RESUMO
Vitamin A (retinol) is distributed via the blood bound to its specific carrier protein, retinol-binding protein 4 (RBP4). Retinol-loaded RBP4 is secreted into the circulation exclusively from hepatocytes, thereby mobilizing hepatic retinoid stores that represent the major vitamin A reserves in the body. The relevance of extrahepatic retinoid stores for circulating retinol and RBP4 levels that are usually kept within narrow physiological limits is unknown. Here, we show that fasting affects retinoid mobilization in a tissue-specific manner, and that hormone-sensitive lipase (HSL) in adipose tissue is required to maintain serum concentrations of retinol and RBP4 during fasting in mice. We found that extracellular retinol-free apo-RBP4 induces retinol release by adipocytes in an HSL-dependent manner. Consistently, global or adipocyte-specific HSL deficiency leads to an accumulation of retinoids in adipose tissue and a drop of serum retinol and RBP4 during fasting, which affects retinoid-responsive gene expression in eye and kidney and lowers renal retinoid content. These findings establish a novel crosstalk between liver and adipose tissue retinoid stores for the maintenance of systemic vitamin A homeostasis during fasting.
Assuntos
Adipócitos , Jejum , Proteínas Plasmáticas de Ligação ao Retinol , Esterol Esterase , Vitamina A , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Proteínas Plasmáticas de Ligação ao Retinol/genética , Animais , Vitamina A/metabolismo , Vitamina A/sangue , Jejum/metabolismo , Camundongos , Adipócitos/metabolismo , Esterol Esterase/metabolismo , Esterol Esterase/genética , Fígado/metabolismo , Tecido Adiposo/metabolismo , Camundongos Knockout , Camundongos Endogâmicos C57BLRESUMO
In Saccharomyces cerevisiae, Pah1 phosphatidate (PA) phosphatase, which catalyzes the Mg2+-dependent dephosphorylation of PA to produce diacylglycerol, plays a key role in utilizing PA for the synthesis of the neutral lipid triacylglycerol and thereby controlling the PA-derived membrane phospholipids. The enzyme function is controlled by its subcellular location as regulated by phosphorylation and dephosphorylation. Pah1 is initially inactivated in the cytosol through phosphorylation by multiple protein kinases and then activated via its recruitment and dephosphorylation by the protein phosphatase Nem1-Spo7 at the nuclear/endoplasmic reticulum membrane where the PA phosphatase reaction occurs. Many of the protein kinases that phosphorylate Pah1 have yet to be characterized with the identification of the target residues. Here, we established Pah1 as a bona fide substrate of septin-associated Hsl1, a protein kinase involved in mitotic morphogenesis checkpoint signaling. The Hsl1 activity on Pah1 was dependent on reaction time and the amounts of protein kinase, Pah1, and ATP. The Hsl1 phosphorylation of Pah1 occurred on Ser-748 and Ser-773, and the phosphorylated protein exhibited a 5-fold reduction in PA phosphatase catalytic efficiency. Analysis of cells expressing the S748A and S773A mutant forms of Pah1 indicated that Hsl1-mediated phosphorylation of Pah1 promotes membrane phospholipid synthesis at the expense of triacylglycerol, and ensures the dependence of Pah1 function on the Nem1-Spo7 protein phosphatase. This work advances the understanding of how Hsl1 facilitates membrane phospholipid synthesis through the phosphorylation-mediated regulation of Pah1.
RESUMO
4-hydroxyphenylpyruvate dioxygenase (HPPD) Inhibitor Sensitive 1 (HIS1) is an endogenous gene of rice, conferring broad-spectrum resistance to ß-triketone herbicides. Similar genes, known as HIS1-like genes (HSLs), exhibit analogous functions and can complement the herbicide-resistant characteristics endowed by HIS1. The identification of HIS1 and HSLs represents a valuable asset, as the intentional pairing of herbicides with resistance genes emerges as an effective strategy for crop breeding. Encoded by HIS1 is a Fe(II)/2-oxoglutarate-dependent oxygenase responsible for detoxifying ß-triketone herbicides through hydroxylation. However, the precise structure supporting this function remains unclear. This work, which determined the crystal structure of HIS1, reveals a conserved core motif of Fe(II)/2-oxoglutarate-dependent oxygenase and pinpoints the crucial residue dictating substrate preference between HIS1 and HSL.
