scholarly journals Inhibitors of lysosomal function or serum starvation in control or LAMP2 deficient cells do not modify the cellular levels of Parkinson disease-associated DJ-1/PARK 7 protein

2018 ◽  
Author(s):  
Raúl Sánchez-Lanzas ◽  
José G. Castaño
Keyword(s):  
Gene Expression ◽  
Parkinson Disease ◽  
Autosomal Recessive ◽  
Serum Starvation ◽  
Lysosomal Degradation ◽  
Lysosomal Function ◽  
Protein Levels ◽  
Chaperone Mediated Autophagy ◽  
Lamp2 Gene

AbstractMutations in PARK7/DJ-1 gene are associated with familial autosomal recessive Parkinson disease. Recently, lysosomes and chaperone mediated autophagy (CMA) has been reported to participate in the degradation of DJ-1/PARK7 protein. Lamp-2A isoform is considered as the lysosomal receptor for the uptake of proteins being degraded by the CMA pathway. We have used several cell lines with disrupted LAMP2 gene expression and their respective control cells to test the possible role of lysosomal degradation and in particular CMA in DJ-1 /PARK7 degradation. Interruption of LAMP-2 expression did not result in an increase of the steady-state protein levels of DJ-1 /PARK7, as it would have been expected. Furthermore, no change in DJ-1 /PARK7 protein levels were observed upon inhibition of lysosomal function with NH4Cl or NH4Cl plus leupeptin, or after activation of CMA by serum starvation for 24h. Accordingly, we have not found any evidence that DJ-1 /PARK7 protein levels are regulated via lysosomal degradation or the CMA pathway.

scholarly journals Polyamines regulate gene expression by stimulating translation of histone acetyltransferase mRNAs

2020 ◽  
Vol 295 (26) ◽  
pp. 8736-8745 ◽  
Author(s):  
Akihiko Sakamoto ◽  
Yusuke Terui ◽  
Takeshi Uemura ◽  
Kazuei Igarashi ◽  
Keiko Kashiwagi
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Histone Acetyltransferases ◽  
Regulate Gene Expression ◽  
Double Stranded Rna ◽  
Protein Levels ◽  
Lysine Residues ◽  
Regulate Gene ◽  
Stimulation Of

Polyamines regulate gene expression in Escherichia coli by translationally stimulating mRNAs encoding global transcription factors. In this study, we focused on histone acetylation, one of the mechanisms of epigenetic regulation of gene expression, to attempt to clarify the role of polyamines in the regulation of gene expression in eukaryotes. We found that activities of histone acetyltransferases in both the nucleus and cytoplasm decreased significantly in polyamine-reduced mouse mammary carcinoma FM3A cells. Although protein levels of histones H3 and H4 did not change in control and polyamine-reduced cells, acetylation of histones H3 and H4 was greatly decreased in the polyamine-reduced cells. Next, we used control and polyamine-reduced cells to identify histone acetyltransferases whose synthesis is stimulated by polyamines. We found that polyamines stimulate the translation of histone acetyltransferases GCN5 and HAT1. Accordingly, GCN5- and HAT1-catalyzed acetylation of specific lysine residues on histones H3 and H4 was stimulated by polyamines. Consistent with these findings, transcription of genes required for cell proliferation was enhanced by polyamines. These results indicate that polyamines regulate gene expression by enhancing the expression of the histone acetyltransferases GCN5 and HAT1 at the level of translation. Mechanistically, polyamines enhanced the interaction of microRNA-7648-5p (miR-7648-5p) with the 5′-UTR of GCN5 mRNA, resulting in stimulation of translation due to the destabilization of the double-stranded RNA (dsRNA) between the 5′-UTR and the ORF of GCN5 mRNA. Because HAT1 mRNA has a short 5′-UTR, polyamines may enhance initiation complex formation directly on this mRNA.

microRNA-422a Inhibits DCC Expression in a Manner Dependent on SNP rs12607853

2020 ◽  
Vol 160 (2) ◽  
pp. 63-71
Author(s):  
Yunxiao Li ◽  
Xugang Shi ◽  
Xintong Cai ◽  
Yongsheng Zhu ◽  
Yuanyuan Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Opioid Addiction ◽  
Heroin Addiction ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Protein Levels ◽  
Gene Assay ◽  
New Biomarkers ◽  
And Function

