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1.
Dev Dyn ; 252(4): 527-535, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36576725

RESUMO

BACKGROUND: Transcription factor lymphoid enhancer-binding factor 1 (LEF1) is a downstream mediator of the Wnt/ß-catenin signaling pathway. It is expressed in dermal papilla and surrounding cells in the hair follicle, promoting cell proliferation, and differentiation. RESULTS: Here, we report that LEF1 is also expressed all through the hair cycle in the terminal Schwann cells (TSCs), a component of the lanceolate complex located at the isthmus. The timing of LEF1 appearance at the isthmus coincides with that of hair follicle innervation. LEF1 is not found at the isthmus in the aberrant hair follicles in nude mice. Instead, LEF1 in TSCs is found in the de novo hair follicles reconstituted on nude mice by stem cells chamber graft assay. Cutaneous denervation experiment demonstrates that the LEF1 expression in TSCs is independent of nerve endings. At last, LEF1 expression in the interfollicular epidermis during the early stage of skin development is significantly suppressed in transgenic mice with T-cell factor 3 (TCF3) overexpression. CONCLUSION: We reveal the expression dynamics of LEF1 in skin during development and hair cycle. LEF1 expression in TSCs indicates that the LEF1/Wnt signal might help to establish a niche at the isthmus region for the lanceolate complex, the bulge stem cells and other neighboring cells.


Assuntos
Epiderme , Folículo Piloso , Fator 1 de Ligação ao Facilitador Linfoide , Animais , Camundongos , beta Catenina/metabolismo , Epiderme/metabolismo , Fator 1 de Ligação ao Facilitador Linfoide/genética , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Camundongos Nus , Camundongos Transgênicos , Células de Schwann
2.
Exp Dermatol ; 32(12): 2176-2179, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37649203

RESUMO

Dermal papilla (DP) cells are specialized mesenchymal cells that play a crucial role in regulating hair morphology, colour and growth through the secretion of specific factors. It is still unclear what the source of progenitor cells is for dermal cell regeneration during wound healing, and whether DP cells are involved in this process. We analyzed the gene expression profile of various skin cell populations using existing datasets and found that the Hey2 gene was predominantly expressed in DP cells. We introduced Hey2-CreERT2 knockin mice and crossed them with Rosa26-ZsGreen reporter mice. After induction in the double transgenic mice by administration of tamoxifen, the reporter ZsGreen was found to be predominantly expressed in DP cells both at anagen and telogen phases, and broadly expressed in some other dermal cells at anagen. We also created a wound after tamoxifen induction, and found there were abundant ZsGreen+ cells in the regenerated dermis. We conclude that the HEY2+ DP cells and dermal cells exhibit some stemness properties and can contribute to the dermal cell regeneration during wound healing.


Assuntos
Folículo Piloso , Cicatrização , Camundongos , Animais , Folículo Piloso/metabolismo , Regeneração , Camundongos Transgênicos , Células Cultivadas , Tamoxifeno/farmacologia , Tamoxifeno/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo
3.
Transgenic Res ; 32(1-2): 143-152, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36637628

RESUMO

The mouse Agouti gene encodes a paracrine signaling factor which promotes melanocytes to produce yellow instead of black pigment. It has been reported that Agouti mRNA is confined to the dermal papilla after birth in various mammalian species. In this study, we created and characterized a knockin mouse strain in which Cre recombinase was expressed in-frame with endogenous Agouti coding sequence. The Agouti-Cre mice were bred with reporter mice (Rosa26-tdTomato or Rosa26-ZsGreen) to trace the lineage of Agouti-expressing cells during development. In skin, the reporter was detected in some dermal fibroblasts at the embryonic stage and in all dermal fibroblasts postnatally. It was also expressed in all mesenchymal lineage cells in other organs/tissues, including eyes, tongue, muscle, intestine, adipose, prostate and testis. Interestingly, the reporter expression was excluded from epithelial cells in the above organs/tissues. In brain, the reporter was observed in the outermost meningeal fibroblasts. Our work helps to illustrate the Agouti expression pattern during development and provides a valuable mouse strain for conditional gene targeting in mesenchymal lineage cells in multiple organs.