Assuntos
4-Hidroxifenilpiruvato Dioxigenase , Herbicidas , Oryza , Oryza/metabolismo , 4-Hidroxifenilpiruvato Dioxigenase/química , 4-Hidroxifenilpiruvato Dioxigenase/genética , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Cicloexanonas/química , Cicloexanonas/farmacologia , Ácidos Cetoglutáricos , Oxigenases , Herbicidas/farmacologia , Compostos Ferrosos , Inibidores Enzimáticos/farmacologiaRESUMO
Serratia marcescens is commonly noted to be an opportunistic pathogen and is often associated with nosocomial infections. In addition to its high antibiotic resistance, it exhibits a wide range of virulence factors that confer pathogenicity. Targeting quorum sensing (QS) presents a potential therapeutic strategy for treating bacterial infections caused by S. marcescens, as it regulates the expression of various virulence factors. Inhibiting QS can effectively neutralize S. marcescens' bacterial virulence without exerting stress on bacterial growth, facilitating bacterial eradication by the immune system. In this study, the antibacterial and anti-virulence properties of eugenol against Serratia sp. were investigated. Eugenol exhibited inhibitory effects on the growth of Serratia, with a minimal inhibitory concentration (MIC) value of 16.15 mM. At sub-inhibitory concentrations, eugenol also demonstrated antiadhesive and eradication activities by inhibiting biofilm formation. Furthermore, it reduced prodigiosin production and completely inhibited protease production. Additionally, eugenol effectively decreased swimming and swarming motilities in Serratia sp. This study demonstrated through molecular modeling, docking and molecular dynamic that eugenol inhibited biofilm formation and virulence factor production in Serratia by binding to the SmaR receptor and blocking the formation of the HSL-SmaR complex. The binding of eugenol to SmaR modulates biofilm formation and virulence factor production by Serratia sp. These findings highlight the potential of eugenol as a promising agent to combat S. marcescens infections by targeting its virulence factors through quorum sensing inhibition.
Assuntos
Percepção de Quorum , Serratia , Biofilmes , Eugenol/farmacologia , Serratia marcescens , Fatores de Virulência/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismoRESUMO
Pseudomonas aeruginosa (P. aeruginosa) biofilm formation is a crucial cause of enhanced antibiotic resistance. Quorum sensing (QS) is involved in regulating biofilm formation; QS inhibitors block the QS signaling pathway as a new strategy to address bacterial resistance. This study investigated the potential and mechanism of L-HSL (N-(3-cyclic butyrolactone)-4-trifluorophenylacetamide) as a QS inhibitor for P. aeruginosa. The results showed that L-HSL effectively inhibited the biofilm formation and dispersed the pre-formed biofilm of P. aeruginosa. The production of extracellular polysaccharides and the motility ability of P. aeruginosa were suppressed by L-HSL. C. elegans infection experiment showed that L-HSL was non-toxic and provided protection to C. elegans against P. aeruginosa infection. Transcriptomic analysis revealed that L-HSL downregulated genes related to QS pathways and biofilm formation. L-HSL exhibits a promising potential as a therapeutic drug for P. aeruginosa infection. KEY POINTS: ⢠Chemical synthesis of N-(3-cyclic butyrolactone)-4-trifluorophenylacetamide, named L-HSL. ⢠L-HSL does not generate survival pressure on the growth of P. aeruginosa and can inhibit the QS system. ⢠KEGG enrichment analysis found that after L-HSL treatment, QS-related genes were downregulated.
Assuntos
4-Butirolactona , Biofilmes , Caenorhabditis elegans , Pseudomonas aeruginosa , Percepção de Quorum , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/genética , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Percepção de Quorum/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/microbiologia , Animais , 4-Butirolactona/análogos & derivados , 4-Butirolactona/farmacologia , 4-Butirolactona/metabolismo , Antibacterianos/farmacologia , Perfilação da Expressão Gênica , Homosserina/análogos & derivados , Homosserina/metabolismo , Homosserina/farmacologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacosRESUMO
Branched esters of palmitic acid and hydroxy stearic acid are antiinflammatory and antidiabetic lipokines that belong to a family of fatty acid (FA) esters of hydroxy fatty acids (HFAs) called FAHFAs. FAHFAs themselves belong to oligomeric FA esters, known as estolides. Glycerol-bound FAHFAs in triacylglycerols (TAGs), named TAG estolides, serve as metabolite reservoir of FAHFAs mobilized by lipases upon demand. Here, we characterized the involvement of two major metabolic lipases, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), in TAG estolide and FAHFA degradation. We synthesized a library of 20 TAG estolide isomers with FAHFAs varying in branching position, chain length, saturation grade, and position on the glycerol backbone and developed an in silico mass spectra library of all predicted catabolic intermediates. We found that ATGL alone or coactivated by comparative gene identification-58 efficiently liberated FAHFAs from TAG estolides with a preference for more compact substrates where the estolide branching point is located near the glycerol ester bond. ATGL was further involved in transesterification and remodeling reactions leading to the formation of TAG estolides with alternative acyl compositions. HSL represented a much more potent estolide bond hydrolase for both TAG estolides and free FAHFAs. FAHFA and TAG estolide accumulation in white adipose tissue of mice lacking HSL argued for a functional role of HSL in estolide catabolism in vivo. Our data show that ATGL and HSL participate in the metabolism of estolides and TAG estolides in distinct manners and are likely to affect the lipokine function of FAHFAs.
