Leukemia Inhibitory Factor Receptor Research Articles

Low-dose aspirin can downregulate progesterone resistance and increase the expression of LIF in endometriosis during the implantation window

Aim Study the effect of low-dose aspirin on the endometrial receptivity in endometriosis rat models. Materials and methods This study is to explore the expressions of progesterone receptor and LIF among three groups of endometriosis rat models: control group (n = 12), EMs group (n = 15), and aspirin group (n = 17). The expressions of progesterone receptor (PR), PRA, PRB, and leukemia inhibitory factor receptor (LIFR) in eutopic endometrium were determined using immunohistochemistry technology, western blot, and qRT-PCR. The levels of LIF in eutopic endometrium and serum were detected by western blot, qRT-PCR, and ELISA. Results The expressions of PR, PRA, and PRB protein were significantly increased in the eutopic endometrium after low-dose aspirin treatment, and the level of PRB mRNA was also increased while the ratio of PRA/PRB mRNA was decreased in the eutopic endometrium. The levels of LIF in eutopic endometrium and serum were increased compared with the untreated endometriosis rats. However, the expression of LIFR was not statistically different among the three groups. Conclusions The results suggest that the low-dose aspirin treatment could downregulate progesterone resistance and increase the expression of LIF of endometriosis rats during the implantation window, which could improve endometrial receptivity and enhance the pregnant rate of endometriosis. It may provide a potential treatment method for endometriosis-related infertility.

Mutant KRAS Downregulates the Receptor for Leukemia Inhibitory Factor (LIF) to Enhance a Signature of Glycolysis in Pancreatic Cancer and Lung Cancer.

Pancreatic cancer is characterized by aberrant activity of oncogenic KRAS, which is mutated in 90% of pancreatic adenocarcinomas. Because KRAS itself is a challenging therapeutic target, we focused on understanding key signaling pathways driven by KRAS as a way to reveal dependencies that are amenable to therapeutic intervention. Analyses in primary human pancreatic cancers and model systems revealed that the receptor for the cytokine leukemia inhibitory factor (LIF) is downregulated by mutant KRAS. Furthermore, downregulation of the LIF receptor (LIFR) is necessary for KRAS-mediated neoplastic transformation. We found LIFR exerts inhibitory effects on KRAS-mediated transformation by inhibiting expression of the glucose transporter GLUT1, a key mediator of the enhanced glycolysis found in KRAS-driven malignancies. Decreased LIFR expression leads to increased GLUT1 as well as increases in glycolysis and mitochondrial respiration. The repression of GLUT1 by LIFR is mediated by the transcription factor STAT3, indicating a tumor-suppressive role for STAT3 within cancer cells with mutated KRAS. Finally, reflecting a clinically important tumor-suppressive role of LIFR, decreased LIFR expression correlates with shorter survival in pancreatic cancer patients with mutated KRAS. Similar findings were found in non-small cell lung cancers driven by mutated KRAS, suggesting that silencing LIFR is a generalized mechanism of KRAS-mediated cellular transformation. These results indicate that the LIFR/STAT3 pathway may mediate either tumor-promoting or tumor-suppressive signaling pathways depending on the genetic background of tumor cells, and may play diverse roles within other cells in the tumor microenvironment. IMPLICATIONS: Mutant KRAS drives downregulation of the receptor for LIF, thereby allowing an increase in expression of the glucose transporter GLUT1 and increases in glycolysis and mitochondrial respiration.

Changes in the phosphorylation of nucleotide metabolism‑associated proteins by leukemiainhibitory factor in mouse embryonic stem cells.

Leukemia inhibitory factor (LIF) is a stem cell growth factor that maintains self-renewal of mouse embryonic stem cells (mESCs). LIF is a cytokine in the interleukin-6 family and signals via the common receptor subunit gp130 and ligand-specific LIF receptor. LIF causes heterodimerization of the LIF receptor and gp130, activating the Janus kinase/STAT and MAPK pathways, resulting in changes in protein phosphorylation. The present study profiled LIF-mediated protein phosphorylation changes in mESCs via proteomic analysis. mESCs treated in the presence or absence of LIF were analyzed via two-dimensional differential in-gel electrophoresis and protein and phosphoprotein staining. Protein identification was performed by matrix-assisted laser desorption/ionization-time of flight mass spectrophotometry. Increased phosphorylation of 16 proteins and decreased phosphorylation of 34 proteins in response to LIF treatment was detected. Gene Ontology terms enriched in these proteins included ‘organonitrogen compound metabolic process’, ‘regulation of mRNA splicing via spliceosome’ and ‘nucleotide metabolic process’. The present results revealed that LIF modulated phosphorylation levels of nucleotide metabolism-associated proteins, thus providing insight into the mechanism underlying LIF action in mESCs.