Assuntos
Proteína Agouti Sinalizadora , Animais , Masculino , Camundongos , Marcação de Genes , Integrases/genética , Integrases/metabolismo , Camundongos Transgênicos , Proteína Agouti Sinalizadora/genética
4.
Cytometry A ; 101(8): 675-681, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35524584

RESUMO

Dermal papilla (DP) cells regulate hair follicle epithelial cells and melanocytes by secreting functional factors, playing a key role in hair follicle morphogenesis and hair growth. DP cells can reconstitute new hair follicles and induce hair regeneration, providing a potential therapeutic strategy for treating hair loss. However, current methods for isolating DP cells are either inefficient (physical microdissection) or only applied to genetically labeled mice. We systematically screened for the surface proteins specifically expressed in skin DP using mRNA expression databases. We identified two antibodies against receptors LEPTIN Receptor (LEPR ) and Scavenger Receptor Class A Member 5 (SCARA5) which could specifically label and isolate DP cells by flow cytometry from mice back skin at the growth phase. The sorted LEPR+ cells maintained the DP characteristics after culturing in vitro, expressing DP marker alkaline phosphatase and functional factors including RSPO1/2 and EDN3, the three major DP secretory factors that regulate hair follicle epithelial cells and melanocytes. Furthermore, the low-passage LEPR+ DP cells could reconstitute hair follicles on nude mice using chamber graft assay when combined with epithelial stem cells. The method of isolating functional DP cells we established here lays a solid foundation for developing DP cell-based therapy.


Assuntos
Derme , Receptores para Leptina , Animais , Células Cultivadas , Derme/metabolismo , Cabelo/metabolismo , Folículo Piloso , Camundongos , Camundongos Nus , Receptores para Leptina/genética , Receptores para Leptina/metabolismo , Receptores Depuradores Classe A/metabolismo
5.
Exp Dermatol ; 29(4): 400-403, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32037580

RESUMO

Hair follicle central isthmus is surrounded by dense nerve endings and terminal Schwann cells (TSCs), forming a specialized sensory structure called lanceolate complexes. Extracellular matrix protein EGFL6 expressed from epidermis has been found closely associated with lanceolate complexes and important for proper alignment of nerve fibres and TSCs processes, and for proper response to light touch. However, how EGFL6 itself is specifically induced/deposited/maintained at the central isthmus remains to be elucidated. Previous reports and our results showed that nerve endings and TSCs docking at the central isthmus during hair follicle development occur before the specific depositing of EGFL6 protein. Furthermore, we found nude mice rarely maintain the lanceolate complex, and EGFL6 is lost in their aberrant hair follicle. Instead, reconstituted hair follicle in nude mice by stem cells chamber grafting assay expresses EGFL6 at the central isthmus area after hair follicle innervation. At last, long-term but not short-term cutaneous denervation leads to degeneration of TSCs and loss of EGFL6 expression. Together, our results demonstrate that EGFL6 expression in the central isthmus is dependent on the presence of TSCs, proposing that the interplay of epidermis and neuronal components is important for maintaining functional structure of lanceolate complexes.


Assuntos
Proteínas de Ligação ao Cálcio/biossíntese , Moléculas de Adesão Celular/biossíntese , Folículo Piloso/inervação , Folículo Piloso/fisiologia , Células de Schwann/metabolismo , Animais , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Matriz Extracelular/metabolismo , Cabelo/fisiologia , Queratinócitos/citologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fibras Nervosas/metabolismo , Neurônios , Pele/inervação , Células-Tronco/citologia
6.
Mol Carcinog ; 58(8): 1450-1464, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31026381