Assuntos
Lipase/metabolismo , Esterol Esterase/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Ésteres/química , Ácidos Graxos/metabolismo , Feminino , Células HEK293 , Humanos , Lipólise/fisiologia , Metabolismo/fisiologia , Camundongos , Camundongos Knockout , Ácido Palmítico/metabolismo , Ácidos Esteáricos/metabolismo , Triglicerídeos/metabolismoRESUMO
At the physiological level, the interplay between auxin and ethylene has long been recognized as crucial for the regulation of organ abscission in plants. However, the underlying molecular mechanisms remain unknown. Here, we identified transcription factors involved in indoleacetic acid (IAA) and ethylene (ET) signaling that directly regulate the expression of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) and its receptor HAESA (HAE), which are key components initiating abscission. Specifically, litchi IDA-like 1 (LcIDL1) interacts with the receptor HAESA-like 2 (LcHSL2). Through in vitro and in vivo experiments, we determined that the auxin response factor LcARF5 directly binds and activates both LcIDL1 and LcHSL2. Furthermore, we found that the ETHYLENE INSENSITIVE 3-like transcription factor LcEIL3 directly binds and activates LcIDL1. The expression of IDA and HSL2 homologs was enhanced in LcARF5 and LcEIL3 transgenic Arabidopsis plants, but reduced in ein3 eil1 mutants. Consistently, the expressions of LcIDL1 and LcHSL2 were significantly decreased in LcARF5- and LcEIL3-silenced fruitlet abscission zones (FAZ), which correlated with a lower rate of fruitlet abscission. Depletion of auxin led to an increase in 1-aminocyclopropane-1-carboxylic acid (the precursor of ethylene) levels in the litchi FAZ, followed by abscission activation. Throughout this process, LcARF5 and LcEIL3 were induced in the FAZ. Collectively, our findings suggest that the molecular interactions between litchi AUXIN RESPONSE FACTOR 5 (LcARF5)-LcIDL1/LcHSL2 and LcEIL3-LcIDL1 signaling modules play a role in regulating fruitlet abscission in litchi and provide a long-sought mechanistic explanation for how the interplay between auxin and ethylene is translated into the molecular events that initiate abscission.
Assuntos
Etilenos , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Litchi , Proteínas de Plantas , Transdução de Sinais , Ácidos Indolacéticos/metabolismo , Etilenos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais/genética , Litchi/metabolismo , Litchi/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Plantas Geneticamente Modificadas , Frutas/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimentoRESUMO
To our best knowledge, there are no non-invasive and painless means for the diagnosis and treatment of intestinal bleeding as of now, especially the segment of intestine that cannot be reached by endoscopy. We proposed an intelligent intestinal bleeding diagnosis and treatment capsule (IBDTC) system for the first time to diagnose and treat intestinal bleeding with low power consumption, estimated to be about 2.16mW. A hue-saturation-light (HSL) color space method was applied to diagnose bleeding according to H (hue) values of the film dyed by blood. A MEMS-based micro-igniter works as the critical component of the micro-thruster that houses the propellant (74.6% potassium nitrate, 11.9% sulfur, 13.5% charcoal) and the detonating agent (dinitrodiazophenol), to help release drug. Bleeding detection and ignition tests were performed to justify its feasibility and reliability. Results demonstrated that the bleeding diagnosis module of the IBDTC can effectively detect bleeding and the micro-igniter can successfully ignite the propellant. Owing to its simplicity and intelligence, the IBDTC system will pave a way for future accurate treatment of small intestinal bleeding with no injury, no pain, no complicated supporting equipment, no need for in vitro operation and positioning.
