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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

EHMT2 is a metastasis regulator in breast cancer

Highlights: • EHMT2 (a histone methyltransferase) was determined to be significantly overexpressed in breast cancer tissues. • Knockdown of EHMT2 reduced cell migration/invasion and regulated the expression of EMT-related markers. • EHMT2 regulated EMT markers via up-regulation of MSK1-SNAIL1. Various modes of epigenetic regulation of breast cancer proliferation and metastasis have been investigated, but epigenetic mechanisms involved in breast cancer metastasis remain elusive. Thus, in this study, EHMT2 (a histone methyltransferase) was determined to be significantly overexpressed in breast cancer tissues and in Oncomine data. In addition, knockdown of EHMT2 reduced cell migration/invasion and regulated the expression of EMT-related markers (E-cadherin, Claudin 1, and Vimentin). Furthermore, treatment with BIX-01294, a specific inhibitor of EHMT2, affected migration/invasion in MDA-MB-231 cells. Therefore, our findings demonstrate functions of EHMT2 in breast cancer metastasis and suggest that targeting EHMT2 may be an effective therapeutic strategy for preventing breast cancer metastasis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

ELK3-GATA3 axis modulates MDA-MB-231 metastasis by regulating cell-cell adhesion-related genes

Highlights: • GATA3 suppression in ELK3 knockdown MDA-MB-231 restores metastatic characteristics both in vitro and in vivo. • ELK3-GATA3 axis regulates metastasis of MDA-MB-231 independent of TGF-β signaling. • ELK3-GATA3 axis regulates metastasis of MDA-MB-231 through the regulation of adhesion and tight junction proteins. GATA3 is a master regulator that drives mammary epithelial cell differentiation, and the suppression of GATA3 expression is associated with the development of aggressive breast cancer. However, the mechanism through which GATA3 loss drives cancer development is poorly understood. Previously, we reported that ELK3 suppression in MDA-MB-231 (ELK3 KD) resulted in the reprogramming of these cells from a basal to luminal subtype, which was associated with the induction of GATA3 expression, and that the ELK3-GATA3 axis orchestrated the metastatic characteristics of MDA-MB-231. Here, we show that GATA3 suppression in ELK3 knockdown MDA-MB-231 cells (ELK3/GATA3 DKD) restores the metastatic ability comparably to that of control MDA-MB-231 cells, even though the epithelial cell morphology and TGF-β signaling of ELK3 KD are not recovered in ELK3/GATA3 DKD. The expression of E-cadherin and tight junctional proteins, including occludin, claudin and ZO-1, which is activated in ELK3 KD, is suppressed in ELK3/GATA3 DKD. These results reveal the possibility that the ELK3-GATA3 axis determines the metastatic characteristics of MDA-MB-231 by regulating the expression of cell-cell adhesion factors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Micro124-mediated AHR expression regulates the inflammatory response of chronic rhinosinusitis (CRS) with nasal polyps

Highlights: • MiR124 and AHR play very important roles in the inflammatory response. • MiR124 can inhibit AHR expression by directly target 3′ untranslated region (3′-UTR) of AHR. • MiR124 could regulates cellular inflammatory response through negatively regulating AHR expression. MicroRNAs represent a component of the innate immune responses that can restrain inflammatory signaling, miR124 is an important member of inflammation-associated miRNAs, and abnormal miR124 expression is observed in many inflammatory diseases and immune disorders. However, the role and signaling pathways of miR124 in chronic rhinosinusitis with nasal polyps (CRSwNPs) have not been studied in detail. The aryl hydrocarbon receptor (AHR) is a ligand-inducible transcription factor that is highly conserved in evolution and plays important roles in the inflammatory response process. In our study, we describe the role of miR124 in the inflammatory response of CRS with nasal polyps. We found that the expression of miR124 was decreased in nasal polyps, and negatively correlated with the expression of AHR. MiR124 can inhibit AHR expression by directly target 3′ untranslated region (3′-UTR) of AHR. To further investigate the relationship between miR124, AHR and CRS inflammatory response, we transfect HNEpC cells with miR124 mimic, miR124 inhibitors or siRNA of AHR, then all the results showed that miR124 could regulates cellular inflammatory response through negatively regulating AHR expression. This study demonstrated that the regulation of AHR expression by miR124 is critical to the development of inflammatory response in CRSwNPs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Down-regulation of FOXR2 inhibits non-small cell lung cancer cell proliferation and invasion through the Wnt/β-catenin signaling pathway

