The mitochondrial NAD kinase functions as a major metabolic regulator upon increased energy demand.

OBJECTIVE: The mitochondrial nicotinamide adenine dinucleotide (NAD) kinase (MNADK) mediates de novo mitochondrial NADP biosynthesis by catalyzing the phosphorylation of NAD to yield NADP. In this study, we investigated the function and mechanistic basis by which MNADK regulates metabolic homeostasis. METHODS: Generalized gene set analysis by aggregating human patient genomic databases, metabolic studies with genetically engineered animal models, mitochondrial bioenergetic analysis, as well as gain- and loss- of-function studies were performed to address the functions and mechanistic basis by which MNADK regulates energy metabolism and redox state associated with metabolic disease. RESULTS: Human MNADK common gene variants or decreased expression of the gene are significantly associated with the occurrence of type-2 diabetes, non-alcoholic fatty liver disease (NAFLD), or hepatocellular carcinoma (HCC). Ablation of the MNADK gene in mice led to decreased fat oxidation, coincident with increased respiratory exchange ratio (RER) and decreased energy expenditure upon energy demand triggered by endurance exercise or fasting. On an atherogenic high-fat diet (HFD), MNADK-null mice exhibited hepatic insulin resistance and glucose intolerance, indicating a type-2 diabetes-like phenotype in the absence of MNADK. MNADK deficiency led to a decrease in mitochondrial NADP(H) but an increase in cellular reactive oxygen species (ROS) in mouse livers. Consistently, protein levels of the major metabolic regulators or enzymes were decreased, while their acetylation modifications were increased in the livers of MNADK-null mice. Feeding mice with a HFD caused S-nitrosylation (SNO) modification, a posttranslational modification that represses protein activities, on MNADK protein in the liver. Reconstitution of an SNO-resistant MNADK variant, MNADK-S193, into MNADK-null mice mitigated hepatic steatosis induced by HFD. CONCLUSION: MNADK, the only known mammalian mitochondrial NAD kinase, plays important roles in preserving energy homeostasis to mitigate the risk of metabolic disorders.

A ferroptosis defense mechanism mediated by glycerol-3-phosphate dehydrogenase 2 in mitochondria.

Mechanisms of defense against ferroptosis (an iron-dependent form of cell death induced by lipid peroxidation) in cellular organelles remain poorly understood, hindering our ability to target ferroptosis in disease treatment. In this study, metabolomic analyses revealed that treatment of cancer cells with glutathione peroxidase 4 (GPX4) inhibitors results in intracellular glycerol-3-phosphate (G3P) depletion. We further showed that supplementation of cancer cells with G3P attenuates ferroptosis induced by GPX4 inhibitors in a G3P dehydrogenase 2 (GPD2)-dependent manner; GPD2 deletion sensitizes cancer cells to GPX4 inhibition-induced mitochondrial lipid peroxidation and ferroptosis, and combined deletion of GPX4 and GPD2 synergistically suppresses tumor growth by inducing ferroptosis in vivo. Mechanistically, inner mitochondrial membrane-localized GPD2 couples G3P oxidation with ubiquinone reduction to ubiquinol, which acts as a radical-trapping antioxidant to suppress ferroptosis in mitochondria. Taken together, these results reveal that GPD2 participates in ferroptosis defense in mitochondria by generating ubiquinol.

Mitochondrial glutathione peroxidase 4 is indispensable for photoreceptor development and survival in mice.

Glutathione peroxidase 4 (GPx4) is known for its unique function in the direct detoxification of lipid peroxides in the cell membrane and as a key regulator of ferroptosis, a form of lipid peroxidation-induced nonapoptotic cell death. However, the cytosolic isoform of GPx4 is considered to play a major role in inhibiting ferroptosis in somatic cells, whereas the roles of the mitochondrial isoform of GPx4 (mGPx4) in cell survival are not yet clear. In the present study, we found that mGPx4 KO mice exhibit a cone-rod dystrophy-like phenotype in which loss of cone photoreceptors precedes loss of rod photoreceptors. Specifically, in mGPx4 KO mice, cone photoreceptors disappeared prior to their maturation, whereas rod photoreceptors persisted through maturation but gradually degenerated afterward. Mechanistically, we demonstrated that vitamin E supplementation significantly ameliorated photoreceptor loss in these mice. Furthermore, LC-MS showed a significant increase in peroxidized phosphatidylethanolamine esterified with docosahexaenoic acid in the retina of mGPx4 KO mice. We also observed shrunken and uniformly condensed nuclei as well as caspase-3 activation in mGPx4 KO photoreceptors, suggesting that apoptosis was prevalent. Taken together, our findings indicate that mGPx4 is essential for the maturation of cone photoreceptors but not for the maturation of rod photoreceptors, although it is still critical for the survival of rod photoreceptors after maturation. In conclusion, we reveal novel functions of mGPx4 in supporting development and survival of photoreceptors in vivo.

