Friday, April 30, 2010

Osteoclasts Increase Height?

Intuitively, one would think that osteoclasts(bone breakers) would be bad for height increase.  Osteoblasts build up bone and osteoclasts tear down bone.  But, do osteoclasts play a vital role in the height increase process and if so how can we use this in our own grow taller methodology? 

Alendronate affects long bone length and growth plate morphology in the oim mouse model for Osteogenesis Imperfecta. 

"Alendronate, a bisphosphonate drug, has shown promise in reducing remodeling and bone loss in postmenopausal osteoporosis. Alendronate acts directly on the osteoclast, inhibiting its resorption capability. This inhibition of osteoclast activity has led to the use of bisphosphonates in the treatment of the osteogenesis imperfecta condition. Treatment of osteogenesis imperfecta[Osteogenesis imperfecta is a disease where there are brittle bones that fracture easily] with bisphosphonates[which inhibit osteoclasts] enhances bone strength, but the consequences on linear bone growth are not well defined. Using the oim mouse model for type III osteogenesis imperfecta, two doses of alendronate, low (0.125 mg/kg/wk) and high (2.5 mg/kg/wk) were administered weekly via intraperitoneal injection starting at 4 weeks of age and ending at 12 weeks of age to assess the effects of alendronate on humerus and ulna length. The higher dose of alendronate reduced humerus and ulna length in the oim/wt and wt/wt genotypes for both sexes (P < 0.05). The oim/oim humerus and ulna were not significantly affected by the higher dose of alendronate in females, but reduced bone length in males (P < 0.0085). Proximal humerus growth plate area was affected by both genotype and alendronate dose and growth plate diameter was increased at the chondro-osseous junction by both alendronate doses (P < 0.011). Genotype and alendronate dose affected growth plate height. The oim/oim genotype displayed taller growth plates. The high dosage of alendronate increased overall growth plate height, particularly within the hypertrophic zone, which suggests a failure of vascular invasion-induced apoptosis in the hypertrophic cells. In conclusion, these results indicate that high doses of alendronate (>2.5 mg/kg/wk) inhibit long bone length in mice through alteration of the growth plate and possibly reduced resorption at the chondro-osseous junction." 

"Although the mechanism of long bone growth relies upon clonal expansion and subsequent hypertrophy of chondrocytes, endochondral bone growth absolutely requires that chondroclasts resorb the septa of calcified cartilage at the chondro-osseous junction of the growth plate, permitting vascular invasion of the hypertrophic cell lacunae. Inhibition of the resorption impedes the elongation process. In addition, osteoclasts must participate in the ultimate replacement of calcified cartilage by remodeling the metaphyseal primary spongiosa to create a mechanically sound metaphyseal architecture. If a bisphosphonate used to treat OI in children inhibits the function of osteoclasts and chondroclasts, the result could significantly exacerbate the tendency of OI to interfere with the patient’s normal growth and bone development."

"The low dose of alendronate did have a significant effect on the length of the humerus in males"

So it's not a matter of that total inhibition of osteoclasts is bad for height growth.  An incomplete inhibition of osteoclasts can be bad for height growth.  

"Alendronate interferes with osteoclast action by interrupting the prenylation of small guanidine triphosphate-associated proteins involved in the intracellular signaling pathway that modulates osteoclast structural proteins. The osteoclast then becomes unable to attach to bone matrix and loses its resorbing ability. The septoclast (chondroclast) operates in the same manner as the osteoclast, and only differs in the types of hydrolytic enzymes secreted and its location within the growing bone. Thus, it is reasonable to believe that alendronate acts via a similar antiprenylation pathway in this cell. Inhibition of septoclastic resorption would obstruct vascular invasion and reduce chondrocyte apoptosis at the base of the growth plate, leading to an increase in growth plate area and height and diminished bone length. This mechanism would be consistent with the qualitative observation in this study that alendronate treatment diminished removal of cartilagenous cores in the primary spongiosa; persistent calcified cartilage within primary spongiosa as a consequence of alendronate treatment."

