Inhibitory Factor-1 Research Articles

Gene Methylation and Silencing of WIF1 Is a Frequent Genetic Abnormality in Mantle Cell Lymphoma.

We have previously shown that the Wnt canonical pathway (WCP) is constitutively active in most cases of mantle cell lymphoma (MCL). Here, we aimed to elucidate the mechanisms underlying this biochemical deregulation. We hypothesized that gene methylation/silencing of WIF1 (Wnt inhibitory factor-1), a physiologic inhibitor of WCP, contributes to the deregulation of WCP and promotes cell growth in MCL. In support of this hypothesis, we found that the expression of WIF1 was detectable in none of the 4 MCL cell lines, and in only 2 of 5 tumors (40%) examined. Using methylation-specific PCR, we found evidence of gene methylation of WIF1 in 4 of 5 cell lines (80%) and in 24 of 29 (82%) tumors. The addition of the demethylation agent 5-aza-2′-deoxycytidine to Mino and JeKo-1, two WIF1-negative cell lines, restored the expression of WIF1 mRNA in these cells. Gene transfection of WIF1 into JeKo-1 and Mino cells significantly reduced cell growth, and this finding correlated with substantial downregulations of various proteins in WCP, such as β-catenin and pGSK-3β. In conclusion, our results support the concept that gene methylation/silencing of WIF1 is a frequent event in MCL, and this abnormality contributes to the aberrant activation of WCP. These results have provided further evidence that aberrant Wnt signaling is pathogenetically important in MCL and it may represent a potential therapeutic target.

NH‐sulfoximine: A novel pharmacological inhibitor of the mitochondrial F1Fo‐ATPase, which suppresses viability of cancerous cells

Background and PurposeThe mitochondrial F1Fo‐ATPsynthase is pivotal for cellular homeostasis. When respiration is perturbed, its mode of action everts becoming an F1Fo‐ATPase and therefore consuming rather producing ATP. Such a reversion is an obvious target for pharmacological intervention to counteract pathologies. Despite this, tools to selectively inhibit the phases of ATP hydrolysis without affecting the production of ATP remain scarce. Here, we report on a newly synthesised chemical, the NH‐sulfoximine (NHS), which achieves such a selectivity.Experimental ApproachThe chemical structure of the F1Fo‐ATPase inhibitor BTB‐06584 was used as a template to synthesise NHS. We assessed its pharmacology in human neuroblastoma SH‐SY5Y cells in which we profiled ATP levels, redox signalling, autophagy pathways and cellular viability. NHS was given alone or in combination with either the glucose analogue 2‐deoxyglucose (2‐DG) or the chemotherapeutic agent etoposide.Key ResultsNHS selectively blocks the consumption of ATP by mitochondria leading a subtle cytotoxicity associated via the concomitant engagement of autophagy which impairs cell viability. NHS achieves such a function independently of the F1Fo‐ATPase inhibitory factor 1 (IF1).Conclusion and ImplicationsThe novel sulfoximine analogue of BTB‐06584, NHS, acts as a selective pharmacological inhibitor of the mitochondrial F1Fo‐ATPase. NHS, by blocking the hydrolysis of ATP perturbs the bioenergetic homoeostasis of cancer cells, leading to a non‐apoptotic type of cell death.

Associations of content and gene polymorphism of macrophage inhibitory factor-1 and chronic hepatitis C virus infection.

