Phosphorylation Of Growth Factor Receptor Research Articles

New Plant Extracts Exert Complementary Anti-Hair Loss Properties in Human InVitro and ExVivo Models.

Hair loss is linked to dysfunction of the growth (anagen), regression (catagen) and rest (telogen) phases of the hair follicle (HF) cycle. To evaluate the effects of a Silybum marianum extract (SME), manganese PCA (MnPCA), and a Lespedeza capitata extract (LCE) on markers of hair growth and anchorage in human follicle dermal papilla cells (HFDPCs), and to investigate the ability of a topical serum containing these active ingredients to improve HF growth in an ex vivo human scalp skin model. In HFDPCs, we assessed receptor tyrosine kinase phosphorylation and Wnt/β-catenin pathway activation; quantified versican, vascular endothelial growth factor (VEGF) and Dickkopf-1 (DDK1) secretion; and evaluated 5α-reductase (5αR) activity. Using scalp skin biopsies from two female donors, we measured hair shaft elongation, analyzed hair matrix keratinocyte proliferation and apoptosis, and determined HF cycle stage and score. Compared to untreated HFDPCs, SME upregulated phosphorylation of growth factor receptors (EGFR:1.9 × and PDGFR: 2.8 ×) and their downstream effectors (ERK, GSK3, Akt, and STAT: 1.2-2.0 ×); MnPCA enhanced versican (33.0 ×) and VEGF (3.3 ×) secretion, and stimulated the Wnt/β-catenin pathway (+80%); and LCE reduced DKK1 secretion (-72%) and 5αR activity (dihydrotestosterone/testosterone ratio: -60%). Compared to untreated scalp skin biopsies, the serum enhanced hair shaft elongation (+102%), and significantly prolonged the anagen phase by improving hair cycle scores and stimulating hair matrix keratinocyte proliferation (+58%). SME, MnPCA, and LCE displayed complementary anti-hair loss properties. The serum combining these active ingredients may be useful in hair loss treatment.

Gallein, G protein βγ subunits inhibitor, suppresses the TGF-α-induced migration of hepatocellular carcinoma cells via inhibition of the c-Jun N-terminal kinase.

G protein-coupled receptor (GPCR) signaling regulates a wide range of pathophysiological cell functions via G protein α and βγ subunits. Small molecules targeting the subunits of Gα and Gβγ have been developed as cancer therapeutics. We have previously reported that transforming growth factor-α (TGF-α) induces the migration of human hepatocellular carcinoma (HCC) HuH7 cells through the activation of AKT, p38 mitogen-activated protein kinase (MAPK), Rho-kinase and c-Jun N-terminal kinase (JNK). This study aims to determine whether Gβγ subunits regulate the TGF-α-induced migration of HCC HuH7 cells using gallein, a Gβγ subunits inhibitor. The Janus family of tyrosine kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway was also involved in the regulation of the migration. Gallein significantly reduced the TGF-α-induced cell migration. In contrast, fluorescein, a gallein-related compound that has no effect on Gβγ subunits, failed to affect the cell migration. Gallein suppressed the TGF-α-stimulated phosphorylation of JNK without affecting the phosphorylation of epidermal growth factor receptor, AKT, p38 MAPK, target protein of Rho-kinase and STAT3. Conversely, fluorescein did not attenuate the phosphorylation of JNK. These results strongly suggest that Gβγ subunits act as positive regulators in TGF-α-induced migration of HCC cells via the JNK signalling pathway.

QSOX1 exerts anti-inflammatory effects in sepsis-induced acute lung injury: Regulation involving EGFR phosphorylation mediated M1 polarization of macrophages

Sepsis is a systemic inflammatory response caused by an infection, which can easily lead to acute lung injury. Quiescin Q6 sulfhydryl oxidase 1 (QSOX1) is a sulfhydryl oxidase involved in oxidative stress and the inflammatory response. However, there are few reports on the role of QSOX1 in sepsis-induced acute lung injury (SALI). In this study, mice model of SALI was constructed by intraperitoneal injection with lipopolysaccharide (LPS). The increased inflammatory response and lactate dehydrogenase activity in bronchoalveolar lavage fluid (BALF) indicated successful modeling. Increased QSOX1 expression was both observed in lung tissues and lung macrophages of sepsis mice accompanied by increased polarization of M1-type macrophages. To explore the role of QSOX1 in the SALI, lentivirus containing QSOX1-specific overexpression or knockdown vectors were used to change QSOX1 expression in LPS-treated RAW264.7 cells. QSOX1 suppressed LPS-induced M1 polarization and further inhibited inflammatory response in RAW264.7 cells. Interestingly, the phosphorylation of epidermal growth factor receptor (EGFR), the promoter of M1 polarization in macrophages, was found to be downregulated upon QSOX1 overexpression in RAW264.7 cells. Mechanically, the binding of QSOX1 to EGFR protein promoted EGFR ubiquitination and degradation, thereby down-regulating EGFR phosphorylation. Moreover, inhibiting EGFR expression or its phosphorylation restored the impact of QSOX1 silencing on M1 polarization and inflammation in the LPS-treated RAW264.7 cells. In summary, QSOX1 may exert anti-inflammatory effects in SALI by inhibiting EGFR phosphorylation-mediated M1 macrophage polarization. This presented a potential target for the treatment and prevention of SALI.

