Stimulation of Piezo1 by mechanical signals promotes bone anabolism

  1. Xuehua Li
  2. Li Han
  3. Intawat Nookaew
  4. Erin Mannen
  5. Matthew J Silva
  6. Maria Almeida
  7. Jinhu Xiong  Is a corresponding author
  1. University of Arkansas for Medical Sciences, United States
  2. Washington University, United States
6 figures, 1 table and 2 additional files

Figures

Figure 1 with 2 supplements
Piezo1 mediates mechanotransduction in an osteocyte cell line.

(A) mRNA levels of calcium channels regulated by fluid shear stress in MLO-Y4 cells determined by RNA-seq (here and throughout, values are the mean ± s.d.). (B) qPCR of Piezo1 and Piezo2 mRNA in MLO-Y4 cells cultured under static or fluid shear stress conditions for 2 hr. *p<0.05 versus static, using Student’s t-test. (C) Piezo1 and Piezo2 mRNA levels in cortical bone of 3-month-old wildtype C57BL/6J mice. (D) Intracellular calcium concentration measured in control or Piezo1 knock-down MLO-Y4 cells before and after the start of fluid flow. Arrow indicates the time when fluid flow starts. (E) qPCR of Piezo1, Ptgs2, and Tnfrsf11b in control or Piezo1 knock-down MLO-Y4 cells cultured under static or fluid shear stress conditions for 2 hr. n = 3 per group. (F) qPCR of Piezo1, Ptgs2, and Tnfrsf11b in control or Piezo1 overexpressed MLO-Y4 cells cultured under static or fluid shear stress conditions for 2 hr. n = 3 per group. *p<0.05 with the comparisons indicated by the brackets using 2-way ANOVA. Gray indicates the static condition and teal indicates fluid shear stress.

https://doi.org/10.7554/eLife.49631.003
Figure 1—figure supplement 1
Sequencing analysis of mRNA isolated from MLO-Y4 cells cultured under static or fluid shear stress conditions.

(A) PCA analysis of RNAseq. (B) Volcano plot of differentially expressed transcripts in MLO-Y4 cells cultured under fluid shear stress (FF) versus static (ST) conditions.

https://doi.org/10.7554/eLife.49631.004
Figure 1—figure supplement 2
Sequencing analysis of mRNA isolated from MLO-Y4 cells cultured under static or fluid shear stress conditions.

(A) GO-enrichment analysis of genes isloated from MLO-Y4 cells cultured under fluid shear stress (FF) and static (ST) conditions. (B) Calcium channels expressed in MLO-Y4 cells.

https://doi.org/10.7554/eLife.49631.005
Figure 2 with 3 supplements
Loss of Piezo1 in osteoblasts and osteocytes decreases bone formation and bone mass.

(A) qPCR of loxP-flanked Piezo1 genomic DNA isolated from tibial cortical bone of Dmp1-Cre;Piezo1f/f (n = 6) and Piezo1f/f (n = 6) littermates. *p<0.05 using Student’s t-test. (B) Serial BMD of female Dmp1-Cre;Piezo1f/f mice and their littermate controls at 5, 8, and 12 weeks of age. *p<0.05 using 2-way ANOVA at a given age. (C) X-ray images of tibia from 12-week-old Dmp1-Cre;Piezo1f/f and Piezo1f/f littermate. Arrowhead indicates the location of fracture. (D, E) Representative µCT images (scale bar, 0.1 mm) (D) and cortical thickness, periosteal circumference, and endocortical circumference analysis (E) of the femoral diaphysis in Dmp1-Cre;Piezo1f/f (n = 9) and Piezo1f/f (n = 9) littermates. (F) Cortical thickness measured in the 4th lumbar vertebra of 12-week-old female Dmp1-Cre;Piezo1f/f (n = 9) and Piezo1f/f (n = 9) littermates. (G) Bone volume per tissue volume (BV/TV) measured in the femur and the L4 vertebra of 12-week-old female Dmp1-Cre;Piezo1f/f (n = 9) and Piezo1f/f (n = 7) mice. (H) Representative µCT images of the distal femur. Scale bar, 1 mm. (I) Stiffness, ultimate force, Young’s modulus, and ultimate stress measured in the femurs of Dmp1-Cre;Piezo1f/f (n = 9) and Piezo1f/f (n = 9) littermates. (J) Tissue mineral density measured in cortical bone in femoral diaphysis of Dmp1-Cre;Piezo1f/f (n = 9) and Piezo1f/f (n = 9) littermates. (K) Representative histological cross sections (left, yellow dotted line indicates periosteal surface and white dotted line indicates endocortical surface; scale bar = 100 µm) and quantification of mineralizing surface in periosteal and endocortical surface (right) at the femoral diaphysis of 5-week-old female Dmp1-Cre;Piezo1f/f (n = 7) and Piezo1f/f (n = 5) littermates. (L, M) Mineralizing surface per bone surface (MS/BS), mineral apposition rate (MAR), and bone formation rate per bone surface (BFR/BS) (L), Osteoblast number (N.Ob/B.Pm), and osteoclast number (N.Oc/B.Pm) (M) measured in cancellous bone of lumbar vertebra 1–3 from 12-week-old female Dmp1-Cre;Piezo1f/f (n = 5) and Piezo1f/f (n = 5) littermates. *p<0.05 using Student’s t-test.

