Mevalonate pathway: a review of clinical and therapeutical implications

Widely targeted metabolomics analysis reveals the effect of soybean hull polysaccharides on nonvolatile components of plant-based yogurt and its metabolic pattern

Soybean hull polysaccharides (SHPS) enhance the physicochemical properties of plant-based yogurt. However, their effects on the nutritional profile and biochemical mechanisms remain unclear. This study aimed to assess the impact of SHPS addition on the nonvolatile components of plant-based yogurt and its underlying mechanisms through widely targeted metabolomics analysis. The results demonstrated that the addition of SHPS (0.2 %-1.0 % w/v) enhanced the levels of free amino acids, sugars, and organic acids, with the addition of 0.6 % w/v being particularly effective in improving yogurt quality. Widely targeted metabolomics analysis revealed 278 differential metabolites between yogurt supplemented with 0.6 % SHPS (SPY) and the control sample. SHPS increased the content of various metabolites, including amino acids and derivatives, saccharides, organic acids, and flavonoids, among others. Key metabolic pathways affected by SHPS included pantothenate and CoA biosynthesis; valine, leucine, and isoleucine biosynthesis; and benzoate degradation. As the primary component of SHPS, galacturonic acid affected the metabolic products in yogurt by participating in the pentose and glucuronate interconversions and ascorbate and aldarate metabolism pathways. These findings elucidate the role of SHPS in modulating the nutritional composition of plant-based yogurt, offering valuable insights into its functional mechanisms in food processing.

Microbial Gatekeepers of Fertility in the Female Reproductive Microbiome of Cattle

This review paper delves into the intricate relationship between the genital microbiome and fertility outcomes in livestock, with a specific focus on cattle. Drawing upon insights derived from culture-independent metagenomics studies, the paper meticulously examines the composition and dynamics of the genital microbiome. Through advanced techniques such as high-throughput sequencing, the review illuminates the temporal shifts in microbial communities and their profound implications for reproductive health. The analysis underscores the association between dysbiosis-an imbalance in microbial communities-and the development of reproductive diseases, shedding light on the pivotal role of microbial gatekeepers in livestock fertility. Furthermore, the paper emphasizes the need for continued exploration of uncharted dimensions of the female reproductive microbiome to unlock new insights into its impact on fertility. By elucidating the complex interplay between microbial communities and reproductive health, this review underscores the importance of innovative strategies aimed at enhancing fertility and mitigating reproductive diseases in livestock populations.

Kinetic and structural characterization of NUDT15 and NUDT18 as catalysts of isoprene pyrophosphate hydrolysis

Isoprene pyrophosphates play a crucial role in the synthesis of a diverse array of essential nonsterol and sterol biomolecules and serve as substrates for posttranslational isoprenylation of proteins, enabling specific anchoring to cellular membranes. Hydrolysis of isoprene pyrophosphates would be a means to modulate their levels, downstream products, and protein isoprenylation. While NUDIX hydrolases from plants have been described to catalyze the hydrolysis of isoprene pyrophosphates, homologous enzymes with this function in animals have not yet been reported. In this study, we screened an extensive panel of human NUDIX hydrolases for activity in hydrolyzing isoprene pyrophosphates. We found that human nucleotide triphosphate diphosphatase NUDT15 and 8-oxo-dGDP phosphatase NUDT18 efficiently catalyze the hydrolysis of several physiologically relevant isoprene pyrophosphates. Notably, we demonstrate that geranyl pyrophosphate is an excellent substrate for NUDT18, with a catalytic efficiency of 2.1 × 105 m-1·s-1, thus making it the best substrate identified for NUDT18 to date. Similarly, geranyl pyrophosphate proved to be the best isoprene pyrophosphate substrate for NUDT15, with a catalytic efficiency of 4.0 × 104 M-1·s-1. LC-MS analysis of NUDT15 and NUDT18 catalyzed isoprene pyrophosphate hydrolysis revealed the generation of the corresponding monophosphates and inorganic phosphate. Furthermore, we solved the crystal structure of NUDT15 in complex with the hydrolysis product geranyl phosphate at a resolution of 1.70 Å. This structure revealed that the active site nicely accommodates the hydrophobic isoprenoid moiety and helped identify key binding residues. Our findings imply that isoprene pyrophosphates are endogenous substrates of NUDT15 and NUDT18, suggesting they are involved in animal isoprene pyrophosphate metabolism.

Preterm Infant with Generalized Arterial Calcification of Infancy Who Survived Due to Early Diagnosis and Appropriate Treatment with Bisphosphonates: A Case Report

Generalized arterial calcification of infancy (GACI) is a rare disease characterized by arterial calcification. GACI is caused by a mutation in the ENPP1 or ABCC6 genes. GACI causes severe hypertension and heart failure, and approximately 50% of patients die within the first 6 months. In particular, preterm infants with GACI often die due to immature cardiac function. Bisphosphonates are effective in treating GACI; however, no standardized treatment regimen is available. We experienced a case of a preterm infant with GACI born at 30 weeks gestation. Ultrasonography showed high-intensity lesions in the arteries, and computed tomography revealed calcification of the arteries throughout the body, leading to the diagnosis of GACI. We administered intravenous pamidronate, and her cardiac contraction improved. The initial scheduled interval between drug administrations was 2 months. However, the cardiac contraction worsened 1 month after the pamidronate administration. Therefore, we decreased the dosing interval and administered a second course of pamidronate, which improved her cardiac function. We then switched to oral etidronate. To improve the morbidity and mortality rates of preterm infants with GACI, it is important to obtain an early diagnosis of GACI by investigating high-intensity lesions in the arteries and performing early administration of an appropriate type of bisphosphonate.

Oral Health and Nutraceutical Agents

Oral health is essential for both overall health and quality of life. The mouth is a window into the body's health, and nutrition can strongly impact the state of general and oral health. A healthy diet involves the synergistic effect of various nutraceutical agents, potentially capable of conferring protective actions against some inflammatory and chronic-degenerative disorders. Nutraceuticals, mostly present in plant-derived products, present multiple potential clinical, preventive, and therapeutic benefits. Accordingly, preclinical and epidemiological studies suggested a protective role for these compounds, but their real preventive and therapeutic effects in humans still await confirmation. Available evidence suggests that plant extracts are more effective than individual constituents because they contain different phytochemicals with multiple pharmacological targets and additive/synergistic effects, maximizing the benefits for oral health. Moreover, nutritional recommendations for oral health should be personalized and aligned with valid suggestions for overall health. This review is aimed to: introduce the basic concepts of nutraceuticals, including their main food sources; examine the logic that supports their relationship with oral health, and summarize and critically discuss clinical trials testing the utility of nutraceuticals in the prevention and treatment of oral diseases.

Lipid metabolism reprogramming in renal cell carcinomas

This study investigates the intricate mechanisms underlying the correlation between elevated consumption of harmful fats and the onset of kidney malignancies. The rise in global obesity rates has been accompanied by an increased prevalence of renal cancers, prompting an exploration into the molecular pathways and biological processes linking these phenomena. Through an extensive review of current literature and clinical studies, we identify potential key factors contributing to the carcinogenic influence of harmful fats on renal tissues. Our analysis highlights the role of adipose tissue-derived factors, inflammatory mediators, and lipid metabolism dysregulation in fostering a microenvironment conducive to renal tumorigenesis. Furthermore, we delve into the impact of harmful fats on signaling pathways associated with cell proliferation, apoptosis evasion, and angiogenesis within the renal parenchyma. This review underscores the importance of elucidating the molecular intricacies linking lipid metabolism and kidney malignancies, offering a foundation for future research and the development of targeted preventive and therapeutic interventions. The findings discussed herein contribute to our understanding of the complex relationship between lipid mediators and renal cancer, providing a basis for public health strategies aimed at mitigating the impact of harmful fats on kidney health.

Resveratrol is converted to the ring portion of coenzyme Q10 and raises intracellular coenzyme Q10 levels in HepG2 cell

Coenzyme Q10 is an essential lipid in the mitochondrial electron transport system and an important antioxidant. It declines with age and in various diseases, there is a need for a method to compensate for the decrease in coenzyme Q10. Resveratrol, a well-known anti-aging compound, has been shown to undergo metabolism to coenzyme Q10's benzene ring moiety in cells. However, administration of resveratrol did not alter or only slightly increased total intracellular coenzyme Q10 levels in many cell types. Synthesis of coenzyme Q10 requires not only the benzene ring moiety but also the side chain moiety. Biosynthesis of the side chain portion of coenzyme Q10 is mediated by the mevalonic acid pathway. Here, we explore the impact of resveratrol on coenzyme Q10 levels in HepG2 cells, which possess a robust mevalonic acid pathway. As a results, intracellular coenzyme Q10 levels were increased by resveratrol administration. Analysis using 13C6-resveratrol revealed that the benzene ring portion of resveratrol was converted to coenzyme Q10. Inhibition of the mevalonic acid pathway prevented the increase in coenzyme Q10 levels induced by resveratrol administration. These results indicate that resveratrol may be beneficial as a coenzyme Q10-enhancing reagent in cells with a well-developed mevalonic acid pathway.