Culture bovine prospermatogonia with 2i medium.

Germplasm cryopreservation and expansion of gonocytes/prospermatogonia or spermatogonial stem cells (SSCs) are important; however, it's difficult in cattle. Since inhibitors of Mek1/2 and Gsk3β (2i) can enhance pluripotency maintenance, effects of 2i-based medium on the cultivation of bovine prospermatogonia from the cryopreserved tissues were examined. The testicular tissues of newborn bulls were well cryopreserved. High mRNA levels of prospermatogonium/SSC markers (PLZF, GFRα-1) and pluripotency markers (Oct4/Pouf5, Sox2, Nanog) were detected and the PLZF+ /GFRα-1+ prospermatogonia were consistently identified immunohistochemically in the seminiferous cords. Using differential plating and Percoll-based centrifugation, 41.59% prospermatogonia were enriched and they proliferated robustly in 2i medium. The 2i medium boosted mRNA abundances of Pouf5, Sox2, Nanog, GFRα-1, PLZF, anti-apoptosis gene Bcl2, LIF receptor gene LIFR and enhanced PLZF protein expression, but suppressed mRNA expressions of spermatogonial differentiation marker c-kit and pro-apoptotic gene Bax, in the cultured prospermatogonia. It also alleviated H2 O2 -induced apoptosis of the enriched cells and decreased histone H3 lysine (K9) trimethylation (H3K9me3) and its methylase Suv39h1/2 mRNA level in the cultured seminiferous cords. Overall, 2i medium improves the cultivation of bovine prospermatogonia isolated from the cryopreserved testes, by inhibiting Suv39h1/2-mediated H3K9me3 through Mek1/2 and Gsk3β signalling, evidencing successful cryopreservation and expansion of bovine germplasm.

MgFe-LDH Nanoparticles: A Promising Leukemia Inhibitory Factor Replacement for Self-Renewal and Pluripotency Maintenance in Cultured Mouse Embryonic Stem Cells.

Leukemia inhibitory factor (LIF), an indispensable bioactive protein that sustains self‐renewal and pluripotency in stem cells, is vital for mouse embryonic stem cell (mESC) culture. Extensive research is conducted on reliable alternatives for LIF as its clinical application in stable culture and large‐scale expansion of ESCs is limited by its instability and high cost. However, few studies have sought to replace LIF with nanoparticles to provide a xeno‐free culture condition. MgAl‐LDH (layered double hydroxide) nanoparticles can partially replace LIF in maintaining pluripotency of mESCs; however, the requirement and tolerance for aluminum ions in mice are far lesser than those of iron ions. Hence, MgFe‐LDH nanoparticles are selected for this study. MgFe‐LDH is superior to MgAl‐LDH in maintaining self‐renewal and pluripotency of mESCs, in the absence of LIF and mouse embryonic fibroblast. Furthermore, combined transcriptomic and proteomic analysis confirms that MgFe‐LDH can activate the LIF receptor (LIFR)/phosphatidylinositol 3‐kinase (PI3K)/protein kinase B(AKT), LIFR/JAK/janus kinase (JAK)/signal transducer and activator of transcription 3(STAT3), and phospho‐signal transducer and activator of transcription 3(p‐STAT3)/ten‐eleven translocation (TET) signaling pathways, while the extra Fe2+ provided by MgFe‐LDH would also enhance TET1/2 abundance thus affecting the TET1/2 regulated pluripotency related marker expression and TET1/2 meditated DNA demethylation. These results suggest that MgFe‐LDH nanoparticles can thus be used as an affordable and efficient replacement for LIF in mESC cultivation.

