Minimizing long-term lung damage in COVID patients

Date:
February 2, 2022
Source:
American Society for Microbiology
Summary:
A combined treatment strategy targeting SARS-CoV-2 symptoms and
severe lung tissue injury is essential to minimize lung sequelae --
chronic complications resulting from COVID-19 infection, according
to a new review article.



FULL STORY ==========================================================================
A combined treatment strategy targeting SARS-CoV-2 symptoms and severe
lung tissue injury is essential to minimize lung sequelae -- chronic complications resulting from COVID-19 infection, according to a review published this week in Clinical Microbiology Reviews, a journal of the
American Society for Microbiology.


========================================================================== Therapy using lung epithelial stem and progenitor cells shows promise
for mitigating the potentially lethal and highly damaging virus-induced inflammatory storm that can occur in severe cases of COVID-19, said
Huaiyong Chen, Ph.D., principal investigator at Tianjin Institute of Respiratory Diseases, and Director of Tianjin Key Laboratory of Lung Regenerative Medicine, Haihe Hospital, Tianjin University, China.

"To minimize the damage to the lung, we should promote tissue regeneration efficiently by activating surviving lung stem and progenitor cells, or
else by directly transplanting healthy lung stem and progenitor cells
into damaged lungs," said Chen.

Both cell types can differentiate into lung epithelial cells, which cover
the inner surfaces of the lungs where air exchange occurs. In so doing,
they can repair lung damage caused by SARS-CoV-2, including fibrosis.

The first step towards activating these regenerative cells is to prime
the tissue environment with mesenchymal stem cells. These cells do not
normally reside in the lung, but when transplanted there, they secrete
growth factors that support the growth and differentiation of the lung epithelial stem and progenitor cells. That, in turn, can repair the
damage. The investigators are currently using animal models to figure
out how best to accomplish this.

But in severe cases, these regenerative cells may be damaged by cytokines, which are produced by immune cells in excessive numbers during lung inflammation, preventing full restoration of lung structure and function.

In such cases, healthy stem and progenitor cells might have to be
transplanted into a person's lungs. However, as with any transplant,
immune rejection is likely to be a problem. It may be possible to
use gene editing technology, known as CRISPR, to modify these cells
to reduce immunogenicity prior to transplantation, a possibility Chen
is investigating.

For less severe cases, researchers will need to screen for compounds
that boost the capacity of progenitor and stem cells to trigger repair
and regeneration of lungs following these injuries. Previous research
has shown that certain compounds that target signaling pathways in stem
and progenitor cells show potential for enhancing lung regeneration
in patients with asthma and lung fibrosis. They may do likewise for
SARS-CoV-2 patients.

The impetus for the current study was Chen's discovery that even
12 years after recovery, some survivors of the closely related virus,
Severe Acute Respiratory Syndrome (SARS), first identified in 2003, were
living with multiple sequelae, reducing quality of life. "I realized
then that something had to be done to maximize the lung regeneration,
repair and recovery," Chen said.

========================================================================== Story Source: Materials provided by
American_Society_for_Microbiology. Note: Content may be edited for style
and length.


========================================================================== Journal Reference:
1. Fuxiaonan Zhao, Qingwen Ma, Qing Yue, Huaiyong Chen. SARS-CoV-2
Infection
and Lung Regeneration. Clinical Microbiology Reviews, 2022; DOI:
10.1128/ cmr.00188-21 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220202134654.htm

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