Phospholipase C-γ2 via p38 and ERK1/2 MAP kinase mediates diperoxovanadate-asparagine induced human platelet aggregation and sCD40L release

Rh-CSF1 Attenuates Oxidative Stress and Neuronal Apoptosis via the CSF1R/PLCG2/PKA/UCP2 Signaling Pathway in a Rat Model of Neonatal HIE

Oxidative stress (OS) and neuronal apoptosis are major pathological processes after hypoxic-ischemic encephalopathy (HIE). Colony stimulating factor 1 (CSF1), binding to CSF1 receptor (CSF1R), has been shown to reduce neuronal loss after hypoxic-ischemia- (HI-) induced brain injury. In the present study, we hypothesized that CSF1 could alleviate OS-induced neuronal degeneration and apoptosis through the CSF1R/PLCG2/PKA/UCP2 signaling pathway in a rat model of HI. A total of 127 ten-day old Sprague Dawley rat pups were used. HI was induced by right common carotid artery ligation with subsequent exposure to hypoxia for 2.5 h. Exogenous recombinant human CSF1 (rh-CSF1) was administered intranasally at 1 h and 24 h after HI. The CSF1R inhibitor, BLZ945, or phospholipase C-gamma 2 (PLCG2) inhibitor, U73122, was injected intraperitoneally at 1 h before HI induction. Brain infarct volume measurement, cliff avoidance test, righting reflex test, double immunofluorescence staining, western blot assessment, 8-OHdG and MitoSOX staining, Fluoro-Jade C staining, and TUNEL staining were used. Our results indicated that the expressions of endogenous CSF1, CSF1R, p-CSF1R, p-PLCG2, p-PKA, and uncoupling protein2 (UCP2) were increased after HI. CSF1 and CSF1R were expressed in neurons and astrocytes. Rh-CSF1 treatment significantly attenuated neurological deficits, infarct volume, OS, neuronal apoptosis, and degeneration at 48 h after HI. Moreover, activation of CSF1R by rh-CSF1 significantly increased the brain tissue expressions of p-PLCG2, p-PKA, UCP2, and Bcl2/Bax ratio, but reduced the expression of cleaved caspase-3. The neuroprotective effects of rh-CSF1 were abolished by BLZ945 or U73122. These results suggested that rh-CSF1 treatment attenuated OS-induced neuronal degeneration and apoptosis after HI, at least in part, through the CSF1R/PLCG2/PKA/UCP2 signaling pathway. Rh-CSF1 may serve as therapeutic strategy against brain damage in patients with HIE.

miR-145 mediated the role of aspirin in resisting VSMCs proliferation and anti-inflammation through CD40

Background

Aspirin (ASA) is the most widely used medicine to prevent cardiovascular diseases; however, the mechanisms by which ASA exerts its anti-proliferative effect remain not fully understood. This study was designed to investigate whether miR-145 is involved in the regulation of vascular smooth muscle cells’ (VSMCs) proliferation and to determine the anti-inflammatory effects of ASA via its regulation of CD40 to provide a new theoretical basis for the pharmacological effect of aspirin.

Methods

The TNF-α induced proliferation model of VSMCs was divided into different groups with or without aspirin. Cell proliferation was detected by EdU; Real-time PCR was used to detect the mRNA expression of miR-145, CD40, and Calponin, a VSMCs differentiation marker gene. Western blot was used to detect the protein expression of CD40; ELISA was used to determine the concentrations of the inflammatory cytokine IL-6 in cell supernatants.

Results

The proliferation of VSMCs was stimulated by TNF-α and accompanied by decreased levels of Calponin. TNF-α also decreased the levels of miR-145 and increased the levels of CD40 and IL-6. Pretreatment with 20 μg/mL of aspirin in VSMCs could partially block the above-mentioned effects induced by TNF-α. The protective effects of ASA in VSMCs were reversed by a pretreatment with a miR-145 inhibitor. We also found that the expression of miR-145 in peripheral blood mononuclear cells in ischemic stroke patients was significantly increased after a 10-day treatment with aspirin.

Conclusion

miR-145 is involved in the anti-proliferation and anti-inflammation effects of aspirin on VSMCs by inhibiting the expression of CD40.

Synthesis and evaluation of dual antiplatelet activity of bispidine derivatives of N-substituted pyroglutamic acids

N-aralkylpyroglutamides of substituted bispidine were prepared and evaluated for their ability to inhibit collagen induced platelet aggregation, both in vivo and in vitro. Some compounds showed high anti-platelet efficacy (in vitro) of which six inhibited both collagen as well as U46619 induced platelet aggregation with concentration dependent anti-platelet efficacy through dual mechanism. In particular, the compound 4j offered significant protection against collagen epinephrine induced pulmonary thromboembolism as well as ferric chloride induced arterial thrombosis, without affecting bleeding tendency in mice. Therefore, the present study suggests that the compound 4j displays a remarkable antithrombotic efficacy much better than aspirin and clopidogrel.

Vanadium Compounds as Pro-Inflammatory Agents: Effects on Cyclooxygenases

This paper discusses how the activity and expression of cyclooxygenases are influenced by vanadium compounds at anticancer concentrations and recorded in inorganic vanadium poisonings. We refer mainly to the effects of vanadate (orthovanadate), vanadyl and pervanadate ions; the main focus is placed on their impact on intracellular signaling. We describe the exact mechanism of the effect of vanadium compounds on protein tyrosine phosphatases (PTP), epidermal growth factor receptor (EGFR), PLCγ, Src, mitogen-activated protein kinase (MAPK) cascades, transcription factor NF-κB, the effect on the proteolysis of COX-2 and the activity of cPLA₂. For a better understanding of these processes, a lot of space is devoted to the transformation of vanadium compounds within the cell and the molecular influence on the direct targets of the discussed vanadium compounds.