https://doi.org/10.7554/eLife.49631.006
Figure 2—figure supplement 1
Loss of Piezo1 in osteoblasts and osteocytes decreases bone mass.

(A) Body weight of female and male Dmp1-Cre;Piezo1f/f (n = 9 f, 8 m) and Piezo1f/f (n = 9 f, 9 m) mice at 12 weeks of age. (B) Femoral, spinal, and total body bone mineral density of male mice of indicated genotypes at 5, 8, and 12 weeks of age. (C) Femoral cortical thickness of 12-week-old male Dmp1-Cre;Piezo1f/f (n = 8) and Piezo1f/f mice (n = 9). (D) Total cross sectional area, cortical bone area, medullary area in the midshaft of femur in 12-week-old female Dmp1-Cre;Piezo1f/f (n = 5) and Piezo1f/f (n = 5) mice. (E) Femur length of 12-week-old female and male Dmp1-Cre;Piezo1f/f (n = 9 f, 8 m) and Piezo1f/f (n = 9 f, 9 m) mice. *p<0.05 using 2-way ANOVA. (F) Vertebral cortical thickness of 12-week-old male Dmp1-Cre;Piezo1f/f (n = 8) and Piezo1f/f (n = 9) mice. (G,H) Trabecular number (Tb. N), trabecular thickness (Tb. Th), and trabecular separation (Tb. Sp) measured in the femur (G) and the L4 vertebra (H) of 12-week-old female Dmp1-Cre;Piezo1f/f (n = 9) and Piezo1f/f (n = 9) mice. (I,J) Bone volume per tissue volume (BV/TV), trabecular number, trabecular thickness, and trabecular separation measured in the femur (I) and the L4 vertebra (J) of 12-week-old male Dmp1-Cre;Piezo1f/f (n = 8) and Piezo1f/f (n = 9) mice. *p<0.05 using Student’s t-test.

https://doi.org/10.7554/eLife.49631.007
Figure 2—figure supplement 2
Deletion of Piezo1 in osteoblasts and osteocytes decreases cortical bone.

(A) Representative images of cross sections of femoral diaphysis from 5-week-old Dmp1-Cre;Piezo1f/f and Piezo1f/f mice. (B,C) Empty lacunae (B) and osteocyte number (C) measured in the longitudinal section of L1-3 vertebrae in 12-week-old female Dmp1-Cre;Piezo1f/f (n = 5) and Piezo1f/f (n = 5) mice. (D) Representative histological images of osteocytes in vertebral cortical and cancellous bone of 12-week-old female Dmp1-Cre;Piezo1f/f and Piezo1f/f mice. (C) Caspase three activity measured in Piezo1 knock-down MLO-Y4 and control cells. (D) Alizarin Red staining of bone marrow stromal cells isolated from 5-week-old female Dmp1-Cre;Piezo1f/f (n = 3) and Piezo1f/f (n = 3) mice and cultured for 21 days in osteoblast differentiation medium (n = 3 wells/group).

https://doi.org/10.7554/eLife.49631.008
Figure 2—figure supplement 3
Deletion of Piezo1 from Dmp1-Cre-targeted cells does not affect muscle mass.