Mevalonate kinase of Leishmania donovani promotes its survival and plays a pivotal role in pathogenesis

The infectivity of Leishmania is determined by its ability to invade and evade host and its thriving capacity within the macrophage. Our study revealed the role of Leishmania donovani mevalonate kinase (MVK), an enzyme of mevalonate pathway in visceral leishmaniasis pathogenesis. Peritoneal exudate cells (PEC)-derived macrophages from BALB/c mice were infected with wild type (WT), MVK over expressing (MVK OE) and knockdown (KD) parasites and MVK OE parasites were found to be more infective than WT and MVK KD parasites. Incubation of macrophages with MVK OE parasites declined inducible nitric oxide synthase (iNOS) expression as well as nitric oxide (NO) production, both by 2 times in comparison to WT parasites. Moreover, ∼3 fold increase in Arginase1 expression indicated that MVK might induce polarization of macrophage towards M2, favouring the survival of parasite within the macrophages. Post 24 h infection of the macrophages with mutant strains, the levels of different cytokines (TNF-α, IL-12, IL-10 and IFN-γ) were measured. Infection of macrophages with MVK OE parasites showed an increase in the level of anti-inflammatory cytokine: IL-10 while infection with MVK KD parasites exhibited an increase in the level of pro-inflammatory cytokines: TNF-α, IL-12, and IFN-γ. Hence, Leishmania donovani mevalonate kinase (LdMVK) modulates macrophage functions and has a significant role in pathogenesis.

Lipid metabolism in B cell biology

In recent years, the field of immunometabolism has solidified its position as a prominent area of investigation within the realm of immunological research. An expanding body of scientific literature has unveiled the intricate interplay between energy homeostasis, signalling molecules, and metabolites in relation to fundamental aspects of our immune cells. It is now widely accepted that disruptions in metabolic equilibrium can give rise to a myriad of pathological conditions, ranging from autoimmune disorders to cancer. Emerging evidence, although sometimes fragmented and anecdotal, has highlighted the indispensable role of lipids in modulating the behaviour of immune cells, including B cells. In light of these findings, this review aims to provide a comprehensive overview of the current state of knowledge regarding lipid metabolism in the context of B cell biology.

Human-derived fecal microbiota transplantation alleviates social deficits of the BTBR mouse model of autism through a potential mechanism involving vitamin B6 metabolism

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental condition characterized by social communication deficiencies and stereotypic behaviors influenced by hereditary and/or environmental risk factors. There are currently no approved medications for treating the core symptoms of ASD. Human fecal microbiota transplantation (FMT) has emerged as a potential intervention to improve autistic symptoms, but the underlying mechanisms are not fully understood. In this study, we evaluated the effects of human-derived FMT on behavioral and multi-omics profiles of the BTBR mice, an established model for ASD. FMT effectively alleviated the social deficits in the BTBR mice and normalized their distinct plasma metabolic profile, notably reducing the elevated long-chain acylcarnitines. Integrative analysis linked these phenotypic changes to specific Bacteroides species and vitamin B6 metabolism. Indeed, vitamin B6 supplementation improved the social behaviors in BTBR mice. Collectively, these findings shed new light on the interplay between FMT and vitamin B6 metabolism and revealed a potential mechanism underlying the therapeutic role of FMT in ASD.IMPORTANCEAccumulating evidence supports the beneficial effects of human fecal microbiota transplantation (FMT) on symptoms associated with autism spectrum disorder (ASD). However, the precise mechanism by which FMT induces a shift in the microbiota and leads to symptom improvement remains incompletely understood. This study integrated data from colon-content metagenomics, colon-content metabolomics, and plasma metabolomics to investigate the effects of FMT treatment on the BTBR mouse model for ASD. The analysis linked the amelioration of social deficits following FMT treatment to the restoration of mitochondrial function and the modulation of vitamin B6 metabolism. Bacterial species and compounds with beneficial roles in vitamin B6 metabolism and mitochondrial function may further contribute to improving FMT products and designing novel therapies for ASD treatment.

Are statins onco- suppressive agents for every type of tumor? A systematic review of literature

INTRODUCTION

Statins, in the role of anti-cancer agents, have been used in many types of cancers with results in some cases promising while, in others, disappointing.

AREAS COVERED

The purpose of this review is to identify and highlight data from literature on the successes or failure of using statins as anti-cancer agents. We asked ourselves the following two questions:1. Could statins, which are taken mostly to reduce cardiovascular risk, guarantee a lower incidence or a better cancer disease prognosis, concerning local recurrence, metastasis or mortality?2. Does statins intake (before and/or after cancer diagnosis) improve the prognosis or increase the chemotherapeutic action when combined with other anticancer therapies? For the first question twenty-seven manuscripts have been selected, for the second one, twenty-eight.

EXPERT OPINION

There are data which correlate statins with a possible tumor suppressive action among the following cancers: breast, lung, prostate and head and neck. Lastly, for gastric cancer and colorectal there is no evidence of a correlation. The onco-suppressive efficacy of statins is mainly related to the histopathological and/or molecular characteristics of the tumor cells, which have different characteristics.

Short-term test for the toxicogenomic assessment of ecotoxic modes of action in Myriophyllum spicatum

In environmental risk assessment of substances, the 14-day growth inhibition test following OECD test guideline 239 is employed to assess toxicity in the macrophyte Myriophyllum spicatum. Currently, this test evaluates physiological parameters and does not allow the identification of the mode of action (MoA) by which adverse effects are induced. However, for an improved ecotoxicity assessment of substances, knowledge about their ecotoxic MoA in non-target organisms is required. It has previously been suggested that the identification of gene expression changes can contribute to MoA identification. Therefore, we developed a shortened three-day assay for M. spicatum including the transcriptomic assessment of global gene expression changes and applied this assay to two model substances, the herbicide and photosynthesis inhibitor bentazone and the pharmaceutical and HMG-CoA reductase inhibitor atorvastatin. Due to the lack of a reference genome for M. spicatum we performed a de novo transcriptome assembly followed by a functional annotation to use the toxicogenomic results for MoA discrimination. The gene expression changes induced by low effect concentrations of these substances were used to identify differentially expressed genes (DEGs) and impaired biological functions for the respective MoA. We observed both concentration-dependent numbers and differentiated patterns of DEGs for both substances. While bentazone impaired genes involved in the response to reactive oxygen species as well as light response, and also genes involved in developmental processes, atorvastatin exposure led to a differential regulation of genes related to brassinosteroid response as well as potential metabolic shifts between the mevalonate and methyl erythritol 4-phosphate pathway. Based on these responses, we identified biomarker candidates for the assessment of MoA in M. spicatum. Utilizing the shortened assay developed in this study, the investigation of the identified biomarker candidates may contribute to the development of future MoA-specific screening approaches in the ecotoxicological hazard prediction using aquatic non-standard model organisms.

Reverse N-Substituted Hydroxamic Acid Derivatives of Fosmidomycin Target a Previously Unknown Subpocket of 1-Deoxy-d-xylulose 5-Phosphate Reductoisomerase (DXR)

Reverse analogs of the phosphonohydroxamic acid antibiotic fosmidomycin are potent inhibitors of the nonmevalonate isoprenoid biosynthesis enzyme 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR, IspC) of Plasmodium falciparum. Some novel analogs with large phenylalkyl substituents at the hydroxamic acid nitrogen exhibit nanomolar PfDXR inhibition and potent in vitro growth inhibition of P. falciparum parasites coupled with good parasite selectivity. X-ray crystallographic studies demonstrated that the N-phenylpropyl substituent of the newly developed lead compound 13e is accommodated in a subpocket within the DXR catalytic domain but does not reach the NADPH binding pocket of the N-terminal domain. As shown for reverse carba and thia analogs, PfDXR selectively binds the S-enantiomer of the new lead compound. In addition, some representatives of the novel inhibitor subclass are nanomolar Escherichia coli DXR inhibitors, whereas the inhibition of Mycobacterium tuberculosis DXR is considerably weaker.

