Human cerebrovascular contractile receptors are upregulated via a B-Raf/MEK/ERK-sensitive signaling pathway

<p>Abstract</p> <p>Background</p> <p>Cerebral ischemia results in a rapid increase in contractile cerebrovascular receptors, such as the 5-hydroxytryptamine type 1B (5-HT_1B), angiotensin II type 1 (AT₁), and endothelin type B (ET_B) receptors, in the vessel walls within the ischemic region, which further impairs local blood flow and aggravates tissue damage. This receptor upregulation occurs via activation of the mitogen-activated protein kinase pathway. We therefore hypothesized an important role for B-Raf, the first signaling molecule in the pathway. To test our hypothesis, human cerebral arteries were incubated at 37°C for 48 h in the absence or presence of a B-Raf inhibitor: SB-386023 or SB-590885. Contractile properties were evaluated in a myograph and protein expression of the individual receptors and activated phosphorylated B-Raf (p-B-Raf) was evaluated immunohistochemically.</p> <p>Results</p> <p>5-HT_1B, AT₁, and ET_Breceptor-mediated contractions were significantly reduced by application of SB-590885, and to a smaller extent by SB-386023. A marked reduction in AT₁receptor immunoreactivity was observed after treatment with SB-590885. Treatment with SB-590885 and SB-386023 diminished the culture-induced increase of p-B-Raf immunoreactivity.</p> <p>Conclusions</p> <p>B-Raf signaling has a key function in the altered expression of vascular contractile receptors observed after organ culture. Therefore, specific targeting of B-Raf might be a novel approach to reduce tissue damage after cerebral ischemia by preventing the previously observed upregulation of contractile receptors in smooth muscle cells.</p

Identification of pyrimidinyl piperazines as non-iminosugar glucocerebrosidase (GCase) pharmacological chaperones

Glucocerebrosidase (GCase) is a lysosomal enzyme encoded by the GBA1 gene, loss of function variants of which cause an autosomal recessive lysosomal storage disorder, Gaucher disease (GD). Heterozygous variants of GBA1 are also known as the strongest common genetic risk factor for Parkinson's disease (PD). Restoration of GCase enzymatic function using a pharmacological chaperone strategy is considered a promising therapeutic approach for PD and GD. We identified compound 4 as a GCase pharmacological chaperone with sub-micromolar activity from a high-throughput screening (HTS) campaign. Compound 4 was further optimised to ER-001230194 (compound 25). ER-001230194 shows improved ADME and physicochemical properties and therefore represents a novel pharmacological chaperone with which to investigate GCase pharmacology further