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1.
Cell ; 178(6): 1478-1492.e20, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31474362

RESUMO

Liver fibrosis is a very common condition seen in millions of patients with various liver diseases, and yet no effective treatments are available owing to poorly characterized molecular pathogenesis. Here, we show that leukocyte cell-derived chemotaxin 2 (LECT2) is a functional ligand of Tie1, a poorly characterized endothelial cell (EC)-specific orphan receptor. Upon binding to Tie1, LECT2 interrupts Tie1/Tie2 heterodimerization, facilitates Tie2/Tie2 homodimerization, activates PPAR signaling, and inhibits the migration and tube formations of EC. In vivo studies showed that LECT2 overexpression inhibits portal angiogenesis, promotes sinusoid capillarization, and worsens fibrosis, whereas these changes were reversed in Lect2-KO mice. Adeno-associated viral vector serotype 9 (AAV9)-LECT2 small hairpin RNA (shRNA) treatment significantly attenuates fibrosis. Upregulation of LECT2 is associated with advanced human liver fibrosis staging. We concluded that targeting LECT2/Tie1 signaling may represent a potential therapeutic target for liver fibrosis, and serum LECT2 level may be a potential biomarker for the screening and diagnosis of liver fibrosis.


Assuntos
Células Endoteliais/metabolismo , Hepatócitos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Cirrose Hepática/metabolismo , Fígado/metabolismo , Receptores de TIE/metabolismo , Animais , Biomarcadores/metabolismo , Capilares/metabolismo , Células Endoteliais/citologia , Células Endoteliais/patologia , Células HEK293 , Hepatócitos/citologia , Hepatócitos/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Fígado/irrigação sanguínea , Fígado/patologia , Cirrose Hepática/diagnóstico , Camundongos Endogâmicos C57BL
2.
Cytokine ; 181: 156697, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39024680

RESUMO

Leukocyte cell-derived chemotaxin-2 (LECT2), originally identified as a novel neutrophil chemokine, is a multifunctional secreted factor primarily produced in hepatocytes. However, many studies have shown that LECT2 is a pleiotropic protein that not only exerts chemotaxis properties as a cytokine but also plays an important role in inflammatory regulation and immune regulation. Pathogens such as bacteria and the role of the host immune system are key factors in the inflammatory response. In antibacterial, LECT2 can directly destroy bacterial structure or affect the normal metabolism of bacteria to inactivate bacteria and can also achieve this effect by activating immune cells and regulating cytokines. In immunomodulation, LECT2 has neutrophil chemotactic activity and regulates the quantities of Natural killer T (NKT) cells, regulatory T cells, monocytes/macrophages, granulocytes, and/or the expression of associated cytokines, thereby influencing their effect in immune reaction. Inflammation and immune regulation are closely related to a variety of diseases, such as bacterial infection, liver cirrhosis, dermatitis, coronary atherosclerotic heart disease, and so on. This review summarizes the basic and clinical studies of LECT2 in antibacterial effects and its effects on immune cells to explore the mechanism of LECT in inflammatory regulation and immune regulation in physiological and pathological conditions better.


Assuntos
Imunomodulação , Inflamação , Peptídeos e Proteínas de Sinalização Intercelular , Humanos , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Animais , Citocinas/metabolismo , Citocinas/imunologia , Neutrófilos/imunologia , Neutrófilos/metabolismo , Linfócitos T Reguladores/imunologia
3.
Am J Nephrol ; : 1-12, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38865984

RESUMO

BACKGROUND: Amyloidosis includes a diverse group of rare diseases characterized by the misfolding of native or mutant proteins, leading to extracellular accumulation in various organs. While 42 proteins have been identified to date, their distribution differs between systemic and localized forms. SUMMARY: Mass spectrometry analysis of tissue samples in the USA shows immunoglobulin light chain (AL) amyloidosis as the most prevalent systemic type, followed by transthyretin (ATTR). Heart and kidney involvements are common. Although there are 14 recognized types of kidney-related amyloidosis, clinicopathologic studies in the USA have identified 11 types, with AL amyloidosis being the most prevalent cause of kidney involvement. KEY MESSAGES: This review focuses on AL, AA, and ATTR amyloidosis due to their common systemic presentations. Recent US-based clinicopathologic studies challenge conventional beliefs that toxicity is primarily driven by amyloid deposition and highlight the role of the complement pathway. Diagnostic methods, particularly mass spectrometry, are crucial for accurate typing. Treatment strategies vary depending on the underlying type, with AL amyloidosis primarily targeting plasma cell clones, AA amyloidosis addressing underlying inflammation with systemic therapies, and ATTR amyloidosis focusing on ATTR stabilization or gene silencing.