DCC netrin 1 receptor (DCC) affects the structure and function of the dopamine circuitry, which in turn affects the susceptibility to developing addiction. In a previous study, we found that single nucleotide polymorphism (SNP) rs12607853 in the 3′ untranslated region (3′-UTR) of DCC was significantly associated with heroin addiction. In the current study, we first used bioinformatics prediction to identify the DCC rs12607853 C allele as a potential hsa-miR-422a and hsa-miR-378c target site. We then used vector construction and dual-luciferase reporter assays to investigate the targeting relationship of DCC rs12607853 with hsa-miR-422a and hsa-miR-378c. The dual-luciferase reporter gene assay confirmed that the C allele of rs12607853 in combination with hsa-miR-422a led to repressed dual-luciferase gene expression. Moreover, gene expression assays disclosed that hsa-miR-422a inhibited DCC expression at both the mRNA and protein levels. We also found that morphine inhibited the expression of hsa-miR-422a but increased the expression of DCC mRNA, and this change in the expression of hsa-miR-422a could not be reversed by naloxone, which suggested that the role of DCC in opioid addiction might be regulated by hsa-miR-422a. In summary, this study improves our understanding of the role of hsa-miR-422a and identifies the genetic basis of rs12607853, which might contribute to the discovery of new biomarkers or therapeutic targets for opioid addiction.

scholarly journals Hepatocyte Nuclear Factor 4 alpha (HNF4α) Activation is Essential for Termination of Liver Regeneration

2018 ◽  
Author(s):  
Ian Huck ◽  
Sumedha Gunewardena ◽  
Regina Espanol-Suner ◽  
Holger Willenbring ◽  
Udayan Apte
Keyword(s):  
Gene Expression ◽  
Liver Regeneration ◽  
Target Gene ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Hepatic Differentiation ◽  
Target Gene Expression ◽  
Protein Levels ◽  
Hepatocyte Nuclear Factor 4

AbstractHepatocyte Nuclear Factor 4 alpha (HNF4α) is critical for hepatic differentiation. Recent studies have highlighted its role in inhibition of hepatocyte proliferation and tumor suppression. However, the role of HNF4α in liver regeneration is not known. We hypothesized that hepatocytes modulate HNF4α activity when navigating between differentiated and proliferative states during liver regeneration. Western blot analysis revealed a rapid decline in nuclear and cytoplasmic HNF4α protein levels accompanied with decreased target gene expression within 1 hour after 2/3 partial hepatectomy (post-PH) in C57BL/6J mice. HNF4α protein expression did not recover to the pre-PH levels until day 3. Hepatocyte-specific deletion of HNF4α (HNF4α-KO) in mice resulted in 100% mortality post-PH despite increased proliferative marker expression throughout regeneration. Sustained loss of HNF4α target gene expression throughout regeneration indicated HNF4α-KO mice were unable to compensate for loss of HNF4α transcriptional activity. Deletion of HNF4α resulted in sustained proliferation accompanied by c-myc and cyclin D1 over expression and a complete deficiency of hepatocyte function after PH. Interestingly, overexpression of degradation-resistant HNF4α in hepatocytes did not prevent initiation of regeneration after PH. Finally, AAV8-mediated reexpression of HNF4α in hepatocytes of HNF4α-KO mice post-PH restored HNF4α protein levels, induced target gene expression and improved survival of HNF4α-KO mice post-PH. In conclusion, these data indicate that HNF4α reexpression following initial decrease is critical for hepatocytes to exit from cell cycle and resume function during the termination phase of liver regeneration. These results reveal the role of HNF4α in liver regeneration and have implications for therapy of liver failure.

scholarly journals The Role of OXT, OXTR, AVP, and AVPR1a Gene Expression in the Course of Schizophrenia

2022 ◽  
Vol 44 (1) ◽  
pp. 336-349
Author(s):  
Marta Broniarczyk-Czarniak ◽  
Janusz Szemraj ◽  
Janusz Śmigielski ◽  
Piotr Gałecki
Keyword(s):  
Gene Expression ◽  
Early Adulthood ◽  
Depression Scale ◽  
Emotional Behavior ◽  
Social And Emotional ◽  
Protein Levels ◽  
Syndrome Scale ◽  
Negative Syndrome ◽  
First Time

