is known about (a) the potential ecological and toxicological effects of PFOA and (b) how PFOA moves in the environment. This study uses a radiotracer (14 C-PFOA) to study the uptake and translocation of PFOA in hydroponically grown brown mustard [Brassica juncea (L.) Czern.], a representative crop species. Plants were exposed in quadruplicate over the course of 7 d (with plants sampled on Days 4 and 7) to PFOA concentrations of 0, 1, 5, 10, and 15 mg L-1 . Uptake was quantified via liquid scintillation counting of samples from the nutrient solution, roots, stems, and leaves. Transfer factors (roots to shoots) ranged from 0.15 to 4.73 kg kg-1 . Bioconcentration factors (solution to plant) ranged from 0.36 to 62.29 L kg-1 . Factors were influenced by plant compartment, day sampled, and treatment level.

Physical and barrier changes in gastrointestinal mucus induced by the permeation enhancer sodium 8-[(2-hydroxybenzoyl)amino]octanoate (SNAC).

Drug delivery systems (DDS) for oral delivery of peptide drugs contain excipients that facilitate and enhance absorption. However, little knowledge exists on how DDS excipients such as permeation enhancers interact with the gastrointestinal mucus barrier. This study aimed to investigate interactions of the permeation enhancer sodium 8-[(2-hydroxybenzoyl)amino]octanoate (SNAC) with ex vivo porcine intestinal mucus (PIM), ex vivo porcine gastric mucus (PGM), as well as with in vitro biosimilar mucus (BM) by profiling their physical and barrier properties upon exposure to SNAC. Bulk mucus permeability studies using the peptides cyclosporine A and vancomycin, ovalbumin as a model protein, as well as fluorescein-isothiocyanate dextrans (FDs) of different molecular weights and different surface charges were conducted in parallel to mucus retention force studies using a texture analyzer, rheological studies, cryo-scanning electron microscopy (cryo-SEM), and single particle tracking of fluorescence-labelled nanoparticles to investigate the effects of the SNAC-mucus interaction. The exposure of SNAC to PIM increased the mucus retention force, storage modulus, viscosity, increased nanoparticle confinement within PIM as well as decreased the permeation of cyclosporine A and ovalbumin through PIM. Surprisingly, the viscosity of PGM and the permeation of cyclosporine A and ovalbumin through PGM was unaffected by the presence of SNAC, thus the effect of SNAC depended on the regional site that mucus was collected from. In the absence of SNAC, the permeation of different molecular weight and differently charged FDs through PIM was comparable to that through BM. However, while bulk permeation of neither of the FDs through PIM was affected by SNAC, the presence of SNAC decreased the permeation of FD4 and increased the permeation of FD150 kDa through BM. Additionally, and in contrast to observations in PIM, nanoparticle confinement within BM remained unaffected by the presence of SNAC. In conclusion, the present study showed that SNAC altered the physical and barrier properties of PIM, but not of PGM. The effects of SNAC in PIM were not observed in the BM in vitro model. Altogether, the study highlights the need for further understanding how permeation enhancers influence the mucus barrier and illustrates that the selected mucus model for such studies should be chosen with care.

Mechanistic insight into the role of mevalonate kinase by a natural fatty acid-mediated killing of Leishmania donovani.

We evaluated the anti-leishmanial efficacy of different saturated medium-chain fatty acids (FAs, C8-C18) where FA containing C8 chain, caprylic acid (CA), was found to be most potent against Leishmania donovani, the causative agent for visceral leishmaniasis (VL). Different analogs of CA with C8 linear chain, but not higher, along with a carboxyl/ester group showed a similar anti-leishmanial effect. Ergosterol depletion was the major cause of CA-mediated cell death. Molecular docking and molecular dynamic simulation studies indicated the enzyme mevalonate kinase (MevK) of the ergosterol biosynthesis pathway as a possible target of CA. Enzyme assays with purified recombinant MevK and CA/CA analogs confirmed the target with a competitive inhibition pattern. Using biochemical and biophysical studies; strong binding interaction between MevK and CA/CA analogs was established. Further, using parasites with overexpressed MevK and proteomics studies of CA-treated parasites the direct role of MevK as the target was validated. We established the mechanism of the antileishmanial effect of CA, a natural product, against VL where toxicity and drug resistance with current chemotherapeutics demand an alternative. This is the first report on the identification of an enzymatic target with kinetic parameters and mechanistic insights against any organism for a natural medium-chain FA.