LIFR-α-dependent adipocyte signaling in obesity limits adipose expansion contributing to fatty liver disease

SummaryThe role of chronic adipose inflammation in diet-induced obesity (DIO) and its sequelae including fatty liver disease remains unclear. Leukemia inhibitory factor (LIF) induces JAK-dependent adipocyte lipolysis and altered adipo/cytokine expression, suppressing in vivo adipose expansion in normal and obese mouse models. To characterize LIF receptor (LIFR-α)-dependent cytokine signaling in DIO, we created an adipocyte-specific LIFR knockout mouse model (Adipoq-Cre;LIFRfl/fl). Differentiated adipocytes derived from this model blocked LIF-induced triacylglycerol lipolysis. Adipoq-Cre;LIFRfl/fl mice on a high-fat diet (HFD) displayed reduced adipose STAT3 activation, 50% expansion in adipose, 20% body weight increase, and a 75% reduction in total hepatic triacylglycerides compared with controls. To demonstrate that LIFR-α signals adipocytes through STAT3, we also created an Adipoq-Cre;STAT3fl/fl model that showed similar findings when fed a HFD as Adipoq-Cre;LIFRfl/fl mice. These findings establish the importance of obesity-associated LIFR-α/JAK/STAT3 inflammatory signaling in adipocytes, blocking further adipose expansion in DIO contributing to ectopic liver triacylglyceride accumulation.

A novel prognostic mRNA/miRNA signature for esophageal cancer and its immune landscape in cancer progression.

Mounting evidence shows that MicroRNAs (miRNAs) and their target genes are aberrantly expressed in many cancers and are linked to tumor occurrence and progression, especially in esophageal cancer (EC). This study purposed to explore new biomarkers related to the prognosis of EC and to uncover their potential mechanisms in promoting tumor progression. We identified 162 differentially expressed miRNAs and 4555 differentially expressed mRNAs in EC. Then, a risk model involving three miRNAs (miR‐4521, miR‐3682‐3p, and miR‐1269a) was designed to predict prognosis in EC patients. Furthermore, 7 target genes (Rho GTPase‐activating protein 24, Chromobox 3, Contactin‐associated protein 2, ELOVL fatty acid elongase 5, LIF receptor subunit alpha, transmembrane protein 44, and transmembrane protein 67) were selected for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses to reveal their potential mechanisms in promoting EC progression. After a series of correlation analyses, miRNA target genes were found to be significantly positively or negatively associated with immune infiltration, tumor microenvironment, cancer stemness properties, and tumor mutation burden at different degrees in EC. To further elucidate the role of miRNA signature in cancer progression, we performed a pan‐cancer analysis to determine whether these genes exert similar effects on other tumors. Interestingly, the miRNA target genes altered expression on tumor immunity; however, pan‐cancer progression was the same as that of EC. Thus, we explored the immune landscape of the miRNA signature and its target genes in EC and pan‐cancer. These findings demonstrated the versatility and effectiveness of our model in various cancers and provided a new direction for cancer management.

Circular RNA circARPP21 Acts as a Sponge of miR-543 to Suppress Hepatocellular Carcinoma by Regulating LIFR.

BackgroundA large body of evidence has shown that circular RNAs (circRNAs) play a significant role in the progression of some malignant cancers, including hepatocellular carcinoma (HCC). However, the complex mechanism of circRNAs in hepatocellular carcinoma has not been clarified.MethodsWe identified circRNAs by microarray analysis and quantitative real-time polymerase chain reaction (RT-qPCR). We also carried out bioinformatics analysis, luciferase reporter assays, and RNA pull-down assays to define the relationship between microRNA (miR)-543 and circARPP21. Through silencing and overexpression of circARPP21, we investigated the effects of circARPP21 on proliferation, migration, and invasion abilities of HCC cells in vitro and in vivo.ResultsIn this study, we found that a novel circRNA, circARPP21 (hsa_circ_0123629), exerts a strong effect on HCC progression. Reduced expression of circARPP21 in HCC patients is correlated with larger tumor size, higher tug-lymph node metastasis (TNM) stage, and poor prognosis as indicated by elevated levels of alpha-fetoprotein (AFP). Conversely, higher expression of circARPP21 can increase leukemia inhibitory factor receptor (LIFR) expression by sponging miR-543. Finally, overexpression of miR-543 can reverse the anti-proliferation and anti-metastasis effects of circARPP21.ConclusionThe circARPP21/miR-543/LIFR axis suppresses the proliferation, invasion, and migration of hepatocellular carcinoma cells. In addition, circARPP21 can serve as a biomarker in HCC, thus offering a potential new approach to HCC therapy.