Highlights: • Expression of FOXR2 is up-regulated in NSCLC tissues and cell lines. • Down-regulation of FOXR2 inhibits NSCLC cell proliferation and invasion in vitro. • Down-regulation of FOXR2 inhibits NSCLC cell growth and metastasis in vivo. • Down-regulation of FOXR2 inhibits the Wnt/β-catenin pathway in NSCLC cells. Forkhead box R2 (FOXR2), a new member of the FOX family, is an important player in a wide range of cellular processes such as proliferation, migration, differentiation and apoptosis. Recently, FOXR2 has been reported to be implicated in cancer development. However, the biological functions of FOXR2 in non-small cell lung cancer (NSCLC) remain unclear. In this study, we investigated the specific role of FOXR2 in NSCLC. The results showed that down-regulation of FOXR2 significantly inhibited NSCLC cell proliferation and invasion in vitro and suppressed NSCLC cell growth and metastasis in vivo. In addition, the decrease in FOXR2 expression markedly reduced the protein levels of β-catenin, cyclinD1 and c-Myc and hence inactivated the Wnt/β-catenin pathway in NSCLC cells. Taken together, we concluded that FOXR2 might be considered as a promising therapeutic target for NSCLC treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Role of IκB kinase β in regulating the remodeling of the CARMA1-Bcl10-MALT1 complex

Highlights: • IKKβ is involved in membrane fusion. • IKKβ is required for initial formation and the regulation of the CBM complex. • IKKβ regulates CBM complex via phosphorylation of Bcl10 and IKKγ polyubiquitination. The current work investigates the notion that inducible clustering of signaling mediators of the IKK pathway is important for platelet activation. Thus, while the CARMA1, Bcl10, and MALT1 (CBM) complex is essential for triggering IKK/NF-κB activation upon platelet stimulation, the signals that elicit its formation and downstream effector activation remain elusive. We demonstrate herein that IKKβ is involved in membrane fusion, and serves as a critical protein kinase required for initial formation and the regulation of the CARMA1/MALT1/Bcl10/CBM complex in platelets. We also show that IKKβ regulates these processes via modulation of phosphorylation of Bcl10 and IKKγ polyubiquitination. Collectively, our data demonstrate that IKKβ regulates membrane fusion and the remodeling of the CBM complex formation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-130a-3p inhibits migration and invasion by regulating RAB5B in human breast cancer stem cell-like cells

Highlights: • We enriched breast cancer stem-like cells expressing CD44{sup +}CD24{sup -/low} from MCF-7 cells. • We found that miR-130a-3p is down-regulated in human breast cancer tissues and exosomes from circulating blood, and overexpression of miR-130a-3p in BCSCs inhibited cellular proliferation, migration, and invasion. • MiR-130a-3p inhibits migration and invasion by regulating RAB5B in human breast cancer stem cell-like cells. Breast cancer stem cells (BCSCs) constitute a subpopulation of tumor cells that express stem cell-associated markers and have a high capacity for tumor generation in vivo. MicroRNAs (miRNAs) are involved in tumorigenesis by regulating specific oncogenes and tumor suppressor genes, and their roles in BCSCs are becoming more apparent. We try to reveal the mechanism by which specific miRNA plays its function in BCSCs. Herein, we show that miR-130a-3p is down-regulated in human breast cancer tissues and exosomes from circulating blood. Overexpression of miR-130a-3p in BCSCs inhibited cellular proliferation, migration, and invasion, and silencing of miR-130a-3p had the opposite effects. We also confirmed that RAB5B is directly down-regulated by miR-130a-3p. Knockdown of RAB5B also inhibited cell proliferation, migration and invasion. Furthermore, we found that lower levels of exosome-derived miR-130a-3p are associated with lymph node metastasis and advanced TNM stage. Taken together, our results demonstrate that miR-130a-3p may act as a disease progression monitoring indicator and therapeutic target in breast cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Regulation of the gyr operon of Mycobacterium tuberculosis by overlapping promoters, DNA topology, and reiterative transcription