4.
Fish Shellfish Immunol ; 151: 109708, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38908810

RESUMO

Leukocyte-derived chemotaxin-2 (LECT2) is a multifunctional immunoregulator that plays several pivotal roles in the host's defense against pathogens. This study aimed to elucidate the specific functions and mechanisms of LECT2 (CaLECT2) in the northern snakehead (Channa argus) during infections with pathogens such as Nocardia seriolae (N. seriolae). We identified CaLECT2 in the northern snakehead, demonstrating its participation in the immune response to N. seriolae infection. CaLECT2 contains an open reading frame (ORF) of 459 bp, encoding a peptide of 152 amino acids featuring a conserved peptidase M23 domain. The CaLECT2 protein shares 62%-84 % identities with proteins from various other fish species. Transcriptional expression analysis revealed that CaLECT2 was constitutively expressed in all examined tissues, with the highest expression observed in the liver. Following intraperitoneal infection with N. seriolae, CaLECT2 transcription increased in the spleen, trunk kidney, and liver. In vivo challenge experiments showed that injecting recombinant CaLECT2 (rCaLECT2) could protect the snakehead against N. seriolae infection by reducing bacterial load, enhancing serum antibacterial activity and antioxidant capacity, and minimizing tissue damage. Moreover, in vitro analysis indicated that rCaLECT2 significantly enhanced the migration, respiratory burst, and microbicidal activity of the head kidney-derived phagocytes. These findings provide new insights into the role of LECT2 in the antibacterial immunity of fish.


Assuntos
Doenças dos Peixes , Proteínas de Peixes , Imunidade Inata , Nocardiose , Nocardia , Animais , Nocardiose/veterinária , Nocardiose/imunologia , Nocardia/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Imunidade Inata/genética , Filogenia , Sequência de Aminoácidos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Regulação da Expressão Gênica/imunologia , Alinhamento de Sequência/veterinária , Perfilação da Expressão Gênica/veterinária , Peixes/imunologia , Peixes/genética , Perciformes/imunologia , Perciformes/genética , Sequência de Bases
5.
Mol Biol Rep ; 51(1): 240, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300380

RESUMO

The ovaries of high-yield laying hens exhibited signs of aging beyond 400 days of age, subsequently resulting in a decline in both egg production and egg quality. Oxidative stress, characterized by an increase in the production of reactive oxygen species (ROS), stands as one of the principal processes contributing to ovarian aging. Elevated ROS levels are implicated in the induction of apoptosis in granulosa cells (GCs), provoking mitochondrial impairment, and diminishing the capacity of the antioxidant defense system. This investigation stratified laying hens into two distinct groups, predicated upon their egg production levels: high-yield hens (HH) and low-yield hens (LL). The study focused on evaluating oxidative stress markers and identifying differentially expressed genes between these two groups. The findings revealed that the LL group exhibited follicular atresia, mitochondrial disruptions, and apoptotic occurrences in ovarian GCs. Notably, ROS levels, Malondialdehyde (MDA) concentrations, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations in ovarian tissue and follicular GCs were substantially higher in the HH group. Furthermore, the RNA-sequencing results unveiled differential expression of the LECT2 gene between the HH and LL groups. Consequently, an overexpression vector for the LECT2 gene was successfully constructed and introduced into GCs. The quantitative polymerase chain reaction (QPCR) analysis exhibited significant downregulation (p < 0.01) of key apoptotic genes such as Caspase-3 and C-myc and significant upregulation (p < 0.01) of BCL2 following the overexpression of the LECT2 gene in GCs. In conclusion, oxidative stress emerges as a pivotal factor influencing the laying traits of both high and low-yield laying hens. The accumulation of reactive oxygen species (ROS) within the ovaries precipitates apoptosis in GCs, subsequently leading to follicular atresia and a reduction in egg production. Furthermore, we employed RNA sequencing technology to examine the ovarian matrix tissue in high and low laying hens during the late phase of egg laying. Our analysis revealed a substantial upregulation of the LECT2 gene in the ovarian matrix tissue of high laying hens. This observation implies that the LECT2 gene exerts a pivotal influence on driving the proliferation and differentiation of follicular GCs, thereby exerting a crucial regulatory role in follicular development.


