Leptin synergizes with thyroid hormone signaling in promoting growth plate chondrocyte proliferation and terminal differentiation in vitro

AbstractNorth-Eastern Brazil saw intensive application of the insecticide pyriproxyfen (PPF) during the microcephaly outbreak caused by Zika virus (ZIKV). ZIKV requires the neural RNA-binding protein Musashi-1 to replicate. TH represses MSI1. Being a suspected TH disruptor, we hypothesized that co-exposure to the main metabolite of PPF, 4’-OH-PPF, would exacerbate ZIKV effects through increased MSI1 expression. This was tested using in vitro mouse neurospheres and an in vivo TH signaling reporter model, Xenopus laevis. TH signaling was decreased by 4’-OH-PPF in both models. In mouse-derived neurospheres the metabolite reduced neuroprogenitor proliferation as well as markers of neuronal differentiation. The results demonstrated that 4’-OH-PPF significantly induced MSI1 at both the mRNA and protein level, as well as Fasn mRNA. Other TH target genes were also significantly modified. Importantly, several key genes implicated in neuroprogenitor fate and commitment were not dysregulated by 4’-OH-PPF alone, but were in combination with ZIKV infection. These included the neuroprogenitor markers Nestin, Egfr, Gfap, Dlx2 and Dcx. Unexpectedly, 4’-OH-PPF decreased ZIKV replication, although only at the fourth and last day of incubation, and RNA copy numbers stayed within the same order of magnitude. However, intracellular RNA content of neuroprogenitors was significantly decreased in the combined presence of the PPF metabolite and ZIKV. We conclude that 4’-OH-PPF interferes with TH action in vivo and in vitro, inhibiting neuroprogenitor proliferation. In the presence of ZIKV, TH signaling pathways crucial for cortical development are significantly impacted. This provides another example of viral effects that are exacerbated by drug or pesticide use.Significance statementIn 2015, an increase in children born with unusually small heads (microcephaly) in North-Eastern Brazil was linked to infection with the ZIKA virus. An insecticide with thyroid hormone disruptive properties was used in the same areas. We investigated whether simultaneous exposure to the insecticide could increase viral susceptibility. The main metabolite 4’-OH-PPF dysregulated thyroid hormone signaling pathways crucial for brain development in both models used. Neural stem cells proliferated less and contained more Musashi-1, a protein the virus needs to replicate. Infecting stem cells pre-exposed to the endocrine disruptor did not amplify viral replication, but aggravated expression of genes implicated in brain development. Our results suggest the insecticide is particularly deleterious to brain development in areas with ZIKA virus prevalence.

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Persistent COUP-TFII Expression Underlies the Myopathy and Impaired Muscle Regeneration Observed in Resistance to Thyroid Hormone-Alpha

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.1658 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A814-A814

Author(s):

Paola Aguiari ◽

Yan-Yun Liu ◽

Astgik Petrosyan ◽

Sheue-Yann Cheng ◽

Gregory A Brent ◽

...

Keyword(s):

Skeletal Muscle ◽

Thyroid Hormone ◽

Muscle Regeneration ◽

Myogenic Differentiation ◽

Skeletal Muscle Regeneration ◽

Hormone Signaling ◽

Muscle Loss ◽

Resistance To Thyroid Hormone ◽

Skeletal Muscle Loss

Abstract Myopathic changes, including muscular dystrophy and weakness, are commonly described in hypothyroid and hyperthyroid patients. Thyroid hormone signaling, via activation of thyroid nuclear receptor alpha (THRA), plays an essential role in maintaining muscle mass, function, and regeneration. A mouse model of resistance to thyroid hormone carrying a frameshift mutation in the THRA gene (THRA-PV) is associated with accelerated skeletal muscle loss with aging and impaired regeneration after injury(1,2). We previously demonstrated that the expression of nuclear orphan receptor chicken ovalbumin upstream promoter-factor II (COUP-TFII, or Nr2f2) persists during myogenic differentiation in THRA-PV myoblasts and skeletal muscle of aged THRA- PV mice. COUP-TFII is known to regulate myogenesis negatively and has a role in Duchenne-like Muscular Dystrophies(3). COUP-TFII physically and functionally interacts with THRA in primary myoblasts isolated from WT and THRA-PV mice, as demonstrated via co-immunoprecipitation and chromatin-immunoprecipitation. We observed that satellite cells from THRA-PV mice display impaired myoblast proliferation and in vitro myogenic differentiation compared to WT cells. However, the silencing of COUP-TFII expression using siRNA probes restores in vitro myogenic potential of THRA-PV myoblasts and shifts the mRNA expression profile closer to WT myoblasts, with a higher proliferation of myoblasts and a higher number of fully differentiated myotubes after 5 days of myogenic induction. Moreover, RNAseq analysis on myoblasts from THRA-PV mice after COUP-TFII knockdown shows that COUP-TFII silencing reverses the transcriptomic profile of THRA-PV myoblasts and results in reactivation of pathways involved in muscle function and extracellular matrix remodeling/deposition. These findings indicate that the persistent COUP-TFII expression in THRA-PV mice is responsible for the abnormal muscle phenotype. In conclusion, COUP-TFII and THRA cooperate during murine post-natal myogenesis, and COUP-TFII is critical for the accelerated skeletal muscle loss with aging and impaired muscle regeneration after injury in THRA-PV mice. These studies can help increase our knowledge of the mechanisms involved in thyroid hormone signaling during skeletal muscle regeneration, ultimately increasing the possibility of designing more specific treatments for patients with thyroid hormone-induced myopathies. References: 1. Milanesi, A., et al., Endocrinology 2016; 2. Kaneshige, M. et al., Proc Natl Acad Sci U S 2001; 3. Lee HJ, et al, Sci Rep. 2017.

