Bmp2 regulates Serpinb6b expression via cAMP/PKA/Wnt4 pathway during uterine decidualization

Serpinb6b is a novel member of Serpinb family and found in germ and somatic cells of mouse gonads, but its physiological function in uterine decidualization remains unclear. The present study revealed that abundant Serpinb6b was noted in decidual cells, and advanced the proliferation and differentiation of stromal cells, indicating a creative role of Serpinb6b in uterine decidualization. Further analysis found that Serpinb6b modulated the expression of Mmp2 and Mmp9. Meanwhile, Serpinb6b was identified as a target of Bmp2 regulation in stromal differentiation. Treatment with rBmp2 resulted in an accumulation of intracellular cAMP level whose function in this differentiation program was mediated by Serpinb6b. Addition of PKA inhibitor H89 impeded the Bmp2 induction of Serpinb6b, whereas 8‐Br‐cAMP rescued the defect of Serpinb6b expression elicited by Bmp2 knock‐down. Attenuation of Serpinb6b greatly reduced the induction of constitutive Wnt4 activation on stromal cell differentiation. By contrast, overexpression of Serpinb6b prevented this inhibition of differentiation process by Wnt4 siRNA. Moreover, blockage of Wnt4 abrogated the up‐regulation of cAMP on Serpinb6b. Collectively, Serpinb6b mediates uterine decidualization via Mmp2/9 in response to Bmp2/cAMP/PKA/Wnt4 pathway.     

FDPS promotes glioma growth and macrophage recruitment by regulating CCL20 via Wnt/β‐catenin signalling pathway

Glioma is one of the most lethal tumours and common malignant in the central nervous system (CNS), which exhibits diffuse invasion and aggressive growth. Several studies have reported the association of FDPS to tumour development and progression. However, the role of FDPS in progression of glioma and macrophage recruitment is not well‐elucidated. In the current study, a remarkable enhancement in FDPS level was observed in glioma tissues and associated with poor prognosis, contributed to tumour growth. FDPS was correlated with macrophage infiltration in glioma and pharmacological deletion of macrophages largely abrogated the oncogenic functions of FDPS in glioma. Mechanistically, FDPS activated Wnt/β‐catenin signalling pathway and ultimately facilitates macrophage infiltration by inducing CCL20 expression. In conclusion, overexpressed FDPS exhibits an immunomodulatory role in glioma. Therefore, targeting FDPS may be an effective therapeutic strategy for glioma.     

Lipid‐Embedded Molecular Dynamics Simulation Model for Exploring the Reverse Prostaglandin D2 Agonism of CT‐133 towards CRTH2 in the Treatment of Type‐2 Inflammation Dependent Diseases

Chemoattractant receptor‐homologous molecule expressed on Th2 cells (CRTH2) has been involved in several inflammation dependent diseases by mediating the chemotaxis of pro‐inflammatory cells in response to allergy and other responses through PGD2 ligation. This CRTH2‐PGD2 signaling pathway has become a target for treating allergic and type 2 inflammation dependent diseases, with many inhibitors developed to target the PGD2 binding pocket. One of such inhibitors is the ramatroban analog, CT‐133, which exhibited therapeutic potency cigarette smoke‐induced acute lung injury in patients. Nonetheless, the molecular mechanism and structural dynamics that accounts for its therapeutic prowess remain unclear. Employing computational tools, this study revealed that although the carboxylate moiety in CT‐133 and the native agonist PGD2 aided in their stability within the CRTH2 binding pocket, the tetrahydrocarbazole group of CT‐133 engaged in strong interactions with binding pocket residues which could have formed as the basis of the antagonistic advantage of CT‐133. Tetrahydrocarbazole group interactions also enhanced the relative stability CT‐133 within the binding pocket which consequently favored CT‐133 binding affinity. CT‐133 binding also induced an inactive or ‘desensitized’ state in the helix 8 of CRTH2 which could conversely favor the recruitment of arrestin. These revelations would aid in the speedy development of small molecule inhibitors of CRTH2 in the treatment of type 2 inflammation dependent diseases.     

Extracellular vesicle‐mediated crosstalk between NPCE cells and TM cells result in modulation of Wnt signalling pathway and ECM remodelling

Primary open‐angle glaucoma is a leading cause of irreversible blindness, often associated with increased intraocular pressure. Extracellular vesicles (EVs) carry a specific composition of proteins, lipids and nucleotides have been considered as essential mediators of cell‐cell communication. Their potential impact for crosstalk between tissues responsible for aqueous humour production and out‐flow is largely unknown. The study objective was to investigate the effects of EVs derived from non‐pigmented ciliary epithelium (NPCE) primary cells on the expression of Wnt proteins in a human primary trabecular meshwork (TM) cells and define the mechanism underlying exosome‐mediated regulation that signalling pathway. Consistent with the results in TM cell line, EVs released by both primary NPCE cells and NPCE cell line showed diminished pGSK3β phosphorylation and decreased cytosolic levels of β‐catenin in primary TM cells. At the molecular level, we showed that NPCE exosome treatment downregulated the expression of positive GSKβ regulator‐AKT protein but increased the levels of GSKβ negative regulator‐PP2A protein in TM cells. NPCE exosome protein analysis revealed 584 miRNAs and 182 proteins involved in the regulation of TM cellular processes, including WNT/β‐catenin signalling pathway, cell adhesion and extracellular matrix deposition. We found that negative modulator of Wnt signalling miR‐29b was abundant in NPCE exosomal samples and treatment of TM cells with NPCE EVs significantly decreased COL3A1 expression. Suggesting that miR‐29b can be responsible for decreased levels of WNT/β‐catenin pathway. Overall, this study highlights a potential role of EVs derived from NPCE cells in modulating ECM proteins and TM canonical Wnt signalling.     