Microbial chassis as the platform for production of dihydroxy xanthophyll-based carotenoids: an overview of recent advances in biomanufacturing

Physiological and environmental cues prompt microbes to synthesize diverse carotenoids, including dihydroxy xanthophylls, facilitating their adaptation and survival. Lutein and its isomeric counterpart, zeaxanthin, are notable dihydroxy xanthophylls with bioactive properties such as antioxidative, anti-inflammatory, anticancer, and neuroprotective effects, particularly beneficial for human ocular health. However, global natural resources for co-producing lutein and zeaxanthin are scarce, with zeaxanthin lacking commercial sources, unlike lutein sourced from marigold plants and microalgae. Traditionally, dihydroxy xanthophyll production primarily relies on petrochemical synthetic routes, with limited biological sourcing reported. Nonetheless, microbiological synthesis presents promising avenues as a commercial source, albeit challenged by low dihydroxy xanthophyll yield at high cell density. Strategies involving optimization of physical and chemical parameters are essential to achieve high-quality dihydroxy xanthophyll products. This overview briefly discusses dihydroxy xanthophyll biosynthesis and highlights recent advancements, discoveries, and industrial benefits of lutein and zeaxanthin production from microorganisms as alternative biofactories.

Effects of HMGCR deficiency on skeletal muscle development

Pathogenic variants in HMGCR were recently linked to a limb-girdle muscular dystrophy (LGMD) phenotype. The protein product HMG CoA reductase (HMGCR) catalyzes a key component of the cholesterol synthesis pathway. The two other muscle diseases associated with HMGCR, statin-associated myopathy (SAM) and autoimmune anti-HMGCR myopathy, are not inherited in a Mendelian pattern. The mechanism linking pathogenic variants in HMGCR with skeletal muscle dysfunction is unclear. We knocked down Hmgcr in mouse skeletal myoblasts, knocked down hmgcr in Drosophila, and expressed three pathogenic HMGCR variants (c.1327C>T, p.Arg443Trp; c.1522_1524delTCT, p.Ser508del; and c.1621G>A, p.Ala541Thr) in Hmgcr knockdown mouse myoblasts. Hmgcr deficiency was associated with decreased proliferation, increased apoptosis, and impaired myotube fusion. Transcriptome sequencing of Hmgcr knockdown versus control myoblasts revealed differential expression involving mitochondrial function, with corresponding differences in cellular oxygen consumption rates. Both ubiquitous and muscle-specific knockdown of hmgcr in Drosophila led to lethality. Overexpression of reference HMGCR cDNA rescued myotube fusion in knockdown cells, whereas overexpression of the pathogenic variants of HMGCR cDNA did not. These results suggest that the three HMGCR-related muscle diseases share disease mechanisms related to skeletal muscle development.

Statins in Chronic Liver Disease: Review of the Literature and Future Role

Chronic liver disease (CLD) is a major contributor to global mortality, morbidity, and healthcare burden. Progress in pharmacotherapeutic for CLD management is lagging given its impact on the global population. While statins are indicated for the management of dyslipidemia and cardiovascular disease, their role in CLD prevention and treatment is emerging. Beyond their lipid-lowering effects, their liver-related mechanisms of action are multifactorial and include anti-inflammatory, antiproliferative, and immune-protective effects. In this review, we highlight what is known about the clinical benefits of statins in viral and nonviral etiologies of CLD and hepatocellular carcinoma (HCC), and explore key mechanisms and pathways targeted by statins. While their benefits may span the spectrum of CLD and potentially HCC treatment, their role in CLD chemoprevention is likely to have the largest impact. As emerging data suggest that genetic variants may impact their benefits, the role of statins in precision hepatology will need to be further explored.

Coenzyme Q deficiency in endothelial mitochondria caused by hypoxia; remodeling of the respiratory chain and sensitivity to anoxia/reoxygenation

This study examined the effects of hypoxia on coenzyme Q (Q) levels and mitochondrial function in EA. hy926 endothelial cells, shedding light on their responses to changes in oxygen levels. Chronic hypoxia during endothelial cell culture reduced Q synthesis by reducing hydroxy-methylglutaryl-CoA reductase (HMGCR) levels via hypoxia-inducible factor 1α (HIF1α), leading to severe Q deficiency. In endothelial mitochondria, hypoxia led to reorganization of the respiratory chain through upregulation of supercomplexes (I+III2+IV), forming a complete mitochondrial Q (mQ)-mediated electron transfer pathway. Mitochondria of endothelial cells cultured under hypoxic conditions showed reduced respiratory rates and membrane potential, as well as increased production of mitochondrial reactive oxygen species (mROS) as a result of increased mQ reduction levels (mQH2/mQtot). Anoxia/reoxygenation (A/R) in vitro caused impairment of endothelial mitochondria, manifested by reduced maximal respiration, complex III activity, membrane potential, coupling parameters, and increased mQ reduction and mROS production. Weaker A/R-induced changes compared to control mitochondria indicated better tolerance of A/R stress by the mitochondria of hypoxic cells. Moreover, in endothelial mitochondria, hypoxia-induced increases in uncoupling protein 3 (UCP3) and mitochondrial large-conductance Ca2+-activated potassium channel (mitoBKCa) levels and activities appear to have alleviated reoxygenation injury after A/R. These results not only highlight hypoxia-induced changes in mQ redox homeostasis and related mitochondrial function, but also indicate that chronic hypoxia during endothelial cell culture leads to mitochondrial adaptations that help mitochondria better withstand subsequent oxygen fluctuations.

Structural Characterization and Functional Analysis of Mevalonate Kinase from Tribolium castaneum (Red Flour Beetle)

Mevalonate kinase (MevK) is an important enzyme in the mevalonate pathway that catalyzes the phosphorylation of mevalonate into phosphomevalonate and is involved in juvenile hormone biosynthesis. Herein, we present a structure model of MevK from the red flour beetle Tribolium castaneum (TcMevK), which adopts a compact α/β conformation that can be divided into two parts: an N-terminal domain and a C-terminal domain. A narrow, deep cavity accommodating the substrate and cofactor was observed at the junction between the two domains of TcMevK. Computational simulation combined with site-directed mutagenesis and biochemical analyses allowed us to define the binding mode of TcMevK to cofactors and substrates. Moreover, TcMevK showed optimal enzyme activity at pH 8.0 and an optimal temperature of 40 °C for mevalonate as the substrate. The expression profiles and RNA interference of TcMevK indicated its critical role in controlling juvenile hormone biosynthesis, as well as its participation in the production of other terpenoids in T. castaneum. These findings improve our understanding of the structural and biochemical features of insect Mevk and provide a structural basis for the design of MevK inhibitors.

Mesocellular Silica Foam as Immobilization Carrier for Production of Statin Precursors

The employment of 2-deoxyribose-5-phosphate aldolase (DERA) stands as a prevalent biocatalytic route for synthesizing statin side chains. The main problem with this pathway is the low stability of the enzyme. In this study, mesocellular silica foam (MCF) with different pore sizes was used as a carrier for the covalent immobilization of DERA. Different functionalizing and activating agents were tested and kinetic modeling was subsequently performed. The use of succinic anhydride as an activating agent resulted in an enzyme hyperactivation of approx. 140%, and the stability almost doubled compared to that of the free enzyme. It was also shown that the pore size of MCF has a decisive influence on the stability of the DERA enzyme.

Transcriptomic and physiological analysis of atractylodes chinensis in response to drought stress reveals the putative genes related to sesquiterpenoid biosynthesis

BACKGROUND

Atractylodes chinensis (DC) Koidz., a dicotyledonous and hypogeal germination species, is an important medicinal plant because its rhizome is enriched in sesquiterpenes. The development and production of A. chinensis are negatively affected by drought stress, especially at the seedling stage. Understanding the molecular mechanism of A. chinensis drought stress response plays an important role in ensuring medicinal plant production and quality. In this study, A. chinensis seedlings were subjected to drought stress treatment for 0 (control), 3 (D3), and 9 days (D9). For the control, the sample was watered every two days and collected on the second morning after watering. The integration of physiological and transcriptomic analyses was carried out to investigate the effects of drought stress on A. chinensis seedlings and to reveal the molecular mechanism of its drought stress response.

RESULTS

The malondialdehyde, proline, soluble sugar, and crude protein contents and antioxidative enzyme (superoxide dismutase, peroxidase, and catalase) activity were significantly increased under drought stress compared with the control. Transcriptomic analysis indicated a total of 215,665 unigenes with an average length of 759.09 bp and an N50 of 1140 bp. A total of 29,449 differentially expressed genes (DEGs) were detected between the control and D3, and 14,538 DEGs were detected between the control and D9. Under drought stress, terpenoid backbone biosynthesis had the highest number of unigenes in the metabolism of terpenoids and polyketides. To identify candidate genes involved in the sesquiterpenoid and triterpenoid biosynthetic pathways, we observed 22 unigene-encoding enzymes in the terpenoid backbone biosynthetic pathway and 15 unigene-encoding enzymes in the sesquiterpenoid and triterpenoid biosynthetic pathways under drought stress.