Mitochondrial Bioenergetic and Proteomic Phenotyping Reveals Organ-Specific Consequences of Chronic Kidney Disease in Mice.

Chronic kidney disease (CKD) results in reduced kidney function, uremia, and accumulation of uremic metabolites. Mitochondrial alterations have been suggested to play a role in the disease pathology within various tissues. The purpose of this study was to perform a comprehensive bioenergetic and proteomic phenotyping of mitochondria from skeletal muscle (SkM), cardiac muscle (CM), and renal tissue from mice with CKD. The 5-month-old C57BL/6J male mice were fed a casein control or adenine-supplemented diet for 6 months. CKD was confirmed by blood urea nitrogen. A mitochondrial diagnostic workflow was employed to examine respiratory function, membrane and redox potential, reactive oxygen species production, and maximal activities of matrix dehydrogenases and electron transport system (ETS) protein complexes. Additionally, tandem-mass-tag-assisted proteomic analyses were performed to uncover possible differences in mitochondrial protein abundance. CKD negatively impacted mitochondrial energy transduction (all p < 0.05) in SkM, CM, and renal mitochondria, when assessed at physiologically relevant cellular energy demands (ΔGATP) and revealed the tissue-specific impact of CKD on mitochondrial health. Proteomic analyses indicated significant abundance changes in CM and renal mitochondria (115 and 164 proteins, p < 0.05), but no differences in SkM. Taken together, these findings reveal the tissue-specific impact of chronic renal insufficiency on mitochondrial health.

Acsbg1-dependent mitochondrial fitness is a metabolic checkpoint for tissue Treg cell homeostasis.

Regulatory T (Treg) cells are critical for immunological tolerance and immune homeostasis. Treg cells strongly rely on mitochondrial metabolism and show a lower level of glycolysis. However, little is known about the role of lipid metabolism in the regulation of Treg cell homeostasis. Some members of the ACSL family of acyl-coenzyme A (CoA) synthases are expressed in T cells, but their function remains unclear. A combination of RNA-sequencing and proteome analyses shows that Acsbg1, a member of ACSL, is selectively expressed in Treg cells. We show that the genetic deletion of Acsbg1 not only causes mitochondrial dysfunction, but it also dampens other metabolic pathways. The extrinsic supplementation of Acsbg1-deficient Treg cells with oleoyl-CoA restores the phenotype of the Treg metabolic signature. Furthermore, this pathway in ST2+ effector Treg cells enhances immunosuppressive capacity in airway inflammation. Thus, Acsbg1 serves as a metabolic checkpoint governing Treg cell homeostasis and the resolution of lung inflammation.

Mitochondrial complex II in intestinal epithelial cells regulates T cell-mediated immunopathology.

Intestinal epithelial cell (IEC) damage by T cells contributes to graft-versus-host disease, inflammatory bowel disease and immune checkpoint blockade-mediated colitis. But little is known about the target cell-intrinsic features that affect disease severity. Here we identified disruption of oxidative phosphorylation and an increase in succinate levels in the IECs from several distinct in vivo models of T cell-mediated colitis. Metabolic flux studies, complemented by imaging and protein analyses, identified disruption of IEC-intrinsic succinate dehydrogenase A (SDHA), a component of mitochondrial complex II, in causing these metabolic alterations. The relevance of IEC-intrinsic SDHA in mediating disease severity was confirmed by complementary chemical and genetic experimental approaches and validated in human clinical samples. These data identify a critical role for the alteration of the IEC-specific mitochondrial complex II component SDHA in the regulation of the severity of T cell-mediated intestinal diseases.

A dedicated flavin-dependent monooxygenase catalyzes the hydroxylation of demethoxyubiquinone into ubiquinone (coenzyme Q) in Arabidopsis.

