Hypothyroidism affects corneal homeostasis and wound healing in mice

[helvella]

After numerous papers from other specialists, in particular cardiac folk, all painting a positive picture of the use of liothyronine (T3), along come the ophthalmologists!

Exp Eye Res. 2022 May 12;109111.

doi: 10.1016/j.exer.2022.109111. Online ahead of print.

Hypothyroidism affects corneal homeostasis and wound healing in mice

Yijia Huang 1 , Ting Fu 1 , Xinwei Jiao 2 , Sijing Liu 1 , Yunxia Xue 3 , Jun Liu 3 , Zhijie Li 4

Affiliations

• PMID: 35569517

• DOI: 10.1016/j.exer.2022.109111

Abstract

Purpose: Thyroid hormones have a critical role in maintaining metabolic and physiological homeostasis. However, understanding of the possible effects of thyroid dysfunction on corneal homeostasis and the wound healing process is quite limited. To explore the influence of hypothyroidism on corneal homeostasis and the post-wound repair processes of the murine cornea.

Methods: A hypothyroidism model was established by total thyroidectomy (TThy) in C57BL/6J mice. On day 10 after TThy, hypothyroidism was confirmed via thyronine (T3 and T4) and thyroid-stimulating hormone serum levels. We further assessed changes in corneal thickness, corneal sensitivity, sub-basal nerve density, and the corneal expression of thyroid hormone receptors. A corneal epithelial abrasion model was established via mechanical removal of a central epithelium 2 mm in diameter. Wound closure and recruitment of inflammatory cells (neutrophils and γδ T-cells) were evaluated. RNA-sequencing and gene set enrichment analysis were performed in injured corneas after abrasion. The effect of local T3 administration on corneal wound healing in thyroidectomized mice was also observed.

Results: Compared with sham-operated control mice, the TThy-treated mice showed the following: (1) a significant decrease in corneal epithelial thickness, sensitivity to external stimuli, and sub-basal nerve density, as well as an alteration in thyroid hormone receptor expression in the steady state; (2) delayed corneal wound repair and enhanced inflammatory response after corneal abrasion; (3) down-regulation of actin-skeleton and DNA replication pathways and up-regulation of inflammation-associated pathways in abraded corneas; and (4) significant restoration of delayed corneal wound repair and inhibition of excessive inflammation following topical T3 administration.

Conclusions: We conclude that deficient thyroid hormone secretion significantly affects corneal homeostasis and post-wound repair processes. Topical T3 administration might have a potential reversal effect on delayed corneal wound repair among hypothyroid individuals.

Keywords: Cornea; Inflammation; Thyroid dysfunction; Wound healing.

Rest of paper is, as so often, behind a paywall:

pubmed.ncbi.nlm.nih.gov/355...

[TSH110]

Very interesting - but I feel sorry for those poor mice.

I have trouble with my corneas. I presume they’d be even worse if I was still on T4 monotherapy not NDT.

[Gingernut44]

That’s interesting- yet another “discipline” looking at T3. The more the merrier I say.

[helvella Administrator Thyroid UK in reply to Gingernut44]

I'm sure it's an exaggeration, but it sometimes feels as if endocrinology is going to end up the last medical discipline to properly recognise the use of T3.

[Gingernut44]

Yes, you’re probably right but they have the biggest “face” to lose and the highest horse to fall off 🤨

[RedApple Administrator in reply to Gingernut44]

Those that fall off their horses will simply take early retirement so that they are not seen to have lost face. We are reliant on the upcoming generation of endos to read, understand and act upon the avalanche of research coming from diogenes and co., and others around the world that are coming forward with their own research.

[Gingernut44 in reply to RedApple]

There’s only one problem with that fantasy- they may retire from the NHS but I know the idiot I saw privately is still practicing at two private hospitals and, to my horror, is lecturing at the med school in the local University 😱

[RedApple Administrator in reply to Gingernut44]

😧🙀

[Greybeard]

I too have problems with a thinning epithelial layer in my cornea. The diagnosis was Fuch's epithelial syndrome, the comment was " we don't know what cause it and we have no treatment for it " my eye sight improved dramatically when I raised my Ft3 level.

[helvella Administrator Thyroid UK in reply to Greybeard]

That is very interesting.

[BB001]

Encouraging. 😀