Schizophrenia is a serious and chronic mental illness, the symptoms of which usually appear for the first time in late adolescence or early adulthood. To date, much research has been conducted on the etiology of schizophrenia; however, it is still not fully understood. Oxytocin and vasopressin as neuromodulators that regulate social and emotional behavior are promising candidates for determining the vulnerability to schizophrenia. The aim of this study was to evaluate the expression of OXT, OXTR, AVP, and AVPR1a genes at the mRNA and protein levels in patients with schizophrenia. Due to the neurodegenerative nature of schizophrenia, the study group was divided into two subgroups, namely, G1 with a diagnosis that was made between 10 and 15 years after the onset of the illness, and G2 with a diagnosis made up to two years after the onset of the illness. Moreover, the relationship between the examined genes and the severity of schizophrenia symptoms, assessed using PANSS (Positive and Negative Syndrome Scale) and CDSS scales (Clinical Depression Scale for Schizophrenia) was evaluated. The analysis of the expression of the studied genes at the mRNA and protein levels showed statistically significant differences in the expression of all the investigated genes. OXT and AVPR1a gene expression at both the mRNA and protein levels were significantly lower in the schizophrenia group, and OXTR and AVP gene expression at both the mRNA and protein levels was higher in the schizophrenia subjects than in the controls. Furthermore, a significant correlation of OXT gene expression at the mRNA and protein levels with the severity of depressive symptoms in schizophrenia as assessed by CDSS was found.

scholarly journals Two functionally redundant FK506-binding proteins regulate multidrug resistance gene expression and govern azole antifungal resistance

2021 ◽  
Author(s):  
Romila Moirangthem ◽  
Kundan Kumar ◽  
Rupinder Kaur
Keyword(s):  
Gene Expression ◽  
Binding Proteins ◽  
Target Genes ◽  
Fungal Infections ◽  
Antifungal Resistance ◽  
Azole Resistance ◽  
Multidrug Resistance Gene ◽  
Protein Levels ◽  
Fk506 Binding Proteins

Increasing resistance to antifungal therapy is an impediment to effective treatment of fungal infections. Candida glabrata is an opportunistic human fungal pathogen which is inherently less susceptible to cost-effective azole antifungals. Gain-of-function mutations in the Zn-finger pleiotropic drug resistance transcriptional activator-encoding gene, CgPDR1, are the most prevalent cause of azole resistance in clinical settings. CgPDR1 is also transcriptionally activated upon azole exposure, however, factors governing CgPDR1 gene expression are not yet fully understood. Here, we have uncovered a novel role for two FK506-binding proteins, CgFpr3 and CgFpr4, in regulation of the CgPDR1 regulon. We show that CgFpr3 and CgFpr4 possess peptidyl-prolyl isomerase domain, and act redundantly to control CgPDR1 expression, as Cgfpr3Δ4Δ mutant displayed elevated expression of CgPDR1 gene, along with overexpression of its target genes, CgCDR1, CgCDR2 and CgSNQ2, that code for ATP-binding cassette multidrug transporters. Further, CgFpr3 and CgFpr4 are required for maintenance of histone H3 and H4 protein levels, and fluconazole exposure leads to elevated H3 and H4 protein levels. Consistent with a role of histone proteins in azole resistance, disruption of genes coding for the histone demethylase CgRph1 and histone H3K36-specific methyltransferase CgSet2 leads to increased and decreased susceptibility to fluconazole, respectively, with Cgrph1Δ mutant displaying significantly lower basal expression of CgPDR1 and CgCDR1 genes. These data underscore a hitherto unknown role of histone methylation in modulating the most common azole antifungal resistance mechanism. Altogether, our findings establish a link between CgFpr-mediated histone homeostasis and CgPDR1 gene expression, and implicate CgFpr in virulence of C. glabrata.

Abstract 536: Lysosome Insufficiency in Atherosclerosis Prone DBA/2 Mouse Macrophages Associated With Impaired Autolysosome Formation and Lipid Drop Clearance

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Peggy Robinet ◽  
Jonathan D Smith
Keyword(s):  
Cathepsin L ◽  
Foam Cells ◽  
Lysosomal Degradation ◽  
Over Expression ◽  
Protein Levels ◽  
Lysosome Biogenesis ◽  
Mouse Macrophages ◽  
Macrophage Foam Cells ◽  
And Function

