Building Neurovascular tissue from autologous blood for modeling brain activity

Abstract

There are no faithful individualized stem cell-based bioengineered neuro-vascularized models that can recapitulate the physiological hemodynamic phenomenon of neuro-vascular coupling (NVC)- the principal behind BOLD (blood oxygen level- dependent) signal in functional neuroimaging, thereby dissuading the research in exploring the brain activity-based investigative studies in neurological/neurosensory diseases. This encouraged us to establish a preclinical optoacoustic (Hb/dHb hemoglobin/deoxyhemoglobin) imaging-competent in vitro neuro-vascularized model by employing a novel cellular reprograming PITTRep (Plasma Induced Transcriptomics/ epi-Transcriptomics Reprograming) approach. The current reprograming approach is based on coaxing autologous blood components to ecto-mesodermal lineage intermediates that can subsequently self-pattern into neurovascular tissue by harnessing the hemorheological properties of RBCs. The nature of blood flow is non-Newtonian and is a function of RBC concentration /haematocrit when they flow through the regions of low shear rates as seen in cerebral microcirculation. The current reprograming approach is a modification of our previous cellular reprograming approach that employed a Newtonian plasma fluid. We tested a potential (yet completely unexplored) hypothesis of haemodynamic reprograming by leveraging the fluid mechanic feature of blood erythrocytes as seen in thrombus formation during cerebral ischemic stroke, that is characterized by physiologically intriguing yet clinically meaningful neurological recovery during an early time window. Intriguingly, post-stroke heightened neuroplasticity marked by dendrites, synapses, astrogliosis, microglia activation, and growth factor signaling is accompanied by adult neurogenesis, that is otherwise a non-resilient phenomenon. The current study attempted to induce a post stroke-like (adult) neurogenesis with functional synaptogenesis by instructing autologous blood components into thrombus formation by incorporation of erythrocytes in varying concentrations. The induction of neuro-vascularized niches (NVNs) and functional neuro vascular coupling (NVC) was characterized by confocal microscopy, scanning electron microscopy, proteomic profiling, and Hb/dHb spectra based optoacoustic imaging. The blood thrombus formation was checked by rotational thromboelastometry (ROTEM), and switching of adult to embryonic hemoglobin was confirmed by hemoglobin typing. We also attempted to establish patient-specific neuro-vascularized niches from autologous blood of sensorineural hearing loss (SNHL) patients. The individualized neovascularised tissues are intended to be employed for investigating deregulated synaptic plasticity/ long term potentiation underlying poor auditory comprehension outcomes in school going kids suffering from SNHL that greatly compromises their academic performance and socio-behavioural-cognitive development. The attendant multiomics of patient-specific NVNs may have potential implications in developing potential stem cell based therapies for neurosensory and cerebrovascular diseases.