RESUMO

Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. High intratumor heterogeneity of advanced gastric cancer poses great challenges to targeted therapy due to simultaneous activation of many redundant cancer-driving pathways. A central common signaling mechanism in cancer is proline-directed phosphorylation, which is further regulated by the unique proline isomerase Pin1. Pin1 inhibition exerts anticancer activity by blocking multiple cancer-driving pathways in some cancers, but its role in gastric cancer is not fully understood. Here we detected Pin1 protein expression in 1065 gastric cancer patients and paired normal tissues using immunohistochemistry and Western blot, and then examined the effects of Pin1 overexpression, and genetic and chemical Pin1 inhibition using Pin1 short hairpin RNA or small molecule inhibitor all-trans retinoic acid (ATRA) on tumorigenesis of human gastric cancer in vitro and in vivo, followed by biochemical analyses to elucidate Pin1 regulated oncogenic pathways. We found that Pin1 was significantly overexpressed in primary and metastasized tumors, with Pin1 overexpression being correlated with advanced stage and poor prognosis. Furthermore, whereas Pin1 overexpression promoted the transformed phenotype in immortalized and nontransformed human gastric cells, either genetic or chemical Pin1 inhibition in multiple human gastric cancer cells potently suppressed cell growth, G1/S transition and colony formation in vitro, as well as tumor growth in xenograft tumor models in vivo, which were further supported by downregulation of multiple key oncoproteins in PI3K/AKT and Wnt/ß-catenin signaling pathways. These results not only provide the first evidence for a critical role of Pin1 in the tumorigenesis of gastric cancer but also suggest that targeting Pin1 using ATRA or other inhibitors offers an effective new therapeutic approach for treating advanced gastric cancer.


Assuntos
Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/patologia , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Animais , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Peptidilprolil Isomerase de Interação com NIMA/antagonistas & inibidores , Peptidilprolil Isomerase de Interação com NIMA/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Tretinoína/farmacologia , Via de Sinalização Wnt
7.
J Cell Sci ; 126(Pt 20): 4614-26, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23902692

RESUMO

Migratory cells, including mammalian leukocytes and Dictyostelium, use G-protein-coupled receptor (GPCR) signaling to regulate MAPK/ERK, PI3K, TORC2/AKT, adenylyl cyclase and actin polymerization, which collectively direct chemotaxis. Upon ligand binding, mammalian GPCRs are phosphorylated at cytoplasmic residues, uncoupling G-protein pathways, but activating other pathways. However, connections between GPCR phosphorylation and chemotaxis are unclear. In developing Dictyostelium, secreted cAMP serves as a chemoattractant, with extracellular cAMP propagated as oscillating waves to ensure directional migratory signals. cAMP oscillations derive from transient excitatory responses of adenylyl cyclase, which then rapidly adapts. We have studied chemotactic signaling in Dictyostelium that express non-phosphorylatable cAMP receptors and show through chemotaxis modeling, single-cell FRET imaging, pure and chimeric population wavelet quantification, biochemical analyses and TIRF microscopy, that receptor phosphorylation is required to regulate adenylyl cyclase adaptation, long-range oscillatory cAMP wave production and cytoskeletal actin response. Phosphorylation defects thus promote hyperactive actin polymerization at the cell periphery, misdirected pseudopodia and the loss of directional chemotaxis. Our data indicate that chemoattractant receptor phosphorylation is required to co-regulate essential pathways for migratory cell polarization and chemotaxis. Our results significantly extend the understanding of the function of GPCR phosphorylation, providing strong evidence that this evolutionarily conserved mechanism is required in a signal attenuation pathway that is necessary to maintain persistent directional movement of Dictyostelium, neutrophils and other migratory cells.