In a previous study, we identified autolysosome formation as the limiting step for turnover of cholesterol esters in lipid droplets of macrophage foam cells from the atherosclerosis sensitive DBA/2 strain compared to the atherosclerosis resistant AKR mouse strain. As autophagosome formation was similar in these two strains, we wanted to evaluate the role of lysosome biogenesis and function on autolysosome formation in AKR and DBA/2 cells. The transcription factor TFEB is a key regulator for lysosome biogenesis and function that positively regulates the expression of lysosomal enzymes and structural proteins, and controls lysosomes number. For all our studies, we cultured AKR and DBA/2 macrophages with or without acetylated LDL (AcLDL) for 24h. First, we analyzed TFEB protein expression by western blot. Upon loading, TFEB was increased in AKR (48%, p<0.01) but not DBA/2 cells leading to a 45% higher TFEB level in AKR vs. DBA/2 foam cells (p<0.05), suggesting that lysosome number and function may be impaired in DBA/2 foam cells. To assess lysosome function and number, cells were labeled with Lysotracker red DND-99 (LyT) and analyzed by flow cytometry. We found that AcLDL loading did not affect LyT intensity. However, in both unloaded and loaded conditions, DBA/2 cells exhibited a 30 to 50% lower LyT intensity suggesting that they have intrinsically decreased lysosome number/function. Lysosomal degradation capacity was assayed by incubation with DQ-ovalbumin and we observed a 27% decrease in lysosome function in DBA/2 vs. AKR foam cells (p<0.01). In addition, upon loading, the mature form of cathepsin L was increased in AKR (43%, p<0.05) but not DBA/2 cells. Together these data suggest an impairment of lysosomal degradation capacity in DBA/2 foam cells. Finally, we investigated the role of TPC2, a lysosomal membrane protein which over expression has been previously linked to a defect in autolysosome formation. We found that upon AcLDL loading TPC2 protein levels were increased by 35% in DBA/2 cells, which are defective in autolysosome formation, while they were unchanged in AKR cells. In conclusion, we found that DBA/2 vs. AKR foam cells express more TPC2 and have fewer and/or dysfunctional lysosomes that may explain the autolysosome formation defect in these cells.

scholarly journals Forms, Crosstalks, and the Role of Phospholipid Biosynthesis in Autophagy

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Leanne Pereira ◽  
John Paul Girardi ◽  
Marica Bakovic
Keyword(s):  
Phospholipid Synthesis ◽  
Phospholipid Biosynthesis ◽  
Lysosomal Degradation ◽  
Specific Mechanism ◽  
Membrane Formation ◽  
Cytoplasmic Material ◽  
Specific Proteins ◽  
Chaperone Mediated Autophagy ◽  
Periods Of Stress

Autophagy is a highly conserved cellular process occurring during periods of stress to ensure a cell's survival by recycling cytosolic constituents and making products that can be used in energy generation and other essential processes. Three major forms of autophagy exist according to the specific mechanism through which cytoplasmic material is transported to a lysosome. Chaperone-mediated autophagy is a highly selective form of autophagy that delivers specific proteins for lysosomal degradation. Microautophagy is a less selective form of autophagy that occurs through lysosomal membrane invaginations, forming tubes and directly engulfing cytoplasm. Finally, macroautophagy involves formation of new membrane bilayers (autophagosomes) that engulf cytosolic material and deliver it to lysosomes. This review provides new insights on the crosstalks between different forms of autophagy and the significance of bilayer-forming phospholipid synthesis in autophagosomal membrane formation.

scholarly journals Rotenone Upregulates Alpha-Synuclein and Myocyte Enhancer Factor 2D Independently from Lysosomal Degradation Inhibition

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Gessica Sala ◽  
Alessandro Arosio ◽  
Giovanni Stefanoni ◽  
Laura Melchionda ◽  
Chiara Riva ◽  
...  
Keyword(s):  
Ammonium Chloride ◽  
De Novo ◽  
Protective Role ◽  
Alpha Synuclein ◽  
Limited Information ◽  
Lysosomal Degradation ◽  
Protective Function ◽  
Protein Levels ◽  
Nuclear Levels ◽  
Chaperone Mediated Autophagy

Dysfunctions of chaperone-mediated autophagy (CMA), the main catabolic pathway for alpha-synuclein, have been linked to the pathogenesis of Parkinson’s disease (PD). Since till now there is limited information on how PD-related toxins may affect CMA, in this study we explored the effect of mitochondrial complex I inhibitor rotenone on CMA substrates, alpha-synuclein and MEF2D, and effectors, lamp2A and hsc70, in a human dopaminergic neuroblastoma SH-SY5Y cell line. Rotenone induced an upregulation of alpha-synuclein and MEF2D protein levels through the stimulation of theirde novosynthesis rather than through a reduction of their CMA-mediated degradation. Moreover, increased MEF2D transcription resulted in higher nuclear protein levels that exert a protective role against mitochondrial dysfunction and oxidative stress. These results were compared with those obtained after lysosome inhibition with ammonium chloride. As expected, this toxin induced the cytosolic accumulation of both alpha-synuclein and MEF2D proteins, as the result of the inhibition of their lysosome-mediated degradation, while, differently from rotenone, ammonium chloride decreased MEF2D nuclear levels through the downregulation of its transcription, thus reducing its protective function. These results highlight that rotenone affects alpha-synuclein and MEF2D protein levels through a mechanism independent from lysosomal degradation inhibition.