Crucial roles of exosomes secreted from ganglioside GD3/GD2-positive glioma cells in enhancement of the malignant phenotypes and signals of GD3/GD2-negative glioma cells.

Neuroectoderm-derived tumors characteristically express gangliosides such as GD3 and GD2. Many studies have reported that gangliosides GD3/GD2 enhance malignant phenotypes of cancers. Recently, we reported that human gliomas expressing GD3/GD2 exhibited enhanced malignant phenotypes. Here, we investigated the function of GD3/GD2 in glioma cells and GD3/GD2-expressing glioma-derived exosomes. As reported previously, transfectant cells of human glioma U251 MG expressing GD3/GD2 showed enhanced cancer phenotypes compared with GD3/GD2-negative controls. When GD3/GD2-negative cells were treated with exosomes secreted from GD3/GD2-positive cells, clearly increased malignant properties were observed. Furthermore, increased phosphorylation of signaling molecules was detected after 5-15 min of exosome treatment, ie, higher tyrosine phosphorylation of platelet-derived growth factor receptor, focal adhesion kinase, and paxillin was found in treated cells than in controls. Phosphorylation of extracellular signal-regulated kinase-1/2 was also enhanced. Consequently, it is suggested that exosomes secreted from GD3/GD2-positive gliomas play important roles in enhancement of the malignant properties of glioma cells, leading to total aggravation of heterogenous cancer tissues, and also in the regulation of tumor microenvironments.

Evaluation of antitumor potential of an anti-glypican-1 monoclonal antibody in preclinical lung cancer models reveals a distinct mechanism of action.

The main objective of this study was to investigate the antitumor effect of a mouse anti-human glypican-1 (GPC1) monoclonal antibody (mAb) on non-small cell lung carcinoma (NSCLC) and associated molecular mechanisms. The anti-proliferative and anti-migratory activities of anti-GPC1 mAb were examined in A549 and H460 NSCLC cells and LL97A lung fibroblasts. The inhibitory effect of anti-GPC1 mAb on tumor growth was evaluated in an orthotopic lung tumor model. The in vitro study showed that anti-GPC1 mAb profoundly inhibited the anchorage-independent growth of A549 and H460 NSCLC cells and exhibited relatively high cytotoxic activities towards LL97A lung fibroblasts, A549/LL97A and H460/LL97A coculture spheroids. Moreover, anti-GPC1 mAb significantly decreased the expression of phospho-Src (p-Src; Tyr416), p-Akt (Ser473) and β-catenin in the co-cultured LL97A lung fibroblasts, and the expression of phospho-mitogen-activated protein kinase kinase (p-MEK; Ser217/221) and phospho-90 kDa ribosomal s6 kinase (p-p90RSK; Ser380) in co-cultured A549 cells. When anti-GPC1 mAb was administered to tumor-bearing mice, the inhibitory effect of anti-GPC1 mAb on the orthotopic lung tumor growth was not statistically significant. Nonetheless, results of Western blot analysis showed significant decrease in the phosphorylation of fibroblast growth factor receptor 1 (FGFR1) at Tyr766, Src at Tyr416, extracellular signal-regulated kinase (ERK) at Thr202/Tyr204, 90 kDa ribosomal S6 kinase (RSK) at Ser380, glycogen synthase kinases 3α (GSK3α) at Ser21 and GSK3β at Ser9 in tumor tissues. These data implicate that anti-GPC1 mAb treatment impairs the interaction between tumor cells and tumor associated fibroblasts by attenuating the paracrine FGFR signal transduction. The relatively potent cytotoxicity of anti-GPC1 mAb in lung fibroblasts and its potential inhibitory effect on the paracrine FGFR signal transduction warrant further studies on the combined use of this mAb with targeted therapeutics to improve therapeutic outcomes in lung cancer.

