Subunits Of NADH Research Articles

Physioxia rewires mitochondrial complex composition to protect stem cell viability

Human induced pluripotent stem cells (hiPSCs) are an invaluable tool to study molecular mechanisms on a human background. Culturing stem cells at an oxygen level different from their microenvironmental niche impacts their viability. To understand this mechanistically, dermal skin fibroblasts of 52 probands were reprogrammed into hiPSCs, followed by either hyperoxic (20 % O2) or physioxic (5 % O2) culture and proteomic profiling. Analysis of chromosomal stability by Giemsa-banding revealed that physioxic -cultured hiPSC clones exhibited less pathological karyotypes than hyperoxic (e.g. 6 % vs. 32 % mosaicism), higher pluripotency as evidenced by higher Stage-Specific Embryonic Antigen 3 positivity, higher glucose consumption and lactate production. Global proteomic analysis demonstrated lower abundance of several subunits of NADH:ubiquinone oxidoreductase (complex I) and an underrepresentation of pathways linked to oxidative phosphorylation and cellular senescence. Accordingly, release of the pro-senescent factor IGFBP3 and β-galactosidase staining were lower in physioxic hiPSCs. RNA- and ATAC-seq profiling revealed a distinct hypoxic transcription factor-binding footprint, amongst others higher expression of the HIF1α-regulated target NDUFA4L2 along with increased chromatin accessibility of the NDUFA4L2 gene locus. While mitochondrial DNA content did not differ between groups, physioxic hiPSCs revealed lower polarized mitochondrial membrane potential, altered mitochondrial network appearance and reduced basal respiration and electron transfer capacity. Blue-native polyacrylamide gel electrophoresis coupled to mass spectrometry of the mitochondrial complexes detected higher abundance of NDUFA4L2 and ATP5IF1 and loss of incorporation into complex IV or V, respectively. Taken together, physioxic culture of hiPSCs improved chromosomal stability, which was associated with downregulation of oxidative phosphorylation and senescence and extensive re-wiring of mitochondrial complex composition.

Aged fragmented-polypropylene microplastics induced ageing statues-dependent bioenergetic imbalance and reductive stress: In vivo and liver organoids-based in vitro study

Ageing is a nature process of microplastics that occurrs daily, and human beings are inevitably exposed to aged microplastics. However, a systematic understanding of ageing status and its toxic effect is currently still lacking. In this study, plastic cup lids-originated polypropylene (PP) microplastics were UV-photoaged until the carbonyl index (CI), a canonical indicator for plastic ageing, achieved 0.08, 0.17, 0.22 and 0.28. The adverse hepatic effect of these aged PPs (aPPs) was evaluated in Balb/c mice (75 ng/mL water, about 200 particles/day) and human-originated liver organoids (LOs, 50 particles/mL, ranged from 5.94 to 13.15 ng/mL) at low-dose equivalent to human exposure level. Low-dose of aged PP could induce hepatic reductive stress both in vitro and in vivo, by elevating the NADH/NAD+ratio in a CI-dependent manner, together with hepatoxicity (indicated by increased AST secretion and cytotoxicity), and disrupted the genes encoding the nutrients transporters and NADH subunits accompanied by the restricted ATP supply, declined mitochondrial membrane potential and mitochondrial complexI/IV activities, without significant increase in MDA levels in the liver. These changes in the liver disrupted systematic metabolism, representing a circulatory panel of increases in the lactate, triglyceride, Fgf21 levels, and decreases in the pyruvate level, linked the reductive stress to the declined body weight gain but elevated hepatic NADH contents following aPPs exposure. Additionally, assessing by the LOs, it was found that digestion drastically accelerated the ageing of aPPs and worsen the energy supply upon mitochondria, representing a “scattergun effect” induced by the formation of micro- and nano-plastics mixture toward NADH/NAD+imbalance.