Medium-chain fatty acid esters are effective even in azole-resistant Malassezia pachydermatis.

BACKGROUND: Malassezia (M.) pachydermatis as a frequent reason for dermatological consultation in dogs and cats was recently shown to be lipid-dependent, too. Lipolytic activity is a prerequisite for activating antimicrobial effectivity of fatty acid esters. OBJECTIVES: It was therefore of interest whether it is possible to induce this mechanism in M. pachydermatis and to identify possible differences between minimal and strong lipid-dependent strains. METHODS: In an agar dilution test, the minimal inhibitory concentrations of six fatty acid esters were determined for seventeen M. pachydermatis strains. GC analysis of parent compounds and liberated fatty acids was used to quantify ester cleavage. RESULTS: Hydrolysis was observed in all test strains in a homogenous manner but was dependent on the chemical structure. Lowest MICs (500 ppm after 14 days of incubation) were obtained applying glyceryl monocaprylate and 3-hydroxylpropyl caprylate, while the corresponding esters of undecylenic acid showed nearly twice the value. As shown by GC analysis with the reference strains CBS 1879 and CBS 1892 and 3-hydroxypropyl caprylate, hydrolysis and caprylic acid formation starts immediately and was dependent on yeast density. Furthermore, nine azole-resistant strains isolated from dogs with treatment failures showed MIC values comparable to the other strains and no resistance to monohydric fatty acid esters. CONCLUSIONS: Medium-chain fatty acid esters may represent a new therapeutic option for veterinary use even in azole-resistant strains. The in vivo verification in M. pachydermatis-associated dermatitis in dogs and cats will be the next step for the successful development of new therapeutics.

Ionic liquid-mediated delivery of a BCL-2 inhibitor for topical treatment of skin melanoma.

Skin melanoma is one of the most common cancer types in the United States and worldwide, and its incidence continues to grow. Primary skin melanoma can be removed surgically when feasible and if detected at an early stage. Anti-cancer drugs can be applied topically to treat skin cancer lesions and used as an adjunct to surgery to prevent the recurrence of tumor growth. We developed a topical formulation composed of Navitoclax (NAVI), a BCL-2 inhibitor that results in apoptosis, and an ionic liquid of choline octanoate (COA) to treat early-stage melanoma. NAVI is a small hydrophobic molecule that solubilizes at 20% (w/v) when dissolved in 50% COA. Although NAVI is a highly effective chemotherapeutic, it is equally thrombocytopenic. We found that COA-mediated topical delivery of NAVI enhanced its penetration into the skin and held the drug in the deeper skin layers for an extended period. Topical delivery of NAVI produced a higher cancer-cell killing efficacy than orally administrated NAVI. In vivo experiments in a mouse model of human melanoma-induced skin cancer confirmed the formulation's effectiveness via an apoptotic mechanism without any significant skin irritation or systemic absorption of NAVI. Overall, this topical approach may provide a safe and effective option for better managing skin cancer in the clinic.

Octanoic Acid-Enrichment Diet Improves Endurance Capacity and Reprograms Mitochondrial Biogenesis in Skeletal Muscle of Mice.

Background: Medium Chain Fatty Acids (MCFAs) are a dietary supplement that exhibit interesting properties, due to their smaller molecular size. The acute consumption of MCFAs is expected to enhance exercise performance. However, the short-term effects of MCFAs on endurance performance remains poorly understood. The aim of our study is to evaluate the octanoic acid (C8)-rich diet effect on endurance capacity, and to explore their molecular and cellular effects. Methods: C57BL/6J mice were fed with a chow diet (Control group) or an octanoic acid-rich diet (C8 diet) for 6 weeks. Spontaneous activity, submaximal and maximal exercise tests were carried out to characterize the exercise capacities of the mice. Beta-oxidation and mitochondrial biogenesis pathways were explored in skeletal muscle by RT-qPCR, Western Blot (Quadriceps) and histochemical staining (Gastrocnemius). Results: Mice fed with a C8-rich diet presented a higher spontaneous activity (p < 0.05) and endurance capacities (p < 0.05) than the control, but no effect on maximal effort was observed. They also presented changes in the skeletal muscle metabolic phenotype, with a higher number of the oxidative fibers, rich in mitochondria. At the molecular level, the C8-diet induced an AMPK activation (p < 0.05), associated with a significant increase in PGC1a and CS gene expression and protein levels. Conclusion: Our study provided evidence that C8-enrichment as a food supplementation improves endurance capacities and activates mitochondrial biogenesis pathways leading to higher skeletal muscle oxidative capacities.