Assuntos
Endoscopia por Cápsula , Humanos , Reprodutibilidade dos Testes , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/terapia , Inteligência , CorRESUMO
KEY MESSAGE: RbIDL1 and RbIDL4 are up-regulated in an ethylene-responsive manner during rose petal abscission and restored the Arabidopsis ida-2 mutant abscission defect suggesting functional conservation of the IDA pathway in rose. Abscission is an ethylene-regulated developmental process wherein plants shed unwanted organs in a controlled manner. The INFLORESCENCE DEFICIENT IN ABSCISSION family has been identified as a key regulator of abscission in Arabidopsis, encoding peptides that interact with receptor-like kinases to activate abscission. Loss of function ida mutants show abscission deficiency in Arabidopsis. Functional conservation of the IDA pathway in other plant abscission processes is a matter of interest given the discovery of these genes in several plants. We have identified four members of the INFLORESCENCE DEFICIENT IN ABSCISSION-LIKE family from the ethylene-sensitive, early-abscising fragrant rose, Rosa bourboniana. All four are conserved in sequence and possess well-defined PIP, mIDa and EPIP motifs. Three of these, RbIDL1, RbIDL2 and RbIDL4 show a three-fourfold increase in transcript levels in petal abscission zones (AZ) during ethylene-induced petal abscission as well as natural abscission. The genes are also expressed in other floral tissues but respond differently to ethylene in these tissues. RbIDL1 and RbIDL4, the more prominently expressed IDL genes in rose, can complement the abscission defect of the Arabidopsis ida-2 mutant; while, promoters of both genes can drive AZ-specific expression in an ethylene-responsive manner even in Arabidopsis silique AZs indicating recognition of AZ-specific and ethylene-responsive cis elements in their promoters by the abscission machinery of rose as well as Arabidopsis.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Inflorescência/metabolismo , Flores/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Etilenos/farmacologia , Etilenos/metabolismo , Plantas/metabolismo , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Phthalic acid esters (PAEs), which are widespread environmental contaminants, can be efficiently biodegraded, mediated by enzymes such as hydrolases. Despite great advances in the characterization of PAE hydrolases, which are the most important enzymes in the process of PAE degradation, their molecular catalytic mechanism has rarely been systematically investigated. Acinetobacter sp. LUNF3, which was isolated from contaminated soil in this study, demonstrated excellent PAE degradation at 30 °C and pH 5.0-11.0. After sequencing and annotating the complete genome, the gene dphAN1, encoding a novel putative PAE hydrolase, was identified with the conserved motifs catalytic triad (Ser201-Asp295-His325) and oxyanion hole (H127GGG130). DphAN1 can hydrolyze DEP (diethyl phthalate), DBP (dibutyl phthalate) and BBP (benzyl butyl phthalate). The high activity of DphAN1 was observed under a wide range of temperature (10-40 °C) and pH (6.0-9.0). Moreover, the metal ions (Fe2+, Mn2+, Cr2+ and Fe3+) and surfactant TritonX-100 significantly activated DphAN1, indicating a high adaptability and tolerance of DphAN1 to these chemicals. Molecular docking revealed the catalytic triad, oxyanion hole and other residues involved in binding DBP. The mutation of these residues reduced the activity of DphAN1, confirming their interaction with DBP. These results shed light on the catalytic mechanism of DphAN1 and may contribute to protein structural modification to improve catalytic efficiency in environment remediation.
Assuntos
Acinetobacter , Hidrolases , Acinetobacter/genética , Simulação de Acoplamento Molecular , Clonagem MolecularRESUMO
Traditionally, lipolysis has been regarded as an enzymatic activity that liberates fatty acids as metabolic fuel. However, recent work has shown that novel substrates, including a variety of lipid compounds such as fatty acids and their derivatives, release lipolysis products that act as signaling molecules and transcriptional modulators. While these studies have expanded the role of lipolysis, the mechanisms underpinning lipolysis signaling are not fully defined. Here, we uncover a new mechanism regulating glucose uptake, whereby activation of lipolysis, in response to elevated cAMP, leads to the stimulation of thioredoxin-interacting protein (TXNIP) degradation. This, in turn, selectively induces glucose transporter 1 surface localization and glucose uptake in 3T3-L1 adipocytes and increases lactate production. Interestingly, cAMP-induced glucose uptake via degradation of TXNIP is largely dependent upon adipose triglyceride lipase (ATGL) and not hormone-sensitive lipase or monoacylglycerol lipase. Pharmacological inhibition or knockdown of ATGL alone prevents cAMP-dependent TXNIP degradation and thus significantly decreases glucose uptake and lactate secretion. Conversely, overexpression of ATGL amplifies the cAMP response, yielding increased glucose uptake and lactate production. Similarly, knockdown of TXNIP elicits enhanced basal glucose uptake and lactate secretion, and increased cAMP further amplifies this phenotype. Overexpression of TXNIP reduces basal and cAMP-stimulated glucose uptake and lactate secretion. As a proof of concept, we replicated these findings in human primary adipocytes and observed TXNIP degradation and increased glucose uptake and lactate secretion upon elevated cAMP signaling. Taken together, our results suggest a crosstalk between ATGL-mediated lipolysis and glucose uptake.