CISD3/MiNT is required for complex I function, mitochondrial integrity, and skeletal muscle maintenance

Mitochondria play a central role in muscle metabolism and function. A unique family of iron-sulfur proteins, termed CDGSH Iron Sulfur Domain-containing (CISD/NEET) proteins, support mitochondrial function in skeletal muscles. The abundance of these proteins declines during aging leading to muscle degeneration. Although the function of the outer mitochondrial CISD/NEET proteins, CISD1/mitoNEET and CISD2/NAF-1, has been defined in skeletal muscle cells, the role of the inner mitochondrial CISD protein, CISD3/MiNT, is currently unknown. Here, we show that CISD3 deficiency in mice results in muscle atrophy that shares proteomic features with Duchenne muscular dystrophy. We further reveal that CISD3 deficiency impairs the function and structure of skeletal muscles, as well as their mitochondria, and that CISD3 interacts with, and donates its [2Fe-2S] clusters to, complex I respiratory chain subunit NADH Ubiquinone Oxidoreductase Core Subunit V2 (NDUFV2). Using coevolutionary and structural computational tools, we model a CISD3-NDUFV2 complex with proximal coevolving residue interactions conducive of [2Fe-2S] cluster transfer reactions, placing the clusters of the two proteins 10 to 16 Å apart. Taken together, our findings reveal that CISD3/MiNT is important for supporting the biogenesis and function of complex I, essential for muscle maintenance and function. Interventions that target CISD3 could therefore impact different muscle degeneration syndromes, aging, and related conditions.

Using recent genetic history to inform conservation options of two Lesser Caymans iguana (Cyclura nubila caymanensis) populations

The Sister Islands rock iguana (Cyclura nubila caymanensis) is critically endangered and endemic to the Caribbean islands Little Cayman and Cayman Brac. The Cayman Brac population and indeed the entire species is under threat from habitat destruction, invasive species, and anthropogenic impacts on the island. We assessed the genetic diversity, estimated effective population sizes, and tested for differentiation of populations between these two islands to inform potential future translocation should this be needed for the Cayman Brac population. Two mitochondrial DNA markers (cytochrome b and NADH subunit 4) and seven DNA microsatellite markers were used to assess the genetic diversity, genetic structure, demographic history, and effective population size of the two iguana populations. Mitochondrial DNA showed no genetic differentiation between populations; however, we found little to moderate divergence with microsatellites. We compared multiple demographic scenarios and revealed that ongoing gene flow is likely. The demographic history implied a significant genetic bottleneck around 10,000 years ago, coinciding with the sea level rise at the close of the last glacial period, and the start of the Holocene. Estimates of current effective population sizes indicate a small-scale number of breeders on each island of similar magnitude to the census mature population size (between 100 and 800 individuals). The relatively low differentiation between populations supports the possible development of active genetic management plans to manage the declining populations of the Sister Islands rock iguana.

Strategies of chemolithoautotrophs adapting to high temperature and extremely acidic conditions in a shallow hydrothermal ecosystem

BackgroundActive hydrothermal vents create extreme conditions characterized by high temperatures, low pH levels, and elevated concentrations of heavy metals and other trace elements. These conditions support unique ecosystems where chemolithoautotrophs serve as primary producers. The steep temperature and pH gradients from the vent mouth to its periphery provide a wide range of microhabitats for these specialized microorganisms. However, their metabolic functions, adaptations in response to these gradients, and coping mechanisms under extreme conditions remain areas of limited knowledge. In this study, we conducted temperature gradient incubations of hydrothermal fluids from moderate (pH = 5.6) and extremely (pH = 2.2) acidic vents. Combining the DNA-stable isotope probing technique and subsequent metagenomics, we identified active chemolithoautotrophs under different temperature and pH conditions and analyzed their specific metabolic mechanisms.ResultsWe found that the carbon fixation activities of Nautiliales in vent fluids were significantly increased from 45 to 65 °C under moderately acidic condition, while their heat tolerance was reduced under extremely acidic conditions. In contrast, Campylobacterales actively fixed carbon under both moderately and extremely acidic conditions under 30 − 45 °C. Compared to Campylobacterales, Nautiliales were found to lack the Sox sulfur oxidation system and instead use NAD(H)-linked glutamate dehydrogenase to boost the reverse tricarboxylic acid (rTCA) cycle. Additionally, they exhibit a high genetic potential for high activity of cytochrome bd ubiquinol oxidase in oxygen respiration and hydrogen oxidation at high temperatures. In terms of high-temperature adaption, the rgy gene plays a critical role in Nautiliales by maintaining DNA stability at high temperature. Genes encoding proteins involved in proton export, including the membrane arm subunits of proton-pumping NADH: ubiquinone oxidoreductase, K+ accumulation, selective transport of charged molecules, permease regulation, and formation of the permeability barrier of bacterial outer membranes, play essential roles in enabling Campylobacterales to adapt to extremely acidic conditions.ConclusionsOur study provides in-depth insights into how high temperature and low pH impact the metabolic processes of energy and main elements in chemolithoautotrophs living in hydrothermal ecosystems, as well as the mechanisms they use to adapt to the extreme hydrothermal conditions.4ap83QbxwyKb6GHBwDJLyuVideo