Alternatively, Alendronate may inhibit height by a non-osteoclast related mechanism...
"Furthermore, prenylation of guanidine triphosphate-associated proteins (such as Ras, Rac, and Rho) is involved in the intracellular regulation of growth factors controlling growth plate function and alendronate may affect growth via this pathway. For example, inhibition of prenylation may disrupt cell progression within the growth plate by disrupting the ability of terminal hypertrophic chondrocytes to respond to hormones and signaling molecules. This too would be consistent with the experimental observations of reduced bone length, increased overall growth plate height, increased height of the hypertrophic zone, and obvious derangement of the growth plate and adjacent metaphyseal bone."

The apoptosis of hypertrophic cells is a critical part of endochondral ossification(long bone growth).  In the zone of calcification in the growth plate dead cartilage cells are consumed by bone-forming cells.  Alendronate, a biophosphate actually increased the growth plate height, but did not result in an increase in the length of the bone.  Osteoclasts are a critical part of growth plate remodeling which is vital for height growth.  Epiphyseal distraction was a method tried by scientists to increase height and reduce limb length discrepancies which although increased growth rate ultimately failed to improve final adult stature.  Showing that longer growth plates does not necessarily lead to increased final adult height.

A single nucleotide polymorphism on exon-4 of the gene encoding PPARdelta is associated with reduced height in adults and children. 

"CONTEXT: Peroxisome proliferator-activated receptor (PPAR)-delta is a nuclear transcription factor that plays a key role in many metabolic processes, including energy metabolism, and lipid and glucose metabolism. Candidate gene studies have identified a putative functional variant, rs2016520, in the gene encoding PPARdelta (PPARD), which is associated in some studies with metabolic traits. In addition, this single-nucleotide polymorphism was associated with adult height in several whole-genome scans, but this association did not achieve whole genome significance. OBJECTIVE: This study sought to determine whether PPARD variation influenced height. DESIGN: Haplotype tagging analysis across PPARD was performed in about 11,000 individuals from the Wellcome Trust U.K. Type 2 Diabetes Case Control Collection (Go-DARTS2). RESULTS: There was an association between rs2016520 and height in both patients with type 2 diabetes and controls without diabetes (combined P = 5 x 10(-5)). In a metaanalysis using published data from Caucasian cohorts totaling more than 38,000 participants, compelling evidence was found for this locus and its association with height (P = 10(-8)) with an overall effect size of about 0.5 cm per allele. A similar analysis in a group of 2700 prepubescent children also displayed a similar effect size to that seen in the adults. CONCLUSION: PPARD variation is clearly associated with a phenotype of reduced stature in both adults and children. Because height is an important indicator of metabolic and nutritional status, this provides additional support for a key role for PPARdelta in critical metabolic functions. PPARdelta may affect height through a variety of mechanisms including altered metabolic efficiency or effects on osteoclast function." 

Proper osteoclast function seems to be necessary for achieving maximum adult stature but it doesn't seem like improving osteoclast function would take you past that stature. 

"With this in mind, it has been shown that PPAR{delta} activation modulates cholesterol uptake from the gut[cholesterol is important for height growth so lack of cholesterol uptake may stunt growth]. Other evidence suggests that PPAR{delta} may exert a direct effect on the control of bone growth in the early rapid growth phase shown by young children because it has been demonstrated that activation of PPAR{delta} by agonists promotes bone remodeling by osteoclasts" 

PPAR delta stimulates osteoclasts without that stimulation height growth is reduced.

Deficiency of insulin receptor substrate-1 impairs skeletal growth through early closure of epiphyseal cartilage. 