Assuntos
Proteínas de Transporte/genética , Transportador de Glucose Tipo 1/genética , Glucose/metabolismo , Lipase/genética , Lipólise/genética , Tiorredoxinas/genética , Células 3T3-L1 , Adipócitos/enzimologia , Adipócitos/metabolismo , Animais , AMP Cíclico/metabolismo , AMP Cíclico/farmacologia , Glucose/genética , Humanos , Ácido Láctico/biossíntese , Ácido Láctico/metabolismo , Camundongos , Proteólise/efeitos dos fármacos , Esterol Esterase/genéticaRESUMO
Hormone-sensitive lipase (HSL) is a key enzyme in animal fat metabolism and is involved in the rate-limiting step of catalyzing the decomposition of fat and cholesterol. It also plays an important regulatory role in maintaining seminiferous epithelial structure, androgen synthesis and primordial germ cell differentiation. We previously reported that HSL is involved the synthesis of steroids in Bactrian camels, although it is unclear what role it plays in testicular development. The present study was conducted to characterize the biological function and expression pattern of the HSL gene in the hypothalamic pituitary gonadal (HPG) axis and the development of testis in Bactrian camels. We analyzed cloning of the cDNA sequence of the HSL gene of Bactrian camels by RT-PCR, as well as the structural features of HSL proteins, using bioinformatics software, such as ProtParam, TMHMM, Signal P 4.1, SOPMA and MEGA 7.0. We used qRT-PCR, Western blotting and immunofluorescence staining to clarify the expression pattern of HSL in the HPG axis and testis of two-week-old (2W), two-year-old (2Y), four-year-old (4Y) and six-year-old (6Y) Bactrian camels. According to sequence analysis, the coding sequence (CDS) region of the HSL gene is 648 bp in length and encodes 204 amino acids. According to bioinformatics analysis, the nucleotide and amino acid sequence of Bactrian camel HSL are most similar to those of Camelus pacos and Camelusdromedarius, with the lowest sequence similarity with Mus musculus. In adult Bactrian camel HPG axis tissues, both HSL mRNA and protein expression were significantly higher in the testis than in other tissues (hypothalamus, pituitary and pineal tissues) (p < 0.05). The expression of mRNA in the testis increased with age and was the highest in six-year-old testis (p < 0.01). The protein expression levels of HSL in 2Y and 6Y testis were clearly higher than in 2W and 4Y testis tissues (p < 0.01). Immunofluorescence results indicate that the HSL protein was mainly localized in the germ cells, Sertoli cells and Leydig cells from Bactrian camel testis, and strong positive signals were detected in epididymal epithelial cells, basal cells, spermatocytes and smooth muscle cells, with partially expression in hypothalamic glial cells, pituitary suspensory cells and pineal cells. According to the results of gene ontology (GO) analysis enrichment, HSL indirectly regulates the anabolism of steroid hormones through interactions with various targets. Therefore, we conclude that the HSL gene may be associated with the development and reproduction of Bactrian camels in different stages of maturity, and these results will contribute to further understanding of the regulatory mechanisms of HSL in Bactrian camel reproduction.