Application of Flow Cytometric Analysis for Measuring Multiple Mitochondrial Parameters in 3D Brain Organoids.

Mitochondrial dysfunction is a common primary or secondary contributor to many types of neurodegeneration, and changes in mitochondrial mass, mitochondrial respiratory chain (MRC) complexes, and mitochondrial DNA (mtDNA) copy number often feature in these processes. Human brain organoids derived from human induced pluripotent stem cells (iPSCs) recapitulate the brain's three-dimensional (3D) cytoarchitectural arrangement and offer the possibility to study disease mechanisms and screen new therapeutics in a complex human system. Here, we report a unique flow cytometry-based approach to measure multiple mitochondrial parameters in iPSC-derived cortical organoids. This report details a protocol for generating cortical brain organoids from iPSCs, single-cell dissociation of generated organoids, fixation, staining, and subsequent flow cytometric analysis to assess multiple mitochondrial parameters. Double staining with antibodies against the MRC complex subunit NADH: Ubiquinone Oxidoreductase Subunit B10 (NDUFB10) or mitochondrial transcription factor A (TFAM) together with voltage-dependent anion-selective channel 1 (VDAC 1) permits assessment of the amount of these proteins per mitochondrion. Since the quantity of TFAM corresponds to the amount of mtDNA, it provides an indirect estimation of the number of mtDNA copies per mitochondrial content. This entire procedure can be completed within a span of 2-3 h. Crucially, it allows for the concurrent quantification of multiple mitochondrial parameters, including both total and specific levels relative to the mitochondrial mass.

Iron status influences mitochondrial disease progression in Complex I-deficient mice.

Mitochondrial dysfunction caused by aberrant Complex I assembly and reduced activity of the electron transport chain is pathogenic in many genetic and age-related diseases. Mice missing the Complex I subunit NADH dehydrogenase [ubiquinone] iron-sulfur protein 4 (NDUFS4) are a leading mammalian model of severe mitochondrial disease that exhibit many characteristic symptoms of Leigh Syndrome including oxidative stress, neuroinflammation, brain lesions, and premature death. NDUFS4 knockout mice have decreased expression of nearly every Complex I subunit. As Complex I normally contains at least 8 iron-sulfur clusters and more than 25 iron atoms, we asked whether a deficiency of Complex I may lead to iron perturbations, thereby accelerating disease progression. Consistent with this, iron supplementation accelerates symptoms of brain degeneration in these mice, while iron restriction delays the onset of these symptoms, reduces neuroinflammation, and increases survival. NDUFS4 knockout mice display signs of iron overload in the liver including increased expression of hepcidin and show changes in iron-responsive element-regulated proteins consistent with increased cellular iron that were prevented by iron restriction. These results suggest that perturbed iron homeostasis may contribute to pathology in Leigh Syndrome and possibly other mitochondrial disorders.