Protective effect of Agrimonia pilosa polysaccharides on dexamethasone‐treated MC3T3‐E1 cells via Wnt/β‐Catenin pathway

A water‐soluble polysaccharide (APP‐AW) was isolated from Agrimonia pilosa and prepared to three sulphated derivatives (S1, S2 and S3). The results showed that pre‐treatment with APP‐AW, S1, S2 and S3 each at the concentration of 50 μg/mL for 48 hours was able to prevent cytotoxicity induced by 1 μmol/L dexamethasone (Dex) in MC3T3‐E1 cells via inhibition of apoptosis, which is in line with the findings in flow cytometry analysis. Meanwhile, the decreased ALP activity, collagen content, mineralization, BMP2, Runx2, OSX and OCN protein expression in DEX‐treated MC3T3‐E1 cells were reversed by the addition of APP‐AW, S1, S2 and S3. Moreover, APP‐AW, S1, S2 and S3 rescued DEX‐induced increase of Bax, cytochrome c and caspase‐3 and decrease of Bcl‐2, Wnt3, β‐catenin and c‐Myc protein expression in MC3T3‐E1 cells. Our findings suggest that pre‐treatment with APP‐AW, S1, S2 and S3 could significantly protect MC3T3‐E1 cells against Dex‐induced cell injury via inhibiting apoptosis and activating Wnt/β‐Catenin signalling pathway, thus application of these polysaccharides may be a promising alternative strategy for steroid‐induced avascular necrosis of the femoral head (SANFH) therapy.     

LncRNA TUG1 alleviates cardiac hypertrophy by targeting miR-34a/DKK1/Wnt-β-catenin signalling

The current study was designed to explore the role and underlying mechanism of lncRNA taurine up-regulated gene 1 (TUG1) in cardiac hypertrophy. Mice were treated by transverse aortic constriction (TAC) surgery to induce cardiac hypertrophy, and cardiomyocytes were treated by phenylephrine (PE) to induce hypertrophic phenotype. Haematoxylin-eosin (HE), wheat germ agglutinin (WGA) and immunofluorescence (IF) were used to examine morphological alterations. Real-time PCR, Western blots and IF staining were used to detect the expression of RNAs and proteins. Luciferase assay and RNA pull-down assay were used to verify the interaction. It is revealed that TUG1 was up-regulated in the hearts of mice treated by TAC surgery and in PE-induced cardiomyocytes. Functionally, overexpression of TUG1 alleviated cardiac hypertrophy both in vivo and in vitro. Mechanically, TUG1 sponged and sequestered miR-34a to increase the Dickkopf 1 (DKK1) level, which eventually inhibited the activation of Wnt/β-catenin signalling. In conclusion, the current study reported the protective role and regulatory mechanism of TUG1 in cardiac hypertrophy and suggested that TUG1 may serve as a novel molecular target for treating cardiac hypertrophy.     

Deleterious cardiovascular effect of exosome in digitalis‐treated decompensated congestive heart failure

Heart failure (HF) is a medical condition inability of the heart to pump sufficient blood to meet the metabolic demand of the body to take place. The number of hospitalized patients with cardiovascular diseases is estimated to be more than 1 million each year, of which 80% to 90% of patients ultimately progress to decompensated HF. Digitalis glycosides exert modest inotropic actions when administered to patients with decompensated HF. Although its efficacy in patients with HF and atrial fibrillation is clear, its value in patients with HF and sinus rhythm has often been questioned. A series of recent studies have cast serious doubt on the benefit of digoxin when added to contemporary HF treatment. We are hypothesizing the role and mechanism of exosome and its biological constituents responsible for worsening the disease state and mortality in decompensated HF patients on digitalis.     

Thiophene bioisosteres of GluN2B selective NMDA receptor antagonists: Synthesis and pharmacological evaluation of [7]annuleno[b]thiophen-6-amines

Thiophene bioisosteres of potent GluN2B receptor negative allosteric modulators were prepared and evaluated pharmacologically. The five-step synthesis of 4,5,7,8-tetrahydro[7]annuleno[b]thiophen-6-one (10) was considerably improved by carboxylation of thiophene-3-carboxylic acid (8) in the first reaction step. Reductive amination and alkylation led to three homologous series of secondary and tertiary phenylalkylamines 5, 11 and 12. Metalation, reaction with 1-formylpiperidine and subsequent reduction provided hydroxymethyl derivatives 15 and 16, which had been designed as bioisosteres of phenols. 2-Bromo derivatives 18 were obtained by bromination of ketone 10 with NBS and subsequent reductive amination. High GluN2B affinity was achieved with [7]annuleno[b]thiophenes bearing a 3-phenylpropylamino or 4-phenylbutylamino moiety (e.g. 5c: K_i = 5.9 nM; 11d: K_i = 9.0 nM). Tertiary ethylamines 12 showed lower GluN2B affinity than tertiary methylamines 11 or secondary amines 5 (e.g. 5c: K_i = 5.9 nM; 11c: K_i = 6.0; 12c: K_i = 51 nM). A Br-atom or a hydroxymethyl moiety in 2-position were less tolerated by the GluN2B receptor. Very similar relationships between the structure and GluN2B affinity and structure and σ affinity, in particular σ₂ affinity, were detected. A slight preference for the ifenprodil binding site of GluN2B receptors over σ₁ and σ₂ receptors was found for methylamines 11c (≈2-fold) and 11d (≈1.5–2-fold) as well as for bromo derivative 18c (≈3-fold).