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1.
Clin Cosmet Investig Dermatol ; 16: 3229-3239, 2023.
Article in English | MEDLINE | ID: mdl-37965102

ABSTRACT

Purpose: Epidermal keratinocytes with an abnormal glucose metabolism have been identified in psoriasis. Hexokinase 2 (HK2) is a crucial enzyme involved in glycolytic metabolic pathways. However, the expression of HK2 and its potential therapeutic effects in psoriasis remains unclear. This study aimed to investigate the expression pattern of HK2 and evaluate its therapeutic effects in psoriasis. Patients and Methods: A gene expression dataset (GSE121212) downloaded from the Gene Expression Omnibus (GEO) database was used to examine the expression of HK2 in psoriasis. HK2 RNA and protein expression were investigated in psoriasis vulgaris (n=5) and healthy (n=5) samples. Immunohistochemistry for HK2 was performed on psoriasis vulgaris (n=22) and healthy skin (n=10) samples. Additionally, HaCaT cells were treated with M5 (interleukin [IL]-17A, tumor necrosis factor-α, IL-1α, IL-22, and Oncostatin-M) to induce a psoriatic inflammation cell model. A mouse model of psoriatic inflammation was established using topical 5% imiquimod cream. Psoriasis-like cells and mouse models were treated with the HK2 inhibitor 3-bromopyruvate (3-BrPA). Cell proliferation, glucose consumption, and lactate production were assessed. Furthermore, the activation of nuclear factor-kappa B (NF-Kb) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) was investigated using Western blot analysis. Results: According to the GEO dataset, HK2 expression was significantly elevated in psoriasis. Upregulation of HK2 in psoriatic tissues was confirmed by quantitative real-time polymerase chain reaction and Western blotting. The immunohistochemistry score for HK2 was higher in psoriatic lesions than in healthy skin. 3-BrPA inhibited the proliferation and glycolysis of M5-stimulated HaCaT cells. Topical 3-BrPA ameliorated imiquimod-induced psoriasis-like dermatitis. Activation of NF-kB and NLRP3 was downregulated by 3-BrPA treatment. Conclusion: Our study revealed that the glycolytic enzyme HK2 was upregulated in psoriasis and that the HK2 inhibitor 3-BrPA exhibited therapeutic effects in psoriasis cell and mouse models.

2.
Clin Cosmet Investig Dermatol ; 16: 1641-1651, 2023.
Article in English | MEDLINE | ID: mdl-37396710

ABSTRACT

Purpose: Melanomas are highly malignant and rapidly develop drug resistance due to dysregulated apoptosis. Therefore, pro-apoptotic agents could be effective for the management of melanoma. Hydrogen sulfide is ubiquitous in the body, and exogenous hydrogen sulfide has been reported to show inhibitory and pro-apoptotic effects on cancer cells. However, whether high concentrations of exogenous hydrogen sulfide have pro-apoptotic effects on melanoma and its mechanisms remain unknown. Hence, this study aimed to explore the pro-apoptotic effects and mechanisms of exogenous hydrogen sulfide on the A375 melanoma cell line treated with a hydrogen sulfide donor (NaHS). Methods: The cell proliferation test, flow cytometric analysis, Hoechst 33258 staining, and Western blotting of B-cell lymphoma 2 and cleaved caspase-3 were used to explore the pro-apoptotic effects of hydrogen sulfide on A375 cells. The transcriptional profile of NaHS-treated A375 cells was further explored via high-throughput sequencing. Western blotting of phosphorylated inositol-requiring enzyme 1α (p-IRE1α), phosphorylated protein kinase R-like ER kinase (p-PERK), phosphorylated eukaryotic translation initiation factor 2α (p-eIF2α), C/EBP homologous protein, glucose-regulating protein 78, IRE1α, PERK, and eIF2α was performed to verify the changes in the transcriptional profile. Results: NaHS inhibited A375 melanoma cell proliferation and induced apoptosis. The endoplasmic reticulum stress unfolded protein response and apoptosis-associated gene expression was upregulated in NaHS-treated A375 melanoma cells. The overactivation of the unfolded protein response and increase in endoplasmic reticulum stress was verified at the protein level. Conclusion: Treatment with NaHS increased endoplasmic reticulum stress, which triggered the overactivation of the unfolded protein response and ultimately lead to melanoma cell apoptosis. The pro-apoptotic effect of NaHS suggests that it can be explored as a potential therapeutic agent in melanoma.