Highlights: • Demonstrated reiterative transcription at the gyr overlapping promoters in Mycobacterium tuberculosis. • Regulation by reiterative transcription is DNA topology-dependent. • Another player in the regulation of DNA Gyrase. DNA gyrase introduces negative supercoils into DNA to maintain topological homeostasis. The genes encoding gyrase, gyrB and gyrA, form a dicistronic operon in Mycobacterium tuberculosis (Mtb) and other actinobacteria. Earlier work indicated that DNA relaxation stimulates the expression of the gyr genes, a phenomenon termed relaxation-stimulated transcription (RST). The present study addresses the underlying mechanism of gyr operon regulation. The operon is regulated by overlapping and divergently oriented promoters located upstream of gyrB. The principal promoter, P{sub gyrB1}, drives transcription of the operon, while a weak “reverse” promoter, P{sub gyrR}, transcribes in opposite direction. We demonstrate that P{sub gyrR} plays a role in fine tuning gyr gene expression by reiterative transcription (RT), a regulatory mechanism hitherto not found in Mtb. In vitro transcription assays showed that RT at P{sub gyrR} depended on the negatively supercoiled state of the DNA template. The principal promoter, P{sub gyrB1}, was also sensitive to DNA supercoiling, but it was stimulated by DNA relaxation. Moreover, RNA polymerase binding to the promoter was efficient at P{sub gyrB1} when template DNA was relaxed, whereas binding to P{sub gyrR} was preferred when DNA was supercoiled. Thus, a collaboration between RST and RT governs the regulation of the gyr operon; the differing sensitivity of the two overlapping promoters to superhelix density explains how gyrase expression responds to changes in supercoiling to determine the efficiency of transcription initiation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Mechanisms involved in epigenetic down-regulation of Gfap under maternal hypothyroidism

Highlights: • Maternal hypothyroidism delays ontogenetic Gfap expression in developing neocortex. • Maternal hypothyroidism increases Gfap promoter methylation. • Maternal hypothyroidism decreases Gfap promoter histone acetylation. Thyroid hormones (TH) of maternal origin are crucial regulator of mammalian brain development during embryonic period. Although maternal TH deficiency during the critical periods of embryonic neo-cortical development often results in irreversible clinical outcomes, the fundamental basis of these abnormalities at a molecular level is still obscure. One of the key developmental process affected by maternal TH insufficiency is the delay in astrocyte maturation. Glial fibrillary acidic protein (Gfap) is a predominant cell marker of mature astrocyte and is regulated by TH status. Inspite, of being a TH responsive gene during neocortical development the mechanistic basis of Gfap transcriptional regulation by TH has remained elusive. In this study using rat model of maternal hypothyroidism, we provide evidence for an epigenetic silencing of Gfap under TH insufficiency and its recovery upon TH supplementation. Our results demonstrate increased DNA methylation coupled with decreased histone acetylation at the Gfap promoter leading to suppression of Gfap expression under maternal hypothyroidism. In concordance, we also observed a significant increase in histone deacetylase (HDAC) activity in neocortex of TH deficient embryos. Collectively, these results provide novel insight into the role of TH regulated epigenetic mechanisms, including DNA methylation, and histone modifications, which are critically important in mediating precise temporal neural gene regulation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Tankyrase regulates apoptosis by activating JNK signaling in Drosophila

Highlights: • Ectopic expression of DTNKS induces wing and eye defects. • DTNKS positively regulates cell apoptosis. • DTNKS regulates apoptosis by controlling JNK signaling activity. Programmed cell death (PCD), or apoptosis, plays essential roles in various cellular and developmental processes, and dysregulation of apoptosis causes many diseases. Thus, regulation of apoptotic process is very important. Drosophila tankyrase (DTNKS) is an evolutionarily conserved protein with poly(ADP-ribose) polymerase activity. In mammalian cells, tankyrases (TNKSs) have been reported to regulate cell death. To determine whether DTNKS plays function in inducing apoptosis in in vivo development, we used Drosophila as a model system and generated transgenic flies expressing DTNKS. We show that ectopic expression of DTNKS promotes caspase-dependent apoptosis and knockdown of DTNKS by RNAi dramatically alleviates apoptotic defect caused by ectopic expression of pro-apoptotic protein hid or rpr in the adult eye. Moreover, our result shows that ectopic expression of DTNKS triggers the activation of c-Jun N-terminal kinase (JNK) signaling, which is required for DTNKS-mediated apoptosis. Taken together, our finding identifies the role of DTNKS in regulating apoptosis by activating JNK signaling in Drosophila.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