CONCLUSION

Our study provides transcriptome profiles and candidate genes involved in sesquiterpenoid and triterpenoid biosynthesis in A. chinensis in response to drought stress. Our results improve our understanding of how drought stress might affect sesquiterpenoid and triterpenoid biosynthetic pathways in A. chinensis.

The Current and Emerging Role of Statins in the Treatment of PCOS: The Evidence to Date

Polycystic ovary syndrome (PCOS) manifests a multifactorial pathology characterized by polycystic ovaries, menstrual cycle disorders, varying degrees of hyperandrogenism, and an ad-verse metabolic risk profile. The position of hyperandrogenism in this syndrome has been extensively studied. A multitude of mechanisms place it in the position of cause but also of consequence; therefore, ongoing research efforts are focused on identifying medications that can effectively reduce levels of androgens in women with PCOS. Moreover, lipid abnormalities are common in this population, with up to 70% of patients having dyslipidemia. Statins may have potential therapeutic benefits for women with PCOS, as they have been shown to improve insulin resistance and reduce the risk of cardiovascular disease. In addition, their role in accelerated steroidogenesis by limiting one source of cholesterol, influencing enzymatic activity, and providing several other beneficial mechanisms is widely investigated. This review aimed to provide a comprehensive overview of the pathogenesis of androgen excess and dyslipidemia in PCOS, as well as the therapeutic potential of statins.

Lipids in inflammasome activation and autoinflammatory disorders

Autoinflammatory diseases (AIDs) are a group of rare monogenetic disorders characterized by recurrent episodes of fever and systemic inflammation. A major pathologic hallmark of AIDs is excessive inflammasome assembly and activation, often the result of gain-of-function mutations in genes encoding core inflammasome components, including pyrin and cryopyrin. Recent advances in lipidomics have revealed that dysregulated metabolism of lipids such as cholesterol and fatty acids, especially in innate immune cells, exerts complex effects on inflammasome activation and the pathogenesis of AIDs. In this review, we summarize and discuss the impact of lipids and their metabolism on inflammasome activation and the disease pathogenesis of the most common AIDs, including familial Mediterranean fever, cryopyrin-associated periodic syndromes, and mevalonate kinase deficiency. We postulate that lipids hold diagnostic value in AIDs and that dietary and pharmacologic intervention studies could represent a promising approach to attenuate inflammasome activation and AID progression.

Increased Expression of Mevalonate Pathway-Related Enzymes in Angiotensin II-Induced Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA) is characterized by permanent luminal expansion and a high mortality rate due to aortic rupture. Despite the identification of abnormalities in the mevalonate pathway (MVA) in many diseases, including cardiovascular diseases, the potential impact of this pathway on AAA remains unclear. This study aims to investigate whether the expression of the MVA-related enzyme is altered during the progression of angiotensin II (Ang II) -induced AAA.Ang II 28D and Ang II 5D groups were continuously perfused with Ang II for 28 days and 5 days, respectively, and the Sham group was perfused with saline. The general and remodeling characteristics of AAA were determined by biochemical and histological analysis. Alteration of MVA-related enzyme expressions was revealed by western blot and single-cell RNA sequencing (scRNA-seq).The continuous Ang II infusion for 28 days showed significant aorta expansion and arterial remodeling. Although the arterial diameter slightly increased, the aneurysm formation was not found in Ang II induction for 5 days. MVA-related enzyme expression and activation of small GTP-binding proteins were significantly increased after Ang II-induced. As verified by scRNA-seq, the key enzyme gene expression was also higher in Ang II 28D. Similarly, it was detected that the expression levels of the above enzymes and the activity of small G proteins were elevated in the early stage of AAA as induced by Ang II infusion for 5 days.Continuous Ang II infusion-induced abdominal aortic expansion and arterial remodeling were accompanied by altered expression of key enzymes in the MVA.

An updated review of chemical compounds with anti-Toxoplasma gondii activity

The opportunistic apicomplexan parasite Toxoplasma gondii is the etiologic agent for toxoplasmosis, which can infect a widespread range of hosts, particularly humans and warm-blooded animals. The present chemotherapy to treat or prevent toxoplasmosis is deficient and is based on diverse drugs such as atovaquone, trimethoprim, spiramycine, which are effective in acute toxoplasmosis. Therefore, a safe chemotherapy is required for toxoplasmosis considering that its responsible agent, T. gondii, provokes severe illness and death in pregnant women and immunodeficient patients. A certain disadvantage of the available treatments is the lack of effectiveness against the tissue cyst of the parasite. A safe chemotherapy to combat toxoplasmosis should be based on the metabolic differences between the parasite and the mammalian host. This article covers different relevant molecular targets to combat this disease including the isoprenoid pathway (farnesyl diphosphate synthase, squalene synthase), dihydrofolate reductase, calcium-dependent protein kinases, histone deacetylase, mitochondrial electron transport chain, etc.

Wolbachia interferes with Zika virus replication by hijacking cholesterol metabolism in mosquito cells

IMPORTANCE

Arthropod-borne viruses are emerging pathogens that are spread widely by mosquitos. Zika virus is an arbovirus that can infect humans and be transmitted from an infected mother to the fetus, potentially leading to microcephaly in infants. One promising strategy to prevent disease caused by arboviruses is to target the insect vector population. Recent field studies have shown that mosquito populations infected with Wolbachia bacteria suppress arbovirus replication and transmission. Here, we describe how intracellular bacteria redirect resources within their host cells and suppress Zika virus replication at the cellular level. Understanding the mechanism behind Wolbachia-induced interference of arbovirus replication could help advance strategies to control arbovirus pathogens in insect vectors and human populations.

Comparative Analysis of Secondary Metabolites Produced by Ascochyta fabae under In Vitro Conditions and Their Phytotoxicity on the Primary Host, Vicia faba, and Related Legume Crops

Ascochyta blight, caused by Ascochyta fabae, poses a significant threat to faba bean and other legumes worldwide. Necrotic lesions on stems, leaves, and pods characterize the disease. Given the economic impact of this pathogen and the potential involvement of secondary metabolites in symptom development, a study was conducted to investigate the fungus's ability to produce bioactive metabolites that might contribute to its pathogenicity. For this investigation, the fungus was cultured in three substrates (Czapek-Dox, PDB, and rice). The produced metabolites were analyzed by NMR and LC-HRMS methods, resulting in the dereplication of seven metabolites, which varied with the cultural substrates. Ascochlorin, ascofuranol, and (R)-mevalonolactone were isolated from the Czapek-Dox extract; ascosalipyrone, benzoic acid, and tyrosol from the PDB extract; and ascosalitoxin and ascosalipyrone from the rice extract. The phytotoxicity of the pure metabolites was assessed at different concentrations on their primary hosts and related legumes. The fungal exudates displayed varying degrees of phytotoxicity, with the Czapek-Dox medium's exudate exhibiting the highest activity across almost all legumes tested. The species belonging to the genus Vicia spp. were the most susceptible, with faba bean being susceptible to all metabolites, at least at the highest concentration tested, as expected. In particular, ascosalitoxin and benzoic acid were the most phytotoxic in the tested condition and, as a consequence, expected to play an important role on necrosis's appearance.

Synthetic Lethality Screening with Recursive Feature Machines

Synthetic lethality refers to a genetic interaction where the simultaneous perturbation of gene pairs leads to cell death. Synthetically lethal gene pairs (SL pairs) provide a potential avenue for selectively targeting cancer cells based on genetic vulnerabilities. The rise of large-scale gene perturbation screens such as the Cancer Dependency Map (DepMap) offers the opportunity to identify SL pairs automatically using machine learning. We build on a recently developed class of feature learning kernel machines known as Recursive Feature Machines (RFMs) to develop a pipeline for identifying SL pairs based on CRISPR viability data from DepMap. In particular, we first train RFMs to predict viability scores for a given CRISPR gene knockout from cell line embeddings consisting of gene expression and mutation features. After training, RFMs use a statistical operator known as average gradient outer product to provide weights for each feature indicating the importance of each feature in predicting cellular viability. We subsequently apply correlation-based filters to re-weight RFM feature importances and identify those features that are most indicative of low cellular viability. Our resulting pipeline is computationally efficient, taking under 3 minutes for analyzing all 17, 453 knockouts from DepMap for candidate SL pairs. We show that our pipeline more accurately recovers experimentally verified SL pairs than prior approaches. Moreover, our pipeline finds new candidate SL pairs, thereby opening novel avenues for identifying genetic vulnerabilities in cancer.

Prenyltransferase gene expression reveals an essential role of prenylation for the inflammatory response in human gingival fibroblasts

BACKGROUND

Prenyltrasferases (PTases) are a class of enzymes known to be responsible for promoting posttranslational modification at the carboxyl terminus of proteins containing a so-called CaaX-motif. The process is responsible for proper membrane localization and the appropriate function of several intracellular signaling proteins. Current research demonstrating the pathomechanistic importance of prenylation in inflammatory illnesses emphasizes the requirement to ascertain the differential expression of PT genes under inflammatory settings, particularly in periodontal disease.