RESUMO
MAIN CONCLUSION: Based on the phenotypic, physiological and transcriptomic analysis, receptor-like kinase HAESA-like 1 was demonstrated to positively affect seed longevity in Arabidopsis. Seed longevity is very important for both genetic resource conservation and crop production. Receptor-like kinases (RLKs) are widely involved in plant growth, development and stress responses. However, the role of most RLKs, especially in seed longevity, is largely unknown. In this study, we report that Arabidopsis HAESA-like 1 (AtHSL1) positively regulated seed longevity. Disruption of HSL1 significantly decreased the germination rate to 50% at 7 days after cold stratification (DAC), compared with that of the wild type (93.5% at 7 DAC), after accelerated aging treatment. Expression of the HSL1 gene in hsl1 basically restored the defective phenotype (86.3%), while HSL1-overexpressing lines (98.3%) displayed slower accelerated aging than WT (93.5%). GUS staining revealed HSL1 was highly expressed universally, especially in young seedlings, mature seeds and embryos of imbibed seeds, and its expression could be induced by accelerated aging. No difference in the dyeing color and area of mucilage were identified between WT and hsl1. The soluble pectin content also was not different, while the adherent pectin content was significantly increased in hsl1. Global transcriptomics revealed that disruption of HSL1 mainly downregulated genes involved in trehalose synthesis, nucleotide sugar metabolism and protection and repair mechanisms. Therefore, an increase in adherent pectin content and downregulation of genes involved in trehalose synthesis may be the main reasons for decreasing seed longevity owing to disruption of HSL1 in Arabidopsis. Our work provides valuable information for understanding the function and mechanism of a receptor-like kinase, AtHSL1, in seed longevity.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Longevidade , Pectinas/metabolismo , Proteínas Repressoras/genética , Sementes , TrealoseRESUMO
AIMS: Hormone sensitive lipase (HSL), encoded by the LIPE gene, is involved in lipolysis. Based on prior animal and human studies, LIPE was analysed as a candidate gene for the development of type 2 diabetes (T2D) in a community-based sample of American Indians. MATERIALS AND METHODS: Whole-exome sequence data from 6782 participants with longitudinal clinical measures were used to identify variation in LIPE. RESULTS: Amongst the 16 missense variants identified, an Arg611Cys variant (rs34052647; Cys-allele frequency = 0.087) significantly associated with T2D (OR [95% CI] = 1.38 [1.17-1.64], p = 0.0002, adjusted for age, sex, birth year, and the first five genetic principal components) and an earlier onset age of T2D (HR = 1.22 [1.09-1.36], p = 0.0005). This variant was further analysed for quantitative traits related to T2D. Amongst non-diabetic American Indians, those with the T2D risk Cys-allele had increased insulin levels during an oral glucose tolerance test (0.07 SD per Cys-allele, p = 0.04) and a mixed meal test (0.08 log10 µU/ml per Cys-allele, p = 0.003), and had increased lipid oxidation rates post-absorptively and during insulin infusion (0.07 mg [kg estimated metabolic body size {EMBS}]-1 min-1 per Cys-allele for both, p = 0.01 and 0.009, respectively), compared to individuals with the non-risk Arg-allele. In vitro functional studies showed that cells expressing the Cys-allele had a 17.2% decrease in lipolysis under isoproterenol stimulation (p = 0.03) and a 21.3% decrease in lipase enzyme activity measured by using p-nitrophenyl butyrate as a substrate (p = 0.04) compared to the Arg-allele. CONCLUSION: The Arg611Cys variant causes a modest impairment in lipolysis, thereby affecting glucose homoeostasis and risk of T2D.
Assuntos
Diabetes Mellitus Tipo 2 , Esterol Esterase , Animais , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Insulina/metabolismo , Lipólise/genética , Esterol Esterase/genética , Esterol Esterase/metabolismo , Indígena Americano ou Nativo do AlascaRESUMO
BACKGROUND: Hormone-sensitive lipase (HSL) is a neutral lipase capable of hydrolysing various kinds of lipids. In comparison to single human Hormone Sensitive Lipase (hHSL), that is induced under nutritional stress, twelve serine hydrolases are annotated as HSL in Mycobacterium tuberculosis (mHSL). Mycobacterium is exposed to multiple stresses inside the host. Therefore, the present study was carried out to investigate if mHSL are also expressed under stress condition and if there is any correlation between various stress conditions and expression pattern of mHSL. METHODS AND RESULTS: The expression pattern of mHSL under different environmental conditions (in-vitro and ex-vivo) were studied using qRT-PCR in M. tuberculosis H37Ra strain with 16 S rRNA as internal control. Out of 12, only two genes (lipU and lipY) were expressed at very low level in mid log phase culture under aerobic conditions, while 9 genes were expressed at stationary phase of growth. Ten mHSLs were expressed post-infection under ex-vivo conditions in time dependent manner. LipH and lipQ did not express at any time point under ex-vivo condition. The relative expression of most of the genes under individual stress was much higher than observed in ex-vivo conditions. The expression pattern of genes varied with change in stress condition. CONCLUSIONS: Different sets of mHSL genes were expressed under different individual stress conditions pointing towards the requirement of different mHSL to combat different stress conditions. Overall, most of the mHSLs have demonstrated stress dependent expression pointing towards their role in intracellular survival of mycobacteria.
