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Klotho preservation via histone deacetylase inhibition attenuates chronic kidney disease-associated bone injury in mice

View Article: PubMed Central - PubMed

ABSTRACT

Bone loss and increased fracture are the devastating outcomes of chronic kidney disease-mineral and bone disorder (CKD-MBD) resulting from Klotho deficit-related mineral disturbance and hyperparathyroidism. Because Klotho down-regulation after renal injury is presumably affected by aberrant histone deacetylase (HDAC) activities, here we assess whether HDAC inhibition prevents Klotho loss and attenuates the CKD-associated bone complication in a mouse model of CKD-MBD. Mice fed adenine-containing diet developed the expected renal damage, a substantial Klotho loss and the deregulated key factors causally affecting bone remodeling, which were accompanied by a marked reduction of bone mineral density. Intriguingly, administration of a potent HDAC inhibitor trichostatin A (TSA) impressively alleviated the Klotho deficit and the observed alterations of serum, kidney and bone. TSA prevented Klotho loss by increasing the promoter-associated histone acetylation, therefore increasing Klotho transcription. More importantly the mice lacking Klotho by siRNA interference largely abolished the TSA protections against the serum and renal abnormalities, and the deranged bone micro-architectures. Thus, our study identified Klotho loss as a key event linking HDAC deregulation to the renal and bone injuries in CKD-MBD mice and demonstrated the therapeutic potentials of endogenous Klotho restoration by HDAC inhibition in treating CKD and the associated extrarenal complications.

No MeSH data available.


Related in: MedlinePlus

Klotho is essential for the bone protection by HDAC inhibition.(A) Representative H&E staining of mouse distal femur sections from siRNA-control or siRNA-Klotho-injected control, TSA, adenine and TSA-treated adenine mice (6 weeks, n = 6 in each group). (B) Average bone mRNA levels of Runx2 and Spp1 examined by qRT-PCR (n = 6). (C) Representative micro-CT 3D images of trabecular architectures of the distal femurs from mice as in Fig. 6A. (D) Quantitative analyses of the ratio of bone volume to tissue volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) from micro-CT examinations (n = 6). Data are presented as the mean ± SD. *P < 0.05, **P < 0.01 versus control, #P < 0.05, ##P < 0.01 versus adenine treatment in siR-control mice; ΔP < 0.05, ΔΔP < 0.01 versus control in siR-Klotho mice.
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f6: Klotho is essential for the bone protection by HDAC inhibition.(A) Representative H&E staining of mouse distal femur sections from siRNA-control or siRNA-Klotho-injected control, TSA, adenine and TSA-treated adenine mice (6 weeks, n = 6 in each group). (B) Average bone mRNA levels of Runx2 and Spp1 examined by qRT-PCR (n = 6). (C) Representative micro-CT 3D images of trabecular architectures of the distal femurs from mice as in Fig. 6A. (D) Quantitative analyses of the ratio of bone volume to tissue volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) from micro-CT examinations (n = 6). Data are presented as the mean ± SD. *P < 0.05, **P < 0.01 versus control, #P < 0.05, ##P < 0.01 versus adenine treatment in siR-control mice; ΔP < 0.05, ΔΔP < 0.01 versus control in siR-Klotho mice.

Mentions: We further examined the distal femur by H&E staining and found that TSA treatment reduced the thinner and deranged trabeculae and the enlarged bone marrow cavity in siRNA control-injected adenine mice, but lack of Klotho by siRNA interference largely eliminated the protective effects (Fig. 6A). In addition, TSA attenuation of decreased Runx2 and Spp1 was also diminished in siRNA-Klotho mice (Fig. 6B). To better quantitatively determine the changes of bone structures, we examined the femur micro-architectures by micro-CT (computed tomography) 3D analysis. The results showed that adenine mice displayed the typical osteoporotic changes such as less trabecular bone volume versus tissue volume (BV/TV), reduced trabecular bone number (Tb.N) and trabecular thickness (Tb,Th), and increased trabecular bone separation (Tb.Sp) (comparing column 1 and 3 in Fig. 6C and lane 1/4 and 3/7 in Fig. 6D) in siRNA control-injected mice, whereas TSA treatment significantly inhibited these alterations (comparing column/lane 4 and 3 upper panel in Fig. 6C and D). However the protective effects were largely abolished in siRNA-Klotho-injected mice (comparing column 4 and 3 lower panel in Fig. 6C and lane 8 and 7 in Fig. 6D). Altogether these results strongly indicate that Klotho plays a critical role in the bone protection by HDAC inhibition in CKD-MBD mice.


