Telomere Length a Promising Avenue in ILD Research

Mounting evidence suggests telomere shortening is an important research focus in interstitial lung disease (ILD) that may soon lead to novel therapeutic options.¹ A recent article published in The Clinical Respiratory Journal reviewed the latest research about telomere shortening in ILD.

The authors began by reviewing the challenges associated with ILD diagnosis. One of the major challenges, they said, is the similar clinical presentations in patients with different types of ILD. However, they noted that telomere shortening occurs in all patients with ILD, but telomere length and telomere shortening cells vary between the different types of ILD.² Thus, they said, measuring telomere length may be a useful tool in diagnosing and differentiating ILD.

In the case of idiopathic pulmonary fibrosis (IPF), previous research has shown that the disease’s development is linked with telomere shortening in peripheral blood leukocytes.³ Conversely, telomere shortening did not play a role in the development of chronic obstructive pulmonary disease (COPD). That research, the authors said, is part of a growing body of evidence that telomere shortening is a “clear risk factor” and valuable diagnostic tool in IPF.

The cause of telomere shortening in IPF has been linked with the presence of telomerase gene mutations, the authors said. A 2007 study looked at the genetic mutations behind IPF and found that mutations in the TERC and TERT genes of telomerase led to telomere shortening, which in turn could make a person much more likely to develop adult-onset IPF.⁴

Yet, there are other possible causes of telomere shortening. For exmaple, one theory is that abnormal epithelial damage-repair causes the telomere shortening.

“Different studies have confirmed that transforming growth factor-beta (TGF-β) inhibits telomerase gene activity via mothers against decapentaplegic homolog 3 (Smad3) in tumor cells and cultured mouse fibroblasts,” they noted.

Smad3 can interfere with the telomerase gene promoter’s transcription and translation, and knocking down the TGF-β receptor in mouse lung epithelial cells has been shown to reduce lung fibrosis in mice.⁵

Turning their attention to the therapeutic implications, the authors noted that current treatments can only delay—and not reverse—ILD. The targeting of telomerase and telomere function “has broad therapeutic promise” for patients with telomere abnormality-related pulmonary fibrosis, according to the authors. They said both molecular and gene therapies have been investigated for this purpose.

For instance, they noted the TERT gene promoter has estrogen receptors. Previous research has shown that estrogen can upregulate TERT expression and therefore increase telomerase activity.⁶

The novel telomerase activator GRN510 has also been used to successfully increase telomerase activity in a mouse model of TERT gene-mutant pulmonary fibrosis.⁷ 

Another option is inhibition of PAP-associated domain-containing protein 5 (PAPD5). The protein opposes the PARN gene, and the PARN gene regulates the function of TERC and thereby helps maintain telomere length.¹ The theory—backed up by early research—is that inhibiting PAPD5 can ultimately result in enhanced telomerase activity.

Aside from the therapeutic implications of telomere length in ILD, the investigators said telomere length also appears to be a predictor of survival in patients with IPF, though not for patients with non-IPF ILDs.

Moving forward, the authors said more investigation is warranted to better understand the relationships between telomeres, telomere-related gene mutations, and ILD. Such investigation, they said, could help predict—and ideally, change—the trajectory of the disease.

References

1. Jin H, Song J, Gao R, et al. Telomere shortening in interstitial lung disease: challenges and promises. Clin Respir J. 2025;19(7):e70103. doi:10.1111/crj.70103

2. Snetselaar R, van Moorsel CHM, Kazemier KM, et al. Telomere length in interstitial lung diseases. Chest. 2015;148(4):1011-1018. doi:10.1378/chest.14-3078

3. Duckworth A, Gibbons MA, Allen RJ, et al. Telomere length and risk of idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease: a mendelian randomisation study. Lancet Respir Med. 2021;9(3):285-294. doi:10.1016/S2213-2600(20)30364-7

4. Tsakiri KD, Cronkhite JT, Kuan PJ, et al. Adult-onset pulmonary fibrosis caused by mutations in telomerase. Proc Natl Acad Sci U S A. 2007;104(18):7552-7557. doi:10.1073/pnas.0701009104

5. Li M, Krishnaveni MS, Li C, et al. Epithelium-specific deletion of TGF-β receptor type II protects mice from bleomycin-induced pulmonary fibrosis. J Clin Invest. 2011;121(1):277-287. doi:10.1172/JCI42090

6. Bayne S, Liu JP. Hormones and growth factors regulate telomerase activity in ageing and cancer. Mol Cell Endocrinol. 2005;240(1-2):11-22. doi:10.1016/j.mce.2005.05.009

7. Le Saux CJ, Davy P, Brampton C, et al. A novel telomerase activator suppresses lung damage in a murine model of idiopathic pulmonary fibrosis. PLoS One. 2013;8(3):e58423. doi:10.1371/journal.pone.0058423