Myeloproliferative neoplasms ( MPN ) is a class of clonal hematopoietic stem cell disease. Studies found that the JAK-STAT signaling pathway is closely related to the pathogenesis of MPN. The lymphocyte-specific adaptor protein (LNK) gene negatively regulates Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling and may play an important role in the pathogenesis of MPN. Especially in JAK2 mutation-negative MPN, LNK gene specific mutations may be the key to cause MPN subtypes. Certain single nucleotide polymorphism of LNK gene regulation of hematopoietic cells in different directions may also be important influence factors of MPN performance for different subtypes. LNK gene functional changes lead to abnormal activation of the JAK-STAT signaling pathway, and may be a new mechanism of MPN. In this review, the role of LNK gene in MPN pathogenesis is briefly summarized.
Humans ; Janus Kinases ; metabolism ; Mutation ; Myeloproliferative Disorders ; genetics ; Proteins ; genetics ; STAT Transcription Factors ; metabolism ; Signal Transduction

Animals ; Breast Neoplasms ; metabolism ; pathology ; therapy ; Cell Proliferation ; Female ; Hedgehog Proteins ; metabolism ; Humans ; Neoplastic Stem Cells ; metabolism ; pathology ; Phosphatidylinositol 3-Kinases ; metabolism ; Receptors, CXCR4 ; metabolism ; Receptors, Notch ; metabolism ; STAT Transcription Factors ; metabolism ; Signal Transduction ; Wnt Proteins ; metabolism

Carcinoma, Squamous Cell ; metabolism ; pathology ; Esophageal Neoplasms ; metabolism ; pathology ; Humans ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; NF-kappa B ; metabolism ; Prognosis ; STAT Transcription Factors ; metabolism ; Signal Transduction ; Transforming Growth Factor beta ; metabolism ; Wnt Proteins ; metabolism

Intracellular signal transduction plays an important role in the process of cellular metabolism, segmentation, differentiation, biological behaviour and cell death. Overactive signal transduction relates to tumor development and progression. Signaling pathways operated by protein tyrosine kinases (PTKs) will be illuminated here briefly. The Ras/Raf/MAPK and PI-3K/Akt pathways through receptor protein tyrosine kinases (RTKs), the Src, Bcr-Abl and JAK/STAT pathways by non-receptor protein tyrosine kinases (nrPTKs) are shown separately. Antitumor agents targeting the key proteins involved in the above five signalling routes are also summarized in this review.
Animals ; Antineoplastic Agents ; pharmacology ; Humans ; Phosphatidylinositol 3-Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Receptor Protein-Tyrosine Kinases ; metabolism ; STAT Transcription Factors ; metabolism ; Signal Transduction ; drug effects ; ras Proteins ; metabolism ; src-Family Kinases ; metabolism

OBJECTIVETo evaluate the effect of JAK/STAT signaling pathway activation on the transdifferentiation and secretion of transforming growth factor-beta1 (TGF-beta1) induced by high glucose in renal proximal tubular epithelial cells.

METHODSHuman kidney cells (HKC) were cultured and then divided into four groups: low glucose (LG) group, high glucose (HG) group, high mannitol (LG + M) group, and HG + AG490 group. Immunoprecipitation and Western blot analysis were used to determine the expression of tryosine phosphorylated Janus kinase 2 ( p-JAK2). The protein expressions of STAT1, STAT3, p-STAT1, and p-STAT3 and the expressions of alpha-SMA and E-Cadherin were observed by Western blot. The contents of TGF-B1, fibronectin and type I collagen in the supernatants of the cultured HKC were detected by enzyme-linked immunosorbent assay (ELISA). The expression of TGF-beta1 mRNA was measured by reverse transcription and polymerase chain reaction (RT-PCR).

RESULTSCompared with LG group, the expressions of JAK2, p-STAT1, p-STAT3, and TGF-beta1, mRNA were significantly increased in HG group from 6 to 72 hours. Meanwhile, the contents of TGF-beta1 and collagen I in the supernatants and the expression of alpha-SMA increased and the expression of E-Cadherin decreased. The expressions of JAK2, p-STAT1, p-STAT3, and TGF-beta mRNA as well as the levels of TGF-beta1 and collagen I in the supernatant s in HG + AG490 group were significantly lower than in the HG group. The expressions of alpha-SMA and E-Cadherin were also decreased in HG + AG490 group.