BACKGROUNDThe expression of macrophage inhibitory factor-1 (MIC-1) is increased in peripheral blood of patients with chronic hepatitis and liver cirrhosis. However, whether MIC-1 gene polymorphism is correlated with relevant diseases is not yet reported.AIMTo explore the correlation between gene polymorphism in MIC-1 exon region and chronic hepatitis C virus (HCV) infection.METHODSThis case-control study enrolled 178 patients with chronic hepatitis C (CHC) in the case group, and 82 healthy subjects from the same region who had passed the screening examination comprised the control group. The genotypes of rs1059369 and rs1059519 loci in the MIC-1 gene exon were detected by DNA sequencing. Also, the MIC-1 level, liver function metrics, liver fibrosis metrics, and HCV RNA load were determined. Univariate analysis was used to compare the differences and correlations between the two groups with respect to these parameters. Multivariate logistic regression was used to analyze the independent relevant factors of CHC.RESULTSThe plasma MIC-1 level in the CHC group was higher than that in the control group (P < 0.05), and it was significantly positively correlated with alanine aminotransferase, aspartate aminotransferase (AST), type III procollagen N-terminal peptide (known as PIIINP), type IV collagen, and HCV RNA (P < 0.05), whereas negatively correlated with total protein and albumin (P < 0.05). The genotype and allele frequency distribution at the rs1059519 locus differed between the two groups (P < 0.05). The allele frequency maintained significant difference after Bonferroni correction (Pc < 0.05). Logistic multiple regression showed that AST, PIIINP, MIC-1, and genotype GG at the rs1059519 locus were independent relevant factors of CHC (P < 0.05). Linkage disequilibrium (LD) was found between rs1059369 and rs1059519 loci, and significant difference was detected in the distribution of haplotype A-C between the CHC and control groups (P < 0.05). Meanwhile, we found the MIC-1 level trend to increase among rs1059519 genotypes (P = 0.006) and the level of MIC-1 in GG genotype to be significantly higher than CC genotype (P = 0.009, after Bonferroni correction).CONCLUSIONPlasma MIC-1 level was increased in CHC patients and correlated with liver cell damage, liver fibrosis metrics, and viral load. The polymorphism at the MIC-1 gene rs1059519 locus was correlated with HCV infection, and associated with the plasma MIC-1 level. G allele and GG genotype may be an important susceptible factor for CHC.

Dietary cholesterol supplementation and inhibitory factor 1 serum levels in two dizygotic Smith-Lemli-Opitz syndrome twins: a case report

BackgroundSmith-Lemli-Opitz syndrome (SLOS) is a rare genetic neurodevelopmental disorder caused by the defect in the 7-dehydrocholesterol reductase. This defect leads to the deficiency of cholesterol biosynthesis with accumulation of 7-dehydrocholesterol. Inhibitory factor 1 (IF1) is a well-known mitochondrial protein. Recently, it has been discovered in the human serum where it is reported to be involved in the HDL-cholesterol intake. Here we report the IF1 presence in the serum of two paediatric SLOS dizygotic twins treated with dietary cholesterol supplementation.Case presentationThe patients showed a typical phenotype. They started dietary supplementation with cholesterol when 2 months old. The cholesterol intake was periodically titrated on the basis of weight increase and the twin 1 required a larger supplementation than the twin 2 during the follow-up. When 6.4-year-old, they underwent IF1 assay that was 7-fold increased in twin 2 compared to twin 1 (93.0 pg/ml vs 13.0 pg/ml, respectively).ConclusionsWe report, for the first time, the presence of circulating IF1 in the serum of SLOS patients, showing different levels among them. Our findings confirm that IF1 could be a novel research target in cholesterol-related disorders and also in SLOS, and could contribute to the general debate on IF1 as a new modulator of cholesterol levels.

Analysis of translating mitoribosome reveals functional characteristics of translation in mitochondria of fungi

Mitoribosomes are specialized protein synthesis machineries in mitochondria. However, how mRNA binds to its dedicated channel, and tRNA moves as the mitoribosomal subunit rotate with respect to each other is not understood. We report models of the translating fungal mitoribosome with mRNA, tRNA and nascent polypeptide, as well as an assembly intermediate. Nicotinamide adenine dinucleotide (NAD) is found in the central protuberance of the large subunit, and the ATPase inhibitory factor 1 (IF1) in the small subunit. The models of the active mitoribosome explain how mRNA binds through a dedicated protein platform on the small subunit, tRNA is translocated with the help of the protein mL108, bridging it with L1 stalk on the large subunit, and nascent polypeptide paths through a newly shaped exit tunnel involving a series of structural rearrangements. An assembly intermediate is modeled with the maturation factor Atp25, providing insight into the biogenesis of the mitoribosomal large subunit and translation regulation.