Assuntos
Mycobacterium tuberculosis , Tuberculose , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Lipase/genética , Lipase/metabolismo , Mycobacterium tuberculosis/metabolismo , Esterol Esterase/metabolismo , Tuberculose/microbiologiaRESUMO
Cortisol-producing adenoma (CPA) is composed of clear and compact cells. Clear cells are lipid abundant, and compact ones lipid poor but associated with higher production of steroid hormones. PRKACA mutation (PRKACA mt) in CPA patients was reported to be associated with more pronounced clinical manifestation of Cushing's syndrome. In this study, we examined the association of histological features and genotypes with cholesterol uptake receptors and synthetic enzymes in 40 CPA cases, and with the quantitative results obtained by gas chromatography-mass spectrometry (GC-MS) analysis in 33 cases to explore their biological and clinical significance. Both cholesterol uptake receptors and synthetic enzymes were more abundant in compact cells. GC-MS analysis demonstrated that the percentage of compact cells was inversely correlated with the concentrations of cholesterol and cholesterol esters, and positively with the activity of cholesterol biosynthesis from cholesterol esters. In addition, hormone-sensitive lipase (HSL), which catalyzes cholesterol biosynthesis from cholesterol esters, tended to be more abundant in compact cells of PRKACA mt CPAs. These results demonstrated that both cholesterol uptake and biosynthesis were more pronounced in compact cells in CPA. In addition, more pronounced HSL expression in compact cells of PRKACA mt CPA could contribute to their more pronounced clinical manifestation.
Assuntos
Adenoma , Síndrome de Cushing , Adenoma/genética , Adenoma/metabolismo , Ésteres do Colesterol , Síndrome de Cushing/metabolismo , Genótipo , Humanos , Hidrocortisona/metabolismoRESUMO
Hormone-sensitive lipase (HSL) was considered as an essential enzyme in glucolipid metabolism. It has been proposed to be a lead candidate gene for genetic markers of lipid deposition in livestock. The aim of this study was to identify sequence variants (SVs) of the bovine HSL gene and evaluate the relations to intramuscular fat in two indigenous Chinese beef cattle breeds. Expression analysis by quantitative real-time polymerase chain reactions (qPCR) indicated that expression levels of bovine HSL gene were highest in the perirenal fat and heart within two different age stage (adult and calf), respectively. Five SVs were identified by direct DNA sequencing, which included four missense mutations (g.16563C>T, g.16734G>A, g.16896A>G, g.17388G>T) in exon 8 and a synonymous mutation (g.17402C>T) in exon 9. Population genetic analysis showed that except for g.16563C>T and g.17402C>T, all the other detected SVs strongly affected the bovine intramuscular fat content (P < 0.01 or P < 0.05). The individuals with Hap5/5 diplotypes (CC-GG-GG-GG-CC) was highly significantly associated with intramuscular fat content than the other diplotypes (P < 0.01). The above results suggested that the HSL gene can used as potential candidate markers gene for the beef breed improvement through marker assisted selection in Chinese cattle breeds.
Assuntos
Tecido Adiposo/metabolismo , Bovinos/genética , Músculo Esquelético/metabolismo , Polimorfismo de Nucleotídeo Único , Carne Vermelha , Esterol Esterase/genética , Sequência de Aminoácidos , Animais , Estudos de Associação Genética , Haplótipos , Desequilíbrio de Ligação , Especificidade da Espécie , Esterol Esterase/químicaRESUMO
Hyperspectral LiDAR (HSL) is a new remote sensing detection method with high spatial and spectral information detection ability. In the process of laser scanning, the laser echo intensity is affected by many factors. Therefore, it is necessary to calibrate the backscatter intensity data of HSL. Laser incidence angle is one of the important factors that affect the backscatter intensity of the target. This paper studied the radiometric calibration method of incidence angle effect for HSL. The reflectance of natural surfaces can be simulated as a combination of specular reflection and diffuse reflection. The linear combination of the Lambertian model and Beckmann model provides a comprehensive theory that can be applied to various surface conditions, from glossy to rough surfaces. Therefore, an adaptive threshold radiometric calibration method (Lambertian-Beckmann model) is proposed to solve the problem caused by the incident angle effect. The relationship between backscatter intensity and incident angle of HSL is studied by combining theory with experiments, and the model successfully quantifies the difference between diffuse and specular reflectance coefficients. Compared with the Lambertian model, the proposed model has higher calibration accuracy, and the average improvement rate to the samples in this study was 22.67%. Compared with the results before calibration with the incidence angle of less than 70°, the average improvement rate of the Lambertian-Beckmann model was 62.26%. Moreover, we also found that the green leaves have an obvious specular reflection effect near 650-720 nm, which might be related to the inner microstructure of chlorophyll. The Lambertian-Beckmann model was more helpful to the calibration of leaves in the visible wavelength range. This is a meaningful and a breakthrough exploration for HSL.