3.
Clin Cosmet Investig Dermatol ; 16: 1009-1018, 2023.
Article in English | MEDLINE | ID: mdl-37077860

ABSTRACT

Background: Anti-programmed cell death ligand-1 (anti-PD-L1) immunotherapy is often used for advanced urothelial carcinoma and melanoma, including amelanotic melanoma, a relatively rare subtype with little to no pigment in the tumor cells. However, cellular heterogeneity of amelanotic melanoma during or after anti-PD-L1 immunotherapy treatments has not been described. Purpose: To investigate cellular heterogeneity in acral amelanotic melanoma after immunotherapy exposure. Methods: We evaluated subtle visual changes of the melanoma by dermoscopy and performed a pathological examination to analyze the heterogeneity of microscopic morphological and immunohistochemistry changes. The cellular transcriptional heterogeneity and corresponding biological function profiles of the melanoma were determined by single-cell RNA sequencing (scRNA-seq). Results: The dermoscopic examination revealed black globules and scar-like depigmentation areas against a homogeneous red background. Pigmented and amelanotic melanoma cells were observed microscopically. The pigmented cells were large and contained melanin granules expressing Melan-A and HMB45; the amelanotic cells were small and did not express HMB45. Ki-67 immunohistochemical staining revealed that the pigmented melanoma cells had a higher proliferative ability than the amelanotic cells. scRNA-seq identified three cell clusters: amelanotic cell cluster 1, amelanotic cell cluster 2, and pigmented cell cluster. Furthermore, a pseudo-time trajectory analysis showed that amelanotic cell cluster 2 originated from amelanotic cell cluster 1 and transformed into the pigmented melanoma cell cluster. The expression pattern of melanin synthesis-related and lysosome-endosome-related genes in different cell clusters supported the cell cluster transformation results. Also, upregulated expression of cell cycle genes indicated that the pigmented melanoma cells had a high proliferative ability. Conclusion: Coexisting amelanotic and pigmented melanoma cells indicated cellular heterogeneity in an acral amelanotic melanoma from a patient who underwent immunotherapy treatment. Additionally, the pigmented melanoma cells acquired a higher proliferative ability than the amelanotic melanoma cells.

4.
J Invest Dermatol ; 143(3): 398-407.e5, 2023 03.
Article in English | MEDLINE | ID: mdl-36122800

ABSTRACT

Multiomic studies, including RNA sequencing, single-cell RNA sequencing, and epigenomics, can provide insight into the connection between anatomically heterogeneous gene expression profile of the skin and dermatoses-predisposed sites, in which RNA sequencing is essential. Therefore, in this study, 159 skin samples collected mainly from discarded normal skin tissue during surgical treatment for benign skin tumors were used for RNA sequencing. On the basis of cluster analysis, the skin was divided into four regions, with each region showing specific physiological characteristics through differentially expressed gene analysis. The results showed that the head and neck region, perineum, and palmoplantar area were closely associated with lipid metabolism, hormone metabolism, blood circulation, and related neural regulation, respectively. Transcription factor enrichment indicated that different regions were associated with the development of adjacent tissues. Specifically, the head and neck region, trunk and extremities, perineum, and palmoplantar area were associated with the central nervous, axial, urogenital, and vascular systems, respectively. The results were imported into an open website (https://dermvis.github.io/) for retrieval. Our transcriptomic data elucidated that human skin exhibits transcriptomic heterogeneity reflecting physiological and developmental variation at different anatomic sites and provided guidance for further studies on skin development and dermatoses predisposed sites.