TUG1 is involved in liver fibrosis and activation of HSCs by regulating miR-29b

Highlights: • Tug1 is over-expressed in liver fibrosis and activated HSCs. • Tug1 promotes the expression of pro-fibrogenic genes in HSCs. • Tug1 regulates the expression of target genes through down-regulation of miR-29b. • Elevated TUG1 was expressed in liver cirhhosis patients. TUG1 has been shown to be involved in diverse human diseases by regulating gene expression at transcriptional and post-transcriptional levels via interaction with miRNA or proteins. However, the role of TUG1 in liver fibrosis remains unclear. Here, we found that Tug1 is dysregulated in liver fibrosis according to the microarray analysis. Moreover, we investigated the expression files of Tug1 by using CCl{sub 4}-and BDL-induced liver fibrosis model mice as well as in the primary cells isolated from the mice. We demonstrated that Tug1 is over-expressed in the fibrotic livers and activated HSCs, but not injured hepatocytes. In addition, we assessed the function of Tug1 in HSCs and found that Tug1 promotes the expression of α-SMA, Col1α1, Mmp2/9/10 and Timp1. Mechanically, Tug1 promotes the expression of these pro-fibrogenic genes by down-regulating miR-29b, thus accelerating the progression of liver fibrosis. Further study revealed that TUG1was up-regulated in liver tissues of patients with cirrhosis. All together, our data indicate that TUG1 might be a potential therapy target of liver fibrosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Fluvastatin activates sirtuin 6 to regulate sterol regulatory element-binding proteins and AMP-activated protein kinase in HepG2 cells

Highlights: • Effects of fluvastatin in human hepatocytes via SIRT6 activation were investigated. • Fluvastatin plays the role of an SIRT6 activator. • Fluvastatin can be used as a new drug for patients with liver steatosis. • Fluvastatin inhibited lipid synthesis by regulating SREBP1 via LKB1/AMPK pathway. Sirtuins, a family of NAD{sup +}-dependent deacetylase enzymes, have been identified as mammalian homologs of yeast silent information regulator 2 (SIR2). Sirtuin 6 (SIRT6) plays important roles in cell homeostasis, DNA damage repair, cancer suppression, and aging. SIRT6 overexpression improves metabolic diseases, such as hypercholesterolemia, cholesterol-related disease, and type 2 diabetes via AMP-activated protein kinase (AMPK) activation. SIRT6 is abundant in the liver and is a crucial target for patients with liver steatosis. Compounds for drug repositioning were screened to identify potential SIRT6 activators, and fluvastatin, a synthetic inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase that reduces cholesterol synthesis, was identified to activate SIRT6. When HepG2 cells were treated with fluvastatin, the expression of SIRT6 and phosphorylation of sterol regulatory element-binding protein (SREBP)-1 and AMPKα, which is regulated by SIRT6, increased. In this study, we examined the mechanism underlying cholesterol regulation by fluvastatin via SREBP-1 and AMPKα pathway and suggested that fluvastatin is an SIRT6 activator that regulates cholesterol homeostasis and fatty liver disease.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Reverse the down regulation of miR-92b-3p by hypoxia can suppress the proliferation of pulmonary artery smooth muscle cells by targeting USP28

Highlights: • miR-92b-3p reverse the proliferaton of pulmonary artery smooth muscle cells under hypoxia condition. • miR-92b-3p regulate the protein level of USP28. • miR-92b-3p maybe a novel treatment target of pulmonary hypertension. MiR-92b-3p has been shown to take part in several disease by regulate proliferation, apoptosis, differentiation and metastasis. However, the role of miR-92b-3p in pulmonary arterial hypertension (PAH) has not been illustrated clearly. Here, we found the level of miR-92b-3p which mainly located in the smooth muscle layer was down-regulation under hypoxic condition. It can inhibit pulmonary artery smooth muscle cells (PASMCs) proliferation and cell cycle progression. Through luciferase assay, miR-92b-3p bound to the 3′-UTR of USP28. we found that there was a significant negative relation between the level of miR-92b-3p and USP28 at protein level and reversed the down regulation of miR-92b-3p by hypoxia can suppress the proliferation of pulmonary artery smooth muscle cells by targeting USP28. These results suggested that miR-92b-3p acted a potential proliferation regulator in PASMCs and it maybe a novel treatment target of PAH.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Hsa{sub c}ircRNA{sub 1}03809 regulated the cell proliferation and migration in colorectal cancer via miR-532–3p / FOXO4 axis