Jinmaitong ameliorates diabetes-induced peripheral neuropathy in rats through Wnt/β-catenin signaling pathway

Ethnopharmacological relevanceJinmaitong (JMT) is a prescription of Traditional Chinese Medicine, which is composed of ten herbal drugs and two animal drugs. It has long been used for the treatment of diabetic peripheral neuropathy (DPN). Aim of studyWnt/β-catenin pathway is considered as an essential and direct driver of myelinogenesis. This study aims to evaluate the protective effect of JMT against DPN dynamically during a 16-weeks’ treatment, and to investigate the underlying mechanism in which the Wnt/β-catenin pathway is involved. Materials and methodsDiabetic model was induced by single intraperitoneal injection of Streptozotocin (STZ) using male Sprague-Dawley rats. The model rats were divided into five groups and administrated with JMT at three doses (0.437, 0.875, and 1.75 g/kg per day), neurotropin (positive drug, 2.67 NU/kg per day), and placebo (deionized water), respectively, for continuous 8 weeks (n = 9–10), 12 weeks (n = 8–10), or 16 weeks (n = 7–9). Meanwhile, rats in control group were administrated with placebo (n = 10 for 8 weeks, n = 9 for 12 and 16 weeks, respectively). Blood glucose and body weight were monitored every four weeks. Mechanical allodynia was assessed using mechanical withdrawal threshold (MWT) test. The morphological change of sciatic nerves were observed by transmission electron microscope (TEM) and hematoxylin and eosin (HE) stain. The mRNA and protein levels of targeted genes were evaluated by quantitative real time-PCR and western bolt, respectively. Myelin protein zero (MPZ) and mediators involved in Wnt/β-catenin pathway, such as β-catenin, glycogen synthase kinase 3β (GSK-3β), and WNT inhibitory factor-1 (WIF-1), were compared among different groups after treatment of 8, 12, and 16 weeks, respectively. ResultsThe mechanical allodynia and peripheral nerve morphology were degenerated in DPN rats over time, and notably improved after JMT-treatment of 12 and 16 weeks. The decreased MPZ level in DPN rats were also significantly amended by JMT. More importantly, we found that the suppressed Wnt/β-catenin pathway in sciatic nerves of DPN rats was overtly up-regulated by JMT in a time-dependent manner. Among the three doses, JMT at the middle dose showed the best effect. ConclusionsJMT effectively ameliorated diabetic-induced peripheral neuropathy, which was mediated by the activation of Wnt/β-catenin signaling pathway. This study provided new perspective to understand the neuroprotective mechanism of JMT.

Changes of WIF-1 and WT-1 genes expression following the anti-cancer effects of omega-3 and omega-6 on gastric cancer cells

Gastric cancer is one of the most common cancers. Environmental factors, especially diet, play an important role in causing gastric cancer. The omega-3 (ω−3) and omega-6 (ω−6) from the polyunsaturated fatty acids (PUFAs) group as the natural compounds indicated significant effects on inhibiting various types of tumors. In this study, we investigated the anti-cancer properties of ω−3 and ω−6 on gastric cancer cells with focusing on WNT signaling pathway via WNT inhibitory Factor-1 (WIF-1) and The Wilms Tumor-1 (WT-1) genes.AGS cells were used to investigate the effects of ω−3 and ω−6 on cell viability, apoptosis and the expression of WIF-1 and WT-1 genes in gastric cancer. AGS cells were treated with different concentrations of ω−3 and ω−6 for 24, 48, and 72 h, and then cell viability was assessed by MTT assay. The apoptosis rate was assessed using the flow cytometery test in every three times. The mRNA expression of WIF-1 and WT-1 were examined by quantitative real-time PCR (qRT-PCR).Our study revealed that ω−3 and ω−6 provide various antitumor activities such as inhibition of cell viability in a dose and time-dependent manner. The results of flow cytometery showed that cytotoxicity effects are due to the ability of ω−3 and ω−6 to induce apoptosis. In addition, ω−3 and ω−6 significantly increased the expression of WIF-1, whereas WT-1 level decreased in AGS cells compared to the control group.These results suggested that ω−3 and ω−6 can serve as therapeutics in against gastric cancer by targeting of the WNT signaling pathway.