Molecular Mechanisms of N-Acetylcysteine in RSV Infections and Air Pollution-Induced Alterations: A Scoping Review.

N-acetylcysteine (NAC) is a mucolytic agent with antioxidant and anti-inflammatory properties. The respiratory syncytial virus (RSV) is one of the most important etiological factors of lower respiratory tract infections, and exposure to air pollution appears to be additionally associated with higher RSV incidence and disease severity. We aimed to systematically review the existing literature to determine which molecular mechanisms mediate the effects of NAC in an RSV infection and air pollution, and to identify the knowledge gaps in this field. A search for original studies was carried out in three databases and a calibrated extraction grid was used to extract data on the NAC treatment (dose, timing), the air pollutant type, and the most significant mechanisms. We identified only 28 studies conducted in human cellular models (n = 18), animal models (n = 7), and mixed models (n = 3). NAC treatment improves the barrier function of the epithelium damaged by RSV and air pollution, and reduces the epithelial permeability, protecting against viral entry. NAC may also block RSV-activated phosphorylation of the epidermal growth factor receptor (EGFR), which promotes endocytosis and facilitates cell entry. EGFR also enhances the release of a mucin gene, MUC5AC, which increases mucus viscosity and causes goblet cell metaplasia; the effects are abrogated by NAC. NAC blocks virus release from the infected cells, attenuates the cigarette smoke-induced shift from necrosis to apoptosis, and reverses the block in IFN-γ-induced antiviral gene expression caused by the inhibited Stat1 phosphorylation. Increased synthesis of pro-inflammatory cytokines and chemokines is induced by both RSV and air pollutants and is mediated by the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways that are activated in response to oxidative stress. MCP-1 (monocyte chemoattractant protein-1) and RANTES (regulated upon activation, expressed and secreted by normal T cells) partially mediate airway hyperresponsiveness (AHR), and therapeutic (but not preventive) NAC administration reduces the inflammatory response and has been shown to reduce ozone-induced AHR. Oxidative stress-induced DNA damage and cellular senescence, observed during RSV infection and exposure to air pollution, can be partially reversed by NAC administration, while data on the emphysema formation are disputed. The review identified potential common molecular mechanisms of interest that are affected by NAC and may alleviate both the RSV infection and the effects of air pollution. Data are limited and gaps in knowledge include the optimal timing or dosage of NAC administration, therefore future studies should clarify these uncertainties and verify its practical use.

Shexiang Tongxin Dropping Pill Promotes Angiogenesis through VEGF/eNOS Signaling Pathway on Diabetic Coronary Microcirculation Dysfunction.

To study the effect of Shexiang Tongxin Dropping Pill (STDP) on angiogenesis in diabetic cardiomyopathy mice with coronary microcirculation dysfunction (CMD). According to a random number table, 6 of 36 SPF male C57BL/6 mice were randomly selected as the control group, and the remaining 30 mice were injected with streptozotocin intraperitoneally to replicate the type 1 diabetes model. Mice successfully copied the diabetes model were randomly divided into the model group, STDP low-dose group [15 mg/(kg·d)], medium-dose group [30 mg/(kg·d)], high-dose group [60 mg/(kg·d)], and nicorandil group [15 mg/(kg·d)], 6 in each group. The drug was given by continuous gavage for 12 weeks. The cardiac function of mice in each group was detected at the end of the experiment, and coronary flow reserve (CFR) was detected by chest Doppler technique. Pathological changes of myocardium were observed by hematoxylin-eosin staining, collagen fiber deposition was detected by masson staining, the number of myocardial capillaries was detected by platelet endothelial cell adhesion molecule-1 staining, and the degree of myocardial hypertrophy was detected by wheat germ agglutinin staining. The expression of the vascular endothlial growth factor (VEGF)/endothelial nitric oxide synthase (eNOS) signaling pathway-related proteins in myocardial tissue was detected by Western blot. Compared with the model group, medium- and high-dose STDP significantly increased the left ventricular ejection fraction and left ventricular fraction shortening (P<0.01), obviously repaired the disordered cardiac muscle structure, reduced myocardial fibrosis, reduced myocardial cell area, increased capillary density, and increased CFR level (all P<0.01). Western blot showed that high-dose STDP could significantly increase the expression of VEGF and promote the phosphorylation of vascular endothelial growth factor receptor 2, phosphoinositide 3-kinase, protein kinase B, and eNOS (P<0.05 or P<0.01). STDP has a definite therapeutic effect on diabetic CMD, and its mechanism may be related to promoting angiogenesis through the VEGF/eNOS signaling pathway.