Assuntos
Galinhas , Atresia Folicular , Feminino , Animais , Galinhas/genética , Espécies Reativas de Oxigênio , 8-Hidroxi-2'-Desoxiguanosina , Proliferação de Células/genética , Células da Granulosa
6.
Indian J Clin Biochem ; 39(1): 146-150, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38223013

RESUMO

Amyloidosis is an infiltrative disease where amyloid fibrils get deposited in the organs like kidney, liver and spleen. Amyloid deposition in the kidneys classically meant deposition in the glomeruli and mesangium until 2008 when interstitial amyloid deposits were isolated and named as` Leukocyte cell-derived chemotaxin 2-associated amyloidosis. It is a progressive disease which clinically manifests as slowly progressive renal dysfunction and/or proteinuria. Our case 34 year old renal transplant recipient underwent graft biopsy post transplantation which revealed interstitial LECT-2 amyloid deposits. Unfortunately, he developed page kidney post biopsy which was managed conservatively with percutaneous drainage. Supplementary Information: The online version contains supplementary material available at 10.1007/s12291-022-01072-6.

7.
J Cell Mol Med ; 26(13): 3598-3607, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35656863

RESUMO

LECT2 (leucocyte cell-derived chemotaxin 2) is a 16-kDa protein mainly produced by hepatocytes. It was first isolated in PHA-activated human T-cell leukaemia SKW-3 cells and originally identified as a novel neutrophil chemotactic factor. However, many lines of studies suggested that LECT2 was a pleiotropic protein, it not only functioned as a cytokine to exhibit chemotactic property, but also played multifunctional roles in some physiological conditions and pathological abnormalities, involving liver regeneration, neuronal development, HSC(haematopoietic stem cells) homeostasis, liver injury, liver fibrosis, hepatocellular carcinoma, metabolic disorders, inflammatory arthritides, systemic sepsis and systemic amyloidosis. Among the above studies, it was discovered that LECT2 could be a promising molecular biomarker and therapeutic target. This review summarizes LECT2-related receptors and pathways, basic and clinical researches, primarily in mice and human, for a better comprehension and management of these diseases in the future.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Fatores Quimiotáticos , Peptídeos e Proteínas de Sinalização Intercelular , Camundongos
8.
J Cell Physiol ; 237(1): 480-488, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34550600

RESUMO

Leukocyte cell-derived chemotaxin-2 (LECT2 or LECT-2), also called chondromodulin II (ChM-II or CHM2) plays a versatile role in various tissues. It was first identified as a chemotactic factor to promote the migration of neutrophils. It was also reported as a hepatokine to regulate glucose metabolism, obesity, and nonalcoholic fatty liver disease. As a secreted factor, LECT2 binds to several cell surface receptors CD209a, Tie1, and Met to regulate inflammatory reaction, fibrogenesis, vascular invasion, and tumor metastasis in various cell types. As an intracellular molecule, it is associated with LECT2-mediated amyloidosis, in which LECT2 misfolding results in insoluble fibrils in multiple tissues such as the kidney, liver, and lung. Recently, LECT2 was found to be associated with the development of rheumatoid arthritis and osteoarthritis, involving the dysregulation of osteoclasts, mesenchymal stem cells, osteoblasts, chondrocytes, and endothelial cells in the bone microenvironment. LECT2 is implicated in the development of cancers, such as hepatocellular carcinoma via MET-mediated PTP1B/Raf1/ERK signaling pathways and is proposed as a biomarker. The mechanisms by which LECT2 regulates diverse pathogenic conditions in various tissues remain to be fully elucidated. Further research to understand the role of LECT2 in a tissue tropism-dependent manner would facilitate the development of LECT2 as a biomarker for diagnosis and therapeutic target.