RESUMO
BACKGROUD: Many Gram-negative bacteria use N-acyl-homoserine lactones (AHLs) to communicate each other and to coordinate their collective behaviors. Recently, accumulating evidence shows that host plants are able to sense and respond to bacterial AHLs. Once primed, plants are in an altered state that enables plant cells to more quickly and/or strongly respond to subsequent pathogen infection or abiotic stress. RESULTS: In this study, we report that pretreatment with N-3-oxo-octanoyl-homoserine lactone (3OC8-HSL) confers resistance against the pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 (PstDC3000) in Arabidopsis. Pretreatment with 3OC8-HSL and subsequent pathogen invasion triggered an augmented burst of hydrogen peroxide, salicylic acid accumulation, and fortified expression of the pathogenesis-related genes PR1 and PR5. Upon PstDC3000 challenge, plants treated with 3OC8-HSL showed increased activities of defense-related enzymes including peroxidase, catalase, phenylalanine ammonialyase, and superoxide dismutase. In addition, the 3OC8-HSL-primed resistance to PstDC3000 in wild-type plants was impaired in plants expressing the bacterial NahG gene and in the npr1 mutant. Moreover, the expression levels of isochorismate synthases (ICS1), a critical salicylic acid biosynthesis enzyme, and two regulators of its expression, SARD1 and CBP60g, were potentiated by 3OC8-HSL pretreatment followed by pathogen inoculation. CONCLUSIONS: Our data indicate that 3OC8-HSL primes the Arabidopsis defense response upon hemibiotrophic bacterial infection and that 3OC8-HSL-primed resistance is dependent on the SA signaling pathway. These findings may help establish a novel strategy for the control of plant disease.
Assuntos
4-Butirolactona/análogos & derivados , Arabidopsis , Imunidade Vegetal/efeitos dos fármacos , Pseudomonas syringae/patogenicidade , Ácido Salicílico/metabolismo , 4-Butirolactona/farmacologia , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a Calmodulina/efeitos dos fármacos , Proteínas de Ligação a Calmodulina/genética , Proteínas de Ligação a Calmodulina/metabolismo , Genes de Plantas , Transferases Intramoleculares/efeitos dos fármacos , Transferases Intramoleculares/genética , Transferases Intramoleculares/metabolismo , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Percepção de Quorum/fisiologia , Transdução de Sinais/efeitos dos fármacosRESUMO
(1) Background: Acute administration of the cannabinoid receptor 1 (CB1R) inverse agonist Rimonabant (SR141716A) to fed Wistar rats was shown to elicit a rapid and short-lasting elevation of serum free fatty acids. (2) Methods: The effect of Rimonabant on lipolysis in isolated primary rat adipocytes was studied to raise the possibility for direct mechanisms not involving the (hypothalamic) CB1R. (3) Results: Incubation of these cells with Rimonabant-stimulated lipolysis to up to 25% of the maximal isoproterenol effect, which was based on both CB1R-dependent and independent mechanisms. The CB1R-dependent one was already effective at Rimonabant concentrations of less than 1 µM and after short-term incubation, partially additive to ß-adrenergic agonists and blocked by insulin and, in part, by adenosine deaminase, but not by propranolol. It was accompanied by protein kinase A (PKA)-mediated association of hormone-sensitive lipase (HSL) with lipid droplets (LD) and dissociation of perilipin-1 from LD. The CB1R-independent stimulation of lipolysis was observed only at Rimonabant concentrations above 1 µM and after long-term incubation and was not affected by insulin. It was recapitulated by a cell-free system reconstituted with rat adipocyte LD and HSL. Rimonabant-induced cell-free lipolysis was not affected by PKA-mediated phosphorylation of LD and HSL, but abrogated by phospholipase digestion or emulsification of the LD. Furthermore, LD isolated from adipocytes and then treated with Rimonabant (>1 µM) were more efficient substrates for exogenously added HSL compared to control LD. The CB1R-independent lipolysis was also demonstrated in primary adipocytes from fed rats which had been treated with a single dose of Rimonabant (30 mg/kg). (4) Conclusions: These data argue for interaction of Rimonabant (at high concentrations) with both the LD surface and the CB1R of primary rat adipocytes, each leading to increased access of HSL to LD in phosphorylation-independent and dependent fashion, respectively. Both mechanisms may lead to direct and acute stimulation of lipolysis at peripheral tissues upon Rimonabant administration and represent targets for future obesity therapy which do not encompass the hypothalamic CB1R.