(A) Abundance of Piezo1 genomic DNA measured by qRT-PCR in gastrocnemius of Dmp1-Cre;Piezo1f/f and Piezo1f/f mice. (B) Piezo1 mRNA in tibia and gastrocnemius muscle in male wild type mice (n = 5). (C,D) Lean body weight (C) and gastrocnemius muscle mass (D) measured in 12-week-old Dmp1-Cre;Piezo1f/f (n = 9 f, 8 m) and Piezo1f/f (n = 9 f, 9 m) mice. *p<0.05 using Student’s t-test.

https://doi.org/10.7554/eLife.49631.009
Loss of Piezo1 in osteoblasts and osteocytes blunts the skeletal response to mechanical loads.

(A) Schematic illustration of anabolic loading on mouse tibia. (B) Cortical thickness (Ct.Th) in the tibial shaft of 4-month-old loaded or control Dmp1-Cre;Piezo1f/f (n = 5) and Piezo1f/f (n = 7) littermates. (C) Mineralizing surface (MS/BS), mineral apposition rate (MAR), and bone formation rate (BFR/BS) in periosteal surface of the tibia of 4-month-old female Dmp1-Cre;Piezo1f/f (n = 5) and Piezo1f/f (n = 7) littermates. (D) Representative histological cross section images of the tibial shaft of 4-month-old female Dmp1-Cre;Piezo1f/f and Piezo1f/f littermates. Scale bar, 100 µm. *p<0.05 with the comparisons indicated by the brackets using 2-way ANOVA.

https://doi.org/10.7554/eLife.49631.010
Figure 4 with 2 supplements
Piezo1 controls Wnt1 expression via YAP1 and TAZ.

(A) qPCR of Wnt1 mRNA in tibial cortical bone of 5-week-old female Piezo1f/f (n = 6) and Dmp1-Cre;Piezo1f/f mice (n = 6). *p<0.05 using Student’s t-test. (B) Relative mRNA levels of Wnt1, Sost, Tnfsf11 (RANKL), and Tnfrsf11b (OPG) in tibia cortical bone of 12-week-old female Piezo1f/f (n = 9) and Dmp1-Cre;Piezo1f/f (n = 9) mice. *p<0.05 using Student’s t-test. (C) Wnt1 and Cyr61 mRNA levels in control or Piezo1 knock-down MLO-Y4 cells cultured under static or fluid shear stress conditions. *p<0.05 with the comparisons indicated by the brackets using 2-way ANOVA. (D) Ptgs2, Wnt1, and Cyr61 mRNA levels in control or Yap1/Taz knock-down MLO-Y4 cells cultured under static or fluid shear stress conditions. *p<0.05 with the comparisons indicated by the brackets using 2-way ANOVA. (E) YAP1 immunofluorescence in control or Piezo1 knock-down MLO-Y4 cells cultured under static or fluid shear stress conditions. Scale bar, 100 µm. (F) Quantification of mean fluorescence intensity in nucleus versus cytoplasm in the cells described in (E). (G) Wnt1 and Cyr61 mRNA levels measured in tibia of female Dmp1-Cre;Piezo1f/f (n = 8) and Piezo1f/f (n = 7) mice loaded with one bout of compressive loading. Mice were harvested 5 hr after loading. *p<0.05 with the comparisons indicated by the brackets using 2-way ANOVA.

https://doi.org/10.7554/eLife.49631.011
Figure 4—figure supplement 1
Loss of YAP1 and TAZ in osteoblasts and osteocytes decreases cortical bone.