Decoding the synergistic potential of MAZ-51 and zingerone as therapy for melanoma treatment in alignment with sustainable development goals.

Melanoma, an invasive class of skin cancer, originates from mutations in melanocytes, the pigment-producing cells. Globally, approximately 132,000 new cases are reported each year, and in South Africa, the incidence stands at 2.7 per 100,000 people, signifying a worrisome surge in melanoma rates. Therefore, there is a need to explore treatment modalities that will target melanoma's signalling pathways. Melanoma metastasis is aided by ligand activity of transforming growth factor-beta 1 (TGF-β1), vascular endothelial growth factor-C (VEGF-C)and C-X-C chemokine ligand 12 (CXCL12) which bind to their receptors and promote tumour cell survival, lymphangiogenesisand chemotaxis. (3-(4-dimethylaminonaphthelen-1-ylmethylene)-1,3-dihydroindol-2-one) MAZ-51 is an indolinone-based molecule that inhibits VEGF-C induced phosphorylation of vascular endothelial growth factor receptor 3 (VEGFR-3). Despite the successful use of conventional cancer therapies, patients endure adverse side effects and cancer drug resistance. Moreover, conventional therapies are toxic to the environment and caregivers. The use of medicinal plants and their phytochemical constituents in cancer treatment strategies has become more widespread because of the rise in drug resistance and the development of unfavourable side effects. Zingerone, a phytochemical derived from ginger exhibits various pharmacological properties positioning it as a promising candidate for cancer treatment. This review provides an overview of melanoma biology and the intracellular signalling pathways promoting cell survival, proliferationand adhesion. There is a need to align health and environmental objectives within sustainable development goals 3 (good health and well-being), 13 (climate action)and 15 (life on land) to promote early detection of skin cancer, enhance sun-safe practices, mitigation of environmental factorsand advancing the preservation of biodiversity, including medicinal plants. Thus, this review discusses the impact of cytostatic cancer drugs on patients and the environment and examines the potential use of phytochemicals as adjuvant therapy.

Epidermal growth factor receptor phosphorylation contributes to levobupivacaine-induced contraction in isolated rat aorta

Vasoconstriction induced by levobupivacaine, a local anesthetic, is mediated by increased levels of calcium, tyrosine kinase, c-Jun NH2-terminal kinase (JNK), and phospholipase D, which are associated with prolonged local anesthesia. Epidermal growth factor receptor (EGFR) phosphorylation is associated with vasoconstriction. However, its role in levobupivacaine-induced contractions remains unknown. We determined whether EGFR phosphorylation is associated with levobupivacaine-induced contractions in isolated rat thoracic aortas and identified the underlying cellular signaling pathways. The effects of various inhibitors and a calcium-free solution alone or in combination on levobupivacaine-induced contractions were then assessed. Furthermore, we examined the effects of various inhibitors on levobupivacaine-induced EGFR and JNK phosphorylation and calcium levels in vascular smooth muscle cells (VSMCs) of rat aortas. The EGFR tyrosine kinase inhibitor AG1478, matrix metalloproteinase (MMP) inhibitor GM6001, Src kinase inhibitors PP1 and PP2, and JNK inhibitor SP600125 attenuated levobupivacaine-induced contractions. Moreover, although the calcium-free solution abolished levobupivacaine-induced contractions, calcium reversed this inhibitory effect. The magnitude of the calcium-mediated reversal of abolished levobupivacaine-induced contractions was lower in the combination treatment with calcium-free solution and AG1478 than in the treatment with calcium-free solution alone. Levobupivacaine induced EGFR and JNK phosphorylation. However, AG1478, GM6001, and PP2 attenuated levobupivacaine-induced EGFR and JNK phosphorylation. Moreover, although levobupivacaine induced JNK phosphorylation in control siRNA-transfected VSMCs, EGFR siRNA inhibited levobupivacaine-induced JNK phosphorylation. Furthermore, AG1478 inhibited levobupivacaine-induced calcium increases in VSMCs. Collectively, these findings suggest that levobupivacaine-induced EGFR phosphorylation, which may occur via the Src kinase–MMP pathway, contributes to vasoconstriction via JNK phosphorylation and increased calcium levels.