METHODS

Telomerase-immortalized human gingival fibroblasts (HGF-hTert) were cultured and treated with either inhibitors of prenylation (PTI) lonafarnib, tipifarnib, zoledronic acid, or atorvastatin at concentrations of 10 μM in combination with or without 10 μg Porphyromonas gingivalis lipopolysaccharide (LPS) for 24 h. Prenyltransferase genes FNTB, FNTA, PGGT1B, RABGGTA, RABGGTB, and PTAR1 as well as inflammatory marker genes MMP1 and IL1B were detected using quantitative real-time polymerase chain reaction (RT-qPCR). Immunoblot and protein immunoassay were used to confirm the results on the protein level.

RESULTS

RT-qPCR experiments revealed significant upregulation of IL1B, MMP1, FNTA, and PGGT1B upon LPS treatment. PTase inhibitors caused significant downregulation of the inflammatory cytokine expression. Interestingly, FNTB expression was significantly upregulated in response to any PTase inhibitor in combination with LPS, but not upon LPS treatment only, indicating a vital role of protein farnesyltransferase in the proinflammatory signaling cascade.

CONCLUSIONS

In this study, distinct PTase gene expression patterns in pro-inflammatory signaling were discovered. Moreover, PTase inhibiting drugs ameliorated inflammatory mediator expression by a significant margin, indicating that prenylation is a major pre-requisite for innate immunity in periodontal cells.

Expression of cholesterol synthesis and steroidogenic markers in females of the Chinese brown frog (Rana dybowskii) during prespawning and prehibernation

The oviduct of the Chinese brown frog (Rana dybowskii) expands in prehibernation rather than in prespawning, which is one of the physiological phenomena that occur in the preparation for hibernation. Steroid hormones are known to regulate oviductal development. Cholesterol synthesis and steroidogenesis may play an important role in the expansion of the oviduct before hibernation. In this study, we investigated the expression patterns of the markers that are involved in the de novo steroid synthesis pathway in the oviduct of R. dybowskii during prespawning and prehibernation. According to histological analysis, the oviduct of R. dybowskii contains epithelial cells, glandular cells, and tubule lumens. During prehibernation, oviductal pipe diameter and weight were significantly larger than during prespawning. 3-Hydroxy-3-methylglutaryl CoA reductase (HMGCR), low-density lipoprotein receptor (LDLR), steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), and steroidogenic factor 1 (SF-1) were detected in epithelial cells in prehibernation and glandular cells during prespawning. HMGCR, LDLR, StAR, and P450scc protein expression levels were higher in prehibernation than during prespawning, but the SF-1 protein expression level did not significantly differ. HMGCR, LDLR, StAR, P450scc (CYP11A1), and SF-1 (NR5A1) mRNA expression levels were significantly higher in prehibernation compared with prespawning. The transcriptome results showed that the steroid synthesis pathway was highly expressed during prehibernation. Existing results indicate that the oviduct is able to synthesize steroid hormones using cholesterol, and that steroid hormones may affect the oviductal functions of R. dybowskii.

Bisphosphonates attenuate age-related muscle decline in Caenorhabditis elegans

BACKGROUND

Age-related muscle decline (sarcopenia) associates with numerous health risk factors and poor quality of life. Drugs that counter sarcopenia without harmful side effects are lacking, and repurposing existing pharmaceuticals could expedite realistic clinical options. Recent studies suggest bisphosphonates promote muscle health; however, the efficacy of bisphosphonates as an anti-sarcopenic therapy is currently unclear.

METHODS

Using Caenorhabditis elegans as a sarcopenia model, we treated animals with 100 nM, 1, 10, 100 and 500 μM zoledronic acid (ZA) and assessed lifespan and healthspan (movement rates) using a microfluidic chip device. The effects of ZA on sarcopenia were examined using GFP-tagged myofibres or mitochondria at days 0, 4 and 6 post-adulthood. Mechanisms of ZA-mediated healthspan extension were determined using combined ZA and targeted RNAi gene knockdown across the life-course.

RESULTS

We found 100 nM and 1 μM ZA increased lifespan (P < 0.001) and healthspan [954 ± 53 (100 nM) and 963 ± 48 (1 μM) vs. 834 ± 59% (untreated) population activity AUC, P < 0.05]. 10 μM ZA shortened lifespan (P < 0.0001) but not healthspan (758.9 ± 37 vs. 834 ± 59, P > 0.05), whereas 100 and 500 μM ZA were larval lethal. ZA (1 μM) significantly improved myofibrillar structure on days 4 and 6 post-adulthood (83 and 71% well-organized myofibres, respectively, vs. 56 and 34% controls, P < 0.0001) and increased well-networked mitochondria at day 6 (47 vs. 16% in controls, P < 0.01). Genes required for ZA-mediated healthspan extension included fdps-1/FDPS-1 (278 ± 9 vs. 894 ± 17% population activity AUC in knockdown + 1 μM ZA vs. untreated controls, respectively, P < 0.0001), daf-16/FOXO (680 ± 16 vs. 894 ± 17%, P < 0.01) and agxt-2/BAIBA (531 ± 23 vs. 552 ± 8%, P > 0.05). Life/healthspan was extended through knockdown of igdb-1/FNDC5 (635 ± 10 vs. 523 ± 10% population activity AUC in gene knockdown vs. untreated controls, P < 0.01) and sir-2.3/SIRT-4 (586 ± 10 vs. 523 ± 10%, P < 0.05), with no synergistic improvements in ZA co-treatment vs. knockdown alone [651 ± 12 vs. 635 ± 10% (igdb-1/FNDC5) and 583 ± 9 vs. 586 ± 10% (sir-2.3/SIRT-4), both P > 0.05]. Conversely, let-756/FGF21 and sir-2.2/SIRT-4 were dispensable for ZA-induced healthspan [630 ± 6 vs. 523 ± 10% population activity AUC in knockdown + 1 μM ZA vs. untreated controls, P < 0.01 (let-756/FGF21) and 568 ± 9 vs. 523 ± 10%, P < 0.05 (sir-2.2/SIRT-4)].

CONCLUSIONS

Despite lacking an endoskeleton, ZA delays Caenorhabditis elegans sarcopenia, which translates to improved neuromuscular function across the life course. Bisphosphonates might, therefore, be an immediately exploitable anti-sarcopenia therapy.

Porokeratoses-A Comprehensive Review on the Genetics and Metabolomics, Imaging Methods and Management of Common Clinical Variants

Porokeratosis is a heterogeneous group of keratinising disorders characterised by the presence of particular microscopic structural changes, namely the presence of the cornoid lamella. This structure develops as a consequence of a defective isoprenoid pathway, critical for cholesterol synthesis. Commonly recognised variants include disseminated superficial actinic porokeratosis, disseminated superficial porokeratosis, porokeratosis of Mibelli, palmoplantar porokeratosis (including porokeratosis palmaris et plantaris disseminata and punctate porokeratosis), linear porokeratosis, verrucous porokeratosis (also known as genitogluteal porokeratosis), follicular porokeratosis and porokeratoma. Apart from the clinical presentation and epidemiology of each variant listed, this review aims at providing up-to-date information on the precise genetic background, introduces imaging methods facilitating the diagnosis (conventional and ultraviolet-induced fluorescence dermatoscopy, reflectance confocal microscopy and pathology), discusses their oncogenic potential and reviews the literature data on the efficacy of the treatment used, including the drugs directly targeting the isoprenoid-mevalonate pathway.

CaaX-motif-adjacent residues influence G protein gamma (Gγ) prenylation under suboptimal conditions

Prenylation is an irreversible post-translational modification that supports membrane interactions of proteins involved in various cellular processes, including migration, proliferation, and survival. Dysregulation of prenylation contributes to multiple disorders, including cancers and vascular and neurodegenerative diseases. Prenyltransferases tether isoprenoid lipids to proteins via a thioether linkage during prenylation. Pharmacological inhibition of the lipid synthesis pathway by statins is a therapeutic approach to control hyperlipidemia. Building on our previous finding that statins inhibit membrane association of G protein γ (Gγ) in a subtype-dependent manner, we investigated the molecular reasoning for this differential inhibition. We examined the prenylation of carboxy-terminus (Ct) mutated Gγ in cells exposed to Fluvastatin and prenyl transferase inhibitors and monitored the subcellular localization of fluorescently tagged Gγ subunits and their mutants using live-cell confocal imaging. Reversible optogenetic unmasking-masking of Ct residues was used to probe their contribution to prenylation and membrane interactions of the prenylated proteins. Our findings suggest that specific Ct residues regulate membrane interactions of the Gγ polypeptide, statin sensitivity, and extent of prenylation. Our results also show a few hydrophobic and charged residues at the Ct are crucial determinants of a protein's prenylation ability, especially under suboptimal conditions. Given the cell and tissue-specific expression of different Gγ subtypes, our findings indicate a plausible mechanism allowing for statins to differentially perturb heterotrimeric G protein signaling in cells depending on their Gγ-subtype composition. Our results may also provide molecular reasoning for repurposing statins as Ras oncogene inhibitors and the failure of using prenyltransferase inhibitors in cancer treatment.