(A) Cortical thickness (left), periosteal circumference (middle), and endocortical circumference (right) at the femoral diaphysis of Dmp1-Cre;Yap1f/f,Tazf/f (n = 10) and Yap1f/f,Tazf/f (n = 12) littermates. (B) mRNA of Piezo1 in control and Piezo1 knock-down MLO-Y4 cells. (C) mRNA levels of Yap1 and Taz in control and Yap1/Taz knock-down MLO-Y4 cells. *p<0.05 using Student’s t-test.

https://doi.org/10.7554/eLife.49631.012
Figure 4—figure supplement 2
Deletion of Piezo1 in osteoblastic cells blunts their response to fluid flow.

qRT-PCR of Piezo1, Ptgs2, Wnt1, and Cyr61 in control (Cas9) and Piezo1 knockout (Cas9 + Piezo1 sgRNAs) UAMS-32 cells cultured under static and fluid flow conditions. *p<0.05 using 2-way ANOVA. Osteoblastic UAMS-32 cells were transfected with Cas9 or Cas9 with two sgRNAs targeting introns 3 and 4 of the Piezo1 gene. Single Cells were then flow-sorted into 96-well plates for screening. Cells with homologous deletion of the exon 4 of Piezo1 were pooled together for analysis.

https://doi.org/10.7554/eLife.49631.013
Figure 5 with 1 supplement
Activation of Piezo1 mimics the effects of mechanical stimulation on osteocytes.

(A) Intracellular calcium concentration measured in control or Piezo1 knock-down MLO-Y4 cells immediately after the treatment of DMSO or 10 µM Yoda1. (B) qPCR of Ptgs2, Wnt1, and Tnfrsf11b in control or Piezo1 knock-down MLO-Y4 cells treated with DMSO or 10 µM Yoda1 for 2 hr. n = 3 per group. *p<0.05 versus vehicle treated controls of the same genotype by 2-way ANOVA. (C) qPCR of Ptgs2, Wnt1, and Tnfrsf11b in control or Yap1/Taz knock-down MLO-Y4 cells treated with DMSO or 10 µM Yoda1 for 2 hr. n = 3 per group. *p<0.05 versus vehicle treated controls of the same genotype by 2-way ANOVA. (D) qPCR of Ptgs2, Wnt1, Tnfrsf11b, Cyr61, and Sost in ex vivo cultured femoral cortical bone from 5-week-old mice treated with DMSO or 10 µM Yoda1 for 4 hr. n = 3 per group. (E) qPCR of Wnt1 in tibia of C57BL/6J mice treated with Veh or Yoda1 for 4 hr. n = 12 per group. (F) Schedule of in vivo Yoda1 administration. (G, H) Cortical thickness and cancellous BV/TV in distal femur (G) and the 4th lumbar (H) of 4-month-old vehicle or Yoda1 treated female C57BL/6J mice (n = 12 per group). (I) Circulating osteocalcin levels in the serum of 4-month-old vehicle or Yoda1 treated female C57BL/6J mice (n = 12 per group). *p<0.05 versus vehicle treated controls by Student’s t-test.

https://doi.org/10.7554/eLife.49631.014
Figure 5—figure supplement 1
Yoda1 does not affect body weight and serum bone resorption marker.

(A) Body weight of C57BL/6J mice before and after 2 weeks of vehicle or Yoda1 administration (n = 12 mice per group). (B) Serum CTX measured by ELISA in mice as described in (A).

https://doi.org/10.7554/eLife.49631.015
Author response image 1
Gene expression analysis of Piezo1-deficient cells.

(A) RT-qPCR analysis of Sost, Dkk1, Wnt1, Wnt7b, Bmp2, and Tgfb1 in tibia cortical bone of12-week-old female Piezo1f/f (n = 9) and Dmp1-Cre;Piezo1f/f (n = 9) mice. *p < 0.05 using Student’s t-test. (B) Wnt1, Dkk1, and Tgfb1 mRNA levels in control or Piezo1 knock-down MLO-Y4 cells cultured under static or fluid shear stress conditions. *p < 0.05 with the comparisons indicated by the brackets using 2-way ANOVA.