Investigation of Polymorphisms in the Upstream Sequence of LIF and LIFR Genes in the Infertile Women

: During pregnancy, the embryo implantation stage is a highly dynamic and molecularly controlled phenomenon. Several genes are involved in the implantation process, among which the leukemia inhibitory factor (LIF) is a marker of implantation. LIF is a multi-functional cytokine located on chromosome 22. The expression of this gene is increased in the middle of the secretion phase from the sexual cycle, and any defect in its expression will cause the implantation failure. LIF receptor or LIFR gene, as the LIF receptor, consists of two membrane proteins called LIFR and GP130. LIFR acts as a signal receptor for LIF in a low-affinity level. In this study, we focused on the screening of polymorphisms in the promoter region of the LIF and LIFR genes in the infertile women using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) method. In this study, blood samples were collected from 100 women with primary and secondary infertility and 50 healthy women as a control group. Extraction of DNA was done by the phenol-chloroform method, and in the next step, using specific primers for upstream regions of the LIF and LIFR genes, target sequences were amplified and analyzed by the SSCP method. Finally, PCR products with different configurations were selected for sequencing analysis. The results showed two polymorphisms in the upstream region of LIF and LIFR genes of two women, but there were no genetic changes in the control group. The present study was the first in this field, and the results indicated the importance of examining such genes in infertility with an unknown cause.

Hsa_circ_0001073 targets miR-626/LIFR axis to inhibit lung cancer progression.

Circular RNAs (circRNAs) are associated with lung cancer progression. However, it is unclear whether and how circRNA hsa_circ_0001073 (circ_0001073) are involved in lung cancer progression. circ_0001073, microRNA (miR)-626, and leukemia inhibitory factor receptor (LIFR) abundances were determined via quantitative reverse transcription polymerase chain reaction or western blot. Cell viability, invasion, and apoptosis were analyzed by cell counting kit-8, transwell analysis and flow cytometry, respectively. The target correlation was tested by dual-luciferase reporter analysis or RNA immunoprecipitation. Results showed that circ_0001073 abundance was down-regulated in lung cancer cells. circ_0001073 constrained cell viability and invasion and facilitated apoptosis in lung cancer cells. miR-626 was targeted via circ_0001073, and circ_0001073 inhibited lung cancer progression via reducing miR-626 expression. LIFR was targeted via miR-626, and miR-626 knockdown constrained cell viability and invasion and facilitated apoptosis in lung cancer cells via up-regulating LIFR. circ_0001073 increased LIFR expression via miR-626 in lung cancer cells. In conclusion, circ_0001073 represses lung cancer progression via miR-626/LIFR axis, indicating the potential value of circ_0001073 in lung cancer treatment.

LncRNA LIFR‑AS1 inhibits gastric carcinoma cell proliferation, migration and invasion by sponging miR‑4698.

The vital functions of long non-coding (lnc)RNAs have been verified in gastric carcinoma (GC). However, as a novel cancer-related lncRNA, the influence of leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) in GC cell biological behaviors remains unreported. The present study explored the biological effects of lncRNA LIFR-AS1 on GC progression. Reverse transcription-quantitative PCR was performed to examine lncRNA LIFR-AS1 expression in GC tissues and cells. Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine incorporation, cell wound healing and Transwell invasion assays were used to assess the functions of lncRNA LIFR-AS1 in GC cell proliferation, migration and invasion. Additionally, associations among lncRNA LIFR-AS1, microRNA (miR)-4698 and microtubule-associated tumor suppressor 1 (MTUS1) were investigated via bioinformatics software and a luciferase reporter system. In addition, western blotting was used to examine the expression of MEK and ERK. Decreased lncRNA LIFR-AS1 expression was observed in GC tissues and cells. Upregulated lncRNA LIFR-AS1 inhibited GC cell proliferation, migration and invasion. Upregulated miR-4698 and downregulated MTUS1 were identified in GC tissues and cells. The inhibitory interaction between lncRNA LIFR-AS1 and miR-4698 was confirmed. Additionally, MTUS1 was predicted as a target gene of miR-4698 positively regulated by lncRNA LIFR-AS1. The MEK/ERK pathway was inhibited by lncRNA LIFR-AS1 via regulating MTUS1. These findings revealed the inhibitory functions of lncRNA LIFR-AS1 in GC cell proliferation, migration and invasion. The process was mediated via miR-4698, MTUS1 and the MEK/ERK pathway.