ReDirection: an R-package to compute the probable dissociation constant for every reaction of a user-defined biochemical network

Biochemical networks integrate enzyme-mediated substrate conversions with non-enzymatic complex formation and disassembly to accomplish complex biochemical and physiological functions. The choice of parameters and constraints used in most of these studies is numerically motivated and network-specific. Although sound in theory, the outcomes that result depart significantly from the intracellular milieu and are less likely to retain relevance in a clinical setting. There is a need for a computational tool which is biochemically relevant, mathematically rigorous, and unbiased, and can ascribe functionality to and generate potentially testable hypotheses for a user-defined biochemical network. Here, we present "ReDirection," an R-package which computes the probable dissociation constant for every reaction of a biochemical network directly from a null space-generated subspace of the stoichiometry number matrix of the modeled network. "ReDirection" delineates this subspace by excluding all trivial and redundant or duplicate occurrences of non-trivial vectors, combinatorially summing the vectors that remain and verifying that the upper or lower bounds of the sequence of terms formed by each row of this subspace belong to the open real-valued intervals - ∞ , - 1 or 1 , ∞ or whether the number of terms that are differently signed are almost equal. "ReDirection" iterates these steps until these bounds are consistent and unambiguous for all reactions of the modeled biochemical network. Thereafter, "ReDirection" filters the terms from each row of this subspace, bins them to outcome-specific subsets, sums and maps this to an outcome-specific reaction vector, and computes the p1-norm, which is the probable dissociation constant for a reaction. "ReDirection" works on first principles, does not discriminate between enzymatic and non-enzymatic reactions, offers a biochemically relevant and mathematically rigorous environment to explore user-defined biochemical networks under baseline and perturbed conditions, and can be used to address empirically intractable biochemical problems. The utility and relevance of "ReDirection" are highlighted by numerical studies on stoichiometric number models of biochemical networks of galactose metabolism and heme and cholesterol biosynthesis. "ReDirection" is freely available and accessible from the comprehensive R archive network (CRAN) with the URL (https://cran.r-project.org/package=ReDirection).

Mevalonate pathway and male reproductive aging

Male fertility declines with age. The mevalonate pathway, through which cholesterol and nonsteroidal isoprenoids are synthesized, plays key role in metabolic processes and is an essential pathway for cholesterol production and protein prenylation. Male reproductive aging is accompanied by dramatic changes in the metabolic microenvironment of the testis. Since the mevalonate pathway has an important role in spermatogenesis, we attempted to explore the association between male reproductive aging and the mevalonate pathway to explain the mechanism of male reproductive aging. Alterations in the mevalonate pathway may affect male reproductive aging by decreasing cholesterol synthesis and altering testis protein prenylation. Decreased cholesterol levels affect cholesterol modification, testosterone production, and remodeling of germ cell membranes. Aging-related metabolic disorders also affect the metabolic coupling between somatic cells and spermatogenic cells, leading to male fertility decline. Therefore, we hypothesized that alterations in the mevalonate pathway represent one of the metabolic causes of reproductive aging.

Characterisation of geranylgeranyl diphosphate synthase from the sandfly Lutzomyia longipalpis

Leishmaniasis is a debilitating and often fatal neglected tropical disease. Males from sub-populations of the Leishmania-harbouring sandfly, Lutzomyia longipalpis, produce the diterpene sex and aggregation pheromone, sobralene, for which geranylgeranyl diphosphate (GGPP) is the likely isoprenoid precursor. We have identified a GGPP synthase (lzGGPPS) from L. longipalpis, which was recombinantly expressed in bacteria and purified for functional and kinetic analysis. In vitro enzymatic assays using LC-MS showed that lzGGPPS is an active enzyme, capable of converting substrates dimethylallyl diphosphate (DMAPP), (E)-geranyl diphosphate (GPP), (E,E)-farnesyl diphosphate (FPP) with co-substrate isopentenyl diphosphate (IPP) into (E,E,E)-GGPP, while (Z,E)-FPP was also accepted with low efficacy. Comparison of metal cofactors for lzGGPPS highlighted Mg2+ as most efficient, giving increased GGPP output when compared against other divalent metal ions tested. In line with previously characterised GGPPS enzymes, GGPP acted as an inhibitor of lzGGPPS activity. The molecular weight in solution of lzGGPPS was determined to be ∼221 kDa by analytical SEC, suggesting a hexameric assembly, as seen in the human enzyme, and representing the first assessment of GGPPS quaternary structure in insects.

The bisphosphonates alendronate and zoledronate induce adaptations of aerobic metabolism in permanent human endothelial cells

Nitrogen-containing bisphosphonates (NBPs), compounds that are widely used in the treatment of bone disorders, may cause side effects related to endothelial dysfunction. The aim of our study was to investigate the effects of chronic 6-day exposure to two common bone-preserving drugs, alendronate and zoledronate, on endothelial function and oxidative metabolism of cultured human endothelial cells (EA.hy926). NBPs reduced cell viability, induced oxidative stress and a pro-inflammatory state and downregulated the prenylation-dependent ERK1/2 signaling pathway in endothelial cells. In addition, NBPs induced increased anaerobic respiration and slightly increased oxidative mitochondrial capacity, affecting mitochondrial turnover through reduced mitochondrial fission. Moreover, by blocking the mevalonate pathway, NBPs caused a significant decrease in the level of coenzyme Q10, thereby depriving endothelial cells of an important antioxidant and mitochondrial electron carrier. This resulted in increased formation of reactive oxygen species (ROS), upregulation of antioxidant enzymes, and impairment of mitochondrial respiratory function. A general decrease in mitochondrial respiration occurred with stronger reducing fuels (pyruvate and glutamate) in NBP-treated intact endothelial cells, and significantly reduced phosphorylating respiration was observed during the oxidation of succinate and especially malate in NBP-treated permeabilized endothelial cells. The observed changes in oxidative metabolism caused a decrease in ATP levels and an increase in oxygen levels in NBP-treated cells. Thus, NBPs modulate the energy metabolism of endothelial cells, leading to alterations in the cellular energy state, coenzyme Q10 redox balance, mitochondrial respiratory function, and mitochondrial turnover.

Aminobisphosphonates reactivate the latent reservoir in people living with HIV-1

Antiretroviral therapy (ART) is not curative due to the existence of cellular reservoirs of latent HIV-1 that persist during therapy. Current research efforts to cure HIV-1 infection include "shock and kill" strategies to disrupt latency using small molecules or latency-reversing agents (LRAs) to induce expression of HIV-1 enabling cytotoxic immune cells to eliminate infected cells. The modest success of current LRAs urges the field to identify novel drugs with increased clinical efficacy. Aminobisphosphonates (N-BPs) that include pamidronate, zoledronate, or alendronate, are the first-line treatment of bone-related diseases including osteoporosis and bone malignancies. Here, we show the use of N-BPs as a novel class of LRA: we found in ex vivo assays using primary cells from ART-suppressed people living with HIV-1 that N-BPs induce HIV-1 from latency to levels that are comparable to the T cell activator phytohemagglutinin (PHA). RNA sequencing and mechanistic data suggested that reactivation may occur through activation of the activator protein 1 signaling pathway. Stored samples from a prior clinical trial aimed at analyzing the effect of alendronate on bone mineral density, provided further evidence of alendronate-mediated latency reversal and activation of immune effector cells. Decay of the reservoir measured by IPDA was however not detected. Our results demonstrate the novel use of N-BPs to reverse HIV-1 latency while inducing immune effector functions. This preliminary evidence merits further investigation in a controlled clinical setting possibly in combination with therapeutic vaccination.