Ubiquinone (Coenzyme Q) is a vital respiratory cofactor and liposoluble antioxidant. In plants, it is not known how the C-6 hydroxylation of demethoxyubiquinone, the penultimate step in ubiquinone biosynthesis, is catalyzed. The combination of cross-species gene network modeling along with mining of embryo-defective mutant databases of Arabidopsis thaliana identified the embryo lethal locus EMB2421 (At1g24340) as a top candidate for the missing plant demethoxyubiquinone hydroxylase. In marked contrast with prototypical eukaryotic demethoxyubiquinone hydroxylases, the catalytic mechanism of which depends on a carboxylate-bridged di-iron domain, At1g24340 is homologous to FAD-dependent oxidoreductases that instead use NAD(P)H as an electron donor. Complementation assays in Saccharomyces cerevisiae and Escherichia coli demonstrated that At1g24340 encodes a functional demethoxyubiquinone hydroxylase and that the enzyme displays strict specificity for the C-6 position of the benzoquinone ring. Laser-scanning confocal microscopy also showed that GFP-tagged At1g24340 is targeted to mitochondria. Silencing of At1g24340 resulted in 40 to 74% decrease in ubiquinone content and de novo ubiquinone biosynthesis. Consistent with the role of At1g24340 as a benzenoid ring modification enzyme, this metabolic blockage could not be bypassed by supplementation with 4-hydroxybenzoate, the immediate precursor of ubiquinone's ring. Unlike in yeast, in Arabidopsis overexpression of demethoxyubiquinone hydroxylase did not boost ubiquinone content. Phylogenetic reconstructions indicated that plant demethoxyubiquinone hydroxylase is most closely related to prokaryotic monooxygenases that act on halogenated aromatics and likely descends from an event of horizontal gene transfer between a green alga and a bacterium.

Improving Consistency of Photobiomodulation Therapy: A Novel Flat-Top Beam Hand-Piece versus Standard Gaussian Probes on Mitochondrial Activity.

The tremendous therapeutic potential of photobiomodulation therapy in different branches of medicine has been described in the literature. One of the molecular mechanisms for this treatment implicates the mitochondrial enzyme, cytochrome C oxidase. However, the efficacy and consistency of clinical outcomes with photobiomodulation treatments has been fiercely debated. This work was motivated by this need to improve photobiomodulation devices and delivery approaches. We designed a novel hand-piece with a flat-top beam profile of irradiation. We compared the beam profile versus a standard hand-piece and a fibre probe. We utilized isolated mitochondria and performed treatments at various spots within the beam, namely, the centre, left and right edge. We examined mitochondrial activity by assessing ATP synthesis with the luciferin/luciferase chemiluminescent method as a primary endpoint, while mitochondrial damage was assessed as the secondary endpoint. We observed a uniform distribution of the power density with the flat-top prototype compared to a wide Gaussian beam profile with the standard fibre and standard hand-piece. We noted increased production of ATP in the centre of all three beams with respect to the non-treated controls (p < 0.05). Both the fibre and standard hand-piece demonstrated less increase in ATP synthesis at the edges than the centre (p < 0.05). In contrast, ATP synthesis was increased homogenously in the flat-top handpiece, both in the centre and the edges of the beam. Fibre, standard hand-piece and the flat-top hand-piece prototype have discrete beam distribution characteristics. This significantly affected the mitochondrial activity with respect to their position within the treated areas. Flat-top hand-piece enhances the uniformity of photobiomodulation treatments and can improve the rigour and reproducibility of PBM clinical outcomes.

Parp mutations protect from mitochondrial toxicity in Alzheimer's disease.