Subject(s)
Skin Neoplasms , Transcriptome , Humans , Skin/metabolism , Gene Expression Profiling , Gene Expression Regulation , Skin Neoplasms/metabolism
6.
Yi Chuan ; 44(5): 383-397, 2022 May 20.
Article in English | MEDLINE | ID: mdl-35729696

ABSTRACT

During the development of the mammalian cardiovascular system, the formation of a mature and fully functional cardiovascular system needs the fine coordination of the morphogenesis of various molecules, cells, tissues, and organs. Abnormalities in these processes usually lead to serious congenital heart defects. The determination and maintenance of cell fate in multicellular organisms depend to a large extent on the precise timing and control of RNA polymerase II (Pol II) transcription, and the transcription Mediator complex plays an irreplaceable role in the Pol II transcription process. Mediator is an evolutionarily conserved multi-subunit protein complex, including four parts: head, middle, tail, and kinase. It is a functional bridge between transcription factors and basic transcription machines. In recent years, due to the key role of Mediator in the transcriptional regulation of gene expression, many of human heart diseases have been confirmed to be related to specific Mediator gene mutations, such as heart valve defects, translocation of the great arteries, DiGeorge syndrome and some cardiovascular diseases related to energy homeostasis. In this review, we summarize the role of Mediator in cardiovascular development and disease, focusing on the role of Mediator in the development of cardiovascular disease, and provides a broad idea for the research on Mediator-related cardiovascular system development and diseases.


Subject(s)
Mediator Complex , RNA Polymerase II , Animals , Cell Nucleus , Gene Expression Regulation , Humans , Mammals/genetics , Mediator Complex/genetics , Mediator Complex/metabolism , RNA Polymerase II/genetics , RNA Polymerase II/metabolism , Transcription Factors/genetics , Transcription, Genetic
7.
World J Clin Cases ; 10(7): 2301-2306, 2022 Mar 06.
Article in English | MEDLINE | ID: mdl-35321164

ABSTRACT

BACKGROUND: Leishmaniasis includes a range of chronic infections in humans and animals and can be caused by more than 20 species of Leishmania protozoa. The manifestations of leishmaniasis are diverse and dependent on the immune response capacity of the host and the type of Leishmania. In East Asia, leishmaniasis is relatively rare and prone to misdiagnosis and underdiagnosis. CASE SUMMARY: We report a case of a 36-year-old male with cutaneous leishmaniasis. The patient had been misdiagnosed with a bacterial skin infection and was given a dressing change and oral levofloxacin, which proved ineffective. Histopathological examination revealed amastigote (Leishman-Donovan body) in the histocytes, and nucleic acid sequencing proved that the pathogen was Leishmania major. The patient was treated successfully by regional injection of sodium gluconate (600 mg) three times. The ulcer healed and did not recur at 1.5-year follow-up. CONCLUSION: Skin ulcers caused by leishmaniasis are easily misdiagnosed in non-epidemic countries, yet it should not be overlooked.

8.
Mol Med Rep ; 22(4): 2715-2722, 2020 10.
Article in English | MEDLINE | ID: mdl-32945375

ABSTRACT

Psoriasis is one of the most common chronic inflammatory skin diseases, it is characterized by hyperproliferation of keratinocytes and infiltration of inflammatory cells. Several in vitro studies have reported that interleukin (IL)­22 is involved in excessive proliferation and abnormal differentiation of human keratinocytes. However, the association between IL­22 and CCAAT enhancer binding protein α (C/EBPα) in the pathogenesis of psoriasis remains unclear. Therefore, the present study aimed to investigate the association between IL­22 and C/EBPα, and the effects of IL­22 on the proliferation and differentiation of keratinocytes. Keratinocytes were treated with different concentrations of IL­22 (30, 60 and 90 ng/ml) and subsequently cells were collected at different time intervals. The expression levels of the key molecules of the mitogen­activated protein kinase (MAPK) signaling pathway were detected using western blot analysis. In addition, the effect of IL­22 on the proliferation rate of keratinocytes and the mRNA expression levels of C/EBPα were determined using a Cell Counting Kit­8 assay and reverse transcription­quantitative PCR, respectively. Furthermore, keratinocytes were transfected with C/EBPα small interfering (si)RNA or control using Lipofectamine® 2000. The results revealed that IL­22 significantly induced the proliferation of keratinocytes and the expression of phosphorylated (p)­JNK, p­ERK and p­p38 (P<0.05). Additionally, IL­22 significantly inhibited the differentiation of keratinocytes, and the mRNA and protein expression of C/EBPα (P<0.05). Furthermore, downregulation of C/EBPα increased the proliferation rate of keratinocytes and reduced the expression levels of cytokeratin 10 and involucrin. Therefore, these results suggested that the effect of IL­22 on the proliferation and differentiation of keratinocytes may be mediated via the regulation of the MAPK signaling pathway and the expression of C/EBPα.