CaaX-motif adjacent residues control G protein prenylation under suboptimal conditions

Prenylation is a universal and irreversible post-translational modification that supports membrane interactions of proteins involved in various cellular processes, including migration, proliferation, and survival. Thus, dysregulation of prenylation contributes to multiple disorders, including cancers, vascular diseases, and neurodegenerative diseases. During prenylation, prenyltransferase enzymes tether metabolically produced isoprenoid lipids to proteins via a thioether linkage. Pharmacological inhibition of the lipid synthesis pathway by statins has long been a therapeutic approach to control hyperlipidemia. Building on our previous finding that statins inhibit membrane association of G protein γ (Gγ) in a subtype-dependent manner, we investigated the molecular reasoning for this differential. We examined the prenylation efficacy of carboxy terminus (Ct) mutated Gγ in cells exposed to Fluvastatin and prenyl transferase inhibitors and monitored the subcellular localization of fluorescently tagged Gγ subunits and their mutants using live-cell confocal imaging. Reversible optogenetic unmasking-masking of Ct residues was used to probe their contribution to the prenylation process and membrane interactions of the prenylated proteins. Our findings suggest that specific Ct residues regulate membrane interactions of the Gγ polypeptide statin sensitivity, and prenylation efficacy. Our results also show that a few hydrophobic and charged residues at the Ct are crucial determinants of a protein's prenylation ability, especially under suboptimal conditions. Given the cell and tissue-specific expression of different Gγ subtypes, our findings explain how and why statins differentially perturb heterotrimeric G protein signaling in specific cells and tissues. Our results may provide molecular reasoning for repurposing statins as Ras oncogene inhibitors and the failure of using prenyltransferase inhibitors in cancer treatment.

Expression of housekeeping genes varies depending on mevalonate pathway inhibition in cancer cells

Statins have anticancer effects and may be used as anticancer agents via drug repositioning. In reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays, the internal reference gene must not be affected by any experimental conditions. As statins exert a wide range of effects on cells by inhibiting the mevalonate pathway, it is possible that statin treatment might alter the expression of housekeeping genes used as internal reference genes, thereby misleading the assessment of obtained gene expression data. Here, we evaluated the expression stability of internal reference genes in atorvastatin-treated cancer cell lines. We treated both statin-sensitive and statin-resistant cancer cell lines with atorvastatin at seven different concentrations and performed RT-qPCR on 15 housekeeping genes whose expression stability was then assessed using five different algorithms. In both statin-sensitive and statin-resistant cancer cell lines, atorvastatin affected the expression of certain internal reference genes in a dose-dependent and cancer cell line-dependent manner; therefore, caution should be exercised when comparing target gene expression between cells. Our findings emphasize the importance of the validation of internal reference genes in gene expression analyses in drug treatment-based cancer research.

Pharmacological options in the treatment of osteogenesis imperfecta: A comprehensive review of clinical and potential alternatives

Osteogenesis imperfecta (OI) is a genetically heterogeneous connective tissue disorder characterized by bone fragility and different extra-skeletal manifestations. The severity of these manifestations makes it possible to classify OI into different subtypes based on the main clinical features. This review aims to outline and describe the current pharmacological alternatives for treating OI, grounded on clinical and preclinical reports, such as antiresorptive agents, anabolic agents, growth hormone, and anti-TGFβ antibody, among other less used agents. The different options and their pharmacokinetic and pharmacodynamic properties will be reviewed and discussed, focusing on the variability of their response and the molecular mechanisms involved to attain the main clinical goals, which include decreasing fracture incidence, improving pain, and promoting growth, mobility, and functional independence.

Decreased Imiquimod-Induced Psoriasis-Like Skin Inflammation in a Novel MvdF250S/+ Knock-In Mouse Model

The mevalonate-diphosphate decarboxylase (MVD) gene, a member of the mevalonate pathway, plays a critical role in regulating the biosynthesis of cholesterol, steroid hormones, and non-steroid isoprenoids. Previous studies have suggested that the MVD c.746 T > C mutation is a major pathogenic gene of porokeratosis (PK), an autoinflammatory keratinization disease (AIKD) with unclear pathogenesis, few effective treatments, and no suitable animal model. To investigate the function of Mvd^F250S/+ mutation, we developed a novel Mvd^F250S/+ mouse model carrying an equivalent point mutation to the most common genetic variation among Chinese PK patients (MVD^F249S/+) using CRISPR/Cas9 technology, which exhibited reduced cutaneous expression of Mvd protein. In the absence of external stimulation, Mvd^F250S/+ mice did not display specific phenotypes. However, upon induction with imiquimod (IMQ), Mvd^F250S/+ mice exhibited decreased susceptibility to skin acute inflammation compared to wild-type (WT) mice, as evidenced by reduced cutaneous proliferation and lower protein levels of IL-17a and IL-1β. Additionally, after IMQ induction, the Mvd^F250S/+mice exhibited downregulated collagen generation and upregulated expression of Fabp3 compared to WT mice, whereas no significant changes in the key genes related to cholesterol regulation were found. Furthermore, the Mvd^F250S/+ mutation activated autophagy. Our findings provided insights into the biological function of MVD in the skin.

Role of secondary metabolites in distressed microalgae

Proficient photosynthetic microalgae/cyanobacteria produce a remarkable amount of various biomolecules. Secondary metabolites (SM) represent high value products for global biotrend application. Production improvement can be achieved by nutritional, environmental, and physiological stress as a first line tools for their stimulation. In recent decade, an increasing interest in algal stress biology and omics techniques have deepened knowledge in this area. However, deep understanding and connection of specific stress elucidator are missing. Hence, the present review summarizes recent evidence with an emphasis on the carotenoids, phenolic, and less-discussed compounds (glycerol, proline, mycosporins-like amino acids). Even when they are synthesized at very low concentrations, it highlights the need to expand knowledge in this area using genome-editing tools and omics approaches.

Structure Elucidation and Biosynthesis of Nannosterols A and B, Myxobacterial Sterols from Nannocystis sp. MNa10993

Myxobacteria represent an underinvestigated source of chemically diverse and biologically active secondary metabolites. Here, we report the discovery, isolation, structure elucidation, and biological evaluation of two new bacterial sterols, termed nannosterols A and B (1, 2), from the terrestrial myxobacterium Nannocystis sp. (MNa10993). Nannosterols feature a cholestanol core with numerous modifications including a secondary alcohol at position C-15, a terminal vicinal diol side chain at C-24-C-25 (1, 2), and a hydroxy group at the angular methyl group at C-18 (2), which is unprecedented for bacterial sterols. Another rare chemical feature of bacterial triterpenoids is a ketone group at position C-7, which is also displayed by 1 and 2. The combined exploration based on myxobacterial high-resolution secondary metabolome data and genomic in silico investigations exposed the nannosterols as frequently produced sterols within the myxobacterial suborder of Nannocystineae. The discovery of the nannosterols provides insights into the biosynthesis of these new myxobacterial sterols, with implications in understanding the evolution of sterol production by prokaryotes.

A Systematic Review and Meta-Analysis on the Impact of Statin Treatment in HIV Patients on Antiretroviral Therapy

The rate of new human immunodeficiency virus (HIV) infections globally is alarming. Although antiretroviral therapy (ART) improves the quality of life among this group of patients, ARTs are associated with risk of cardiovascular diseases (CVD). Moreover, virally suppressed patients still experience immune activation associated with HIV migration from reservoir sites. Statins are widely recommended as therapeutic agents to control ART-related CVD; however, their impacts on the cluster of differentiation (CD)4 count and viral load are inconsistent. To assess the effect of statins on markers of HIV infections, immune activation and cholesterol, we thoroughly reviewed evidence from randomised controlled trials. We found 20 relevant trials from three databases with 1802 people living with HIV (PLHIV) on statin-placebo treatment. Our evidence showed no significant effect on CD4 T-cell count standardised mean difference (SMD): (-0.59, 95% confidence intervals (CI): (-1.38, 0.19), p = 0.14) following statin intervention in PLHIV on ART. We also found no significant difference in baseline CD4 T-cell count (SD: (-0.01, 95%CI: (-0.25, 0.23), p = 0.95). Our findings revealed no significant association between statins and risk of viral rebound in PLHIV with undetectable viral load risk ratio (RR): (1.01, 95% CI: (0.98, 1.04), p = 0.65). Additionally, we found a significant increase in CD8⁺CD38⁺HLA-DR⁺ T-cells (SMD (1.10, 95% CI: (0.93, 1.28), p < 0.00001) and CD4⁺CD38⁺HLA-DR⁺ T-cells (SMD (0.92, 95% CI: (0.32, 1.52), p = 0.003). Finally, compared to placebo, statins significantly reduced total cholesterol (SMD: (-2.87, 95% CI: (-4.08, -1.65), p < 0.0001)). Our results suggest that the statin lipid-lowering effect in PLHIV on ART may elevate immune activation without influencing the viral load and CD4 count. However, due to the limited evidence synthesised in this meta-analysis, we recommend that future powered trials with sufficient sample sizes evaluate statins' effect on CD4 count and viral load, especially in virally suppressed patients.