The Anti-tumor Function of Shikonin by Targeting EGFR/AKT/mTOR Signaling in Human Osteosarcoma Cells

Background: Shikonin, a purified naphthoquinone separated from a Traditional Chinese medicinal herb Lithospermum erythrorhixon, which exhibits anticancer properties. Objectives: To clarify the molecular mechanisms of therapeutic effects of shikonin against osteosarcoma. Materials and Methods: Cell Counting Kit-8 (CCK-8) assay was employed to evaluate cell viability. Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) double-staining was conducted to evaluate the apoptotic ratio of the MG-63 cells. The effects of shikonin on the invasiveness of osteosarcoma cells were implemented by a transwell cell migration assay. In the meantime, a western blot assay was employed to detect alterations in the relevant mechanism proteins within osteosarcoma cells. Molecular docking analysis was conducted to anticipate the binding interaction between shikonin and EGFR/protein kinase B (AKT)/mTOR. Results: We observed that shikonin suppressed proliferation and induced apoptosis in the MG-63 cells in a dose-dependent manner. Pursuing these findings, the potential molecular mechanisms were detected. Shikonin intervention blocked epidermal growth factor receptor (EGFR) phosphorylation and decreased epidermal growth factor (EGF)-induced activation of downstream signaling molecules, such as AKT and mammalian target of rapamycin (mTOR) in the MG-63 cells. However, the additional recombinant human epidermal growth factor (rHuEGF) could stimulate the activation of EGFR/AKT/mTOR signaling and reverse cell apoptosis caused by shikonin. Molecular docking analysis showed that shikonin presented the highest bonding ability with EGFR, AKT, and mTOR. Conclusion: Our results show that shikonin inhibits human osteosarcoma development via inactivating EGFR/AKT/mTOR signaling. It demonstrates that shikonin may act as a potential therapeutic agent in osteosarcoma treatment.

Sphingosine kinase 1/S1P receptor signaling axis is essential for cellular uptake of Neisseria meningitidis in brain endothelial cells.

Invasion of brain endothelial cells (BECs) is central to the pathogenicity of Neisseria meningitidis infection. Here, we established a key role for the bioactive sphingolipid sphingosine-1-phosphate (S1P) and S1P receptor (S1PR) 2 in the uptake process. Quantitative sphingolipidome analyses of BECs infected with N. meningitidis revealed elevated S1P levels, which could be attributed to enhanced expression of the enzyme sphingosine kinase 1 and its activity. Increased activity was dependent on the interaction of meningococcal type IV pilus with the endothelial receptor CD147. Concurrently, infection led to increased expression of the S1PR2. Blocking S1PR2 signaling impaired epidermal growth factor receptor (EGFR) phosphorylation, which has been shown to be involved in cytoskeletal remodeling and bacterial endocytosis. Strikingly, targeting S1PR1 or S1PR3 also interfered with bacterial uptake. Collectively, our data support a critical role of the SphK/S1P/S1PR axis in the invasion of N. meningitidis into BECs, defining a potential target for adjuvant therapy.

GO nanosheets inhibit the proliferation of hPDLCs by covering the membrane to block the EGFR-AKT signaling pathway

Graphene-based materials show potential applications in dentistry due to their outstanding physicochemical properties. However, the use of graphene and its derivatives increases their exposure risk to periodontal cells. This study aimed to evaluate the cytotoxicity caused by graphene in periodontal cells and clarify the potential molecular mechanism. Through a series of experiments, we isolated human periodontal ligament cells (hPDLCs) and subsequently investigated the cytotoxic behaviors and related signaling pathway through which graphene oxide (GO) nanohseets injured hPDLCs. Our findings illustrated that the cytotoxicity of GO against hPDLCs was derived from the covering of GO nanosheets on the membrane surface, which blocked the phosphorylation of epidermal growth factor receptor on the membrane. It further inhibited the activation of the serine/threonine kinase signaling pathway that promoted the proliferation and cycle progression of cells. This study revealed the toxic behavior of GO nanosheets to oral cells and elucidated the potential molecular mechanism, thereby providing theoretical guidance for the safe application of graphene-based materials in dentistry.

FGF21 protects against doxorubicin-induced cardiotoxicity by inhibiting connexin 43 ubiquitination