scholarly journals Role of the transcriptional factors FOXO1 and PPARG on gene expression of SLC2A4 in endometrial tissue from women with polycystic ovary syndrome

Reproduction ◽  
2010 ◽  
Vol 140 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Karla Kohan ◽  
Rodrigo Carvajal ◽  
Fernando Gabler ◽  
David Vantman ◽  
Carmen Romero ◽  
...  
Keyword(s):  
Gene Expression ◽  
Polycystic Ovary Syndrome ◽  
Western Blot ◽  
Polycystic Ovary ◽  
Subcellular Location ◽  
Peroxisome Proliferator ◽  
Ovary Syndrome ◽  
Protein Levels ◽  
Gene And Protein Expression

Fifty to seventy percent of patients with polycystic ovary syndrome (PCOS) present hyperinsulinemia. On the other hand, reports indicate that forkhead box class O 1 (FOXO1) and peroxisome proliferator-activated receptor-γ (PPARG) are involved in the insulin signaling pathway, regulating the gene expression of SLC2A4 (GLUT4). The negative effect of FOXO1 over PPARG transcription disappears when FOXO1 is phosphorylated (p-FOXO1) and excluded from the nucleus, whereas PPARG can suppress gene expression of SLC2A4. Scarce knowledge is available in endometrium of women with PCOS and hyperinsulinemia (PCOSE h-Ins) about the role of these factors. We aimed to evaluate whether the endocrine and metabolic status of PCOS modify the levels of gene and protein expression of FOXO1, PPARG, and SLC2A4 in the endometria from hyperinsulinemic PCOS women compared with controls. In endometria from control (CE,n=7) or PCOSE h-Ins (n=7), we determined the subcellular location and protein levels of p-FOXO1Ser319 and FOXO1/FOXO4 by immunohistochemistry and western blot respectively; gene and/or protein levels of PPARG and SLC2A4 were evaluated by RT-PCR and/or western blot. Cytoplasm location for FOXO1 and p-FOXO1Ser319 was immunodetected in both groups of endometria, showing significantly higher staining in PCOSE h-Ins for these proteins (P<0.05). In PCOSE h-Ins, gene and protein levels of PPARG were significantly higher than in CE, whereasSLC2A4mRNA was decreased (P<0.05). In conclusion, the derepression of PPARG transcription by the high levels of p-FOXO1Ser319 could partially account for the lower levels of SLC2A4 found in PCOSE h-Ins, suggesting an alteration of the endometrial function in these patients.

scholarly journals Upregulation of TLR1, TLR2, TLR4, and IRAK-2 Expression During ML-1 Cell Differentiation to Macrophages: Role in the Potentiation of Cellular Responses to LPS and LTA

ISRN Oncology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kassim Traore ◽  
Barry Zirkin ◽  
Rajesh K. Thimmulappa ◽  
Shyam Biswal ◽  
Michael A. Trush
Keyword(s):  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Cell Differentiation ◽  
Inflammatory Cytokines ◽  
Cellular Responses ◽  
Signaling Cascade ◽  
Oxygen Species ◽  
Induced Differentiation ◽  
Protein Levels

12-O-tetradecanoylphorbol 13-acetate (TPA) induces the differentiation of human myeloid ML-1 cells to macrophages. In the current study, the expression, responsiveness, and regulation of toll-like receptors (TLRs) in TPA-induced ML-1-derived macrophages were investigated. We have found that TPA-induced differentiation of ML-1 cells was accompanied by the upregulation of TLR1, TLR2, TLR4, and CD14 expression at both the mRNA and protein levels. Interestingly, TLR1 and TLR4 protein expression on ML-1 cells could be blocked by pretreatment with U0126, suggesting the role of an Erk1/2-induced differentiation signal in this process. In addition, the expression of IRAK-2, a key member of the TLR/IRAK-2/NF-κB-dependent signaling cascade was also induced in response to TPA. Accordingly, we demonstrated an increased cellular release of inflammatory cytokines (TNF-α and various interleukins) upon stimulation with LPS and LTA ligands for TLR4 and TLR2, respectively. Furthermore, using luminol-dependent chemiluminescence, addition of LPS and LTA induces a sustained DPI-inhibitable generation of reactive oxygen species (ROS) by the differentiated ML-1 cells. Together, these data suggest that the increase in the responsiveness of TPA-treated ML-1 cells to LPS and LTA occurs in response to the upregulation of their respective receptors as well as an induction of the IRAK-2 gene expression.

Sign in / Sign up

Export Citation Format

Share Document