Discovery and excavation of lichen bioactive natural products

Lichen natural products are a tremendous source of new bioactive chemical entities for drug discovery. The ability to survive in harsh conditions can be directly correlated with the production of some unique lichen metabolites. Despite the potential applications, these unique metabolites have been underutilized by pharmaceutical and agrochemical industries due to their slow growth, low biomass availability, and technical challenges involved in their artificial cultivation. At the same time, DNA sequence data have revealed that the number of encoded biosynthetic gene clusters in a lichen is much higher than in natural products, and the majority of them are silent or poorly expressed. To meet these challenges, the one strain many compounds (OSMAC) strategy, as a comprehensive and powerful tool, has been developed to stimulate the activation of silent or cryptic biosynthetic gene clusters and exploit interesting lichen compounds for industrial applications. Furthermore, the development of molecular network techniques, modern bioinformatics, and genetic tools is opening up a new opportunity for the mining, modification, and production of lichen metabolites, rather than merely using traditional separation and purification techniques to obtain small amounts of chemical compounds. Heterologous expressed lichen-derived biosynthetic gene clusters in a cultivatable host offer a promising means for a sustainable supply of specialized metabolites. In this review, we summarized the known lichen bioactive metabolites and highlighted the application of OSMAC, molecular network, and genome mining-based strategies in lichen-forming fungi for the discovery of new cryptic lichen compounds.

Transcriptomic Changes Predict Metabolic Alterations in LC3 Associated Phagocytosis in Aged Mice

LC3b (Map1lc3b) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b to promote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes, such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells, utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis, and neuroprotection. In a mouse model of retinal lipid steatosis-mice lacking LC3b (LC3b-/-), we observed increased lipid deposition, metabolic dysregulation, and enhanced inflammation. Herein, we present a non-biased approach to determine if loss of LAP mediated processes modulate the expression of various genes related to metabolic homeostasis, lipid handling, and inflammation. A comparison of the RPE transcriptome of WT and LC3b-/- mice revealed 1533 DEGs, with ~73% upregulated and 27% downregulated. Enriched gene ontology (GO) terms included inflammatory response (upregulated DEGs), fatty acid metabolism, and vascular transport (downregulated DEGs). Gene set enrichment analysis (GSEA) identified 34 pathways; 28 were upregulated (dominated by inflammation/related pathways) and 6 were downregulated (dominated by metabolic pathways). Analysis of additional gene families identified significant differences for genes in the solute carrier family, RPE signature genes, and genes with a potential role in age-related macular degeneration. These data indicate that loss of LC3b induces robust changes in the RPE transcriptome contributing to lipid dysregulation and metabolic imbalance, RPE atrophy, inflammation, and disease pathophysiology.

Phosphomevalonate Kinase Controls β-Catenin Signaling via the Metabolite 5-Diphosphomevalonate

β-catenin signaling is abnormally activated in cancer. Here, this work screens the mevalonate metabolic pathway enzyme PMVK to stabilize β-catenin signaling using a human genome-wide library. On the one hand, PMVK-produced MVA-5PP competitively binds to CKIα to prevent β-catenin Ser45 phosphorylation and degradation. On the other hand, PMVK functions as a protein kinase to directly phosphorylate β-catenin Ser184 to increase its protein nuclear localization. This synergistic effect of PMVK and MVA-5PP together promotes β-catenin signaling. In addition, PMVK deletion impairs mouse embryonic development and causes embryonic lethal. PMVK deficiency in liver tissue alleviates DEN/CCl4 -induced hepatocarcinogenesis. Finally, the small molecule inhibitor of PMVK, PMVKi5, is developed and PMVKi5 inhibits carcinogenesis of liver and colorectal tissues. These findings reveal a non-canonical function of a key metabolic enzyme PMVK and a novel link between the mevalonate pathway and β-catenin signaling in carcinogenesis providing a new target for clinical cancer therapy.

Transcriptomic changes predict metabolic alterations in LC3 associated phagocytosis in aged mice

LC3b ( Map1lc3b ) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b, to pro-mote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis and neuroprotection. In a mouse model of retinal lipid steatosis - mice lacking LC3b ( LC3b ^-/- ), we observed increased lipid deposition, metabolic dysregulation and enhanced inflammation. Herein we present a non-biased approach to determine if loss of LAP mediated processes modulate the expression of various genes related to metabolic homeostasis, lipid handling, and inflammation. A comparison of the RPE transcriptome of WT and LC3b ^-/- mice revealed 1533 DEGs, with ~73% upregulated and 27% down-regulated. Enriched gene ontology (GO) terms included inflammatory response (upregulated DEGs), fatty acid metabolism and vascular transport (downregulated DEGs). Gene set enrichment analysis (GSEA) identified 34 pathways; 28 were upregulated (dominated by inflammation/related pathways) and 6 were downregulated (dominated by metabolic pathways). Analysis of additional gene families identified significant differences for genes in the solute carrier family, RPE signature genes, and genes with potential role in age-related macular degeneration. These data indicate that loss of LC3b induces robust changes in the RPE transcriptome contributing to lipid dysregulation and metabolic imbalance, RPE atrophy, inflammation, and disease pathophysiology.

Circular RNA ACACA negatively regulated p53-modulated mevalonate pathway to promote colorectal tumorigenesis via regulating miR-193a/b-3p/HDAC3 axis

This study aimed to explore the biological functions and underlying mechanism of circRNA acetyl-CoA carboxylase alpha (circACACA) in colorectal cancer (CRC). The RNA and protein levels were detected by qRT-PCR and western blot assays. The malignant capacities of CRC cells were analyzed by cell counting kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays. The target relationship between miR-193a/b-3p and circACACA/histone deacetylase 3 (HDAC3) was determined by luciferase reporter assay and RNA immunoprecipitation. The binding of HDAC3 to the p53 promoter was validated by chromatin immunoprecipitation (ChIP). CRC cell growth and lung metastasis were evaluated in nude mice in vivo. High expression of circACACA was found in CRC tissues and cells, which was closely associated with the advanced tumor, lymph node, metastasis (TNM) stage, metastasis, and low overall survival rate. circACACA downregulation effectively delayed CRC cell proliferation and metastasis, but triggered apoptosis via inactivating the mevalonic acid (MVA) pathway. However, circACACA overexpression resulted in the opposite effects. Mechanistically, circACACA enhanced HDAC3 expression through sponging miR-193a/b-3p, which activated the MVA pathway via inhibiting the acetylation and transcription of p53. Moreover, rescue experiments confirmed that miR-193a/b-3p inhibition reversed the inhibitory effect of circACACA deficiency on CRC growth and metastasis. Moreover, circACACA overexpression-mediated malignant phenotypes of CRC cells were abrogated by HDAC3 knockdown. circACACA promoted CRC progression via regulating the miR-193a/b-3p/HDAC3/p53 axis to activate the MVA pathway, providing evidence for circACACA as a promising therapeutic target for CRC.

Molecular mechanisms of ferroptosis and their involvement in brain diseases

Ferroptosis is a type of regulated cell death characterized by intracellular accumulation of iron and reactive oxygen species, inhibition of system Xc-, glutathione depletion, nicotinamide adenine dinucleotide phosphate oxidation and lipid peroxidation. Since its discovery and characterization in 2012, many efforts have been made to reveal the underlying mechanisms, modulating compounds, and its involvement in disease pathways. Ferroptosis inducers include erastin, sorafenib, sulfasalazine and glutamate, which, by inhibiting system Xc-, prevent the import of cysteine into the cells. RSL3, statins, Ml162 and Ml210 induce ferroptosis by inhibiting glutathione peroxidase 4 (GPX4), which is responsible for preventing the formation of lipid peroxides, and FIN56 and withaferin trigger GPX4 degradation. On the other side, ferroptosis inhibitors include ferrostatin-1, liproxstatin-1, α-tocopherol, zileuton, FSP1, CoQ10 and BH4, which interrupt the lipid peroxidation cascade. Additionally, deferoxamine, deferiprone and N-acetylcysteine, by targeting other cellular pathways, have also been classified as ferroptosis inhibitors. Increased evidence has established the involvement of ferroptosis in distinct brain diseases, including Alzheimer's, Parkinson's and Huntington's diseases, amyotrophic lateral sclerosis, multiple sclerosis, and Friedreich's ataxia. Thus, a deep understanding of how ferroptosis contributes to these diseases, and how it can be modulated, can open a new window of opportunities for novel therapeutic strategies and targets. Other studies have shown a sensitivity of cancer cells with mutated RAS to ferroptosis induction and that chemotherapeutic agents and ferroptosis inducers synergize in tumor treatment. Thus, it is tempting to consider that ferroptosis may arise as a target mechanistic pathway for the treatment of brain tumors. Therefore, this work provides an up-to-date review on the molecular and cellular mechanisms of ferroptosis and their involvement in brain diseases. In addition, information on the main ferroptosis inducers and inhibitors and their molecular targets is also provided.