Highlights: • The expression of hsa{sub c}ircRNA{sub 1}03809 is down-regulated in the CRC tissues and cells. • Knockdown of hsa{sub c}ircRNA{sub 1}03809 promotes cell proliferation in CRC. • Knockdown of hsa{sub c}ircRNA{sub 1}03809 promotes cell migration in CRC. • Hsa{sub c}ircRNA{sub 1}03809 acts as a suppressor via regulation of miR-532–3P/FOXO4 axis in CRC. Circular RNAs(circRNAs) are a class of non-coding RNAs that are widely expressed in a variety of cell species. The role they play in cancers is poorly understood, especially in colorectal cancer (CRC). Hsa{sub c}ircRNA{sub 1}03809 (hsa{sub c}irc{sub 0}072088, circZFR)has been demonstrated to be lowly expressed in colorectal cancer tissues and is associated with stage and lymph node metastasis of cancer tissues. Real-time quantitative PCR (qRT-PCR) was used to verify the relationship of hsa{sub c}ircRNA{sub 1}03809 between colorectal cancer and paired adjacent tissue in clinical tissue samples. Then, the proliferative capacity, migration ability, cell cycle, and apoptosis were measured using wound-healing assay, CCK8, transwell assay, flow cytometry, and the like, when hsa{sub c}ircRNA{sub 1}03809 expression in SW620 and COCA-2. The qRT-PCR, western bolt and other experiments verify that the expression of hsa{sub c}ircRNA{sub 1}03809 can regulate the expression of miR-532–3P and FOXO4. Hsa{sub c}ircRNA{sub 1}03809 was found to be significantly down regulated in CRC tissues and cell lines and compared with paired adjacent non-tumorous tissues and normal FHC cells. Hsa{sub c}ircRNA{sub 1}03809 participates in the regulation of biological functions through the miR-532–3P/FOXO4 axis in the CRC. Hsa{sub c}ircRNA{sub 1}03809 may be a potential novel gene target for the diagnosis and treatment of CRC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

A role of GUNs-Involved retrograde signaling in regulating Acetyl-CoA carboxylase 2 in Arabidopsis

Highlights: • The expression level of ACC2 is up-regulated in the mutant of BPG2. • GUN1 and GUN5-mediated plastid signals play a role in the upregulation of ACC2 in the bpg2 mutant. • The level of ACC2 is markedly increased in a GUN-dependent manner under plastid gene expression inhibitor treatment. In Arabidopsis thaliana (Arabidopsis), Acetyl-CoA Carboxylase 2 (ACC2) is a nuclear DNA-encoded and plastid-targeted enzyme that catalyzes the conversion of acetyl-CoA to malonyl-CoA. ACC2 improves plant growth and development when chloroplast translation is impaired. However, little is known about the upstream signals that regulate ACC2. Here, through analyzing the transcriptome changes in brz-insensitive-pale green (bpg) 2-2, a pale-green mutant with impaired chloroplast gene expression resulting from loss of the BPG2 function, we found that the level of ACC2 was significantly up-regulated. Through performing genetic analysis, we further demonstrated that loss of the GENOMES UNCOUPLED 1 (GUN1) or GUN5 function partly perturbed the up-regulation of ACC2 in the bpg2-2 mutant, whereas ABA INSENSITIVE 4 (ABI4)-function-loss had no clear effect on the ACC2 expression. Furthermore, when plants were treated with plastid translation inhibitors, such as lincomycin and spectinomycin, the ACC2 transcriptional level was also markedly increased in a GUN-dependent manner. In conclusion, our results suggested that the GUN-involved plastid-to-nucleus retrograde communication played a role in regulating ACC2 in Arabidopsis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

STAM-binding protein regulates melanoma metastasis through SLUG stabilization

Highlights: • STAMBP regulates melanoma migration and invasion but not survival in vitro. • STAMBP regulates SLUG stability. • STAMBP suppression inhibits melanoma metastasis in vivo. STAM-binding protein, STAMBP, is a JAMM-family deubiquitinating enzyme containing the microtubule-interacting/transport domain and STAM-binding domain. Although the biological importance of STAMBP in development has been recognized because the microcephaly-capillary malformation syndrome in human is caused by its somatic mutations, the role of STAMBP in cancer has not yet been determined. In this study, we demonstrate that STAMBP is a key molecule for regulating melanoma migration and invasion, but not survival, by knocking down STAMBP in vitro. STAMBP regulates SLUG expression through a post-transcriptional mechanism to control protein stability and further contributes to the in vivo metastatic potential of melanoma. Collectively, these results indicate the importance of STAMBP in melanoma metastasis by regulating SLUG. It is therefore a potential therapeutic target.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Mef2c regulates bone mass through Sost -dependent and -independent mechanisms