Alzheimer's disease is the most common age-related neurodegenerative disorder. Familial forms of Alzheimer's disease associated with the accumulation of a toxic form of amyloid-ß (Aß) peptides are linked to mitochondrial impairment. The coenzyme nicotinamide adenine dinucleotide (NAD+) is essential for both mitochondrial bioenergetics and nuclear DNA repair through NAD+-consuming poly (ADP-ribose) polymerases (PARPs). Here we analysed the metabolomic changes in flies overexpressing Aß and showed a decrease of metabolites associated with nicotinate and nicotinamide metabolism, which is critical for mitochondrial function in neurons. We show that increasing the bioavailability of NAD+ protects against Aß toxicity. Pharmacological supplementation using NAM, a form of vitamin B that acts as a precursor for NAD+ or a genetic mutation of PARP rescues mitochondrial defects, protects neurons against degeneration and reduces behavioural impairments in a fly model of Alzheimer's disease. Next, we looked at links between PARP polymorphisms and vitamin B intake in patients with Alzheimer's disease. We show that polymorphisms in the human PARP1 gene or the intake of vitamin B are associated with a decrease in the risk and severity of Alzheimer's disease. We suggest that enhancing the availability of NAD+ by either vitamin B supplements or the inhibition of NAD+-dependent enzymes such as PARPs are potential therapies for Alzheimer's disease.

Incaspitolide A extracted from Carpesium cernuum induces apoptosis in vitro via the PI3K/AKT pathway in benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is a common disease that occurs mainly in older men. The pathogenesis of BPH is complex and patients face a prolonged treatment course, and novel drugs with better selectivity and lower toxicity are required. Incaspitolide A (compound TMJ-12) is a germacrane-type sesquiterpenoid compound extracted from the plant Carpesium carnuum. Extracts of C. carnuum are known to exert suppressive effects on BPH-1 cells. In the present study, we investigated the molecular mechanisms underlying the suppressive effect of TMJ-12 specifically on BPH-1 cells. A cytotoxicity assay indicated that TMJ-12 inhibited BPH-1 cell proliferation, while flow cytometry assays showed that TMJ-12 induced G2/M phase cell cycle arrest and the apoptosis of BPH-1 cells. TMJ-12 was also shown to regulate the expression of several apoptosis- and cell cycle-related proteins, namely Bcl-2, Bax, Bad, Caspase-9, Caspase-3, cyclin-dependent kinase 1 (CDK1), Cyclin B1, CDC25C, and c-Myc, among others. Collapse of the mitochondrial membrane potential (ΔΨm) following exposure to TMJ-12 was detected with the JC-1 staining assay. Further investigation revealed that treatment with TMJ-12 inhibited the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway by increasing the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Taken together, the results suggest that TMJ-12 prevents BPH-1 cell proliferation via the PI3K/AKT pathway by inducing apoptosis and cell cycle arrest.

Omega-3 Fatty Acids Upregulate SIRT1/3, Activate PGC-1α via Deacetylation, and Induce Nrf1 Production in 5/6 Nephrectomy Rat Model.

Mitochondrial dysfunction contributes to the pathogenesis of kidney injury related with cardiovascular disease. Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) protects renal tubular cells by upregulating nuclear factor erythroid 2-related factor 2 (Nrf2). AMP-activated protein kinase (pAMPK)-mediated phosphorylation and sirtuin 1/3 (SIRT1/3)-mediated deacetylation are required for PGC-1α activation. In the present study, we aimed to investigate whether omega-3 fatty acids (FAs) regulate the expression of mediators of mitochondrial biogenesis in 5/6 nephrectomy (Nx) rats. Male Sprague-Dawley rats were assigned to the following groups: sham control, Nx, and Nx treated with omega-3 FA. The expression of PGC-1α, phosphorylated PGC-1α (pPGC-1α), acetylated PGC-1α, and factors related to mitochondrial biogenesis was examined through Western blot analysis. Compared to the control group, the expression of PGC-1α, pAMPK, SIRT1/3, Nrf1, mTOR, and Nrf2 was significantly downregulated, and that of Keap 1, acetylated PGC-1α, and FoxO1/3, was significantly upregulated in the Nx group. These changes in protein expression were rescued in the omega-3 FA group. However, the expression of pPGC-1α was similar among the three groups. Omega-3 FAs may involve mitochondrial biogenesis by upregulating Nrf1 and Nrf2. This protective mechanism might be attributed to the increased expression and deacetylation of PGC-1α, which was triggered by SIRT1/3.

ETF dehydrogenase advances in molecular genetics and impact on treatment.