Assuntos
Actinas/metabolismo , Quimiotaxia/fisiologia , Dictyostelium/metabolismo , Proteínas de Protozoários/metabolismo , Receptores de AMP Cíclico/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Células Cultivadas , Dictyostelium/citologia , Alvo Mecanístico do Complexo 2 de Rapamicina , Microscopia Confocal , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Complexos Multiproteicos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
8.
Am J Pathol ; 183(4): 1281-1292, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23906809

RESUMO

Twist1 promotes epithelial-mesenchymal transition, invasion, metastasis, stemness, and chemotherapy resistance in cancer cells and thus is a potential target for cancer therapy. However, Twist1-null mice are embryonic lethal, and people with one Twist1 germline mutant allele develop Saethre-Chotzen syndrome; it is questionable whether Twist1 can be targeted in patients without severe adverse effects. We found that Twist1 is expressed in several tissues, including fibroblasts of the mammary glands and dermal papilla cells of the hair follicles. We developed a tamoxifen-inducible Twist1 knockout mouse model; Twist1 knockout in 6-week-old female mice did not affect mammary gland morphogenesis and function during pregnancy and lactation. In both males and females, the knockout did not influence body weight gain, heart rate, or total lean and fat components. The knockout also did not alter blood pressure in males, although it slightly reduced blood pressure in females. Although Twist1 is not cyclically expressed in dermal papilla cells, knockout of Twist1 at postnatal day 13 (when hair follicles have developed) drastically extended the anagen phase and accelerated hair growth. These results indicate that Twist1 is not essential for maintaining an overall healthy condition in young and adult mice and that loss of function facilitates hair growth in adulthood, supporting Twist1 as a preferential target for cancer therapy.


Assuntos
Envelhecimento/metabolismo , Folículo Piloso/crescimento & desenvolvimento , Saúde , Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Animais , Feminino , Folículo Piloso/citologia , Folículo Piloso/metabolismo , Masculino , Glândulas Mamárias Animais/crescimento & desenvolvimento , Glândulas Mamárias Animais/metabolismo , Camundongos , Camundongos Knockout , Morfogênese , Proteínas Nucleares/deficiência , Especificidade de Órgãos , Proteína 1 Relacionada a Twist/deficiência
9.
Exp Dermatol ; 23(3): 195-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24499442

RESUMO

Lgr5/6 proteins are stem cell markers in various tissues. However, what determines their restricted expression pattern in these tissues remains unknown. We found that in skin, Lgr6 is not only expressed in the central isthmus, directly above the hair follicle bulge cells as reported previously, but also in the interfollicular epidermis. Lgr6 expression in skin is highly correlated with the innervation sites of cutaneous nerves. In the hair follicle, Lgr6 closely localizes with the surrounding nerve endings and their corresponding Schwann cells throughout the entire hair cycle. Furthermore, ablation of cutaneous nerves leads to degeneration of Schwann cells and diminished expression of Lgr6. Our results demonstrate that the nerve endings/Schwann cells control Lgr6 expression in skin, implying that they play a role in regulation of skin epithelial cells.


Assuntos
Epiderme/inervação , Epiderme/metabolismo , Folículo Piloso/metabolismo , Terminações Nervosas/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Células de Schwann/fisiologia , Animais , Denervação , Técnicas de Introdução de Genes , Folículo Piloso/citologia , Camundongos , Camundongos Transgênicos , Terminações Nervosas/química , Subunidade beta da Proteína Ligante de Cálcio S100/análise , Células de Schwann/química
10.
Front Cell Dev Biol ; 11: 1263316, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38357530

RESUMO

Self-organized and excitable signaling activities play important roles in a wide range of cellular functions in eukaryotic and prokaryotic cells. Cells require signaling networks to communicate amongst themselves, but also for response to environmental cues. Such signals involve complex spatial and temporal loops that may propagate as oscillations or waves. When Dictyostelium become starved for nutrients, cells within a localized space begin to secrete cAMP. Starved cells also become chemotactic to cAMP. cAMP signals propagate as outwardly moving waves that oscillate at ∼6 min intervals, which creates a focused territorial region for centralized cell aggregation. Proximal cells move inwardly toward the cAMP source and relay cAMP outwardly to recruit additional cells. To ensure directed inward movement and outward cAMP relay, cells go through adapted and de-adapted states for both cAMP synthesis/degradation and for directional cell movement. Although many immediate components that regulate cAMP signaling (including receptors, G proteins, an adenylyl cyclase, phosphodiesterases, and protein kinases) are known, others are only inferred. Here, using biochemical experiments coupled with gene inactivation studies, we model an integrated large, multi-component kinetic pathway involving activation, inactivation (adaptation), re-activation (re-sensitization), feed-forward, and feed-back controls to generate developmental cAMP oscillations.