Subject(s)
CCAAT-Enhancer-Binding Proteins/genetics , CCAAT-Enhancer-Binding Proteins/metabolism , Interleukins/pharmacology , Keratinocytes/cytology , Adolescent , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Child , Dose-Response Relationship, Drug , Foreskin/cytology , Foreskin/drug effects , Foreskin/metabolism , Gene Expression Regulation/drug effects , Humans , Keratin-10/metabolism , Keratinocytes/drug effects , Keratinocytes/metabolism , MAP Kinase Signaling System/drug effects , Male , Primary Cell Culture , Protein Precursors/metabolism , Interleukin-22
9.
PLoS One ; 8(12): e68827, 2013.
Article in English | MEDLINE | ID: mdl-24324571

ABSTRACT

BACKGROUND: Tumor necrosis factor-α (TNF-α) may play an important role in the recalcitrant inflammatory and hyperproliferative dermatosis of psoriasis, and there may be a relationship between TNF-α polymorphisms and psoriasis risk. METHODS: We performed a meta-analysis to evaluate the associations between TNF-α polymorphisms and psoriasis. Electronic searches of Pubmed, Embase, and Web of Science were performed for all publications on the associations between TNF-α polymorphisms and psoriasis through September 26, 2012. The pooled odds ratios (ORs) with their 95% confidence interval (95%CIs) were calculated to assess the associations. RESULTS: Sixteen case-control studies with a total of 2,253 psoriasis cases and 1,947 controls on TNF-α 308 G/A polymorphism and fourteen studies on TNF-α 238 G/A polymorphism with 2,104 cases and 1,838 controls were finally included into the meta-analysis. Overall, TNF-α 308 G/A polymorphism was significantly associated with decreased risk of psoriasis under three genetic comparison models (for A versus G: fixed-effects OR 0.71, 95%CI 0.62-0.82, P < 0.001; for AG versus GG: fixed-effects OR 0.67, 95%CI 0.57-0.78, P < 0.001; for AA/AG versus GG: fixed-effects OR 0.67, 95%CI 0.58-0.78, P < 0.001). In addition, TNF-α 238 G/A polymorphism was associated with increased risk of psoriasis under three genetic models (for A versus G: fixed-effects OR 2.46, 95%CI 2.04-2.96, P < 0.001; for AG versus GG: fixed-effects OR 2.69, 95%CI 2.20-3.28, P < 0.001; for AA/AG versus GG: fixed-effects OR 2.68, 95%CI 2.20-3.26, P < 0.001). Subgroup analysis by ethnicity identified a significant association between TNF-α 308 G/A polymorphism and decreased risk of psoriasis in both Caucasians and Asians and a significant association between TNF-α 238 G/A polymorphism and increased risk of psoriasis in Caucasians. CONCLUSIONS: The meta-analysis suggests that TNF-α 308 G/A polymorphism is associated with decreased risk of psoriasis, while TNF-α 238 G/A is associated with increased risk of psoriasis.