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Thyroid hormone-stimulated differentiation of primary rib chondrocytes in vitro requires thyroid hormone receptor β

Journal of Endocrinology ◽

10.1677/joe.1.06838 ◽

2006 ◽

Vol 191 (1) ◽

pp. 221-228 ◽

Cited By ~ 15

Author(s):

Bénédicte Rabier ◽

Allan J Williams ◽

Frederic Mallein-Gerin ◽

Graham R Williams ◽

O Chassande

Keyword(s):

Thyroid Hormone ◽

Growth Plate ◽

Hormone Receptors ◽

Thyroid Hormone Receptor ◽

Primary Cultures ◽

Wild Type ◽

Proliferation And Differentiation ◽

Thyroid Hormone Receptor Β

The active thyroid hormone, triiodothyronine (T3), binds to thyroid hormone receptors (TR) and plays an essential role in the control of chondrocyte proliferation and differentiation. Hypo- and hyperthyroidism alter the structure of growth plate cartilage and modify chondrocyte gene expression in vivo, whilst TR mutations or deletions in mice result in altered growth plate architecture. Nevertheless, the particular roles of individual TR isoforms in mediating T3 action in chondrocytes have not been studied and are difficult to determine in vivo because of complex cellular and molecular interactions that regulate growth plate maturation. Therefore, we studied the effects of TRα and TRβ on chondrocyte growth and differentiation in primary cultures of neonatal rib chondrocytes isolated from TRα- and TRβ-deficient mice. T3 decreased proliferation but accelerated differentiation of rib chondrocytes from wild-type mice. T3 treatment resulted in similar effects in TRα-deficient chondrocytes, but in TRβ-deficient chondrocytes, all T3 responses were abrogated. Furthermore, T3 increased TRβ1 expression in wild-type and TRα-deficient chondrocytes. These data indicate that T3-stimulated differentiation of primary rib chondrocytes in vitro requires TRβ and suggest that the TRβ1 isoform mediates important T3 actions in mouse rib chondrocytes.

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The Role of p27Kip1 in the Regulation of Growth Plate Chondrocyte Proliferation in Mice

Pediatric Research ◽

10.1203/01.pdr.0000232790.53527.c6 ◽

2006 ◽

Vol 60 (3) ◽

pp. 288-293 ◽

Cited By ~ 11

Author(s):

Joyce A M Emons ◽

Rose Marino ◽

Ola Nilsson ◽

Kevin M Barnes ◽

Naomi Even-Zohar ◽

...

Keyword(s):

Growth Plate ◽

Chondrocyte Proliferation ◽

Growth Plate Chondrocyte ◽

Regulation Of Growth

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DHEA Suppresses Longitudinal Bone Growth by Acting Directly at Growth Plate through Estrogen Receptors

Endocrinology ◽

10.1210/en.2010-0920 ◽

2011 ◽

Vol 152 (4) ◽

pp. 1423-1433 ◽

Cited By ~ 8

Author(s):

Hongzhi Sun ◽

Weijin Zang ◽

Bo Zhou ◽

Lin Xu ◽

Shufang Wu

Keyword(s):

Estrogen Receptor ◽

Growth Plate ◽

Bone Growth ◽

Nuclear Factor Κb ◽

Binding Activity ◽

Skeletal Maturation ◽

Chondrocyte Apoptosis ◽

Chondrocyte Proliferation ◽

Longitudinal Bone Growth ◽

Growth Plate Chondrocyte

Abstract Dehydroepiandrosterone (DHEA) is produced by the adrenal cortex and is the most abundant steroid in humans. Although in some physiological and pathological conditions the increased secretion of DHEA and its sulfated form is associated with accelerated growth rate and skeletal maturation, it is unclear whether DHEA can affect longitudinal bone growth and skeletal maturation by acting directly at the growth plate. In our study, DHEA suppressed metatarsal growth, growth plate chondrocyte proliferation, and hypertrophy/differentiation. In addition, DHEA increased the number of apoptotic chondrocytes in the growth plate. In cultured chondrocytes, DHEA reduced chondrocyte proliferation and induced apoptosis. The DHEA-induced inhibition of metatarsal growth and growth plate chondrocyte proliferation and hypertrophy/differentiation was nullified by culturing metatarsals with DHEA in the presence of ICI 182,780, an inhibitor of estrogen receptor, but not in the presence of Casodex, an inhibitor of androgen receptor. Lastly, nuclear factor-κB DNA binding activity was inhibited by the addition of DHEA in the medium of cultured chondrocyte. Our findings indicate that DHEA suppressed bone growth by acting directly at growth plate through estrogen receptor. Such growth inhibition is mediated by decreased chondrocyte proliferation and hypertrophy/differentiation and by increased chondrocyte apoptosis.

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