11.
Biomolecules ; 13(7)2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37509112

RESUMO

Many people suffer from hair loss and abnormal skin pigmentation, highlighting the need for simple assays to support drug discovery research. Current assays have various limitations, such as being in vitro only, not sensitive enough, or unquantifiable. We took advantage of the bilateral symmetry and large size of mouse whisker follicles to develop a novel in vivo assay called "whisker follicle microinjection assay". In this assay, we plucked mouse whiskers and then injected molecules directly into one side of the whisker follicles using microneedles that were a similar size to the whiskers, and we injected solvent on the other side as a control. Once the whiskers grew out again, we quantitatively measured their length and color intensity to evaluate the effects of the molecules on hair growth and coloring. Several chemicals and proteins were used to test this assay. The chemicals minoxidil and ruxolitinib, as well as the protein RSPO1, promoted hair growth. The effect of the clinical drug minoxidil could be detected at a concentration as low as 0.001%. The chemical deoxyarbutin inhibited melanin production. The protein Nbl1 was identified as a novel hair-growth inhibitor. In conclusion, we successfully established a sensitive and quantitative in vivo assay to evaluate the effects of chemicals and proteins on hair growth and coloring and identified a novel regulator by using this assay. This whisker follicle microinjection assay will be useful when investigating protein functions and when developing drugs to treat hair loss and abnormal skin pigmentation.


Assuntos
Minoxidil , Vibrissas , Camundongos , Animais , Vibrissas/metabolismo , Minoxidil/metabolismo , Minoxidil/farmacologia , Microinjeções , Cabelo , Alopecia/tratamento farmacológico , Alopecia/metabolismo
12.
Front Oncol ; 13: 1189948, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37287912

RESUMO

Because of its significant advantage of fast postoperative recovery, natural orifice specimen extraction surgery (NOSES) has attracted increasing attention worldwide. However, the NOSES in gastric cancer (GC) treatment still needs more clinical practice, especially for the rare anatomical anomaly. Situs inversus totalis (SIT) is a rare autosomal recessive anatomical anomaly with an incidence ranging between 1/8,000 and 1/25,000 births. We present a video of transvaginal specimen extraction following totally laparoscopic D2 distal gastrectomy performed in a 59-year-old woman known to have SIT. Preoperative investigations revealed that the patient had early GC at the antrum. A gastroscopy report from the local hospital showed signet-ring cell carcinoma. The preoperative computed tomography scan revealed irregular thickening of the gastric wall at the junction of the greater curvature and antrum without metastasis to the lymph nodes. In total, laparoscopic D2 distal gastrectomy was performed with transvaginal specimen extraction. Billroth II with Braun anastomosis was performed for reconstruction. The length of the operation was 240 min without intraoperative complications and with minimal blood loss of 50 ml. The patient was uneventfully discharged on postoperative Day 7. The final pathology confirmed signet-ring cell carcinoma confined to the mucosal muscle without metastasis in 16 lymph nodes. Transvaginal specimen extraction following totally laparoscopic D2 distal gastrectomy can be safely performed in patients with SIT and has similar surgical outcomes to usual laparoscopic gastrectomy.