The Poststroke Peripheral Immune Response Is Differentially Regulated by Leukemia Inhibitory Factor in Aged Male and Female Rodents.

Background The goal of this study was to determine whether leukemia inhibitory factor (LIF) promotes anti-inflammatory activity after stroke in a sex-dependent manner. Methods Aged (18-month-old) Sprague-Dawley rats of both sexes underwent sham surgery or permanent middle cerebral artery occlusion (MCAO). Animals received three doses of intravenous LIF (125 μg/kg) or PBS at 6, 24, and 48 h before euthanization at 72 h. Spleen weights were measured immediately following euthanization. Western blot was used to measure protein levels of CCL8, CD11b, CXCL9, CXCL10, IL-12 p40, IL-3, and the LIF receptor (LIFR) in spleen tissue. ELISA was used to measure IL-1β, IL-6, TNFα, and IFNγ in spleen tissue. A Griess Assay was used to indirectly quantify NO levels via measurement of nitrite. Levels of cellular markers and inflammatory mediators were normalized to the baseline (sham) group from each sex. Statistical analysis was performed using two-way ANOVA and followed by Fisher's LSD post hoc test. Results Aged female rats showed a significantly lower spleen weight after MCAO, but showed a significant increase in spleen size after LIF treatment. This effect was observed in aged male rats, but not to as great of an extent. CD11b levels were significantly higher in the spleens of MCAO+PBS males compared to their female counterparts, but there was no significant difference in CD11b levels between MCAO+LIF males and females. LIF significantly increased CXCL9 after LIF treatment in aged male and female rats. LIFR and IL-3 were upregulated after LIF treatment in aged females. Splenic nitrate increased after MCAO but decreased after LIF treatment in aged females. Splenic nitrate levels did not increase after MCAO but did increase after LIF treatment in aged males. The following cytokines/chemokines were not altered by sex or treatment: TNFα, IL-6, IL-12 p40, CCL8, IFNγ, and CXCL10. Conclusions LIF treatment after permanent MCAO induces sex-dependent effects on the poststroke splenic response and the production of proinflammatory cytokines among aged rats.

Gp130 Cytokines Activate Novel Signaling Pathways and Alter Bone Dissemination in ER+ Breast Cancer Cells.

Breast cancer cells frequently home to the bone marrow, where they encounter signals that promote survival and quiescence or stimulate their proliferation. The interleukin-6 (IL-6) cytokines signal through the co-receptor glycoprotein130 (gp130) and are abundantly secreted within the bone microenvironment. Breast cancer cell expression of leukemia inhibitory factor (LIF) receptor (LIFR)/STAT3 signaling promotes tumor dormancy in the bone, but it is unclear which, if any of the cytokines that signal through LIFR, including LIF, oncostatin M (OSM), and ciliary neurotrophic factor (CNTF), promote tumor dormancy and which signaling pathways are induced. We first confirmed that LIF, OSM, and CNTF and their receptor components were expressed across a panel of breast cancer cell lines, although expression was lower in estrogen receptor-negative (ER- ) bone metastatic clones compared with parental cell lines. In estrogen receptor-positive (ER+ ) cells, OSM robustly stimulated phosphorylation of known gp130 signaling targets STAT3, ERK, and AKT, while CNTF activated STAT3 signaling. In ER- breast cancer cells, OSM alone stimulated AKT and ERK signaling. Overexpression of OSM, but not CNTF, reduced dormancy gene expression and increased ER+ breast cancer bone dissemination. Reverse-phase protein array revealed distinct and overlapping pathways stimulated by OSM, LIF, and CNTF with known roles in breast cancer progression and metastasis. In breast cancer patients, downregulation of the cytokines or receptors was associated with reduced relapse-free survival, but OSM was significantly elevated in patients with invasive disease and distant metastasis. Together these data indicate that the gp130 cytokines induce multiple signaling cascades in breast cancer cells, with a potential pro-tumorigenic role for OSM and pro-dormancy role for CNTF. © 2021 American Society for Bone and Mineral Research (ASBMR).