Coordinate \u03b2-adrenergic inhibition of mitochondrial activity and angiogenesis arrest tumor growth

Mitochondrial metabolism has emerged as a promising target against the mechanisms of tumor growth. Herein, we have screened an FDA-approved library to identify drugs that inhibit mitochondrial respiration. The β1-blocker nebivolol specifically hinders oxidative phosphorylation in cancer cells by concertedly inhibiting Complex I and ATP synthase activities. Complex I inhibition is mediated by interfering the phosphorylation of NDUFS7. Inhibition of the ATP synthase is exerted by the overexpression and binding of the ATPase Inhibitory Factor 1 (IF1) to the enzyme. Remarkably, nebivolol also arrests tumor angiogenesis by arresting endothelial cell proliferation. Altogether, targeting mitochondria and angiogenesis triggers a metabolic and oxidative stress crisis that restricts the growth of colon and breast carcinomas. Nebivolol holds great promise to be repurposed for the treatment of cancer patients.

A reference measurement of circulating ATPase inhibitory factor 1 (IF1) in humans by LC-MS/MS: Comparison with conventional ELISA

ATPase inhibitory factor 1 (IF1) is a 9.5 kDa protein that binds to mitochondrial and plasma membrane ATP synthase and selectively inhibits ATP hydrolysis. Recently, IF1 was identified in systemic circulation in humans. IF1 appeared as an independent determinant of HDL-cholesterol with lower levels in coronary heart disease (CHD) patients. Moreover, IF1 was also found to negatively associate with mortality in these patients, supporting the notion that circulating IF1 could be a promising biomarker of cardiovascular disease. However, in previous studies, IF1 was quantified by a non-standardized competitive enzyme-linked immunosorbent assay (ELISA). Herein, we have validated a liquid chromatography–tandem mass spectrometry method (LC-MS/MS) enabling the accurate quantification of IF1 in human plasma. Plasma IF1 was trypsin-digested through an optimized procedure before LC-MS/MS analysis. The method was successfully validated over 4 independent experiments into the range of 100-1500 ng/mL. Intra- and inter-assay variation coefficients had never exceeded 14.2% and accuracy ranged between 95% and 102% for the selected EAGGAFGK peptide marker. Subsequently, the results of the LC-MS/MS method were compared with those obtained using ELISA in 204 individuals from the GENES study. We found that IF1 plasma levels obtained using both techniques were strongly correlated (r = 0.89, p < 0.0001), while the Bland-Altman plot did not indicate any major statistically significant differences. To clinically validate LC-MS/MS, we confirmed the positive correlation between IF1 plasma levels and HDL-cholesterol (r = 0.38, p < 0.0001). Besides, we found lower IF1 plasma levels in CHD patients compared to controls (431 ± 132 ng/mL and 555 ± 173 ng/mL, respectively; p < 0.0001). Hence, it can be concluded that the presented LC-MS/MS analytical method provides a highly specific strategy for IF1 quantification in human plasma and could be proposed as a reference method.

ATPase Inhibitory Factor 1 Promotes Hepatocellular Carcinoma Progression After Insufficient Radiofrequency Ablation, and Attenuates Cell Sensitivity to Sorafenib Therapy.

Epithelial-mesenchymal transition (EMT) and angiogenesis is involved in tumor progression after radiofrequency ablation (RFA). ATPase inhibitory factor 1 (IF1) is a bad predictor of prognosis. Sorafenib inhibited EMT of hepatocellular carcinoma (HCC) after RFA. Whether IF1 promotes the EMT and angiogenesis of HCC and attenuates the effect of sorafenib after insufficient RFA is investigated. In this study, higher expression of IF1 was found in residual tumor after insufficient RFA. Hep3B or Huh7 cells after insufficient RFA were designated as Hep3B-H or Huh7-H cells in vitro. Hep3B-H or Huh7-H cells exhibited enhanced capacities of colony formation, migration, and increased expression of EMT associated markers and IF1 compared with Hep3B or Huh7 cells. IF1 knockdown in Hep3B-H or Huh7-H cells decreased the colony formation and migratory capacity, and IF1 overexpression in Hep3B or Huh7 cells increased these capacities. IF1 in HCC cells directly and indirectly affected angiogenesis of TAECs after insufficient RFA. IF1 promoted HCC cells growth and metastasis after insufficient RFA. IF1 increased HCC cells resistance after insufficient RFA to sorafenib. Higher IF1 expression indicated poor disease survival in HCC patients after sorafenib therapy. NF-κB activation induced by IF1 attenuated the effect of sorafenib on HCC cells after insufficient RFA. Our results demonstrated that IF1 promotes the EMT and angiogenesis, and attenuates HCC cell sensitivity to sorafenib after insufficient RFA through NF-κB signal pathway.