Electron transfer flavoprotein dehydrogenase, also called ETF-ubiquinone oxidoreductase (ETF-QO), is a protein localized in the inner membrane of mitochondria, playing a central role in the electron-transfer system. Indeed, ETF-QO mediates electron transport from flavoprotein dehydrogenases to the ubiquinone pool. ETF-QO mutations are often associated with riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency (RR-MADD, OMIM#231680), a multisystem genetic disease characterized by various clinical manifestations with different degrees of severity. In this review, we outline the clinical features correlated with ETF-QO deficiency and the benefits obtained from different treatments, such as riboflavin, L-carnitine and/or coenzyme Q10 supplementation, and a diet poor in fat and protein. Moreover, we provide a detailed summary of molecular and bioinformatic investigations, describing the mutations identified in ETFDH gene and highlighting their predicted impact on enzymatic structure and activity. In addition, we report biochemical and functional analysis, performed in HEK293 cells and patient fibroblasts and muscle cells, to show the relationship between the nature of ETFDH mutations, the variable impairment of enzyme function, and the different degrees of RR-MADD severity. Finally, we describe in detail 5 RR-MADD patients carrying different ETFDH mutations and presenting variable degrees of clinical symptom severity.

Anti-Inflammatory Effects Induced by Near-Infrared Light Irradiation through M2 Macrophage Polarization.

Near-infrared (NIR) can penetrate the dermis. NIR is able to regulate cutaneous component cells and immune cells and shows significant anti-inflammatory therapeutic effects. However, the mechanisms of these effects are largely unknown. The purpose of this study is to elucidate NIR-induced molecular mechanisms on macrophages because macrophages play initial roles in directing immune responses by their M1 or M2 polarizations. Proteomic analysis revealed that NIR radiation enhanced the expression of mitochondrial respiratory gene citrate synthase. This increased citrate synthase expression was triggered by NIR-induced H3K4 hypermethylation on the citrate synthase gene promoter but not by heat, which led to macrophage M2 polarization and finally resulted in TGFß1 release from CD4+ cells. These cellular effects were validated in human primary macrophages and abdominal NIR-irradiated mouse experiments. In a phorbol 12-myristate 13-acetate‒induced inflammatory model on mouse ear, we confirmed that NIR irradiation induced significant anti-inflammatory effects through decreased M1 counts, reduced TNF-α, and increased CCL22 and/or TGFß1 levels.

A genome-wide copper-sensitized screen identifies novel regulators of mitochondrial cytochrome c oxidase activity.

Copper is essential for the activity and stability of cytochrome c oxidase (CcO), the terminal enzyme of the mitochondrial respiratory chain. Loss-of-function mutations in genes required for copper transport to CcO result in fatal human disorders. Despite the fundamental importance of copper in mitochondrial and organismal physiology, systematic identification of genes that regulate mitochondrial copper homeostasis is lacking. To discover these genes, we performed a genome-wide screen using a library of DNA-barcoded yeast deletion mutants grown in copper-supplemented media. Our screen recovered a number of genes known to be involved in cellular copper homeostasis as well as genes previously not linked to mitochondrial copper biology. These newly identified genes include the subunits of the adaptor protein 3 complex (AP-3) and components of the cellular pH-sensing pathway Rim20 and Rim21, both of which are known to affect vacuolar function. We find that AP-3 and Rim mutants exhibit decreased vacuolar acidity, which in turn perturbs mitochondrial copper homeostasis and CcO function. CcO activity of these mutants could be rescued by either restoring vacuolar pH or supplementing growth media with additional copper. Consistent with these genetic data, pharmacological inhibition of the vacuolar proton pump leads to decreased mitochondrial copper content and a concomitant decrease in CcO abundance and activity. Taken together, our study uncovered novel genetic regulators of mitochondrial copper homeostasis and provided a mechanism by which vacuolar pH impacts mitochondrial respiration through copper homeostasis.

NIK promotes metabolic adaptation of glioblastoma cells to bioenergetic stress.