CONCLUSIONActivation of JAK/STAT signaling pathway may be involved in the high glucose-induced transdifferentiation and overproduction of TGF-beta1, and ECM proteins in HKCs.

Cell Line ; Cell Transdifferentiation ; Epithelial Cells ; cytology ; metabolism ; Glucose ; metabolism ; pharmacology ; Humans ; Janus Kinases ; physiology ; Kidney Tubules, Proximal ; cytology ; metabolism ; STAT Transcription Factors ; physiology ; Signal Transduction ; Transforming Growth Factor beta1 ; biosynthesis ; secretion ; Urothelium ; cytology ; metabolism

Objective To explore the therapeutic effect of ethambutol tablets (EMB) on pulmonary tuberculosis (PTB) in rats and whether the action mechanism of EMB is related to Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway. Methods Sixty SD rats were assigned into a control group,a PTB group,a PTB+EMB group (30 mg/kg),and a PTB+EMB+Colivelin (JAK/STAT pathway activator) group (30 mg/kg+1 mg/kg) via the random number table method,with 15 rats in each group.The rats in other groups except the control group were injected with 0.2 ml of 5 mg/ml Mycobacterium tuberculosis suspension to establish the PTB model.After the modeling,the rats were administrated with corresponding drugs for 4 consecutive weeks (once a day).On days 1,14,and 28 of administration,the body weights of rats were measured and the Mycobacterium tuberculosis colonies were counted.Hematoxylin-eosin staining was carried out to detect the pathological changes in the lung tissue.Enzyme-linked immunosorbent assay was employed to measure the levels of interleukin(IL)-6,tumor necrosis factor-α (TNF-α),IL-1β,and interferon-γ (IFN-γ) in the serum.Flow cytometry was used to determine the levels of T lymphocyte subsets CD3+,CD4+,CD8+,and CD4+/CD8+.The 16S rRNA sequencing was performed to detect the relative abundance of the intestinal microorganisms.Western blotting was employed to determine the expression of the proteins in the JAK/STAT pathway. Results Compared with the control group,the modeling of PTB reduced the rat body weight (on days 14 and 28),increased Mycobacterium tuberculosis colonies,caused severe pathological changes in the lung tissue,and elevated the levels of IL-6,TNF-α,and IL-1β in serum and CD8+.Moreover,the modeling increased the relative abundance of Bacteroides,Peptococcus,Clostridium,Actinomyces,Lactobacillus,Verrucomicrobium,and Veillonella in the intestine,up-regulated the protein levels of phosphorylated JAK2 and phosphorylated STAT3 in the lung tissue,and lowered the levels of CD3+,CD4+,CD4+/CD8+,and IFN-γ levels (all P<0.001).Compared with the PTB group,PTB+EMB increased the rat body weight (on days 14 and 28),reduced Mycobacterium tuberculosis colonies,alleviated the pathological damage in lung tissue,lowered the levels of IL-6,TNF-α,and IL-1β in serum and CD8+.Moreover,the treatment decreased the relative abundance of Bacteroides,Peptococcus,Clostridium,Actinomyces,Lactobacillus,Verrucomicrobium,Veillonella in the intestine,down-regulated the protein levels of phosphorylated JAK2 and phosphorylated STAT3 in the lung tissue,and elevated the levels of CD3+,CD4+,CD4+/CD8+,and IFN-γ (all P<0.001).Colivelin weakened the alleviation effect of EMB on PTB (all P<0.001). Conclusion EMB can inhibit the JAK/STAT signaling pathway to alleviate the PTB in rat.
Animals ; Body Weight ; Ethambutol/pharmacology* ; Interferon-gamma/pharmacology* ; Interleukin-6/metabolism* ; Janus Kinases/pharmacology* ; Mycobacterium tuberculosis/metabolism* ; RNA, Ribosomal, 16S ; Rats ; Rats, Sprague-Dawley ; STAT Transcription Factors/pharmacology* ; Signal Transduction ; Tablets/pharmacology* ; Tuberculosis, Pulmonary/metabolism* ; Tumor Necrosis Factor-alpha/metabolism*

BACKGROUNDTraumatic brain injury (TBI) is a major cause of death and disability in children and young adults worldwide. Therefore, we investigated the role of AG490 in regulating brain oedema, expression of CD40 and neurological function after TBI.

METHODSSprague Dawley rats (n = 240) were randomly divided into a sham operation group, TBI+saline group and TBI+AG490 (JAK/STAT inhibitor) group. Members of each group were euthanized at 6, 12, 24 or 72 hours after injury. Neurological severity score (NSS) was used to evaluate the severity of neurological damage. Brain water was quantitated by wet/dry weight method. The expression of CD40 was assessed by flow cytometry.