Tables

Key resources table
Reagent type
(species) or resource
DesignationSource or
reference
IdentifiersAdditional
information
Genetic reagent (M. musculus)Mouse: Piezo1f/f(Piezo1tm2.1Apat/J)Jackson LaboratoriesJAX: 029213; RRID:IMSR_JAX:029213
Genetic reagent (M. musculus)Mouse: Dmp1-CreBivi et al., 2012N/A
Genetic reagent (M. musculus)Mouse: Yap1f/f;Tazf/fXin et al., 2013N/A
Genetic reagent (M. musculus)Mouse: WT C57BL/6JJackson LaboratoriesJAX: 000664; RRID:IMSR_JAX:000664
Commercial assay or kitMouse Osteocalcin Immunoassay KitThermo FisherCat# J64239
Commercial assay or kitFluo-8 Calcium Flux Assay KitAbcamCat# ab112129
Commercial assay or kitRatLaps (CTX-I) EIA kitImmunodiagnostic SystemsCat# AC-06F1
Commercial assay or kitTruSeq stranded mRNA kitIlluminaCat# 20020594
Commercial assay or kitHigh-capacity cDNA reverse transcription kitLife TechnologiesCat# 4368813
Commercial assay or kitRNeasy mini kitQIAGENCat# 74106
Cell line (Murine)293TATCCCRL-3216
Cell line (Murine)MLO-Y4Kato et al., 1997
Cell line(Murine)UAMS-32O'Brien et al., 1999Cell line maintained in Charles O’Brien lab
Transfected construct (M. musculus)Piezo1 shRNA forwardZhang et al., 2017OligoCCGGTCGGCGCTTGCTAGAACTTCACTCGAGTGAAGTTCTAGCAAGCGCCGATTTTTG
Transfected construct (M. musculus)Piezo1 shRNA reverseZhang et al., 2017OligoAATTCAAAAATCGGCGCTTGCTAGAACTTCACTCGAGTGAAGTTCTAGCAAGCGCCGA
Transfected construct (M. musculus)Yap1 shRNASigma-AldrichTRCN0000238432
Transfected construct (M. musculus)Taz shRNASigma-AldrichTRCN0000095951
Sequenced-based reagentPiezo1Life TechnologiesMm01241549_m1
Sequenced-based reagentPiezo2Life TechnologiesMm01265861_m1
Sequenced-based reagentPtgs2Life TechnologiesMm00478374_m1
Sequenced-based reagentCyr61Life TechnologiesMm00487498_m1
Sequenced-based reagentWnt1Life TechnologiesMm01300555_g1
Sequenced-based reagentYap1Life TechnologiesMm01143263_m1
Sequence-based reagentTazLife TechnologiesMm01289583_m1
Sequence-based reagentTnfsf11Life TechnologiesMm00441906_m1
Sequence-based reagentTnfrsf11bLife TechnologiesMm00435452_m1
Sequence-based reagentSostLife TechnologiesMm00470479_m1
Sequence-based reagentMrps2Life TechnologiesMm00475529_m1
Sequence-based reagentPiezo1 sgRNAThis paperGGTTATTCCTGTGAGGCCCG
Sequence-based reagentPiezo1 sgRNAThis paperTTAGGATTCGGCTCACAGAG
Chemical compound, drugYoda1Sigma-AldrichCat# SML1558
Chemical compound, drugPuromycin dihydrochlorideSigma-AldrichCat# P8833
Chemical compound, drugG418 disulfateSigma-AldrichCat# G8168
AntibodyYAP1Cell SignalingCat# 14074S; RRID:AB_26504911:200
AntibodyGoat anti-Rabbit IgG (Alexa Fluor 488)AbcamCat# ab150077; RRID:AB_26303561:200
Software, algorithmPrism 8GraphPadhttps://www.graphpad.com/scientific-software/prism/
Software, algorithmImageJNIHhttps://imagej.nih.gov/ij

Additional files

Supplementary file 1

RNAseq analysis of MLO-Y4 cells cultured under fluid shear stress (FF) and static (ST) conditions.

https://doi.org/10.7554/eLife.49631.016
Transparent reporting form
https://doi.org/10.7554/eLife.49631.017

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  1. Xuehua Li
  2. Li Han
  3. Intawat Nookaew
  4. Erin Mannen
  5. Matthew J Silva
  6. Maria Almeida
  7. Jinhu Xiong
(2019)
Stimulation of Piezo1 by mechanical signals promotes bone anabolism
eLife 8:e49631.
https://doi.org/10.7554/eLife.49631