Evidence for a novel, effective approach to targeting carcinoma catabolism exploiting the first-in-class, anti-cancer mitochondrial drug, CPI-613.

Clinical targeting of the altered metabolism of tumor cells has long been considered an attractive hypothetical approach. However, this strategy has yet to perform well clinically. Metabolic redundancy is among the limitations on effectiveness of many approaches, engendering intrinsic single-agent resistance or efficient evolution of such resistance. We describe new studies of the multi-target, tumor-preferential inhibition of the mitochondrial tricarboxylic acid (TCA) cycle by the first-in-class drug CPI-613® (devimistat). By suppressing the TCA hub, indispensable to many metabolic pathways, CPI-613 substantially reduces the effective redundancy of tumor catabolism. This TCA cycle suppression also engenders an apparently homeostatic accelerated, inefficient consumption of nutrient stores in carcinoma cells, eroding some sources of drug resistance. Nonetheless, sufficiently abundant, cell line-specific lipid stores in carcinoma cells are among remaining sources of CPI-613 resistance in vitro and during the in vivo pharmacological drug pulse. Specifically, the fatty acid beta-oxidation step delivers electrons directly to the mitochondrial electron transport system (ETC), by-passing the TCA cycle CPI-613 target and producing drug resistance. Strikingly, tested carcinoma cell lines configure much of this fatty acid flow to initially traverse the peroxisome enroute to additional mitochondrial beta-oxidation. This feature facilitates targeting as clinically practical agents disrupting this flow are available. Two such agents significantly sensitize an otherwise fully CPI-613-resistant carcinoma xenograft in vivo. These and related results are strong empirical support for a potentially general class of strategies for enhanced clinical targeting of carcinoma catabolism.

Octanoic Acid-An Insecticidal Metabolite of Conidiobolus coronatus (Entomopthorales) That Affects Two Majors Antifungal Protection Systems in Galleria mellonella (Lepidoptera): Cuticular Lipids and Hemocytes.

The food flavour additive octanoic acid (C8:0) is also a metabolite of the entomopathogenic fungus Conidiobolus coronatus, which efficiently infects and rapidly kills Galleria mellonella. GC-MS analysis confirmed the presence of C8:0 in insecticidal fraction FR3 extracted from C. coronatus filtrate. Topical administration of C8:0 had a dose-dependent effect on survival rates of larvae but not on pupation or adult eclosion times of the survivors. Topically applied C8:0 was more toxic to adults than larvae (LD100 for adults 18.33 ± 2.49 vs. 33.56 ± 2.57 µg/mg of body mass for larvae). The administration of C8:0 on the cuticle of larvae and adults, in amounts corresponding to their LD50 and LD100 doses, had a considerable impact on the two main defense systems engaged in protecting against pathogens, causing serious changes in the developmental-stage-specific profiles of free fatty acids (FFAs) covering the cuticle of larvae and adults and damaging larval hemocytes. In vitro cultures of G. mellonella hemocytes, either directly treated with C8:0 or taken from C8:0 treated larvae, revealed deformation of hemocytes, disordered networking, late apoptosis, and necrosis, as well as caspase 1-9 activation and elevation of 8-OHdG level. C8:0 was also confirmed to have a cytotoxic effect on the SF-9 insect cell line, as determined by WST-1 and LDH tests.

Perfluorooctanoic acid promotes proliferation of the human granulosa cell line HGrC1 and alters expression of cell cycle genes and Hippo pathway effector YAP1.