Assuntos
Artrite , Neoplasias , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Artrite/genética , Artrite/metabolismo , Biomarcadores/metabolismo , Células Endoteliais/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Estrutura Molecular , Neoplasias/genética , Neoplasias/metabolismo , Microambiente Tumoral
9.
Biochem Biophys Res Commun ; 585: 169-176, 2021 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-34808500

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with obesity, insulin resistance, and endoplasmic reticulum (ER) stress. Elevated circulating levels of the hepatokine leukocyte cell-derived chemotaxin-2 (LECT2) have also been noted in NAFLD; however, the mechanism underlying this association is unclear. To investigate a possible link between ER stress/unfolded protein response (UPR) signaling and LECT2 secretion, HepG2 cells were incubated with ER stress inducers with or without an ER stress-reducing chemical chaperone. Additionally, UPR pathway genes were knocked down and overexpressed, and a ChIP assay was performed. In diet-induced obese mice, hepatic expression of LECT2 and activating transcription factor 4 (ATF4) was measured. In HepG2 cells, LECT2 expression was increased by ER stressors, an effect blocked by the chemical chaperone. Among UPR pathway proteins, only knockdown of ATF4 suppressed ER stress-induced LECT2 expression, while overexpression of ATF4 enhanced LECT2 expression. The ChIP assay revealed that ATF4 binds to three putative binding sites on the LECT2 promoter and binding is promoted by an ER stress inducer. In steatotic livers of obese mice, LECT2 and ATF4 expression was concomitantly elevated. Our data indicate that activation of ER stress/UPR signaling induces LECT2 expression in steatotic liver; specifically, ATF4 appears to mediate upregulation of LECT2 transcription.


Assuntos
Fator 4 Ativador da Transcrição/genética , Estresse do Retículo Endoplasmático/genética , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Resposta a Proteínas não Dobradas/genética , Regulação para Cima , Fator 4 Ativador da Transcrição/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/genética , Obesidade/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA
10.
J Nutr ; 150(5): 1076-1085, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31919514

RESUMO

BACKGROUND: Hepatokines such as fibroblast growth factor 21 (FGF21), leukocyte cell-derived chemotaxin 2 (LECT2), fetuin-A, fetuin-B, and selenoprotein P (SeP) are liver-derived proteins that are modulated by chronic energy status and metabolic disease. Emerging data from rodent and cell models indicate that hepatokines may be sensitive to acute nutritional manipulation; however, data in humans are lacking. OBJECTIVE: The aim was to investigate the influence of hyperenergetic, high-fat feeding on circulating hepatokine concentrations, including the time course of responses. METHODS: In a randomized, crossover design, 12 healthy men [mean ± SD: age, 24 ± 4 y; BMI (kg/m2), 24.1 ± 1.5] consumed a 7-d hyperenergetic, high-fat diet [HE-HFD; +50% energy, 65% total energy as fat (32% saturated, 26% monounsaturated, 8% polyunsaturated)] and control diet (36% total energy as fat), separated by 3 wk. Whole-body insulin sensitivity was assessed before and after each diet using oral-glucose-tolerance tests. Fasting plasma concentrations of FGF21 (primary outcome), LECT2, fetuin-A, fetuin-B, SeP, and related metabolites were measured after 1, 3, and 7 d of each diet. Hepatokine responses were analyzed using 2-factor repeated-measures ANOVA and subsequent pairwise comparisons. RESULTS: Compared with the control, the HE-HFD increased circulating FGF21 at 1 d (105%) and 3 d (121%; P ≤ 0.040), LECT2 at 3 d (17%) and 7 d (32%; P ≤ 0.004), and fetuin-A at 7 d (7%; P = 0.028). Plasma fetuin-B and SeP did not respond to the HE-HFD. Whole-body insulin sensitivity was reduced after the HE-HFD by 31% (P = 0.021). CONCLUSIONS: Acute high-fat overfeeding augments circulating concentrations of FGF21, LECT2, and fetuin-A in healthy men. Notably, the time course of response varies between proteins and is transient for FGF21. These findings provide further insight into the nutritional regulation of hepatokines in humans and their interaction with metabolic homeostasis. This study was registered at clinicaltrials.gov as NCT03369145.