Tripeptidyl peptidase I promotes human endometrial epithelial cell adhesive capacity implying a role in receptivity

The endometrium undergoes cyclic remodelling throughout the menstrual cycle in preparation for embryo implantation which occurs in a short window during the mid-secretory phase. It is during this short ‘receptive window’ that the endometrial luminal epithelium acquires adhesive capacity permitting blastocysts firm adhesion to the endometrium to establish pregnancy. Dysregulation in any of these steps can compromise embryo implantation resulting in implantation failure and infertility. Many factors contribute to these processes including TGF-β, LIF, IL-11 and proteases. Tripeptidyl peptidase 1 (TPP1) is a is a lysosomal serine-type protease however the contribution of the TPP1 to receptivity is unknown. We aimed to investigate the role of TPP1 in receptivity in humans.In the current study, TPP1 was expressed in both epithelial and stromal compartments of the endometrium across the menstrual cycle. Expression was confined to the cytoplasm of luminal and glandular epithelial cells and stromal cells. Staining of mid-secretory endometrial tissues of women with normal fertility and primary unexplained infertility showed reduced immunostaining intensity of TPP1 in luminal epithelial cells of infertile tissues compared to fertile tissues. By contrast, TPP1 levels in glandular epithelial and stromal cells were comparable in both groups in the mid-secretory phase. Inhibition of TPP1 using siRNA compromised HTR8/SVneo (trophoblast cell line) spheroid adhesion on siRNA-transfected Ishikawa cells (endometrial epithelial cell line) in vitro. This impairment was associated with decreased sirtuin 1 (SIRT1), BCL2 and p53 mRNA and unaltered, CD44, CDH1, CDH2, ITGB3, VEGF A, OSTEOPONTIN, MDM2, CASP4, MCL1, MMP2, ARF6, SGK1, HOXA-10, LIF, and LIF receptor gene expression between treatment groups. siRNA knockdown of TPP1 in primary human endometrial stromal cells did not affect decidualization nor the expression of decidualization markers prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1). Taken together, our data strongly suggests a role for TPP1 in endometrial receptivity via its effects on epithelial cell adhesion and suggests reduced levels associated with unexplained infertility may contribute to implantation failure.

The NF-κB/leukemia inhibitory factor/STAT3 signaling pathway in antibody-mediated suppression of Sindbis virus replication in neurons

Alphaviruses are positive-sense, enveloped RNA viruses that are important causes of viral encephalomyelitis. Sindbis virus (SINV) is the prototype alphavirus and preferentially infects neurons in rodents to induce an encephalomyelitis similar to the human disease. Using a mouse model of SINV infection of the nervous system, many of the immune processes involved in recovery from viral encephalomyelitis have been identified. Antibody specific to the SINV E2 glycoprotein plays an important role in recovery and is sufficient for noncytolytic suppression of virus replication in vivo and in vitro. To investigate the mechanism of anti-E2 antibody-mediated viral suppression, a reverse-phase protein array was used to broadly survey cellular signaling pathway activation following antibody treatment of SINV-infected differentiated AP-7 neuronal cells. Anti-E2 antibody induced rapid transient NF-κB and later sustained Y705 STAT3 phosphorylation, outlining an intracellular signaling cascade activated by antiviral antibody. Because NF-κB target genes include the STAT3-activating IL-6 family cytokines, expression of these messenger RNAS (mRNAs) was assessed. Expression of leukemia inhibitory factor (LIF) cytokine mRNA, but not other IL-6 family member mRNAs, was up-regulated by anti-E2 antibody. LIF induced STAT3 Y705 phosphorylation in infected differentiated AP-7 cells but did not inhibit virus replication. However, anti-E2 antibody localized the LIF receptor to areas of E2 expression on the infected cell surface, and LIF enhanced the antiviral effects of antibody. These findings identify activation of the NF-κB/LIF/STAT3 signaling cascade as involved in inducing antibody-mediated viral suppression and highlight the importance of nonneutralizing antibody functions in viral clearance from neurons.