13.
Front Oncol ; 13: 1175151, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37293593

RESUMO

Purpose: Silent mating type information regulator 2 homolog 1 (SIRT1) and autophagy have a two-way action (promoting cell death or survival) on the progression and treatment of gastric cancer (GC) under different conditions or environments. This study aimed to investigate the effects and underlying mechanism of SIRT1 on autophagy and the malignant biological behavior of GC cells under conditions of glucose deprivation (GD). Materials and methods: Human immortalized gastric mucosal cell GES-1 and GC cell lines SGC-7901, BGC-823, MKN-45 and MKN-28 were utilized. A sugar-free or low-sugar (glucose concentration, 2.5 mmol/L) DMEM medium was used to simulate GD. Additionally, CCK8, colony formation, scratches, transwell, siRNA interference, mRFP-GFP-LC3 adenovirus infection, flow cytometry and western blot assays were performed to investigate the role of SIRT1 in autophagy and malignant biological behaviors (proliferation, migration, invasion, apoptosis and cell cycle) of GC under GD and the underlying mechanism. Results: SGC-7901 cells had the longest tolerance time to GD culture conditions, which had the highest expression of SIRT1 protein and the level of basal autophagy. With the extension of GD time, the autophagy activity in SGC-7901 cells also increased. Under GD conditions, we found a close relationship between SIRT1, FoxO1 and Rab7 in SGC-7901 cells. SIRT1 regulated the activity of FoxO1 and upregulated the expression of Rab7 through deacetylation, which ultimately affected autophagy in GC cells. In addition, changing the expression of FoxO1 provided feedback on the expression of SIRT1 in the cell. Reducing SIRT1, FoxO1 or Rab7 expression significantly inhibited the autophagy levels of GC cells under GD conditions, decreased the tolerance of GC cells to GD, enhanced the inhibition of GD in GC cell proliferation, migration and invasion and increased apoptosis induced by GD. Conclusion: The SIRT1-FoxO1-Rab7 pathway is crucial for the autophagy and malignant biological behaviors of GC cells under GD conditions, which could be a new target for the treatment of GC.

14.
Adv Sci (Weinh) ; 10(4): e2201949, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36507562

RESUMO

Niche for stem cells profoundly influences their maintenance and fate during tissue homeostasis and pathological disorders; however, the underlying mechanisms and tissue-specific features remain poorly understood. Here, it is reported that fatty acid desaturation catabolized by stearoyl-coenzyme A desaturase 1 (SCD1) regulates hair follicle stem cells (HFSCs) and hair growth by maintaining the bulge, niche for HFSCs. Scd1 deletion in mice results in abnormal hair growth, an effect exerted directly on keratin K14+ keratinocytes rather than on HFSCs. Mechanistically, Scd1 deficiency impairs the level of integrin α6ß4 complex and thus the assembly of hemidesmosomes (HDs). The disruption of HDs allows the aberrant activation of focal adhesion kinase and PI3K in K14+ keratinocytes and subsequently their differentiation and proliferation. The overgrowth of basal keratinocytes results in downward extension of the outer root sheath and interruption of bulge formation. Then, inhibition of PI3K signaling in Scd1-/- mice normalizes the bulge, HFSCs, and hair growth. Additionally, supplementation of oleic acid to Scd1-/- mice reestablishes HDs and the homeostasis of bulge niche, and restores hair growth. Thus, SCD1 is critical in regulating hair growth through stabilizing HDs in basal keratinocytes and thus sustaining bulge for HFSC residence and periodic activity.


Assuntos
Hemidesmossomos , Fosfatidilinositol 3-Quinases , Camundongos , Animais , Queratinócitos , Homeostase , Estearoil-CoA Dessaturase
15.
J Cell Sci ; 123(Pt 6): 983-92, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20200230