Assuntos
Dieta Hiperlipídica , Ingestão de Energia , Fatores de Crescimento de Fibroblastos/sangue , Peptídeos e Proteínas de Sinalização Intercelular/sangue , alfa-2-Glicoproteína-HS/metabolismo , Adulto , Glicemia/efeitos dos fármacos , Estudos Cross-Over , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Insulina/sangue , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Adulto Jovem , alfa-2-Glicoproteína-HS/genética
11.
Ann Pathol ; 40(6): 472-477, 2020 Nov.
Artigo em Francês | MEDLINE | ID: mdl-32446730

RESUMO

Leukocyte cell-derived chemotaxin 2-associated amyloidosis (ALECT2) is a recently described of amyloidosis described in the United States in 2007. It is a systemic disease that is predominantly associated with some ethnics groups. ALECT2 is usually diagnosed on a kidney biopsy performed in the context of slowly progressive chronic renal disease but can also be found incidentally on a liver sample. We report the case of a Syrian patient who benefited from a partial hepatectomy for the treatment of multiple metastasis of a colorectal adenocarcinoma. Microscopic analysis of the surgical specimen revealed numerous amyloid deposits that did not match any of the usual forms of liver amyloidosis after immunohistochemistry typing. Some morphologic features of the deposits were highly suggestive of ALECT2. Complementary immunohistochemical study and mass spectrometry confirmed the diagnosis.


Assuntos
Amiloidose , Fatores Quimiotáticos , Amiloidose/complicações , Amiloidose/diagnóstico , Humanos , Achados Incidentais , Leucócitos , Fígado/patologia , Síria
12.
J Struct Biol ; 207(3): 260-269, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31170474

RESUMO

ALECT2 (leukocyte chemotactic factor 2) amyloidosis is one of the most recently identified amyloid-related diseases, with LECT2 amyloids commonly found in different types of tissues. Under physiological conditions, LECT2 is a 16 kDa multifunctional protein produced by the hepatocytes and secreted into circulation. The pathological mechanisms causing LECT2 transition into the amyloid state are still largely unknown. In the case of ALECT2 patients, there is no disease-causing mutation, yet almost all patients carry a common polymorphism that appears to be necessary but not sufficient to directly trigger amyloidogenesis. In this work, we followed a reductionist methodology in order to detect critical amyloidogenic "hot-spots" during the fibrillation of LECT2. By associating experimental and computational assays, this approach reveals the explicit amyloidogenic core of human LECT2 and pinpoints regions with distinct amyloidogenic properties. The fibrillar architecture of LECT2 polymers, based on our results, provides a wealth of detailed information about the amyloidogenic "hot-spot" interactions and represents a starting point for future peptide-driven intervention in ALECT2 amyloidosis.


Assuntos
Amiloide/química , Amiloidose/genética , Peptídeos e Proteínas de Sinalização Intercelular/química , Polimorfismo de Nucleotídeo Único , Sequência de Aminoácidos , Amiloide/metabolismo , Amiloide/ultraestrutura , Amiloidose/diagnóstico , Amiloidose/metabolismo , Sítios de Ligação/genética , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Microscopia Eletrônica , Modelos Moleculares , Agregados Proteicos , Agregação Patológica de Proteínas , Ligação Proteica , Conformação Proteica
13.
Am J Kidney Dis ; 74(4): 563-566, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31155323

RESUMO

Leukocyte chemotactic factor 2 (LECT2) amyloidosis is a recently recognized entity that often affects the kidneys. Little information is available regarding kidney transplant outcomes in patients with LECT2 amyloidosis or who received kidney allografts containing LECT2 amyloid. We present clinical findings and allograft outcomes of 5 patients who received kidneys with donor-derived LECT2 amyloidosis. In all 5, LECT2 amyloidosis was discovered during protocol biopsies or in evaluation of suspected rejection. Less than 10% of kidney parenchyma was involved, with mostly interstitial and vascular deposits. Allograft function was not impaired and the amyloid deposits persisted for up to 8 years of follow-up. We conclude that kidneys with limited and localized LECT2 amyloid deposits that are otherwise suitable for transplantation need not be automatically discarded.


