PMID- 34653711
OWN - NLM
STAT- MEDLINE
DCOM- 20220127
LR  - 20240214
IS  - 1937-5913 (Electronic)
IS  - 1542-0124 (Print)
IS  - 1542-0124 (Linking)
VI  - 23
DP  - 2022 Jan
TI  - High expression of SARS-CoV2 viral entry-related proteins in human limbal stem 
      cells.
PG  - 197-200
LID - S1542-0124(21)00119-1 [pii]
LID - 10.1016/j.jtos.2021.10.002 [doi]
AB  - PURPOSE: Coronavirus disease 2019 (COVID-19) is caused by severe acute 
      respiratory syndrome coronavirus 2 (SARS-CoV2). While the ocular surface is 
      considered one of the major SARS-CoV2 transmission routes, the specific cellular 
      tropism of SARS-CoV2 is not fully understood. In the current study, we evaluated 
      the expression and regulation of two SARS-CoV2 viral entry proteins, TMPRSS2 and 
      ACE2, in human ocular epithelial cells and stem cells. METHODS: TMPRSS2 and ACE2 
      expression in ABCB5-positive limbal stem cells (LSCs) were assessed by RNAseq, 
      flow cytometry and immunohistochemistry. PAX6, TMPRSS2, and ACE2 mRNA expression 
      values were obtained from the GSE135455 and DRA002960 RNA-seq datasets. 
      siRNA-mediated PAX6 knockdown (KD) was performed in limbal and conjunctival 
      epithelial cells. TMPRSS2 and ACE2 expression in the PAX6 KD cells was analyzed 
      by qRT-PCR and Western blot. RESULTS: We found that ABCB5-positive LSCs express 
      high levels of TMPRSS2 and ACE2 compared to ABCB5-negative limbal epithelial 
      cells. Mechanistically, gene knockout and overexpression models revealed that the 
      eye transcription factor PAX6 negatively regulates TMPRSS2 expression. Therefore, 
      low levels of PAX6 in ABCB5-positive LSCs promote TMPRSS2 expression, and high 
      levels of TMPRSS2 and ACE2 expression by LSCs indicate enhanced susceptibility to 
      SARS-CoV2 infection in this stem cell population. CONCLUSIONS: Our study points 
      to a need for COVID-19 testing of LSCs derived from donor corneas before 
      transplantation to patients with limbal stem cell deficiency. Furthermore, our 
      findings suggest that expandable human ABCB5+ LSC cultures might represent a 
      relevant novel model system for studying cellular SARS-CoV2 viral entry 
      mechanisms and evaluating related targeting strategies.
CI  - Published by Elsevier Inc.
FAU - Sasamoto, Yuzuru
AU  - Sasamoto Y
AD  - Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; 
      Transplant Research Program, Boston Children's Hospital, Boston, MA, United 
      States.
FAU - Lee, Catherine A A
AU  - Lee CAA
AD  - Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; 
      Transplant Research Program, Boston Children's Hospital, Boston, MA, United 
      States.
FAU - Yoshihara, Masahito
AU  - Yoshihara M
AD  - Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, 
      Sweden.
FAU - Martin, Gabrielle
AU  - Martin G
AD  - Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; 
      Transplant Research Program, Boston Children's Hospital, Boston, MA, United 
      States.
FAU - Ksander, Bruce R
AU  - Ksander BR
AD  - Massachusetts Eye & Ear Infirmary, Schepens Eye Research Institute, Boston, MA, 
      United States.
FAU - Frank, Markus H
AU  - Frank MH
AD  - Transplant Research Program, Boston Children's Hospital, Boston, MA, United 
      States; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; 
      Harvard Skin Disease Research Center, Department of Dermatology, Brigham and 
      Women's Hospital, Boston, MA, USA; School of Medical and Health Sciences, Edith 
      Cowan University, Perth, Western Australia, Australia.
FAU - Frank, Natasha Y
AU  - Frank NY
AD  - Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; 
      Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; Department 
      of Medicine, VA Boston Healthcare System, Boston, MA, United States. Electronic 
      address: nyfrank@bwh.harvard.edu.
LA  - eng
GR  - R24 EY028767/EY/NEI NIH HHS/United States
GR  - K99 EY031741/EY/NEI NIH HHS/United States
GR  - P30 EY003790/EY/NEI NIH HHS/United States
GR  - T32 EB016652/EB/NIBIB NIH HHS/United States
GR  - R01 HL161087/HL/NHLBI NIH HHS/United States
GR  - R01 EY025794/EY/NEI NIH HHS/United States
GR  - I01 RX000989/RX/RRD VA/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20211013
PL  - United States
TA  - Ocul Surf
JT  - The ocular surface
JID - 101156063
RN  - 0 (ABCB5 protein, human)
RN  - 0 (ATP Binding Cassette Transporter, Subfamily B)
RN  - 0 (RNA, Viral)
RN  - 0 (Viral Proteins)
SB  - IM
MH  - ATP Binding Cassette Transporter, Subfamily B
MH  - *COVID-19
MH  - COVID-19 Testing
MH  - Humans
MH  - *RNA, Viral
MH  - SARS-CoV-2
MH  - Stem Cells
MH  - Viral Proteins
MH  - Virus Internalization
PMC - PMC8511872
OTO - NOTNLM
OT  - ACE2
OT  - COVID-19
OT  - Limbal stem cells
OT  - PAX6
OT  - SARS-CoV2
OT  - TMPRSS2
EDAT- 2021/10/16 06:00
MHDA- 2022/01/28 06:00
PMCR- 2021/10/13
CRDT- 2021/10/15 20:17
PHST- 2021/05/30 00:00 [received]
PHST- 2021/09/24 00:00 [revised]
PHST- 2021/10/07 00:00 [accepted]
PHST- 2021/10/16 06:00 [pubmed]
PHST- 2022/01/28 06:00 [medline]
PHST- 2021/10/15 20:17 [entrez]
PHST- 2021/10/13 00:00 [pmc-release]
AID - S1542-0124(21)00119-1 [pii]
AID - 10.1016/j.jtos.2021.10.002 [doi]
PST - ppublish
SO  - Ocul Surf. 2022 Jan;23:197-200. doi: 10.1016/j.jtos.2021.10.002. Epub 2021 Oct 
      13.