Subject(s)
Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Psoriasis/genetics , Tumor Necrosis Factor-alpha/genetics , Case-Control Studies , Databases, Bibliographic , Humans , Models, Genetic , Odds Ratio , Psoriasis/diagnosis , Risk
10.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 29(2): 113-6, 2013 Mar.
Article in Chinese | MEDLINE | ID: mdl-23772489

ABSTRACT

OBJECTIVE: To study the effect of Q-switched 1 064 nm Nd:YAG laser treatment on the proliferation of dermal collagen and expression of immunoglobulin binding protein/glucose related protein 78 (BiP/GRP78) in rats' skin and the mechanism of endoplasmic reticulum stress. METHODS: Dorsal skin of 25 Wistar rats was divided into two parts equally after hair removal. Q-switched 1 064nm Nd:YAG laser was applied to treat rats' dorsal skin for 4 times at an interval of 2 days in the experiment part. The control part received no laser treatments. The rats' dorsal skin samples were taken on the 14th and 30th day after laser treatment to measure the dermis thickness and collagen bundles under HE stain and to measure the hydroxyproline content by alkaline hydrolysis method after laser treatment. The expression of BiP/GRP78 was also detected by immunohistochemical method. Statistics was used to analyze the data. RESULTS: The dermis thickness increased by 29. 6% on the 14th day and 16.7% on the 30th day after laser treatment. The collagen bundles became thicker and denser. The hydroxyproline in the skin was also raised after laser treatment (P < 0.05). The immunohistochemical result showed the expression of BiP/GRP78 increased to 100% after laser treatment, showing a significant difference from the control group(X2 = 28.76, P < 0.01). CONCLUSIONS: The Q-switched 1064 nm Nd:YAG laser treatment can induce endoplasmic reticulum stress, so as to enhance the protein folding and synthesizing precisely. The proliferation of dermis collagen is the base of effect of non-ablative skin rejuvenation.


Subject(s)
Endoplasmic Reticulum Stress , Lasers, Solid-State , Rejuvenation , Skin/radiation effects , Animals , Female , Hydroxyproline/chemistry , Rats , Rats, Wistar , Skin Aging
11.
J Int Med Res ; 41(2): 365-70, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23569025

ABSTRACT

OBJECTIVES: To investigate pigment epithelium-derived factor (PEDF) mRNA and protein levels in condyloma acuminatum, and their relationship with angiogenesis and keratinocyte proliferation. METHODS: Lesions from male patients with condyloma acuminatum and skin from healthy male (control) subjects were collected. Levels of PEDF protein and its corresponding mRNA (SERPINF1) were determined via Western blotting and reverse transcription-polymerase chain reaction, respectively. Immunohistochemical staining for Ki-67 and CD34 was performed to calculate keratinocyte proliferation index (PI) and microvessel density (MVD), respectively. RESULTS: Levels of both PEDF protein and SERPINF1 mRNA were significantly lower in lesions from patients with condyloma acuminatum (n = 30) than in skin from healthy control subjects (n = 30). There were significant negative correlations between PEDF levels and both PI and MVD. CONCLUSIONS: The reduction in PEDF levels in condyloma acuminatum was associated with an increase in angiogenesis and cell proliferation. PEDF may be involved in the pathogenesis of condyloma acuminatum.


Subject(s)
Condylomata Acuminata/genetics , Down-Regulation/genetics , Eye Proteins/genetics , Nerve Growth Factors/genetics , Serpins/genetics , Adolescent , Adult , Case-Control Studies , Cell Proliferation , Condylomata Acuminata/pathology , Eye Proteins/metabolism , Humans , Male , Microvessels/pathology , Middle Aged , Nerve Growth Factors/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Serpins/metabolism , Skin/metabolism , Skin/pathology , Young Adult
12.
J Int Med Res ; 41(1): 138-45, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23569139

ABSTRACT

OBJECTIVE: Retrospective, observational study to explore the role of dendritic cells (DCs) in condyloma acuminatum lesions (genital warts) and their relationship with duration of the disease. METHODS: Condyloma acuminatum lesion samples were collected from male patients with the condition and compared with normal foreskin samples from male volunteers. Cellular locations of dendritic cell lysosome-associated membrane protein (DC-LAMP) and dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN) were detected using immunohistochemistry. Levels of both proteins were determined using Western blot analysis; levels of their corresponding mRNAs were measured using reverse transcription-polymerase chain reaction. RESULTS: The mRNA and protein levels of DC-LAMP and DC-SIGN were both significantly higher in condyloma acuminatum lesions (n = 30 samples) compared with normal skin samples (n = 13). Levels of DC-LAMP and DC-SIGN protein and duration of disease were inversely correlated. CONCLUSIONS: DC-LAMP and DC-SIGN may be involved in the pathogenesis of condyloma acuminatum. Their levels were inversely correlated with the duration of disease, suggesting that DCs might be involved in human papillomavirus clearance.