Assuntos
Amiloidose/diagnóstico , Amiloidose/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Transplante de Rim/métodos , Doadores de Tecidos , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Asian-Australas J Anim Sci ; 32(12): 1942-1949, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31480179

RESUMO

OBJECTIVE: Leukocyte cell-derived chemotaxin 2 (LECT2) is associated with several physiological processes including inflammation, tumorigenesis, and natural killer T cell generation. Chicken LECT2 (chLECT2) gene was originally identified as one of the differentially expressed genes in chicken kidney tissue, where the chickens were fed with different calcium doses. In this study, the molecular characteristics and gene expression of chLECT2 were analyzed under the stimulation of toll-like receptor 3 (TLR3) ligand to understand the involvement of chLECT2 expression in chicken metabolic disorders. METHODS: Amino acid sequence of LECT2 proteins from various species including fowl, fish, and mammal were retrieved from the Ensembl database and subjected to Insilco analyses. In addition, the time- and dose-dependent expression of chLECT2 was examined in DF-1 cells which were stimulated with polyinosinic:polycytidylic acid (poly [I:C]), a TLR3 ligand. Further, to explore the transcription factors required for the transcription of chLECT2, DF-1 cells were treated with poly (I:C) in the presence or absence of the nuclear factor κB (NFκB) and activated protein 1 (AP-1) inhibitors. RESULTS: The amino acid sequence prediction of chLECT2 protein revealed that along with duck LECT2 (duLECT2), it has unique signal peptide different from other vertebrate orthologs, and only chLECT2 and duLECT2 have an additional 157 and 161 amino acids on their carboxyl terminus, respectively. Phylogenetic analysis suggested that chLECT2 is evolved from a common ancestor along with the actinopterygii hence, more closely related than to the mammals. Our quantitative polymerase chain reaction results showed that, the expression of chLECT2 was up-regulated significantly in DF-1 cells under the stimulation of poly (I:C) (p<0.05). However, in the presence of NFκB or AP-1 inhibitors, the expression of chLECT2 is suppressed suggesting that both NFκB and AP-1 transcription factors are required for the induction of chLECT2 expression. CONCLUSION: The present results suggest that chLECT2 gene might be a target gene of TLR3 signaling. For the future, the expression pattern or molecular mechanism of chLECT2 under stimulation of other innate immune receptors shall be studied. The protein function of chLECT2 will be more clearly understood if further investigation about the mechanism of LECT2 in TLR pathways is conducted.