Purified anacardic acids exert multiple neuroprotective effects in pesticide model of Parkinson's disease: in vivo and in silico analysis.

Parkinson's disease (PD) induced by environmental toxins involves a multifactorial cascade of harmful factors, thus motivating the search for therapeutic agents able to act on the greatest number of molecular targets. This study evaluated the efficacy of 50 mg/kg purified anacardic acids (AAs), isolated from cashew nut shell liquid, on multiple steps of oxidative stress and inflammation induced by rotenone in the substantia nigra (SN) and striatum. Adult mice were divided into four groups: Control, rotenone, AAs + rotenone, and AAs alone. Lipoperoxidation, nitric oxide (NO) levels, and reduced glutathione (GSH)/oxidized gluthatione (GSSG) ratio were evaluated. NF-kB-p65, pro-IL-1β, cleaved IL-1β, metalloproteinase-9, Tissue Inhibitory Factor-1 (TIMP-1), tyrosine hydroxylase (TH), and glial fibrillary acidic protein (GFAP) levels were assessed by Western blot. In silico studies were also made using the SwissADME web tool. Rotenone increased lipoperoxidation and NO production and reduced TH levels and GSH/GSSG ratio in both SN and striatum. It also enhanced NF-kB-p65, pro, and cleaved IL-1β, MMP-9, GFAP levels compared to control and AAs groups. The AAs alone reduced pro-IL-1β in the striatum while they augmented TIMP1 and reduced MMP-9 amounts in both regions. AAs reversed rotenone-induced effects on lipoperoxidation, NO production, and GSH/GSSG ratio, as well as increased TH and attenuated pro-IL-1β and MMP-9 levels in both regions, NF-kB-p65 in the SN and GFAP in the striatum. Altogether, the in vivo and in silico analysis reinforced multiple and defined molecular targets of AAs, identifying that they are promising neuroprotective drug candidates for PD, acting against oxidative and inflammatory conditions induced by rotenone.

SUN-126 Distinct Molecular Phenotypes of Non-Diseased Breast Adipose Tissue of Pre-Menopausal Obese and Non-Obese Women May Underlie Differing Breast Cancer Risks

Obesity is a major risk factor for many chronic diseases including postmenopausal breast cancer. Paradoxically, breast cancer susceptibility is inversely linked to obesity in pre-menopausal women. Adipose tissues are active endocrine organs that play major roles in tumor development and progression; however, fat depots at different anatomical sites are biologically and functionally distinct and their singular influence on breast epithelial biology remains unclear. To study the early events by which breast adiposity may provide a microenvironment predisposing normal breast epithelial cells to tumorigenesis, we collected breast tissue from pre-menopausal (n=10/group) non-obese (NO, BMI=27.6±0.8) and obese (O, BMI=44.5±2.8) women of comparable ages (NO: 36.1± 3.3; O: 40.0±2.0) with no breast cancer and undergoing elective breast reduction surgery. Breast adipose tissue and corresponding glandular cells were analyzed histologically and evaluated for expression of genes (adipokines, cytokines, steroid hormone signaling) by QPCR and proteins (proliferation, apoptosis, inflammation) by IHC. Adipocyte size distributions from NO and O breasts did not differ (P=0.9). However, adipose mRNA levels for pro-inflammatory cytokines (IL-6, IL-8, CSF-1, MCP-1) and adipokines (LEP, CFD) were higher for O than NO (P<0.05). AdipoQ, ER-α, and ER-β transcript levels were lower for O than NO (P<0.05), while those for CYP19 and PTGS2 showed reverse trends (O>NO, P<0.05). In the corresponding glandular cells, NO had higher mRNA levels for IL-6, IL-8, ER-α, and ER-β than O (P<0.05). Immunostaining with anti-Ki67 antibodies indicated that O glandular cells were 3-fold less proliferative than those for NO, consistent with their lower Cyclin D1 mRNA levels (P<0.05). Galectin-1, a pro-fibrotic protein, showed predominant myo- vs. luminal epithelial localization, with staining intensities for O tending to be higher (P=0.07) than for NO. Perilipin immunostaining was specific for adipocytes and did not differ for O and NO. A non-targeted approach using a Human Cytokine Array (R&D Systems) was employed to further evaluate the inflammation status of O vs. NO adipose. The analyses confirmed the higher expression of IL-8, Leptin and CFD (by QPCR) in O vs. NO and identified C-reactive protein, EMMPRIN, Trefoil Factor-3, Cystatin-3 and Macrophage Migration Inhibitory Factor-1 as greater in O than NO (~2-fold). Our findings demonstrate marked differences in gene and protein expression patterns of O and NO breast adipose tissue, which were accompanied by a suppression of proliferation of O relative to NO breast epithelium. We speculate that early exposure of the breast epithelium to a highly inflammatory environment fueled by breast adiposity may promote a senescent state that confers protection from pre-menopausal breast cancer.