A new species of bent-toed geckos of the genus Cyrtodactylus Gray, 1827 from western Arunachal Pradesh, India

A new species of bent-toed geckos of the genus Cyrtodactylus is described from western Arunachal Pradesh. The new species is a member of the Indo-Burma clade and is embedded within the “peguensis” group, a relationship deduced contingent on a partial fragment of mitochondrial NADH subunit 2 gene. Cyrtodactylus kamengensissp. nov. is morphologically similar to C. himalayicus from which it differs in bearing a distinct ventrolateral fold and 6–8 basal lamellae on digit IV of pes. Genetically, the new species is sister to the Indian lineage of the “peguensis” group containing C. bhupathyi and C. gubernatoris. The Indian lineage of the “peguensis” group diverged from its Burmese relatives during the mid-Oligocene likely followed by the beginning of the Himalayan uplift, highlighting the role of the Himalayas in the diversification of biota.

Structured phylogeography and restricted gene flow among populations of Fairy Tern (Sternula nereis) across Australasia: implications for the endangered New Zealand population

The Fairy Tern Sternula nereis is an Australasian tern that breeds in Australia, New Caledonia and New Zealand, with the last having the smallest breeding population, listed as ‘Threatened – Nationally Critical’ by the New Zealand Department of Conservation. Here, we investigate the genetic relatedness and level of endemism (gene flow) of the New Zealand Fairy Tern S. n. davisae population compared with the larger breeding populations in Australia, S. n. nereis, and New Caledonia, S. n. exsul, using the NADH subunit 2 (ND2) region of the mitochondrial DNA. We found that the three main populations (n = 86) were genetically distinct, with a different fixed haplotype restricted to New Zealand (n = 15) and New Caledonia (n = 16), and that the estimated gene flow was low to zero, indicating no interbreeding between the populations. The current genetic evidence is consistent with observations of morphological and behavioural differences among the populations, and we suggest continued independent management of the population in New Zealand and further surveys and independent management of the New Caledonia population.

Molecular data attest to the occurrence of autochthonous Daphnia pulex (Crustacea, Branchiopoda) populations in Sicily, Italy

Biological invasions are known to be among the most important threats to the long-term conservation of native biota, and their effects might be even more difficult to contrast when they are cryptic, i.e., when the non-native invaders cannot be easily recognised based on morphology, and can thus be confused with native taxa. Such cryptic invasions are known to widely occur in the cladoceran genus Daphnia O.F. Müller, 1785, so that the actual distribution and status of most species and lineages need to be checked with a genetic approach. In the frame of this work, we investigated if the Sicilian populations of D. (Daphnia) pulex Leydig, 1860 belonged to the allochthonous North American lineage, which is known to occur in several regions of the Palearctic and Afrotropical biogeographical regions, or rather to the autochthonous European lineage of the species. The molecular results obtained, based on a fragment of the mitochondrial gene encoding for NADH subunit dehydrogenase 5 (ND5), allowed us to rule out the allochthonous status of the species, confirming the presence of autochthonous relictual lineages of D. pulex in Sicily. The native status of these populations is in agreement with their local distribution, limited to natural and poorly-impacted water bodies mostly located in wooded areas at medium and high altitudes. The current local distribution of D. pulex in Sicily is possibly linked to the end of the last glacial maximum and the onset of warmer climatic conditions in the early Holocene, which led the species to take refuge in colder microthermal refugia located at high altitudes, determining their current relictual distribution.

Prenatal particulate matter exposure and mitochondrial mutational load at the maternal-fetal interface: Effect modification by genetic ancestry

Prenatal ambient particulate matter (PM2.5) exposure impacts infant development and alters placental mitochondrial DNA abundance. We investigated whether the timing of PM2.5 exposure predicts placental mitochondrial mutational load using NextGen sequencing in 283 multi-ethnic mother-infant dyads. We observed increased PM2.5exposure, particularly during mid- to late-pregnancy and among genes coding for NADH dehydrogenase and subunits of ATP synthase, was associated with a greater amount of nonsynonymous mutations. The strongest associations were observed for participants of African ancestry. Further work is needed to tease out the role of mitochondrial genetics and its impact on offspring development and emerging disease disparities.