RESULTSIn both the TBI+saline group and the TBI+AG490 group, the brain water content was elevated after TBI, reached a peak at 24-hour and remained high for the rest of the period investigated; the expression of CD40 reached a peak 24 hours after TBI; the NSS was elevated after TBI and then decreased after 6 hours. Elevations in the level of CD40, degree of brain edema and NSS after TBI were significantly reduced in TBI+AG490 group.

CONCLUSIONInhibition of the JAK/STAT signalling pathway reduces brain oedema, decreases the expression of CD40 and exerts neuroprotective effects after TBI.

Animals ; Brain Edema ; metabolism ; Brain Injuries ; drug therapy ; CD40 Antigens ; analysis ; Flow Cytometry ; Janus Kinases ; metabolism ; Male ; Neuroprotective Agents ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; STAT Transcription Factors ; metabolism ; Tyrphostins ; therapeutic use

OBJECTIVETo elucidate the roles of JAK/STATs signal pathway on anti-proliferative effects induced by IFN-alpha in MHCC97.

METHODSAn IRF9 expression vector was transfected into MHCC97 with Dosper. The expression of IRF9, cycle regulating proteins and the forming of ISGF3 complex were detected using Western blot and EMSA, respectively. Cell proliferation and distribution were monitored using MTT and flow cytometry.

RESULTSHigh expression of IRF9 restored the anti-proliferative response of MHCC97 on IFN-alpha treatment and delayed the cell transition from S phase to G2 phase induced by IFN-alpha.

CONCLUSIONThe integrity and functions of JAK/STATs signal pathway played an important role in mediating the anti-proliferative effects of IFN-alpha in MHCC97.

Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Interferon-Stimulated Gene Factor 3, gamma Subunit ; genetics ; Interferon-alpha ; metabolism ; pharmacology ; Janus Kinases ; genetics ; physiology ; Liver Neoplasms ; genetics ; metabolism ; pathology ; STAT Transcription Factors ; genetics ; physiology ; Signal Transduction ; Transfection

Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway is one of the downstream pathways of cytokine signaling transduction. It regulates cell development, differentiation, proliferation, apoptosis and so on. The pathway is not only involved in the regulation of normal physiological processes, but also significant in the development of tumors, especially in hematologic malignancies. In recent years, with the further research of JAK/STAT signaling pathway, it has been found that the pathway also plays a key role in the development of solid tumors. Here we reviewed the research advances of JAK/STAT signaling pathway in lung cancer, especially the mechanisms of development, metastasis and drug resistance, and the application of inhibitors which targeting JAK/STAT signaling pathway in the treatment of lung cancer.
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Animals ; Antineoplastic Agents ; therapeutic use ; Biomedical Research ; methods ; trends ; Humans ; Janus Kinases ; antagonists & inhibitors ; metabolism ; Lung Neoplasms ; drug therapy ; metabolism ; pathology ; Neoplasm Metastasis ; STAT Transcription Factors ; antagonists & inhibitors ; metabolism ; Signal Transduction

Stem cell niche is a specialized microenvironment crucial to self-renewal. The testis in Drosophila contains two different types of stem cells, the germline stem cells and the somatic cyst stem cells that are sustained by their respective niche signals, thus is a good system for studying the interaction between the stem cells and their hosting niche. The JAK-STAT and BMP pathways are known to play critical roles in the self-renewal of different kinds of stem cells, but the roles of several other pathways have emerged recently in a complex signaling network in the testis niche. Reports of independent observations from three research groups have uncovered an important role of Hedgehog (Hh) in the Drosophila testis niche. In this review, we summarize these recent findings and discuss the interplay between the Hh signaling mechanisms and those of the JAK-STAT and BMP pathways. We also discuss directions for further investigation.
Adult Germline Stem Cells ; metabolism ; Animals ; Bone Morphogenetic Proteins ; metabolism ; Drosophila ; cytology ; metabolism ; Drosophila Proteins ; metabolism ; Female ; Hedgehog Proteins ; metabolism ; Janus Kinases ; metabolism ; Male ; Ovary ; metabolism ; STAT Transcription Factors ; metabolism ; Signal Transduction ; Stem Cell Niche ; Testis ; cytology ; metabolism ; Transcription Factors ; metabolism