Table 2.
Non-coding RNAs identified as showing significant differential expression with age
| Gene identity | Species | Tendon type | Observed effect of age | Reference | |
|---|---|---|---|---|---|
| micro-RNAs | |||||
| miR-1245a | Human | Achilles tendon | Reduced expression with ageing. | 23 | |
| miR-500a-5p, miR-548j-5p, miR-618, miR-10 | Human | MSCs differentiated into tenogenic tissue | miR-500, miR-548 and miR-618 increased expression with ageing. miR-10 methylation significantly increased with ageing. | 62 | |
| 26 miRs | Human | Achilles tendon | 26 DE miRs identified in old versus young female-derived tissue, 4 of which (miR-1287, miR-1304, miR-1909, miR-3614) also DE in old versus young male-derived tissue. Direction of change not stated. | 17 | |
| miR-217 | Human | Achilles tendon | Tenogenic differentiation capacity of TSPCs decreases with age due to p16 induced upregulation of miR-127 resulting in reduced EGR1 expression. | 42 | |
| miR-140-5p | Human | Achilles tendon | miR-140-5p associated with TSPC senescence via direct inhibition of Pin1 expression. | 86 | |
| miR-135a | Rat | Achilles tendon | Down regulation of miR-135a with ageing promotes senescence in TSPCs via interaction with ROCK1. | 87 | |
| miR-29a, miR-34a, miR-34b, miR-181b, miR-199a, miR-199b | Equine | SDFT | miRs -34b and -181b upregulated with age, miRs -29a, −34a, −199a and -199b downregulated with age. | 88 | |
| lncRNAs | |||||
| 45 lncRNAs of unknown function, XIST LINC00261 TSIX DLX6-AS1 | Human | Achilles tendon | 29 lncRNAs of unknown function increased expression with ageing. 4 functionally annotated lncRNAs overexpressed with ageing (XIST, TSIX, LINC00261, DLX6-AS1). 16 lncRNAs of unknown function reduced expression with ageing. | 23 | |
| Not given | Human | MSCs differentiated into tenogenic tissue | 5 lncRNAs identified as showing significant DE, 1 up regulated, 4 downregulated with ageing. | 7 | |
| 18 lncRNAs | Human | Achilles tendon | 18 DE lncRNAs identified in old v young female-derived tissue, 2 of which (LINC00662, LINC00843) also DE in old versus young male-derived tissue. Direction of change not stated. | 17 | |
| H19 | Mouse (in vivo) human (in vitro) | Human mesenchymal and tendon-derived stem cells Murine patellar tendon | H19 accelerates tenogenic differentiation by targeting miR-29b-3p and activating TGF-β1 signaling. | 56 | |
| snoRNAs | |||||
| RNVU1–6 Y-RNA | Human | Achilles tendon | RNVU1–6 increased with age (spliceosomal function). Y-RNA reduced with age (DNA replication/cell proliferation.) | 23 | |
| SNORA1, SNORA18, SNORA25, SNORA32, SNORA40, SNORA8, SNORD5, snoU13 | Human | Achilles tendon | snoU138 only DE in old versus young female-derived tissue, all others also DE in old versus young male-derived tissue. Direction of change not stated. | 17 | |
| Pseudogenes | |||||
| RP11–578024.2, AP003041.1, MKRN7P, RPS4XP22, RP11-346 M5.1, RN7SKP234, CTD-2114 J12.1, AL021068.1, MXRA5P1, RNY3P2, RP11-494 K3.2, CTC-260E6.10 | Human | Achilles tendon | All functionally un-annotated; 8 upregulated and 4 downregulated with ageing. | 23 | |
| SDHAP2, NUTM2D, PARGP1 | Human | Achilles tendon | SDHAP2, NUTM2D, PARGP1 DE in old v young female-derived tissue, PARGP1 also DE in old versus young male-derived tissue. Direction of change not stated | 17 | |
TSPCs, tendon stem/progenitor cells; EGR1, early growth response protein 1; Pin1, peptidyl-prolyl cis-trans isomerase NIMA-interacting 1; ROCK1, rho-associated, coiled-coil-containing protein kinase 1; TSIX, antisense transcript to XIST; LINC, long intergenic non-protein coding RNA; DLX6-AS1, Drosophila distal-less 6 antisense RNA 1; H19, H19 imprinted maternally expressed transcript; SNORA, small nucleolar RNA (H/ACA box); SNORD, small nucleolar RNA (C/D) box, MKRN7P, makorin ring finger protein 7; RPS4XP22, ribosomal protein S4X 22; RN7SKP234, RNA 7SK small nuclear 234; AL021068.1. ATP synthase 6; MXRA5P1, matrix remodeling associated 5 Y-linked; RNY3P2, RNA ro-associated Y3 pseudogene 2; RP11-494K3, neurofascin; SDHAP2, succinate dehydrogenase complex flavoprotein subunit A; NUTM2D, NUT family member 2D; PARGP1, poly(ADP-Ribose) glycohydrolase.