Decreased mitochondrial electron transport proteins and increased complement mediators in plasma neural-derived exosomes of early psychosis

Potentially neurotoxic systems involved in traumatic and degenerative diseases of the brain were assessed in acute psychosis. Astrocyte-derived exosomes (ADEs) and neuron-derived exosomes (NDEs) were immunoprecipitated from plasma of ten untreated first-episode psychotics (FPs) and ten matched normal controls (Cs). Neural mitochondrial electron transport and complement proteins were extracted, quantified by ELISAs and normalized with levels of CD81 exosome marker. Levels of subunits 1 and 6 of NADH-ubiquinone oxidoreductase (complex I) and subunit 10 of cytochrome b-c1 oxidase (complex III), but not of subunit 1 of cytochrome C oxidase (complex IV) or superoxide dismutase 1 (SOD1) were significantly lower in ADEs and NDEs of FPs than Cs. This dysregulated pattern of electron transport proteins is associated with increased generation of reactive oxygen species. ADE glial fibrillary acidic protein levels were significantly higher in FPs than Cs, indicating a higher percentage of inflammatory astrocytes in FPs. ADE levels of C3b opsonin were significantly higher and those of C5b-9 attack complex was marginally higher in FPs than Cs. A significantly lower ADE level of the C3 convertase inhibitor CD55 may explain the higher levels of C3 convertase-generated C3b. ADE levels of the neuroprotective protein leukemia inhibitory factor (LIF) were significantly lower in FPs than Cs, whereas levels of IL-6 were no different. Plasma neural exosome levels of electron transport and complement proteins may be useful in predicting FP and guiding therapy. SOD mimetics, C3 convertase inhibitors and LIF receptor agonists also may have therapeutic benefits in FP.

Long noncoding RNA LIFR-AS1 suppresses proliferation, migration and invasion and promotes apoptosis through modulating miR-4262/NF-κB pathway in glioma

ABSTRACT Aim This study aimed to explore the role of lncRNA leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) on glioma and its underlying molecular mechanism. Methods The expression of LIFR-AS1 and miR-4262 was detected by quantitative real-time polymerase chain reaction (qRT-RCR) in both glioma tissues and cell lines. Colony formation assay, 5-ethynyl-20-deoxyuridine (EdU) assay, flow cytometry and transwell assay were respectively conducted to detect cell clones, proliferation, apoptosis, migration and invasion. The effect of LIFR-AS1 on the chemoresistance to temozolomide (TMZ) of glioma cells was also analyzed. In addition, dual-luciferase reporter gene assay was performed to evaluate the luciferase activity. The expressions of nuclear factor-κB (NF-κB) p65, p-NF-κB p65 and inhibitor of κBα (IκBα) in glioma cells were measured by western blot. Results LIFR-AS1 was lowly expressed and miR-4262 was highly expressed in glioma tissues and cell lines. LIFR-AS1 overexpression inhibited the proliferation, migration and invasion and promoted apoptosis of glioma cells. LIFR-AS1 overexpression also reduced the chemoresistance to TMZ of glioma cells. Moreover, LIFR-AS1 overexpression suppressed the activation of NF-κB signaling pathway in glioma cells. miR-4262 was the target gene of LIFR-AS1. We also found that miR-4262 abrogated the functions of LIFR-AS1 on cell proliferation, apoptosis, migration and invasion of glioma cells in the NF-κB pathway. Conclusion LIFR-AS1 could suppress the proliferation, migration and invasion and promote the apoptosis through modulating miR-4262/NF-κB pathway in glioma.

