Relevance of enriched expression of SARS-CoV-2 binding receptor ACE2 in gastrointestinal tissue with pathogenesis of digestive symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 patients

Ashutosh Kumar; Muneeb A. Faiq; Vikas Pareek; Khursheed Raza; Ravi K. Narayan; Pranav Prasoon; Pavan Kumar; Maheswari Kulandhasamy; Chiman Kumari; Kamla Kant; Himanshu N. Singh; Rizwana Qadri; Sada N. Pandey; Santosh Kumar

As described by the source labs, specimens containing normal tissue were collected and sampled from anonymized paraffin embedded material of surgical specimens, in accordance with approval from the local ethics committee. The specimens were derived from surgical material, normal was defined by morphological parameters and absence of . CC-BY-NC-ND 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.14.040204 doi: bioRxiv preprint neoplasia. IHC staining was performed using a standard protocol on normal tissue microarray (https://www.proteinatlas.org/download/IHC_protocol.pdf). Antibodies against human ACE2 (HPA000288, CAB026174) were labeled with DAB (3, 3'diaminobenzidine) stain. Protein expression score was done based on the staining intensity (negative, weak, moderate or strong) and fraction of stained cells (<25%, 25-75% or >75%). For each protein, the IHC staining profile was matched with mRNA expression data and gene/protein characterization data to yield an 'annotated protein expression' profile.