Subject(s)
Cell Adhesion Molecules/metabolism , Condylomata Acuminata/metabolism , Condylomata Acuminata/pathology , Dendritic Cells/metabolism , Lectins, C-Type/metabolism , Lysosomal Membrane Proteins/metabolism , Lysosomes/metabolism , Neoplasm Proteins/metabolism , Receptors, Cell Surface/metabolism , Adult , Cell Adhesion Molecules/genetics , Humans , Immunohistochemistry , Lectins, C-Type/genetics , Lysosomal Membrane Proteins/genetics , Male , Middle Aged , Neoplasm Proteins/genetics , Receptors, Cell Surface/genetics , Young Adult
13.
PLoS One ; 8(4): e60833, 2013.
Article in English | MEDLINE | ID: mdl-23585855

ABSTRACT

BACKGROUND: Glutathione S-transferases (GSTs) have proved to be involved in the detoxifying several carcinogens and may play an important role in carcinogenesis of cancer. Previous studies on the association between Glutathione S-transferase T1 (GSTT1) polymorphism and gastric cancer risk reported inconclusive results. To clarify the possible association, we conducted a meta-analysis of eligible studies. METHODS: We searched in the Pubmed, Embase, and Wangfang Medicine databases for studies assessing the association between GSTT1 null genotype and gastric cancer risk. The pooled odds ratio (OR) and its 95% confidence interval (95%CI) was calculated to assess the strength of the association. A total of 48 studies with a total of 24,440 individuals were ultimately eligible for meta-analysis. RESULTS: Overall, GSTT1 null genotype was significantly associated with increased risk of gastric cancer (Random-effect OR = 1.23, 95%CI 1.13-1.35, P OR <0.001, I(2) = 45.5%). Significant association was also found in Caucasians, East Asians, and Indians (P Caucasians = 0.010; P East Asians = 0.003; P Indians = 0.017). After adjusting for other confounding variables, GSTT1 null genotype was also significantly associated with increased risk of gastric cancer (Random-effect OR = 1.43, 95%CI 1.20-1.71, P OR <0.001, I(2) = 48.1%). CONCLUSION: The meta-analysis provides strong evidence for the significant association between GSTT1 null genotype and increased risk of gastric cancer.


Subject(s)
Genetic Predisposition to Disease , Glutathione Transferase/genetics , Polymorphism, Genetic , Stomach Neoplasms/genetics , Asian People , Case-Control Studies , Databases, Bibliographic , Female , Glutathione Transferase/deficiency , Humans , Male , Odds Ratio , Risk , Stomach Neoplasms/ethnology , White People
14.
Tumour Biol ; 34(2): 1155-60, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23494240

ABSTRACT

Previous studies evaluating the association between excision repair cross-complimentary group 2 (ERCC2) Lys751Gln polymorphism and susceptibility to cutaneous melanoma reported conflicting findings. We searched PubMed and Wangfang Medical databases up to October 16, 2012 to identify eligible studies. A total of 8 case-control studies including 3,492 cases and 5,381 controls were included in the meta-analysis. Statistical analysis was performed with Review Manage version 5.1. Odds ratios (ORs) with 95 % confidence intervals (95 %CIs) were used to assess the strength of the association. There was no obvious between-study heterogeneity among those eight studies under all four comparison models. Overall, there was a significant association between ERCC2 Lys751Gln polymorphism and susceptibility to cutaneous melanoma under three genetic models (for Gln versus Lys: OR = 1.08, 95 % CI = 1.01-1.15, P = 0.02; for GlnGln versus LysLys: OR = 1.16, 95 % CI = 1.01-1.33, P = 0.03; for GlnGln/LysGln versus LysLys: OR = 1.10, 95 % CI = 1.01-1.21, P = 0.04). Sensitivity analysis by omitting one study a time showed the significance of the pooled ORs was stable under all those three genetic models above. Therefore, the meta-analysis suggests that there is a significant association between ERCC2 Lys751Gln polymorphism and susceptibility to cutaneous melanoma.