We report Mef2c is a transcription factor that mediates key cellular behaviors that promote endochondral ossification and bone formation. Previously, Mef2c has been shown to regulate Sost transcription via its osteocyte-specific enhancer, ECR5, and conditional deletions of Mef2 cfl/fl with either Col1-Cre or Dmp1-Cre produced generalized high bone mass (HBM) consistent with Van Buchem Disease phenotypes. However, Sost -/- ; Mef2 cfl/fl ; Dmp1-Cre mice produced a significantly higher bone mass phenotype that Sost-/- alone suggesting that Mef2c modulates bone mass through additional mechanisms, independent of Sost. To identify new Mef2c transcriptional targets important in bone metabolism, we profiled gene expression by single-cell RNA sequencing in subpopulations of cells isolated from Mef2 cfl/fl ; Dmp1-Cre and Mef2 cfl/fl ; Bglap-Cre femurs, both strains exhibiting similar high bone mass phenotypes. However, we found Mef2cfl/fl; Bglap-Cre to also display a growth plate defect characterized by an expansion of several osteoprogenitor subpopulations. Differential gene expression analysis identified a total of 96 up- and 2434 down- regulated genes in Mef2 cfl/fl ; Bglap-Cre and 176 up- and 1041 down- regulated genes in Mef2 cfl/fl ; Dmp1-Cre bone cell subpopulations compared to wildtype mice. Mef2c deletion affected the transcriptomes across several cell types including mesenchymal progenitors (MP), osteoprogenitors (OSP), osteoblast (OB), and osteocyte (OCY) subpopulations. Several energy metabolism genes such as Uqcrb, Ndufv2, Ndufs3, Ndufa13, Ndufb9, Ndufb5, Cox6a1, Cox5a, Atp5o, Atp5g2, Atp5b, Atp5 were significantly down regulated in Mef2c-deficient OBs and OCYs, in both strains. Binding motif analysis of promoter regions of differentially expressed genes identified Mef2c binding in Bone Sialoprotein (BSP/Ibsp), a gene known to cause increased trabecular BV/TV in the femurs of Ibsp -/- mice. Immunohistochemical analysis confirmed the absence of Ibsp protein in OBs and OCYs. These findings suggests that the HBM in Sost -/- ; Mef2 cfl/fl ; Dmp1-Cre is caused by a multitude of transcriptional changes in genes that regulate bone formation, two of which are Sost and Ibsp.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Mitochondrial respiratory chain protein co-regulation in the human brain

Mitochondrial respiratory chain (RC) function requires the stoichiometric interaction among dozens of proteins but their co-regulation has not been defined in the human brain. Here, using quantitative proteomics across three independent cohorts we systematically characterized the co-regulation patterns of mitochondrial RC proteins in the human dorsolateral prefrontal cortex (DLPFC). Whereas the abundance of RC protein subunits that physically assemble into stable complexes were correlated, indicating their co-regulation, RC assembly factors exhibited modest co-regulation. Within complex I, nuclear DNA-encoded subunits exhibited >2.5-times higher co-regulation than mitochondrial (mt)DNA-encoded subunits. Moreover, mtDNA copy number was unrelated to mtDNA-encoded subunits abundance, suggesting that mtDNA content is not limiting. Alzheimer's disease (AD) brains exhibited reduced abundance of complex I RC subunits, an effect largely driven by a 2–4% overall lower mitochondrial protein content. These findings provide foundational knowledge to identify molecular mechanisms contributing to age- and disease-related erosion of mitochondrial function in the human brain.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Unraveling the regulation of sugar beet pulp utilization in the industrially relevant fungus Aspergillus niger

Efficient utilization of agro-industrial waste, such as sugar beet pulp, is crucial for the bio-based economy. The fungus Aspergillus niger possesses a wide array of enzymes that degrade complex plant biomass substrates, and several regulators have been reported to play a role in their production. The role of the regulators GaaR, AraR, and RhaR in sugar beet pectin degradation has previously been reported. However, genetic regulation of the degradation of sugar beet pulp has not been assessed in detail. In this study, we generated a set of single and combinatorial deletion mutants targeting the pectinolytic regulators GaaR, AraR, RhaR, and GalX as well as the (hemi-)cellulolytic regulators XlnR and ClrB to address their relative contribution to the utilization of sugar beet pulp. We show that A. niger has a flexible regulatory network, adapting to the utilization of (hemi-)cellulose at early timepoints when pectin degradation is impaired.

59 BASIC BIOLOGICAL SCIENCES↗