Overexpression of native IF1 downregulates glucose-stimulated insulin secretion by pancreatic INS-1E cells

We have previously reported that transient knock-down of ATPase inhibitory factor 1 (IF1) by siRNA upregulates ATP levels and subsequently augments insulin secretion in model pancreatic β-cells INS-1E. Here we investigated how long-term IF1-overexpression impacts pancreatic β-cell bioenergetics and insulin secretion. We generated INS-1E cell line stably overexpressing native IF1. We revealed that IF1 overexpression leads to a substantial decrease in ATP levels and reduced glucose-stimulated insulin secretion. A decrease in total cellular ATP content was also reflected in decreased free ATP cytosolic and mitochondrial levels, as monitored with ATeam biosensor. Consistently, cellular respiration of IF1-overexpressing cells was decreased. 3D structured illumination microscopy (SIM) revealed a higher amount of insulin granules with higher volume in IF1-overexpressing cells. Similar effects occurred when cells were incubated at low glucose concentrations. Noteworthy, activation of PKA by dibutyryl cAMP entirely abolished the inhibitory effect of IF1 overexpression on ATP production and insulin secretion. Mitochondrial network morphology and cristae ultrastructure in INS-1E overexpressing IF1 remained mostly unchanged. Finally, we show that INS-1E cells decrease their IF1 protein levels relative to ATP synthase α-subunit in response to increased glucose. In conclusion, IF1 actively downregulates INS-1E cellular metabolism and reduces their ability to secrete insulin.

Sex specific effect of ATPase inhibitory factor 1 on body weight: studies in high fat diet induced obese mice and genetic association studies in humans

BackgroundBased on the metabolic effect of exogenous ATPase inhibitory factor 1 (IF1) on glucose metabolism, we tested whether IF1 treatment is effective in ameliorating weight gain and whether its effects are sex specific. MethodsHFD-fed C57BL/6 mice were treated with IF1 (5 mg/kg body weight, injected intraperitoneally). The underlying mechanisms of effect of IF1 on body weight were investigated in vitro and in vivo. Associations between genotypes of IF1 and obesity and relevant phenotype were further tested at the population level. ResultsChronic treatment with IF1 significantly decreased body weight gain by regulating food intake of HFD-fed male mice. IF1 activated the AKT/mTORC pathway and modulated the expression of appetite genes in the hypothalamus of HFD-fed male mice and its effect was confirmed in hypothalamic cell lines as well as hypothalamic primary cells. This required the interaction of IF1 with β-F1-ATPase on the plasma membrane of hypothalamic cells, which led to an increase in extracellular ATP production. In addition, IF1 treatment showed sympathetic nerve activation as measured by serum norepinephrine levels and UCP-1 expression in the subcutaneous fat of HFD-fed male mice. Notably, administration of recombinant IF1 to HFD-fed ovariectomized female mice showed remarkable reductions in food intake as well as body weight, which was not observed in wild-type 5-week female mice. Lastly, sex-specific genotype associations of IF1 with obesity prevalence and metabolic traits were demonstrated at the population level in humans. IF1 genetic variant (rs3767303) was significantly associated with lower prevalence of obesity and lower levels of body mass index, waist circumference, hemoglobin A1c, and glucose response area only in male participants. ConclusionIF1 is involved in weight regulation by controlling food intake and potentially sympathetic nerve activation in a sex-specific manner.

