No-glucose, hypoxic or ischemic (ODG) treatment of pericytes

Brain pericytes are important to maintain vascular integrity of the neurovascular unit under both, physiological and ischemic conditions. Ischemic stroke is known to induce an inflammatory and hypoxic response due to the lack of oxygen and glucose in the brain tissue. How this early response to ischemia is molecularly regulated in pericytes is largely unknown but may be of importance for future therapeutic targets .Here we evaluate the transcriptional responses in in vitro cultured human brain pericytes after oxygen and/or glucose deprivation. Hypoxia has been widely known to stabilise the transcription factor hypoxia inducible factor 1-alpha (HIF1alpha) and mediate the induction of hypoxic transcriptional programs after ischemia. However, we find that the transcription factors Jun Proto-Oncogene (c-JUN), Nuclear Factor Of Kappa Light Polypeptide Gene Enhancer In B-Cells (NFkappaB) and signal transducer and activator of transcription 3 (STAT3) bind genes regulated after 2 hours of omitted glucose and oxygen before HIF1alpha. Potent HIF1alpha responses require 6 hours of hypoxia to substantiate transcriptional regulation comparable to either c-JUN or STAT3. We show that STAT3 and c-JUN are regulating their bound genes before HIF1alpha after 2 hours of hypoxia or omitted glucose and oxygen, suggesting that HIF1alpha is not the initiating trans-acting factor in the response of pericytes to ischemia. No-glucose, hypoxic or ischemic (ODG) treatment of human adult pericyte cell cultures. Sub-vetricular zone (SVZ) pericytes from a temporal lobe epilepsy (TLE) patient material was subjected to normal cell culture, lack of glucose, lack of oxygen (hypoxia), or lack of oxygen and glucose (ischemic condition). Cell cultures were exposed to lack of oxygen in a hypoxic chamber at 0.5-0.7% oxygen. Total RNA was extracted after 2 and 6 hours of treatment. The total RNA was hybridized to an Illumina bead array.