Employing NADH Dehydrogenase Subunit 1 in the Determination of Echinococcus granulosus Strain in Sheep, Cattle and Human in Thi-Qar Province, Iraq

Echinococcosis is a zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus. This disease is an important public health and a significant economic issue in Iraq, where the lungs and livers are the popular places of infection. The aim of the current study focused on using the molecular techniques in the detection of an E. granulosus strain that causes cystic echinococcosis to human, sheep and cattle in Thi-Qar province, Iraq. In the current study, thirty isolates of E. granulosus were collected from 10 human hydatid cysts through surgery done at Al-Hussein Imam Teaching Hospital in Thi-Qar province and 10 sheep with 10 cattle hydatid cysts were obtained from the slaughterhouse in Thi-Qar province, Southern of Iraq to identify strains of E. granulosus which infect human and other intermediate hosts (sheep and cattle). The molecular study was carried out on the isolates and a specific primer set for the mitochondrial dehydrogenase NADH subunit 1 (NAD1) gene was used. This primer set was amplified 400 bp of the NAD1 gene in all selected isolates. The PCR products for the twelve selected isolates of E. granulosus (4 isolates per intermediate host) were sequenced and the results for these twelve isolates showed that all sequenced isolates, except one isolate Eg_5, belonged to the sheep strain G1 and a slight genetic diversity was observed with the reference sequences of the strain G1. The exception was in the isolate Eg_5 isolated from a cattle liver, which was similar to the buffalo strain G3. This study concludes that the common E. granulosus strain in Thi-Qar province is G1.

The NDUFS4 Knockout Mouse: A Dual Threat Model of Childhood Mitochondrial Disease and Normative Aging.

Mice missing the Complex I subunit NADH:Ubiquinone Oxidoreductase Fe-S Protein 4 (NDUFS4) of the electron transport chain are a leading model of the severe mitochondrial disease Leigh syndrome. These mice have enabled a better understanding of mitochondrial dysfunction in human disease, as well as in the discovery of interventions that can potentially suppress mitochondrial disease manifestations. In addition, increasing evidence suggests significant overlap between interventions that increase survival in NDUFS4 knockout mice and that extend life span during normative aging. This chapter discusses the practical aspects of handling and studying these mice, which can be challenging due to their severe disease phenotype. Common procedures such as breeding, genotyping, weaning, or treating these transgenic mice are also discussed.

Ndufa7 plays a critical role in cardiac hypertrophy.

Cardiac hypertrophy is a common pathological change in patients with progressive cardiac function failure, which can be caused by hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) or arterial hypertension. Despite years of study, there is still limited knowledge about the underlying molecular mechanisms for cardiac hypertrophy. NDUFA7, a subunit of NADH:ubiquinone oxidoreductase (complex I), has been reported to be a novel HCM associated gene. However, the biological role of NDUFA7 in heart remains unknown. In this study, we found that NDUFA7 exhibited high expression in the heart, and its level was significantly decreased in mice model of cardiac hypertrophy. Moreover, we demonstrated that ndufa7 knockdown in developing zebrafish embryos resulted in cardiac development and functional defects, associated with increased expression of pathological hypertrophy biomarkers nppa (ANP) and nppb (BNP). Mechanistic study demonstrated that ndufa7 depletion promoted ROS production and calcineurin signalling activation. Moreover, NDUFA7 depletion contributed to cardiac cell hypertrophy. Together, these results report for the first time that ndufa7 is implicated in pathological cardiac hypertrophy.

Molecular characterization of human Echinococcus isolates and the first report of E. canadensis (G6/G7) and E. multilocularis from the Punjab Province of Pakistan using sequence analysis