Perfluorooctanoic acid (PFOA) is a common environmental contaminant that belongs to a group of manmade fluorinated chemicals called per- and polyfluoroalkyl substances (PFAS). Due to the pervasive nature of PFOA, the environmental health risks of PFOA contamination and exposure on reproductive health have increasing concern. In the present study, we exposed HGrC1 cells, an immortalized human granulosa cell line, to environmentally relevant (1-10 µM) concentrations of PFOA. Results indicated that HGrC1 cells treated with PFOA had increased proliferation and migration relative to vehicle treated controls. No differences in cell apoptosis were observed with 1-10 µM PFOA. Gene expression analysis revealed increases in mRNA transcripts for cell cycle regulators CCND1, CCNA2, and CCNB1. Upregulation of YAP1 protein and downstream target CTGF protein was also observed, suggesting that the Hippo pathway is involved in the proliferation and migratory effects of PFOA on HGrC1 cells. Further, the YAP1 inhibitor Verteporfin prevented the stimulatory effects of PFOA on HGrC1 cells. Together, these findings support a role for the Hippo pathway effector YAP1 in response to PFOA exposure in human granulosa cells.

In Silico-Based Experiments on Mechanistic Interactions between Several Intestinal Permeation Enhancers with a Lipid Bilayer Model.

Oral administration of drugs is generally considered convenient and patient-friendly. However, oral administration of biological drugs exhibits low oral bioavailability (BA) due to enzymatic degradation and low intestinal absorption. A possible approach to circumvent the low BA of oral peptide drugs is to coformulate the drugs with permeation enhancers (PEs). PEs have been studied since the 1960s and are molecules that enhance the absorption of hydrophilic molecules with low permeability over the gastrointestinal epithelium. In this study, we investigated the impact of six PEs on the structural properties of a model membrane using molecular dynamics (MD) simulations. The PEs included were the sodium salts of the medium chain fatty acids laurate, caprate, and caprylate and the caprylate derivative SNAC─all with a negative charge─and neutral caprate and neutral sucrose monolaurate. Our results indicated that the PEs, once incorporated into the membrane, could induce membrane leakiness in a concentration-dependent manner. Our simulations suggest that a PE concentration of at least 70-100 mM is needed to strongly affect transcellular permeability. The increased aggregation propensity seen for neutral PEs might provide a molecular-level mechanism for the membrane disruptions seen at higher concentrations in vivo. The ability for neutral PEs to flip-flop across the lipid bilayer is also suggestive of possible intracellular modes of action other than increasing membrane fluidity. Taken together, our results indicate that MD simulations are useful for gaining insights relevant to the design of oral dosage forms based around permeability enhancer molecules.

Efficacy and mechanism of carvacrol with octanoic acid against mastitis causing multi-drug-resistant pathogens.

In the present investigation, we determined the in vitro antimicrobial activity of eight essential oils (EOs) and three medium-chain fatty acids (MCFAs) alone and in combination against Staphylococcus aureus ATCC 700698, Klebsiella pneumoniae ATCC 700603, and E. coli FcW5. The interactions between EOs and MCFAs were determined by fractional inhibitory concentration indices. Moreover, mode of action of selected bioactive components was studied by changes in bacterial surface charge, morphology, and membrane integrity assays. Among EOs, carvacrol (CAR), trans-cinnamaldehyde (TC), and thymol (TM) showed strong antimicrobial activity. In combination study, CAR+OA (octanoic acid), CAR+DA (decanoic acid), and TM+OA were observed as the most significant (P≤0.05) which were also confirmed through time-kill plots. Based on these results, CAR+OA were found to be most efficacious in terms of killing time (P≤0.05). Changes in the surface charge, morphology, and membrane integrity upon the combined treatment of CAR+OA were also observed, which ultimately leads to cell death. Results suggest that CAR+OA when used in combination offer a significant (P≤0.05) additive antimicrobial activity against the selected pathogenic bacteria. Therefore, these natural bioactive molecules could be interesting alternatives to conventional therapy for the control of mastitis caused by multi-drug-resistant pathogens in bovine animals to ensure the milk safety.