BackgroundFibroblast growth factor 21 (FGF21) regulates glycolipid metabolism and insulin homeostasis and acts as a cardioprotective factor by protecting against myocardial ischemia/reperfusion injury, hypertension, and vascular dysfunction. FGF21 has been reported to prevent Doxorubicin (Dox)-induced cardiotoxicity, and the related signaling pathway is worthy of further study. Connexin43 (Cx43) protein was reduced by Dox treatment, especially low phosphorylated form of Cx43. Thus the aim of study is to explore the protection effect of FGF21 on Dox induced cardiotoxicity by improving the expression of Cx43 and the involved signaling pathway. Methods and resultsFGF21 inhibited apoptosis in Dox-treated mice and cardiomyocytes. FGF21 increased the levels of connexin43 phosphorylated at serine (S) 282 (p-Cx43 S282) and total Cx43 to inhibit Dox-induced apoptosis. By RNA sequencing, we found that deubiquitinase monocyte chemoattractant protein-induced protein 1 (MCPIP1) expression was increased by FGF21. We further found that FGF21 induced the phosphorylation of fibroblast growth factor receptor 1 (FGFR1), extracellular signal-regulated kinase 1 and 2 (Erk1/2), and Elk. Phosphorylated Elk translocated to the nucleus and increased the expression of MCPIP1. Then, MCPIP1 bound neural precursor cell expressed developmentally downregulated protein 4 (Nedd4), an E3 ubiquitination ligase, as shown by co-immunoprecipitation (Co-IP), and suppressed Cx43 ubiquitination and degradation, competitively inhibiting the binding of Cx43 with Nedd4. Thus Nedd4 could not bind and ubiquitinate Cx43, leading to the up-regulation of Cx43 and phosphorylation of Cx43 at S282. ConclusionsFGF21 inhibited the effects of Dox on cardiomyocytes by elevating the phosphorylation of Cx43 at S282 and total Cx43 expression. This study suggests a previously unknown mechanism for the FGF21-mediated enhancement of cardiomyocyte survival and provides an effective approach to protect against the adverse cardiac effects of Dox.

Pharmacological inhibition of the mixed lineage leukemia 1-menin interaction aggravates acute kidney injury induced by folic acid and ischemia-reperfusion in mice.

Mixed lineage leukemia 1 (MLL1) is a methyltransferase that induces histone H3 lysine 4 trimethylation (H3K4me3) and partially exerts its untoward functional effects by interacting with multiple subunits including menin and WD repeat-containing protein 5 (WDR5). In this study, we investigated the role and mechanisms of MLL1 in murine models of acute kidney injury induced by folic acid (FA) and ischemia-reperfusion. Injury to the kidney elevated the expression of MLL1, menin, WDR5, and H3K4Me3, which was accompanied by increased serum creatinine and blood urea nitrogen, renal tubular injury, and apoptosis. Pharmacological inhibition of MLL1 activity with MI503 to disrupt the interaction between MLL1 with menin further increased serum creatinine and blood urea nitrogen levels, enhanced expression of neutrophil gelatinase-associated lipocalin and kidney injury molecule-1, and induced more apoptosis in the kidney following FA and ischemia-reperfusion injury. In contrast, MI503 treatment decreased the expression of vimentin and proliferating cell nuclear antigens. Similarly, treatment with MM102 to disrupt the interaction between MLL1 and WDR5 also worsened renal dysfunction, aggravated tubular cell injury, increased apoptosis, and inhibited cellular dedifferentiation and proliferation in mice following FA injection. Moreover, MI503 inhibited FA-induced phosphorylation of epidermal growth factor receptor, signal transducer and activator of transcription 3, and extracellular signal-regulated kinase-1/2 in injured kidneys. Collectively, these data suggest that MLL1 contributes to renal protection and functional recovery and promotes renal regeneration through a mechanism associated with activation of the epidermal growth factor receptor signaling pathway.NEW & NOTEWORTHY Mixed lineage leukemia 1 (MLL1) is a methyltransferase that induces histone H3 lysine 4 trimethylation and exerts its functional roles by interacting with multiple subunits. In this study, we demonstrated that inhibition of MLL1 activity by MI503 or MM102 aggravated renal injury and apoptosis and suppressed renal tubular cell dedifferentiation and proliferation, suggesting that MLL1 activation during acute kidney injury acts as an intrinsic protective mechanism to mediate renal tubular cell survival and regeneration.

Functional Distinctions of Endometrial Cancer-Associated Mutations in the Fibroblast Growth Factor Receptor 2 Gene.

Functional analysis of somatic mutations in tumorigenesis facilitates the development and optimization of personalized therapy for cancer patients. The fibroblast growth factor receptor 2 (FGFR2) gene is frequently mutated in endometrial cancer (EC), but the functional implications of FGFR2 mutations in cancer development remain largely unexplored. In this study, we introduced a reliable and readily deployable screening method to investigate the effects of FGFR2 mutations. We demonstrated that distinct mutations in FGFR2 can lead to differential downstream consequences, specifically affecting a disintegrin- and metalloprotease 17 (ADAM17)-dependent shedding of the epidermal growth factor receptor (EGFR) ligand heparin-binding EGF-like growth factor (HB-EGF) and phosphorylation of mitogen-activated protein kinases (MAPKs). Furthermore, we showed that the distribution of mutations within the FGFR2 gene can influence their oncogenic effects. Together, these findings provide important insights into the complex nature of FGFR2 mutations and their potential implications for EC. By unraveling the distinct effects of different mutations, our study contributes to the identification of personalized treatment strategies for patients with FGFR2-mutated cancers. This knowledge has the potential to guide the development of targeted therapies that specifically address the underlying molecular alterations associated with FGFR2 mutations, ultimately improving patient outcomes in EC and potentially other cancer types characterized by FGFR2 mutations.