15.
Cell Physiol Biochem ; 51(1): 337-355, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30453282

RESUMO

BACKGROUND/AIMS: Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy is a clinical option for non-small cell lung cancer (NSCLC) harboring activating EGFR mutations or for cancer with wild-type (WT) EGFR when chemotherapy has failed. MET receptor activation or MET gene amplification was reported to be a major mechanism of acquired resistance to EGFR-TKI therapy in NSCLC cells. Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that was shown to suppress metastasis of hepatocellular carcinoma via inhibiting MET activity. Until now, the biological function responsible for LECT2's action in human NSCLC remains unclear. METHODS: LECT2-knockout (KO) mice and NOD/SCID/IL2rgnull (NSG) mice were respectively used to investigate the effects of LECT2 on the tumorigenicity and metastasis of murine (Lewis lung carcinoma, LLC) and human (HCC827) lung cancer cells. The effect of LECT2 on in vitro cell proliferation was evaluated, using MTS and colony formation assays. The effect of LECT2 on cell motility was evaluated using transwell migration and invasion assays. An enzyme-linked immunosorbent assay was performed to detect secreted LECT2 in plasma and media. Co-immunoprecipitation and Western blot assays were used to investigate the underlying mechanisms of LECT2 in NSCLC cells. RESULTS: Compared to WT mice, mice with LECT2 deletion exhibited enhanced growth and metastasis of LLC cells, and survival times decreased in LLC-implanted mice. Overexpression of LECT2 in orthotopic human HCC827 xenografts in NSG mice resulted in significant inhibition of tumor growth and metastasis. In vitro, overexpression of LECT2 or treatment with a recombinant LECT2 protein impaired the colony-forming ability and motility of NSCLC cells (HCC827 and PC9) harboring high levels of activated EGFR and MET. Mechanistic investigations found that LECT2 bound to MET and EGFR to antagonize their activation and further suppress their common downstream pathways: phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase. CONCLUSION: EGFR-MET signaling is critical for aggressive behaviors of NSCLC and is recognized as a therapeutic target for NSCLC especially for patients with acquired resistance to EGFR-TKI therapy. Our findings demonstrate, for the first time, that LECT2 functions as a suppressor of the progression of NSCLC by targeting EGFR-MET signaling.


Assuntos
Receptores ErbB/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/efeitos dos fármacos , Receptores ErbB/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Peptídeos e Proteínas de Sinalização Intercelular/genética , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Metástase Neoplásica , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Biochem Biophys Res Commun ; 478(3): 1310-6, 2016 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-27562717

RESUMO

Dieting often leads to body weight cycling involving repeated weight loss and regain. However, little information is available regarding rapid-response serum markers of overnutrition that predict body weight alterations during weight cycling. Here, we report the rapid response of serum leukocyte cell-derived chemotaxin 2 (LECT2), a hepatokine that induces insulin resistance in skeletal muscle, during diet-induced weight cycling in mice. A switch from a high-fat diet (HFD) to a regular diet (RD) in obese mice gradually decreased body weight but rapidly decreased serum LECT2 levels within 10 days. In contrast, a switch from a RD to a HFD rapidly elevated serum LECT2 levels. Serum LECT2 levels showed a positive correlation with liver triglyceride contents but not with adipose tissue weight. This study demonstrates the rapid response of LECT2 preceding body weight alterations during weight cycling in mice and suggests that measurement of serum LECT2 may be clinically useful in the management of obesity.


Assuntos
Peso Corporal , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Tecido Adiposo/patologia , Adiposidade , Animais , Biomarcadores/metabolismo , Dieta Hiperlipídica , Modelos Animais de Doenças , Insulina/sangue , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Hipernutrição/sangue , Hipernutrição/patologia
17.
Fish Shellfish Immunol ; 51: 70-76, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26876329

RESUMO

Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine involved in many diseases in which immune dysfunction is present. Ayu LECT2 (PaLECT2), which interacts with a C-type lectin receptor (PaCLR), was shown to activate ayu head kidney-derived monocytes/macrophages (MO/MΦ) to improve the outcomes of fish upon bacterial infections. However, it is not known if PaCLR mediates PaLECT2 effects on ayu MO/MΦ. In this study, we determined the role of PaCLR in signal transduction of PaLECT2 on ayu MO/MΦ. We expressed the PaCLR ectodomain in Escherichia coli and produced a refolded recombinant protein (rPaCLR) that was then used to produce the anti-PaCLR IgG (anti-PaCLR) for neutralization. Addition of the refolded PaLECT2 mature peptide (rPaLECT2m) to ayu MO/MΦ cultures, increased cytokine expression, induced chemotaxis, and enhanced phagocytosis and bactericidal activity of these cells were observed. When we added anti-PaCLR to block the ectodomain of PaCLR, these effects were significantly inhibited. Based on our previous works and the data presented here, we conclude that PaCLR mediates the immunomodulatory effects of PaLECT2 on ayu MO/MΦ, thus defining a mechanism by which LECT2 protects fish against pathogens.