Highly multiplexed proteomic assessment of human bone marrow in acute myeloid leukemia

AbstractAcute myeloid leukemia (AML) is a genetically heterogeneous disease that is characterized by abnormal clonal proliferation of myeloid progenitor cells found predominantly within the bone marrow (BM) and blood. Recent studies suggest that genetic and phenotypic alterations in the BM microenvironment support leukemogenesis and allow leukemic cells to survive and evade chemotherapy-induced death. However, despite substantial evidence indicating the role of tumor–host interactions in AML pathogenesis, little is known about the complex microenvironment of the BM. To address this, we performed novel proteomic profiling of the noncellular compartment of the BM microenvironment in patients with AML (n = 10) and age- and sex-matched healthy control subjects (n = 10) using an aptamer-based, highly multiplexed, affinity proteomics platform (SOMAscan). We show that proteomic assessment of blood or RNA-sequencing of BM are suboptimal alternate screening strategies to determine the true proteomic composition of the extracellular soluble compartment of AML patient BM. Proteomic analysis revealed that 168 proteins significantly differed in abundance, with 91 upregulated and 77 downregulated in leukemic BM. A highly connected signaling network of cytokines and chemokines, including IL-8, was found to be the most prominent proteomic signature associated with AML in the BM microenvironment. We report the first description of significantly elevated levels of the myelosuppressive chemokine CCL23 (myeloid progenitor inhibitory factor-1) in both AML and myelodysplastic syndrome patients and perform functional experiments supportive of a role in the suppression of normal hematopoiesis. This unique paired RNA-sequencing and proteomics data set provides innovative mechanistic insights into AML and healthy aging and should serve as a useful public resource.

Mitochondrial ATPase inhibitor factor 1, MjATPIF1, is beneficial for WSSV replication in kuruma shrimp (Marsupenaeus japonicus)

ATPase Inhibitory Factor 1 (IF1) is a mitochondrial protein that functions as a physiological inhibitor of F1F0-ATP synthase. In the present study, a mitochondrial ATPase inhibitor factor 1 (MjATPIF1) was identified from kuruma shrimp (Marsupenaeus japonicus), which was demonstrated to participate in the viral immune reaction of white spot syndrome virus (WSSV). MjATPIF1 contained a mitochondrial ATPase inhibitor (IATP) domain, and was widely distributed in hemocytes, heart, hepatopancreas, gills, stomach, and intestine of shrimp. MjATPIF1 transcription was upregulated in hemocytes and intestines by WSSV. WSSV replication decreased after MjATPIF1 knockdown by RNA interference and increased following recombinant MjATPIF1 protein injection. Further study found that MjATPIF1 promoted the production of superoxide and activated the transcription factor nuclear factor kappa B (NF-κB, Dorsal) to induce the transcription of WSSV RNAs. These results demonstrate that MjATPIF1 benefits WSSV replication in kuruma shrimp by inducing superoxide production and NF-κB activation.

Overexpression of Mitochondrial IF1 Prevents Metastatic Disease of Colorectal Cancer by Enhancing Anoikis and Tumor Infiltration of NK Cells.

Increasing evidences show that the ATPase Inhibitory Factor 1 (IF1), the physiological inhibitor of the ATP synthase, is overexpressed in a large number of carcinomas contributing to metabolic reprogramming and cancer progression. Herein, we show that in contrast to the findings in other carcinomas, the overexpression of IF1 in a cohort of colorectal carcinomas (CRC) predicts less chances of disease recurrence, IF1 being an independent predictor of survival. Bioinformatic and gene expression analyses of the transcriptome of colon cancer cells with differential expression of IF1 indicate that cells overexpressing IF1 display a less aggressive behavior than IF1 silenced (shIF1) cells. Proteomic and functional in vitro migration and invasion assays confirmed the higher tumorigenic potential of shIF1 cells. Moreover, shIF1 cells have increased in vivo metastatic potential. The higher metastatic potential of shIF1 cells relies on increased cFLIP-mediated resistance to undergo anoikis after cell detachment. Furthermore, tumor spheroids of shIF1 cells have an increased ability to escape from immune surveillance by NK cells. Altogether, the results reveal that the overexpression of IF1 acts as a tumor suppressor in CRC with an important anti-metastatic role, thus supporting IF1 as a potential therapeutic target in CRC.