Downregulation of cellular retinoic acid binding protein 1 fosters epithelial-mesenchymal transition in thyroid cancer.

Cellular retinoic acid binding protein 1 (CRABP1) participates in the regulation of retinoid signaling. Previous studies showed conflicting results regarding the role of CRABP1 in tumor biology, including protumorigenic and tumor-suppressive effects in different types of cancer. Our bioinformatics analyses suggested that CRABP1 expression was downregulated in thyroid cancer. Ectopic expression of CRABP1 in thyroid cancer cells suppressed migratory and invasive activity without affecting cell growth or cell cycle distribution. In transformed normal thyroid follicular epithelial cells, silencing of CRABP1 expression increased invasiveness. Additionally, CRABP1 overexpression was associated with downregulation of the mesenchymal phenotype. Kinase phosphorylation profiling indicated that CRABP1 overexpression was accompanied by a decrease in phosphorylation of epidermal growth factor (EGF) receptor and downstream phosphorylation of Akt, STAT3, and FAK, which were reversed by exogenous EGF treatment. Immunohistochemical analysis of our tissue microarrays revealed an inverse association between CRABP1 expression and disease stage of differentiated thyroid cancer. Taken together, our results suggest that CRABP1 expression is aberrantly lost in thyroid cancer, and this downregulation promotes the epithelial-mesenchymal transition at least partly through modulating EGF receptor signaling.

ErbB2pY -1248 as a predictive biomarker for Parkinson's disease based on research with RPPA technology and in vivo verification.

This study aims to reveal a promising biomarker for Parkinson's disease (PD) based on research with reverse phase protein array (RPPA) technology for the first time and in vivo verification, which gains time for early intervention in PD, thus increasing the effectiveness of treatment and reducing disease morbidity. We employed RPPA technology which can assess both total and post-translationally modified proteins to identify biomarker candidates of PD in a cellular PD model. As a result, the phosphorylation (pY-1248) of the epidermal growth factor receptor (EGFR) ErbB2 is a promising biomarker candidate for PD. In addition, lapatinib, an ErbB2 tyrosine kinase inhibitor, was used to verify this PD biomarker candidate in vivo. We found that lapatinib-attenuated dopaminergic neuron loss and PD-like behavior in the zebrafish PD model. Accordingly, the expression of ErbB2pY-1248 significantly increased in the MPTP-induced mouse PD model. Our results suggest that ErbB2pY-1248 is a predictive biomarker for PD. In this study, we found that ErbB2pY-1248 is a predictive biomarker of PD by using RPPA technology and in vivo verification. It offers a new perspective on PD diagnosing and treatment, which will be essential in identifying individuals at risk of PD. In addition, this study provides new ideas for digging into biomarkers of other neurodegenerative diseases.

Mass Spectrometry and Pharmacological Approaches to Measuring Cooption and Reciprocal Activation of Receptor Tyrosine Kinases.

Receptor tyrosine kinases (RTKs) can show extensive crosstalk, directly and indirectly. Elucidating RTK crosstalk remains an important goal in the clinical combination of anti-cancer therapies. Here, we present mass spectrometry and pharmacological approaches showing the hepatocyte growth factor receptor (MET)-promoting tyrosine phosphorylation of the epidermal growth factor receptor (EGFR) and other membrane receptors in MET-amplified H1993 NSCLC cells. Conversely, in H292 wt-EGFR NSCLC cells, EGFR promotes the tyrosine phosphorylation of MET. Reciprocal regulation of the EGFR and insulin receptor (IR) was observed in the GEO CRC cells, where inhibition of the EGFR drives tyrosine phosphorylation of the insulin receptor. Similarly, in platelet-derived growth factor receptor (PDGFR)-amplified H1703 NSCLC cells, inhibition of the EGFR promotes the tyrosine phosphorylation of the PDGFR. These RTK interactions are used to illustrate basic principles applicable to other RTK signaling networks. More specifically, we focus on two types of RTK interaction: (1) co-option of one RTK by another and (2) reciprocal activation of one receptor following the inhibition of a distinct receptor.