RESUMO

Protein kinases AKT and PKBR1 of Dictyostelium belong to the AGC protein kinase superfamily. AKT and PKBR1 are phosphorylated at similar sites by phosphoinositide-dependent kinase 1 (PDK1) and TORC2 kinases; however, they have different subcellular localizing domains. AKT has a phosphoinositide 3-kinase (PI3K)/phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P(3)]-regulated PH (pleckstrin homology) domain whereas PKBR1 is myristoylated and persistently membrane localized. Using strains defective for PI3K/PtdIns(3,4,5)P(3)-, PDK1- and TORC2-signaling or strains that express phospho-site mutants of AKT and PKBR1, we dissect the different roles of PI3K/PtdIns(3,4,5)P(3), PDK1 and TORC2. We show that activation of AKT and PKBR1 requires PDK1-site phosphorylation, but that phosphorylation by TORC2 is insufficient for AKT or PKBR1 activation. However, PDK1-site phosphorylation is dependent on phosphorylation by TORC2, which suggests that there is regulatory coordination among PDK1, TORC2 and their phospho-site targets. This defines a separate input for signaling in control of chemotaxis and dependency on PDK1 function. We also demonstrate that PDK1 in Dictyostelium functions independently of PI3K/PtdIns(3,4,5)P(3). Finally, we show that AKT and PKBR1 exhibit substrate selectivity and identify two novel lipid-interacting proteins preferentially phosphorylated by AKT. Despite certain similarities, AKT and PKBR1 have distinct regulatory paths that impact activation and effector targeting, with PDK1 serving a central role.


Assuntos
Quimiotaxia , Dictyostelium/citologia , Dictyostelium/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas de Protozoários/metabolismo , Transativadores/metabolismo , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Motivos de Aminoácidos , Animais , Fatores Quimiotáticos/farmacologia , Quimiotaxia/efeitos dos fármacos , AMP Cíclico/farmacologia , Dictyostelium/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Ácido Fólico/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Especificidade por Substrato/efeitos dos fármacos
17.
Dig Liver Dis ; 54(7): 896-904, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34987010

RESUMO

BACKGROUND: Gastric cancer (GC) is a common malignant tumor of the digestive system. Increasing reports have demonstrated the crucial roles of circRNAs in tumorigenesis and progression of GC. METHODS: The relative expression of circ-ABCB10 in GC tissues and cell lines was detected by qRT-PCR. A series of in vitro assays and a xenograft model in vivo were applied to explore the function of circ-ABCB10 in GC cells. RESULTS: Circ-ABCB10 expression was upregulated in GC tissues and cell lines and positively correlated with poor survival of GC patients. Circ-ABCB10 downregulation decreased cell viability, inhibited cell growth, invasion, and migration, while promoted cell apoptosis of GC cell lines SGC-7901 and MKN-48. Circ-ABCB10 could upregulate Rac1 expression by directly sponging miR-1915-3p. Rescue experiments revealed that miR-1915-3p inhibitor obviously reversed the inhibitory effect of si-circ-ABCB10, and Rac1 overexpression obviously reversed the inhibitory effect of miR-1915-3p mimics on cell growth, invasion, migration, apoptosis, and cell cycle progression. Moreover, si-circ-ABCB10 effectively inhibited tumor growth in a xenograft model. CONCLUSIONS: Our study revealed that circ-ABCB10 promoted GC progression via targeting the miR-1915-3p/Rac1 axis, and circ-ABCB10 might be a potential target for GC diagnosis and treatment.


Assuntos
Transportadores de Cassetes de Ligação de ATP , MicroRNAs , RNA Circular , Neoplasias Gástricas , Proteínas rac1 de Ligação ao GTP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , Neoplasias Gástricas/patologia , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo
18.
ACS Med Chem Lett ; 13(10): 1574-1581, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36262386

RESUMO

Since ibrutinib was approved by the FDA as an effective monotherapy for chronic lymphocytic leukemia (CLL) and multilymphoma, more and more FDA-approved covalent drugs are coming back into the market. On this occasion, the resurgence of interest in covalent drugs calls for more hit discovery techniques. However, the limited numbers of covalent libraries prevent the development of this area. Herein, we report the design of covalent DNA-encoded library (DEL) and its selection method for the discovery of covalent inhibitors for target proteins. These triazine-based covalent DELs yielded potent compounds after covalent selection against target proteins, including Bruton's Tyrosine Kinase (BTK), Janus kinase 3 (JAK3), and peptidyl-prolyl cis/trans isomerase NIMA-interacting-1 (Pin1).