Generation of Zone-specific Hepatocyte-like Cells from Human Induced Pluripotent Stem Cells for Accurate Prediction of Drug-induced Hepatotoxicity

Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells (iPS-HLCs) are expected to be applicable to large-scale in vitro hepatotoxicity screening systems. Accordingly, methods for generating HLCs from human iPS cells have been improved over the past decade. However, although human hepatocytes have zone-specific characteristics in vivo, there is currently no technique to generate zone-specific HLCs from human iPS cells. Therefore, to generate HLCs with zone-specific properties from human iPS cells, we cultured iPS-HLCs using a parenchymal or nonparenchymal cell-conditioned medium (CM). The results showed that urea production and gluconeogenesis capacity in iPS-HLCs were increased by culturing with cholangiocyte-CM, and glutamine production and drug metabolism capacity in iPS-HLCs were increased by culturing with hepatocyte-CM. It was thus clarified that iPS-HLCs acquire zone 1 hepatocyte-like properties by culturing with cholangiocyte-CM and that iPS-HLCs acquire zone 3 hepatocyte-like properties by culturing with hepatocyte-CM. In addition, we found that WNT inhibitory factor-1 secreted from cholangiocytes, and WNT7B and WNT8B secreted from hepatocytes play important roles in the zone-specific conversion of iPS-HLCs. We hope that our findings will facilitate the application of iPS-HLCs to drug discovery research.

Structure of a mitochondrial ATP synthase with bound native cardiolipin.

The mitochondrial ATP synthase fuels eukaryotic cells with chemical energy. Here we report the cryo-EM structure of a divergent ATP synthase dimer from mitochondria of Euglena gracilis, a member of the phylum Euglenozoa that also includes human parasites. It features 29 different subunits, 8 of which are newly identified. The membrane region was determined to 2.8 Å resolution, enabling the identification of 37 associated lipids, including 25 cardiolipins, which provides insight into protein-lipid interactions and their functional roles. The rotor-stator interface comprises four membrane-embedded horizontal helices, including a distinct subunit a. The dimer interface is formed entirely by phylum-specific components, and a peripherally associated subcomplex contributes to the membrane curvature. The central and peripheral stalks directly interact with each other. Last, the ATPase inhibitory factor 1 (IF1) binds in a mode that is different from human, but conserved in Trypanosomatids.

ATP synthase inhibitory factor 1 (IF1), a novel myokine, regulates glucose metabolism by AMPK and Akt dual pathways.

ATPase inhibitory factor 1 (IF1) is an ATP synthase-interacting protein that suppresses the hydrolysis activity of ATP synthase. In this study, we observed that the expression of IF1 was up-regulated in response to electrical pulse stimulation of skeletal muscle cells and in exercized mice and healthy men. IF1 stimulates glucose uptake via AMPK in skeletal muscle cells and primary cultured myoblasts. Reactive oxygen species and Rac family small GTPase 1 (Rac1) function in the upstream and downstream of AMPK, respectively, in IF1-mediated glucose uptake. In diabetic animal models, the administration of recombinant IF1 improved glucose tolerance and down-regulated blood glucose level. In addition, IF1 inhibits ATP hydrolysis by β-F1-ATPase in plasma membrane, thereby increasing extracellular ATP and activating the protein kinase B (Akt) pathway, ultimately leading to glucose uptake. Thus, we suggest that IF1 is a novel myokine and propose a mechanism by which AMPK and Akt contribute independently to IF1-mediated improvement of glucose tolerance impairment. These results demonstrate the importance of IF1 as a potential antidiabetic agent.-Lee, H. J., Moon, J., Chung, I., Chung, J. H., Park, C., Lee, J. O., Han, J. A., Kang, M. J., Yoo, E. H., Kwak, S.-Y., Jo, G., Park, W., Park, J., Kim, K. M., Lim, S., Ngoei, K. R. W., Ling, N. X. Y., Oakhill, J. S., Galic, S., Murray-Segal, L., Kemp, B. E., Mantzoros, C. S., Krauss, R. M., Shin, M.-J., Kim, H. S. ATP synthase inhibitory factor 1 (IF1), a novel myokine, regulates glucose metabolism by AMPK and Akt dual pathways.