Cancers, including glioblastoma multiforme (GBM), undergo coordinated reprogramming of metabolic pathways that control glycolysis and oxidative phosphorylation (OXPHOS) to promote tumor growth in diverse tumor microenvironments. Adaptation to limited nutrient availability in the microenvironment is associated with remodeling of mitochondrial morphology and bioenergetic capacity. We recently demonstrated that NF-κB-inducing kinase (NIK) regulates mitochondrial morphology to promote GBM cell invasion. Here, we show that NIK is recruited to the outer membrane of dividing mitochondria with the master fission regulator, Dynamin-related protein1 (DRP1). Moreover, glucose deprivation-mediated metabolic shift to OXPHOS increases fission and mitochondrial localization of both NIK and DRP1. NIK deficiency results in decreased mitochondrial respiration, ATP production, and spare respiratory capacity (SRC), a critical measure of mitochondrial fitness. Although IκB kinase α and ß (IKKα/ß) and NIK are required for OXPHOS in high glucose media, only NIK is required to increase SRC under glucose deprivation. Consistent with an IKK-independent role for NIK in regulating metabolism, we show that NIK phosphorylates DRP1-S616 in vitro and in vivo. Notably, a constitutively active DRP1-S616E mutant rescues oxidative metabolism, invasiveness, and tumorigenic potential in NIK-/- cells without inducing IKK. Thus, we establish that NIK is critical for bioenergetic stress responses to promote GBM cell pathogenesis independently of IKK. Our data suggest that targeting NIK may be used to exploit metabolic vulnerabilities and improve therapeutic strategies for GBM.

TRMU deficiency: A broad clinical spectrum responsive to cysteine supplementation.

TRMU is a nuclear gene crucial for mitochondrial DNA translation by encoding tRNA 5-methylaminomethyl-2-thiouridylate methyltransferase, which thiolates mitochondrial tRNA. Biallelic pathogenic variants in TRMU are associated with transient infantile liver failure. Other less common presentations such as Leigh syndrome, myopathy, and cardiomyopathy have been reported. Recent studies suggested that provision of exogenous L-cysteine or N-acetylcysteine may ameliorate the effects of disease-causing variants and improve the natural history of the disease. Here, we report six infants with biallelic TRMU variants, including four previously unpublished patients, all treated with exogenous cysteine. We highlight the first report of an affected patient undergoing orthotopic liver transplantation, the long-term effects of cysteine supplementation, and the ability of the initial presentation to mimic multiple inborn errors of metabolism. We propose that TRMU deficiency should be suspected in all children presenting with persistent lactic acidosis and hypoglycemia, and that combined N-acetylcysteine and L-cysteine supplementation should be considered prior to molecular diagnosis, as this is a low-risk approach that may increase survival and mitigate the severity of the disease course.

Is mitochondrial bioenergetics and coenzyme Q10 the target of a virus causing COVID-19?

COVID-19 ‒ a coronavirus disease, affected almost all countries in the world. It is a new virus disease, nobody has prior immunity to it, human population is prone to infections. In March 11 2020, WHO declared the pandemic status. The main symptoms include: fever, dry cough and fatigue. Virus proteins need mitochondrial energy for their own survival and replication. Upon viral infections, mitochondrial dynamics and metabolism can be modulated, which can influence the energy production in the host cells. Coenzyme Q10 is an integral component of mitochondrial respiratory chain and the key component of mitochondrial ATP production. The exact pathobiochemical mechanism of the disease is unknown. Modulated mitochondrial dynamics and metabolism with lower CoQ10 levels in viral infections leads us to the hypothesis that one of the main pathobiochemical effects of SARS-Cov-2 virus could be mitochondrial bioenergetics dysfunction with CoQ10 deficit leading to the reduction of its endogenous biosynthesis. The mechanism might be virus induced oxidative stress causing a mutation of one or more of the nine COQ genes, resulting in primary CoQ10 deficiency. New perspective for patients with COVID-19 may be supportive targeting therapy with coenzyme Q10 to increase the energy production, immunity and decrease oxidative stress (Fig. 1, Ref. 51). Keywords: COVID-19, virus, mitochondrial bioenergetics, coenzyme Q10, oxidative stress.

An Oil Rich in γ-Linolenic Acid Differently Affects Hepatic Fatty Acid Oxidation in Mice and Rats.