BackgroundEchinococcosis is a zoonotic parasitic disease causing serious health problems in both humans and animals in different endemic regions across the world. There are two different forms of human echinococcosis: Cystic Echinococcosis (CE) and Alveolar Echinococcosis (AE). CE is caused by the larval stage of Echinococcus granulosus sensu lato and AE by the larval stage of Echinococcus multilocularis. Geographically, CE is universally distributed, while AE is prevalent in the northern hemisphere. Although the disease is endemic in neighboring countries (China, Iran and India) of Pakistan, there are limited reports from that country. Besides, there are no comprehensive data on the genotyping of Echinococcus species in humans based on sequence analysis. This study aimed to detect the presence of human CE and to identify Echinococcus spp. in human isolates through genetic characterization of hydatid cysts in the Punjab Province of Pakistan.MethodsGenetic analysis was performed on 38 human hydatid cyst samples collected from patients with echinococcosis using mitochondrial cytochrome c oxidase subunit 1 (cox1), cytochrome b (cytb) and NADH subunit 1 (nad1). Patient data including age, epidemiological history, sex, and location were obtained from hospital records.ResultsAccording to the sequence analysis we detected E. granulosus sensu stricto (n = 35), E. canadensis (G6/G7) (n = 2), and E. multilocularis (n = 1). Thus, the majority of the patients (92.1%, 35/38) were infected with E. granulosus s.s. This is the first molecular confirmation of E. canadensis (G6/G7) and E. multilocularis in human subjects from Pakistan.ConclusionsThese findings suggested that E. granulosus s.s. is the dominant species in humans in Pakistan. In addition, E. canadensis (G6/G7) and E. multilocularis are circulating in the country. Further studies are required to explore the genetic diversity in both humans and livestock.

New and Old World phylogeography of pumpkinseed Lepomis gibbosus (Linnaeus, 1758): the North American origin of introduced populations in Europe

To determine the origin of introduced European populations of pumpkinseed Lepomis gibbosus (Linnaeus, 1758)—a freshwater sunfish, native to eastern North America that has spread across western and central Europe—we investigated the phylogeography of the species by sequencing the mitochondrial NADH subunit 1 gene. A total of 543 pumpkinseeds were sampled from 32 sites across the native range of the species, and from 19 sites covering much of its introduced European range. The presence and geographic distribution of two distinct clades in North American populations were discovered, suggesting that pumpkinseed survived the Pleistocene glaciations in two refugia (Atlantic and Mississippian). Analyses of mitochondrial variation revealed that European pumpkinseed may have been introduced to Europe from at least two distinct sources, but from the Atlantic drainages of North America only, which is consistent with historical records. Within Europe, haplotype distributions of pumpkinseed lend support to the entry of non-native fishes into Iberia via the so-called Perpignan–Barcelona corridor. European populations possessed lower genetic diversity than populations from North America, suggesting that low genetic diversity may not preclude a species from establishing and spreading into new environments outside of their native range.

Mitochondrial DNA Variants in Patients with Liver Injury Due to Anti-Tuberculosis Drugs.

Background: Hepatotoxicity is the most severe adverse effect of anti-tuberculosis therapy. Isoniazid’s metabolite hydrazine is a mitochondrial complex II inhibitor. We hypothesized that mitochondrial DNA variants are risk factors for drug-induced liver injury (DILI) due to isoniazid, rifampicin or pyrazinamide. Methods: We obtained peripheral blood from tuberculosis (TB) patients before anti-TB therapy. A total of 38 patients developed DILI due to anti-TB drugs. We selected 38 patients with TB but without DILI as controls. Next-generation sequencing detected point mutations in the mitochondrial DNA genome. DILI was defined as ALT ≥5 times the upper limit of normal (ULN), or ALT ≥3 times the ULN with total bilirubin ≥2 times the ULN. Results: In 38 patients with DILI, the causative drug was isoniazid in eight, rifampicin in 14 and pyrazinamide in 16. Patients with isoniazid-induced liver injury had more variants in complex I’s NADH subunit 5 and 1 genes, more nonsynonymous mutations in NADH subunit 5, and a higher ratio of nonsynonymous to total substitutions. Patients with rifampicin- or pyrazinamide-induced liver injury had no association with mitochondrial DNA variants. Conclusions: Variants in complex I’s subunit 1 and 5 genes might affect respiratory chain function and predispose isoniazid-induced liver injury when exposed to hydrazine, a metabolite of isoniazid and a complex II inhibitor.