Klotho preservation via histone deacetylase inhibition attenuates chronic kidney disease-associated bone injury in mice
Klotho is essential for the bone protection by HDAC inhibition.(A) Representative H&E staining of mouse distal femur sections from siRNA-control or siRNA-Klotho-injected control, TSA, adenine and TSA-treated adenine mice (6 weeks, n = 6 in each group). (B) Average bone mRNA levels of Runx2 and Spp1 examined by qRT-PCR (n = 6). (C) Representative micro-CT 3D images of trabecular architectures of the distal femurs from mice as in Fig. 6A. (D) Quantitative analyses of the ratio of bone volume to tissue volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) from micro-CT examinations (n = 6). Data are presented as the mean ± SD. *P < 0.05, **P < 0.01 versus control, #P < 0.05, ##P < 0.01 versus adenine treatment in siR-control mice; ΔP < 0.05, ΔΔP < 0.01 versus control in siR-Klotho mice.
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f6: Klotho is essential for the bone protection by HDAC inhibition.(A) Representative H&E staining of mouse distal femur sections from siRNA-control or siRNA-Klotho-injected control, TSA, adenine and TSA-treated adenine mice (6 weeks, n = 6 in each group). (B) Average bone mRNA levels of Runx2 and Spp1 examined by qRT-PCR (n = 6). (C) Representative micro-CT 3D images of trabecular architectures of the distal femurs from mice as in Fig. 6A. (D) Quantitative analyses of the ratio of bone volume to tissue volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) from micro-CT examinations (n = 6). Data are presented as the mean ± SD. *P < 0.05, **P < 0.01 versus control, #P < 0.05, ##P < 0.01 versus adenine treatment in siR-control mice; ΔP < 0.05, ΔΔP < 0.01 versus control in siR-Klotho mice.
Mentions: We further examined the distal femur by H&E staining and found that TSA treatment reduced the thinner and deranged trabeculae and the enlarged bone marrow cavity in siRNA control-injected adenine mice, but lack of Klotho by siRNA interference largely eliminated the protective effects (Fig. 6A). In addition, TSA attenuation of decreased Runx2 and Spp1 was also diminished in siRNA-Klotho mice (Fig. 6B). To better quantitatively determine the changes of bone structures, we examined the femur micro-architectures by micro-CT (computed tomography) 3D analysis. The results showed that adenine mice displayed the typical osteoporotic changes such as less trabecular bone volume versus tissue volume (BV/TV), reduced trabecular bone number (Tb.N) and trabecular thickness (Tb,Th), and increased trabecular bone separation (Tb.Sp) (comparing column 1 and 3 in Fig. 6C and lane 1/4 and 3/7 in Fig. 6D) in siRNA control-injected mice, whereas TSA treatment significantly inhibited these alterations (comparing column/lane 4 and 3 upper panel in Fig. 6C and D). However the protective effects were largely abolished in siRNA-Klotho-injected mice (comparing column 4 and 3 lower panel in Fig. 6C and lane 8 and 7 in Fig. 6D). Altogether these results strongly indicate that Klotho plays a critical role in the bone protection by HDAC inhibition in CKD-MBD mice.

View Article: PubMed Central - PubMed

ABSTRACT

Bone loss and increased fracture are the devastating outcomes of chronic kidney disease-mineral and bone disorder (CKD-MBD) resulting from Klotho deficit-related mineral disturbance and hyperparathyroidism. Because Klotho down-regulation after renal injury is presumably affected by aberrant histone deacetylase (HDAC) activities, here we assess whether HDAC inhibition prevents Klotho loss and attenuates the CKD-associated bone complication in a mouse model of CKD-MBD. Mice fed adenine-containing diet developed the expected renal damage, a substantial Klotho loss and the deregulated key factors causally affecting bone remodeling, which were accompanied by a marked reduction of bone mineral density. Intriguingly, administration of a potent HDAC inhibitor trichostatin A (TSA) impressively alleviated the Klotho deficit and the observed alterations of serum, kidney and bone. TSA prevented Klotho loss by increasing the promoter-associated histone acetylation, therefore increasing Klotho transcription. More importantly the mice lacking Klotho by siRNA interference largely abolished the TSA protections against the serum and renal abnormalities, and the deranged bone micro-architectures. Thus, our study identified Klotho loss as a key event linking HDAC deregulation to the renal and bone injuries in CKD-MBD mice and demonstrated the therapeutic potentials of endogenous Klotho restoration by HDAC inhibition in treating CKD and the associated extrarenal complications.

No MeSH data available.


Related in: MedlinePlus