The effects of different dietary fats on hepatic fatty acid oxidation were compared in male ICR mice and Sprague-Dawley rats. Animals were fed diets containing 100 g/kg of either palm oil (saturated fat), safflower oil (rich in linoleic acid), an oil of evening primrose origin (γ-linolenic acid, GLA oil), perilla oil (α-linolenic acid) or fish oil (eicosapentaenoic and doxosahexaenoic acids) for 21 d. GLA, perilla and fish oils, compared with palm and safflower oils, increased the activity of fatty acid oxidation enzymes in both mice and rats, with some exceptions. In mice, GLA and fish oils greatly increased the peroxisomal palmitoyl-CoA oxidation rate, and the activity of acyl-CoA oxidase and enoyl-CoA hydratase to the same degree. The effects were much smaller with perilla oil. In rats, enhancing effects were more notable with fish oil than with GLA and perilla oils, excluding the activity of enoyl-CoA hydratase, and were comparable between GLA and perilla oils. In mice, strong enhancing effects of GLA oil, which were greater than with perilla oil and comparable to those of fish oil, were confirmed on mRNA levels of peroxisomal but not mitochondrial fatty acid oxidation enzymes. In rats, the effects of GLA and perilla oils on mRNA levels of peroxisomal and mitochondrial enzymes were indistinguishable, and lower than those observed with fish oil. Therefore, considerable diversity in the response to dietary polyunsaturated fats, especially the oil rich in γ-linolenic acid and fish oil, of hepatic fatty acid oxidation pathway exists between mice and rats.

Caterpillar Medicinal Mushroom, Cordyceps militaris (Ascomycetes), Mycelia Attenuates Doxorubicin-Induced Oxidative Stress and Upregulates Krebs Cycle Dehydrogenases Activity and ATP Level in Rat Brain.

Post-chemotherapy-induced cognitive dysfunction remains one of the challenges in cancer survivors. Cytokine-induced neurotoxicity manifests in subjects at any time after doxorubicin (DOX) chemotherapy. We examined the effect of bioactive Cordyceps militaris mycelia extract (CM) on the energy status, oxidative stress, and acetylcholinesterase activity in the brain of DOX treated rats. The CM (150 and 300 mg/kg b.w.) and DL-α lipoic acid (LA, 100 mg/kg b.w) were administered orally once daily for 5 days to male Wistar rats prior to the DOX administration (18 mg/kg as 3 doses of 6 mg/kg, i.p. b.w.) and continued for 6 more days. Cellular antioxidant status, Krebs cycle dehydrogenases, electron transport chain complexes (ETC) (I, III, and IV), adenosine triphosphate (ATP) level, advanced oxidation of protein products (AOPP), and acetylcholinesterase (AchE) activities were determined in the brain homogenate. The DOX alone treated group of animals showed significant decrease (p < 0.05) of brain antioxidant levels, Krebs cycle dehydrogenases activities, ETC complex activities, and decreased ATP level, while lipid peroxidation and AOPP levels were elevated. CM at 300 mg/kg b.w. or LA at 100 mg/kg b.w. elevated antioxidant status, Krebs cycle dehydrogenases, and complex activities and thus alleviated the toxicity. CM also inhibited the AchE activity in brain. The experimental results thus reveal that CM possessed excellent capacity to attenuate oxidative stress, upregulate respiratory chain complex activity and ATP levels, as well as inhibition of AchE activity.

Viburnum opulus L. Juice Phenolic Compounds Influence Osteogenic Differentiation in Human Osteosarcoma Saos-2 Cells.

Bone mass loss occurs with a decrease in osteoblast proliferation and differentiation, or the enhancement of bone resorption, which further leads to the impairment of bone mineral density and increase in bone fracture. Recent studies suggest that some phenolic compounds found in food play positive role in bone metabolism. High content of phenolic compounds with potential beneficial effects on bone metabolism have been identified in the Viburnum opulus fruit. The aim of the study was to determine the influence of V. opulus fresh juice (FJ) and juice purified by solid phase extraction (PJ) on osteogenesis processes with osteosarcoma Saos-2 cell lines. V. opulus purified juice revealed stronger potential as an inducer of Saos-2 osteogenic differentiation. Saos-2 cells matrix mineralization was evaluated with alkaline phosphatase (ALP) activity measurement and alizarin red S staining. Gene expression analysis showed the elevation of the mRNA levels of Runt-related transcription factor 2 (RUNX2), ALP, collagen type 1 and osteonectin, whereas the nuclear factor-κB ligand and osteoprotegerin ratio (RANKL/OPG) decreased. Furthermore, V. opulus was able to diminish the secretion of pro-inflammatory cytokines Il6 and TNFα, however had no effect on vascular endothelial growth factor (VEGF). It decreased intracellular oxidative stress and induced DNA repair, but had no effect on the growth inhibition of lactic acid beneficial microorganisms.