Assuntos
Proteínas de Peixes/genética , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular/genética , Lectinas Tipo C/genética , Lectinas/genética , Osmeriformes/genética , Animais , Quimiotaxia , Escherichia coli/genética , Proteínas de Peixes/metabolismo , Rim Cefálico/metabolismo , Imunomodulação , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Lectinas/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos/metabolismo , Monócitos/metabolismo , Organismos Geneticamente Modificados/genética , Osmeriformes/imunologia , Osmeriformes/metabolismo
18.
Am J Kidney Dis ; 64(5): 790-2, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25064673

RESUMO

Leukocyte chemotactic factor 2 (LECT2) amyloidosis is a recently identified type of amyloidosis that may represent an underdiagnosed cause of chronic kidney disease. LECT2 amyloidosis typically is reported as being renal limited and, in the United States, more prevalent in Hispanic patients. We add to the epidemiologic data of this condition by describing 4 First Nations people from Northern British Columbia, Canada, who presented with slowly progressive chronic kidney disease that was found to be due to LECT2 amyloidosis.


Assuntos
Amiloidose/diagnóstico , Amiloidose/genética , Indígenas Norte-Americanos/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/genética , Idoso , Amiloidose/etnologia , Colúmbia Britânica/etnologia , Feminino , Humanos , Indígenas Norte-Americanos/etnologia , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/etnologia
19.
Fish Shellfish Immunol ; 37(1): 131-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24486631

RESUMO

Leukocyte cell-derived chemotaxin-2 (LECT2) is an important protein of the innate immune system for the defense against bacterial infection. We cloned and characterized the LECT2 gene from Asian seabass (Lates calcarifer). Its complete cDNA consisted of an open reading frame of 459 bp encoding a protein of 152 amino acids. The genomic DNA sequence of this gene consists of four exons and three introns. Quantitative real-time PCR revealed that the LECT2 gene was expressed predominantly in liver while its expression was moderate in spleen and heart, and weak in other tissues. The LECT2 transcript was up-regulated in the kidney, spleen and liver in response to a challenge with a pathogenic bacterium Vibrio harveyi. In addition, we identified three single nucleotide polymorphisms (SNPs) in the LECT2 gene, and found significant associations between these polymorphisms and resistance to the big belly disease. These results suggest that the LECT2 gene play an important role in resistance to bacterial pathogens in fish. The SNP markers in the gene associated with the resistance to bacterial pathogens may facilitate selecting Asian seabass resistant to bacterial diseases.


Assuntos
Bass/genética , Resistência à Doença/genética , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Vibrioses/veterinária , Vibrio/imunologia , Animais , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , DNA Complementar/genética , Resistência à Doença/imunologia , Componentes do Gene , Perfilação da Expressão Gênica/veterinária , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Fígado/metabolismo , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/genética , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Análise de Sequência de DNA/veterinária , Baço/metabolismo , Vibrioses/imunologia
20.
Front Immunol ; 15: 1413466, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38881894

RESUMO

Leukocyte cell-derived chemotaxin-2 (LECT2) is an important cytokine synthesized by liver. Significant research interest is stimulated by its crucial involvement in inflammatory response, immune regulation, disease occurrence and development. However, bibliometric study on LECT2 is lacking. In order to comprehend the function and operation of LECT2 in human illnesses, we examined pertinent studies on LECT2 investigation in the Web of Science database, followed by utilizing CiteSpace, VOSview, and Scimago Graphica for assessing the yearly quantity of papers, countries/regions involved, establishments, authors, publications, citations, and key terms. Then we summarized the current research hotspots in this field. Our study found that the literature related to LECT2 has a fluctuating upward trend. "Angiogenesis", "ALECT2", "diagnosis", and "biliary atresia" are the current investigative frontiers. Our findings indicated that liver diseases (e.g. liver fibrosis and hepatic cell carcinoma), systemic inflammatory disease, and amyloidosis are the current research focus of LECT2. The current LECT2 research outcomes are not exceptional. We hope to promote the scientific research of LECT2 and exploit its potential for clinical diagnosis and treatment of related diseases through a comprehensive bibliometric review.


Assuntos
Bibliometria , Peptídeos e Proteínas de Sinalização Intercelular , Humanos , Animais , Pesquisa Biomédica/tendências
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