Cell signaling pathways in autosomal-dominant leukodystrophy\xa0(ADLD): the intriguing role of the astrocytes

Autosomal-dominant leukodystrophy (ADLD) is a rare fatal neurodegenerative disorder with overexpression of the nuclear lamina component, Lamin B1 due to LMNB1 gene duplication or deletions upstream of the gene. The molecular mechanisms responsible for driving the onset and development of this pathology are not clear yet. Vacuolar demyelination seems to be one of the most significant histopathological observations of ADLD. Considering the role of oligodendrocytes, astrocytes, and leukemia inhibitory factor (LIF)-activated signaling pathways in the myelination processes, this work aims to analyze the specific alterations in different cell populations from patients with LMNB1 duplications and engineered cellular models overexpressing Lamin B1 protein. Our results point out, for the first time, that astrocytes may be pivotal in the evolution of the disease. Indeed, cells from ADLD patients and astrocytes overexpressing LMNB1 show severe ultrastructural nuclear alterations, not present in oligodendrocytes overexpressing LMNB1. Moreover, the accumulation of Lamin B1 in astrocytes induces a reduction in LIF and in LIF-Receptor (LIF-R) levels with a consequential decrease in LIF secretion. Therefore, in both our cellular models, Jak/Stat3 and PI3K/Akt axes, downstream of LIF/LIF-R, are downregulated. Significantly, the administration of exogenous LIF can partially reverse the toxic effects induced by Lamin B1 accumulation with differences between astrocytes and oligodendrocytes, highlighting that LMNB1 overexpression drastically affects astrocytic function reducing their fundamental support to oligodendrocytes in the myelination process. In addition, inflammation has also been investigated, showing an increased activation in ADLD patients’ cells.

EGFR-upregulated LIFR promotes SUCLG2-dependent castration resistance and neuroendocrine differentiation of prostate cancer.

Neuroendocrine (NE) differentiation is a well-recognized phenotypic change of prostate cancer after androgen deprivation therapy (ADT), and it ultimately develops into an aggressive subset of this disease. However, the contribution of signaling pathways that lead to metabolic disorders and NE differentiation of prostate cancer remains unclear. In this study, we identified that ADT induced upregulation of the succinate-CoA ligase GDP-forming beta subunit (SUCLG2), which regulates succinate metabolism and NE differentiation of prostate cancer. We demonstrated a connection that upregulation of epidermal growth factor receptor (EGFR)-leukemia inhibitory factor receptor (LIFR) signaling induced SUCLG2 expression in prostate cancer cells. The LIFR is upregulated by nuclear EGFR, which acts as a transcriptional regulator, directly binds to the LIFR promoter, and drives NE differentiation and glycolysis of prostate cancer. LIFR upregulation is associated with SUCLG2, which increased succinate synthesis and enzymatic activities of mitochondrial nucleoside diphosphate kinase (NDPK) in prostate cancer cells. Knockdown of SUCLG2 suppressed NE differentiation in cultured cells and reduced prostate tumor growth in a xenograft model. Analysis of prostate tissue samples showed increased intensity of nuclear EGFR associated with the LIFR and SUCLG2 in castration-resistant prostate cancer tumors. Our study provides a mechanism whereby ADT upregulates EGFR-LIFR signaling that activates SUCLG2, which subsequently stimulates the metabolic changes associated with NE differentiation and aggressive prostate cancer phenotype.

Leukemia inhibitory factor promotes gastric cancer cell proliferation, migration, and invasion via the LIFR-Hippo-YAP pathway.

The long-term outcome of gastric cancer (GC) patients remains unsatisfactory despite some recent improvements. Leukemia inhibitory factor (LIF) is a prognostic biomarker for some solid tumors, however its role in GC remains unknown. In this study, we demonstrated that LIF and LIF receptor (LIFR) are overexpressed in GC tissues and established that a correlation exists between them. LIF and LIFR expression are associated with tumor differentiation, lymphovascular invasion, tumor stage, lymph node metastasis, and pTNM stage, indicating that they may be useful prognostic factors. LIF promoted GC cell proliferation, colony formation, invasion, migration, and tumor growth; it also promoted cell cycle progression and inhibited apoptosis; and knocking out the LIFR gene reversed the effects of LIF. LIF inhibited the activity of the Hippo pathway, resulting in reduced phosphorylation of YAP, increased YAP nuclear translocation, and increased cell proliferation. Finally, silencing YAP mRNA expression suppressed cell proliferation. Overall, the results demonstrate that LIF promotes the malignant biological behavior of GC cells through LIFR-Hippo-YAP signaling. LIF may therefore be a useful biomarker for GC.