Subject(s)
Melanoma/etiology , Polymorphism, Genetic/genetics , Skin Neoplasms/etiology , Xeroderma Pigmentosum Group D Protein/genetics , Case-Control Studies , Genetic Predisposition to Disease , Humans , Review Literature as Topic , Risk Factors
15.
J Biol Chem ; 286(32): 28403-13, 2011 Aug 12.
Article in English | MEDLINE | ID: mdl-21700709

ABSTRACT

One of the master regulators of adipogenesis and macrophage function is peroxisome proliferator-activated receptor-γ (PPARγ). Here, we report that a deficiency of ß-arrestin-1 expression affects PPARγ-mediated expression of lipid metabolic genes and inflammatory genes. Further mechanistic studies revealed that ß-arrestin-1 interacts with PPARγ. ß-Arrestin-1 suppressed the formation of a complex between PPARγ and 9-cis-retinoic acid receptor-α through its direct interaction with PPARγ. The interaction of ß-arrestin-1 with PPARγ repressed PPARγ/9-cis-retinoic acid receptor-α function but promoted PPARγ/nuclear receptor corepressor function in PPARγ-mediated adipogenesis and inflammatory gene expression. Consistent with these results, a deficiency of ß-arrestin-1 binding to PPARγ abolished its suppression of PPARγ-dependent adipogenesis and inflammatory responses. These results indicate that the regulation of PPARγ by ß-arrestin-1 is critical. Furthermore, in vivo expression of ß-arrestin-1 (but not the binding-deficient mutant) significantly repressed adipogenesis, macrophage infiltration, and diet-induced obesity and improved glucose tolerance and systemic insulin sensitivity. Therefore, our findings not only reveal a molecular mechanism for the modulation of obesity by ß-arrestin-1 but also suggest a potential tactical approach against obesity and its associated metabolic disorders.


Subject(s)
Adipogenesis/physiology , Arrestins/metabolism , Gene Expression Regulation/physiology , PPAR gamma/metabolism , Animals , Arrestins/genetics , Diet/adverse effects , Inflammation/genetics , Inflammation/metabolism , Mice , Mice, Knockout , Obesity/chemically induced , Obesity/genetics , Obesity/metabolism , PPAR gamma/genetics , Protein Binding , Retinoid X Receptors/genetics , Retinoid X Receptors/metabolism , beta-Arrestin 1 , beta-Arrestins
16.
J Biol Chem ; 286(32): 28396-402, 2011 Aug 12.
Article in English | MEDLINE | ID: mdl-21543334

ABSTRACT

Diet-related obesity is a major metabolic disorder. Excessive fat mass is associated with type 2 diabetes, hepatic steatosis, and arteriosclerosis. Dysregulation of lipid metabolism and adipose tissue function contributes to diet-induced obesity. Here, we report that ß-arrestin-1 knock-out mice are susceptible to diet-induced obesity. Knock-out of the gene encoding ß-arrestin-1 caused increased fat mass accumulation and decreased whole-body insulin sensitivity in mice fed a high-fat diet. In ß-arrestin-1 knock-out mice, we observed disrupted food intake and energy expenditure and increased macrophage infiltration in white adipose tissue. At the molecular level, ß-arrestin-1 deficiency affected the expression of many lipid metabolic genes and inflammatory genes in adipose tissue. Consistently, transgenic overexpression of ß-arrestin-1 repressed diet-induced obesity and improved glucose tolerance and systemic insulin sensitivity. Thus, our findings reveal that ß-arrestin-1 plays a role in metabolism regulation.


Subject(s)
Adipose Tissue/metabolism , Arrestins/metabolism , Dietary Fats/adverse effects , Eating , Lipid Metabolism , Obesity/metabolism , Animals , Arrestins/genetics , Body Weight , Dietary Fats/pharmacology , Insulin/genetics , Insulin/metabolism , Mice , Mice, Knockout , Obesity/chemically induced , Obesity/genetics , beta-Arrestin 1 , beta-Arrestins
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