19.
World J Gastrointest Oncol ; 14(7): 1252-1264, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36051096

RESUMO

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is frequently diagnosed and treated in advanced tumor stages with poor prognosis. More effective screening programs and novel therapeutic means are urgently needed. Recent studies have regarded tight junction protein claudin 18.2 (CLDN18.2) as a candidate target for cancer treatment, and zolbetuximab (formerly known as IMAB362) has been developed against CLDN18.2. However, there are few data reported thus far related to the clinicopathological characteristics of CLDN18.2 expression for PDAC. AIM: To investigate the expression of CLDN18.2 in PDAC patients and subsequently propose a new target for the treatment of PDAC. METHODS: The Cancer Genome Atlas, Genotype-Tissue Expression, Gene Expression Omnibus, and European Genome-phenome Archive databases were first employed to analyze the CLDN18 gene expression in normal pancreatic tissue compared to that in pancreatic cancer tissue. Second, we analyzed the expression of CLDN18.2 in 93 primary PDACs, 86 para-cancer tissues, and 13 normal pancreatic tissues by immunohistochemistry. Immunostained tissues were assessed applying the histoscore. subsequently, they fell into two groups according to the expression state of CLDN18.2. Furthermore, the correlations between CLDN18.2 expression and diverse clinicopathological characteristics, including survival, were investigated. RESULTS: The gene expression of CLDN18 was statistically higher (P < 0.01) in pancreatic tumors than in normal tissues. However, there was no significant correlation between CLDN18 expression and survival in pancreatic cancer patients. CLDN18.2 was expressed in 88 (94.6%) of the reported PDACs. Among these tumors, 50 (56.8%) cases showed strong immunostaining. The para-cancer tissues were positive in 81 (94.2%) cases, among which 32 (39.5%) of cases were characterized for strong staining intensities. Normal pancreatic tissue was identified solely via weak immunostaining. Finally, CLDN18.2 expression significantly correlated with lymph node metastasis, distant metastasis, nerve invasion, stage, and survival of PDAC patients, while there was no correlation between CLDN18.2 expression and localization, tumor size, patient age and sex, nor any other clinicopathological characteristic. CONCLUSION: CLDN18.2 expression is frequently increased in PDAC patients. Thus, it may act as a potential therapeutic target for zolbetuximab in PDAC.

20.
Cancer Manag Res ; 13: 4191-4201, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079372

RESUMO

BACKGROUND: Inflammation and nutrition play vital roles in the development of gastric cancer (GC). We combined the preoperative fibrinogen with prognostic nutritional index (PNI) to create a novel scoring system named as the fibrinogen and prognostic nutritional index (FPNI) score and establish a more effective model. PATIENTS AND METHODS: A total of 689 patients with gastric adenocarcinoma who underwent gastrectomy from January 2012 to December 2016 were reviewed. We measured correlations between FPNI score and clinicopathological variables and overall survival (OS). A nomogram predicting OS was constructed. Its predictive performance was verified using the concordance index, calibration curves, receiver operating characteristic curves, decision curve analysis and time-dependent receiver operating characteristic analysis. RESULTS: We observed that the FPNI score was an independent predictor of OS in patients with gastric cancer (P < 0.05). A high FPNI score was significantly related to older age at surgery, tumor size ≥4.6 cm, high ASA score, advanced TNM stage and poor outcome (both P < 0.05). And the FPNI score remained an independent indicator at various TNM stages (P < 0.05). Ultimately, the nomogram based on FPNI score, age, tumor size, histological grade and TNM stage showed a better predictive ability than TNM alone. CONCLUSION: The preoperative FPNI score is a novel, simple, and effective predictor of OS in patients with GC. Furthermore, the nomogram involving FPNI score will help clinicians to optimize individualized treatment plans.

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