The proliferation and angiogenesis in hemangioma-derived endothelial cells is affected by STC2 medicated VEGFR2/Akt/eNOS pathway.

Stanniocalcin-2 (STC2), a secreted glycoprotein that is involved in the regulation of angiogenesis, was proposed as one of the mechanisms of neovascularization in hemangioma (HA). We aimed to investigate the effect of STC2 on proliferation and angiogenesis in hemangioma-derived endothelial cells. The hemangioma samples from HA patients with the median age of six months were surgically collected in the Affiliated Hospital of Weifang Medical University from October 2019 to June 2021, and divided into normal skin tissues (n=10), involuting-phase HAs (n=10) and proliferating-phase HAs (n=10) according to the Mulliken classification. The expression of STC2 was detected in involuting-phase HAs and proliferating-phase HAs. Hemangioma endothelial cells (HemEC) were transfected with small interfering RNA (siRNA) specific for STC2, and cell survival and tube formation were analyzed. STC2 expression in proliferating-phase HAs was markedly higher than in the normal skin tissues and involving-phase HAs. Similarly, STC2 expression was higher in HemEC compared to the control human umbilical vein endothelial cells (HUVEC). Knockdown of STC2 slowed the proliferation of HemEC and decreased the expression of proliferating cell nuclear antigen (PCNA) in HemEC. Moreover, knockdown of STC2 in HemEC inhibited vascular endothelial cell angiogenesis and regulated the expression and phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2). Mechanistically, STC2 knockdown attenuated the activation of Akt/eNOS signaling, which was abolished by insulin growth factor-1 (IGF-1), the activator of Akt signaling, accompanying by increased proliferation and tube formation of HemEC. Inhibition of STC2 suppresses HemEC proliferation and angiogenesis by VEGFR2/Akt/eNOS pathway, which warrants further development of STC2-based strategies for HA treatment.

Both Maternal and Newborn IgMs Inhibit Transmissible Gastroenteritis Virus Internalization in LLC-PK1 Cells

Immunoglobulins M (IgMs) are the evolutionally oldest class of antibodies in higher eukaryotes. This pool of antibodies is one of the first to appear in humans and begins to be-synthesized at the early stages of the neonatal period. Most of the repertoire of IgMs of the newborns consists of the so-called «natural», or «naive», antibodies synthesized by the body without external antigenic stimulation. In addition to the classical functions of human immunoglobulins M (such as antigen recognition and initiation of innate immune responses), antibodies of this class exhibit a variety of non-canonical functions. The non-canonical functions are the action of antibodies as agonists/antagonists of various receptors, cleavage of antigen due to the catalytic activity of IgM, direct inactivation of pathogens in the absence of effector cells and molecules, etc. The aim of this work was to study and compare the antiviral activity of total preparations of immunoglobulin M of newborns and adults, obtained from umbilical cord and venous blood sera, on the LLC-PK1 cell line model infected with the transmissible gastroenteritis virus (TGEV). In addition, in the course of the studies, a decision was made to investigate the effect of combined preparations of immunoglobulin M on the change in signal transduction in the epidermal growth factor receptor as one of the mechanisms of TGEV internalization during infection of target cells. Methods. Highly purified preparations of total IgM of adults or newborns were obtained using the methodologies of sequential salt fractionation and affinity chromatography. This work used the model of the interaction of the transmissible gastroenteritis virus with cells of the LLC-PK1 line and the monitoring of changes in the phosphorylation state of the epidermal growth factor receptor of these cells during virus infection to study the effect of human IgM on the internalization of the virus and its interaction with the receptor system of the host cell. The degree of cytopathogenic effect of the virus was determined visually by changes in cell morphology. The mean infectious dose for transmissible gastroenteritis virus in the cell culture of the LLC-PK1 line was determined by the Reed-Muench method. Analysis of changes in the phosphorylation of the epidermal growth factor receptor was performed using the Western-blot analysis method. Results. The addition of a total high-purified sample of human IgM reduces the degree of efficiency of TGEV infection of the LLC-PK1 cell line and modulates the phosphorylation levels of these cells. Conclusions. The total preparations of IgM obtained from human venous blood of adults and from umbilical cord blood of newborns can affect the internalization of the transmissible gastroenteritis virus in the LLC-PK1 cell line. The original model of virus (TGEV) — cell line (LLC-PK1) was applied and tested to study the effect of native total preparations of immunoglobulin M on the internalization of the virus into the cell. The obtained data can be useful in further studies for a better understanding of the process of development and functioning of the immune system of newborns.