A Mitochondrial Phylogeny of the Sand Cat (Felis margarita Loche, 1858)

The sand cat, Felis margarita Loche, 1858, is a small desert cat with a fragmented distribution across the Sahara, Arabian Peninsula, and Central Asia. It is currently listed as Least Concern by the IUCN; however, its status in many countries is unknown. Sand cats are generally classified into four subspecies: F. m. margarita (North Africa and Sahara), F. m. harrisoni (Arabia), F. m. thinobia (Central Asia), and F. m. scheffeli (Pakistan). The aim of this study was to determine the validity of these subspecies using genetic analysis. Sequences from the mitochondrial control region, mitochondrial NADH subunit 5, and cytochrome b genes (643 bp) were generated in a sample set of 47 animals of known geographical origin, from across the sand cat’s range over the past 100 years. The results of the analysis suggest some degree of genetic differentiation between the African populations (F. m. margarita) and those of Arabian or Central Asian origin, which merits further investigation with nuclear loci and further sampling of intermediate geographical locations. There is little genetic justification for differentiation of the other proposed subspecies (F. m. harrisoni, F. m. thinobia, and F. m. scheffeli), which differ only by 1–3 bp mutations in their haplotypes. The genetic diversity of a set of 86 captive sand cat samples is also generated and compared to facilitate future conservation management of the species in captivity.

Abstract 1119: S100A4 alters mitochondrial metabolism to promote invasion and metastasis of non-small cell lung cancer cells through upregulation of NDUFS2

Abstract It is generally accepted that alterations in metabolism are critical for the metastatic process; however, the mechanisms by which the metabolic changes are controlled by the major drivers of the metastatic process remain elusive. Here, we find that S100A4, a major metastasis-promoting protein, alters metabolic plasticity to drive tumor invasion and metastasis. Investigating how S100A4 regulates metabolism, we find that depletion of S100A4 decreases oxygen consumption rate, mitochondrial activity, and ATP production, and shifts cell metabolism to be more glycolytically active. We further identify that the 49 KD mitochondrial complex I subunit NADH dehydrogenase (ubiquinone) Fe-S protein 2 (NDUFS2) is regulated in an S100A4-dependent manner and that S100A4 and NDUFS2 exhibit co-occurrence at significant levels in various cancer types (cBioPortal). Importantly, we find that knockdown of NDUFS2 inhibits mitochondrial complex I activity, reduces cellular ATP level, and decreases the invasive capacity in three-dimensional (3D) growth, thus mimicking the biological effect resulting from S100A4 knockdown in A549 cells. Likewise, silencing S100A4 and NDUFS2 dramatically decreases the rate of metastasis as well as tumor growth in vivo. Finally, we provide evidence that cells with S100A4 and NDUFS2 depletion shift metabolism toward glycolysis through upregulating hexokinases expression and that suppressing S100A4 signaling sensitizes lung cancer cells to glycolysis inhibition. Together, our findings uncover a novel function of S100A4 in mitochondrial metabolism and highlight the importance of NDUFS2 in regulating the plasticity of mitochondrial metabolism by S100A4 to promote the invasion and metastasis in lung cancer. Citation Format: Lili Liu, Lei Qi, Teresa Knifley, Dava W. Piecoro, Piotr Rychahou, Jinpeng Liu, Mihail I. Mitov, Jeremiah Martin, Chi Wang, Jianrong Wu, Heidi L. Weiss, D. Allan Butterfield, B. Mark Evers, Kathleen L. O'Connor, Min Chen. S100A4 alters mitochondrial metabolism to promote invasion and metastasis of non-small cell lung cancer cells through upregulation of NDUFS2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1119.

Phylogeny of Thripophagini ovenbirds (Aves: Synallaxinae: Furnariidae)

AbstractIn this study, we address the evolutionary relationships and discuss the biogeographical history of a complex and diverse group of ovenbirds, the Thripophagini. We reconstruct the phylogeny and estimate the time of divergence of this group, using sequences from two complete mitochondrial genes (cytochrome b and NADH subunit 2) from a total of 115 fresh tissue samples. The results provide a better understanding of the phylogenetic relationships of the taxa within this group, some of which require a thorough taxonomic revision. We discuss the biogeographical history of the group, and find parallels with other previously studied Andean birds which may indicate that tectonic and climatic events might, at least in part, be linked to its diversification through the uplift of the Andes, the creation of new montane habitats and barriers, the evolution of Amazonian drainages and landscapes, and the climatic oscillations of the Pleistocene.