"Morphological analyses in and around the epiphyseal cartilage of mice deficient in insulin receptor substrate-1 (IRS-1) showed IRS-1 signaling to be important for skeletal growth by preventing early closure of the epiphyseal cartilage and maintaining the subsequent bone turnover at the primary spongiosa[Bone Turnover including osteoclasts is important]. Introduction: IRS-1 is an essential molecule for intracellular signaling by IGF-I and insulin, both of which are potent anabolic regulators of cartilage and bone metabolism. To clarify the role of IRS-1 signaling in the skeletal growth, morphological analyses were performed in and around the epiphyseal cartilage of mice deficient in IRS-1 (IRS-1(-/-)), whose limbs and trunk were 20-30% shorter than wildtype (WT) mice. MATERIALS AND METHODS: The epiphyseal cartilage and the primary spongiosa at proximal tibias of homozygous IRS-1(-/-) and WT male littermates were compared using histological, immunohistochemical, enzyme cytohistochemical, ultrastructural, and bone histomorphometrical analyses. RESULTS: In and around the WT epiphyseal cartilage, IRS-1 and insulin-like growth factor (IGF)-1 receptors were widely expressed, whereas IRS-2 was weakly localized in bone cells. Chronological observation revealed that height of the proliferative zone and the size of hypertrophic chondrocytes were decreased in WT mice as a function of age, and these decreases were accelerated in the IRS-1 (-/-) cartilage, whose findings at 12 weeks were similar to those of WT at 24 weeks. In the IRS-1(-/-) cartilage, proliferating chondrocytes with positive proliferating cell nuclear antigen (PCNA) or parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor immunostaining had almost disappeared by 12 weeks. Contrarily, TUNEL+ apoptotic cells were increased in the hypertrophic zone, at the bottom of which most of the chondrocytes were surrounded by the calcified matrix, suggesting the closure of the cartilage. In the primary spongiosa, bone volume, alkaline phosphatase (ALP)+ osteoblasts, TRACP+ osteoclasts[IRS-1 interacts with osteoclasts], and the osteopontin-positive cement line were markedly decreased. Bone histomorphometrical parameters for both bone formation and resorption were significantly lower in IRS-1(-/-) mice, indicating the suppression of bone turnover. CONCLUSION: The IRS-1(-/-) epiphyseal cartilage exhibited insufficient proliferation of chondrocytes, calcification of hypertrophic chondrocytes, acceleration of apoptosis, and early closure of the growth plate. Thus, the data strongly suggest that IRS-1 signaling is important for the skeletal growth by preventing early closure of the epiphyseal cartilage and by maintaining the subsequent bone turnover at the primary spongiosa." 

IRS-1 deficiency decreases height growth.  IRS-1 interacts with Osteoclasts.

"Regarding osteoclastic cells, because we previously reported that IRS-1 is not expressed in these cells, the downregulation of bone resorption markers is likely to be caused by the decrease in the supporting ability of osteoclastogenesis by osteoblasts through RANKL induction"

Role of tartrate-resistant acid phosphatase (TRAP) in long bone development.

"Tartrate resistant acid phosphatase (TRAP)[TRAP expression is connected to osteoclasts] was shown to be critical for skeleton development, and TRAP deficiency leads to a reduced resorptive activity during endochondral ossification resulting in an osteopetrotic phenotype and shortened long bones in adult mice. A proper longitudinal growth depends on a timely, well-coordinated vascularization and formation of the secondary ossification centre (SOC) of the long bones epiphysis. Our results demonstrate that TRAP is not essential for the formation of the epiphyseal vascular network. Therefore, in wild type (Wt) controls as well as TRAP deficient (TRAP-/-) mutants vascularised cartilage canals are present from postnatal day (P) five[so perhaps osteoclasts are not necessary for the formation of cartilage canals]. However, in the epiphysis of the TRAP-/- mice cartilage mineralization, formation of the marrow cavity and the SOC occur prematurely compared with the controls[so osteoclasts keep "growth plates" open longer]. In the mutant mice the entire growth plate is widened due to an expansion of the hypertrophic zone. This is not seen in younger animals but first detected at week (W) three and during further development. Moreover, an enhanced number of thickened trabeculae, indicative of the osteopetrotic phenotype, are observed in the metaphysis beginning with W three. Epiphyseal excavation was proposed as an important function of TRAP, and we examined whether TRAP deficiency affects this process. We therefore evaluated the marrow cavity volume (MCV) and the epiphyseal volume (EV) and computed the MCV to EV ratio (MCV/EV). We investigated developmental stages until W 12. Our results indicate that both epiphyseal excavation and establishment of the SOC are hardly impaired in the knockouts. Furthermore, no differences in the morphology of the epiphyseal bone trabeculae and remodelling of the articular cartilage layers are noted between Wt and TRAP-/- mice. We conclude that in long bones, TRAP is critical for the development of the growth plate and the metaphysis but apparently not for the epiphyseal vascularization, excavation, and establishment of the SOC. "

So osteoclasts may play a role in height growth other than cartilage canal formation.

"The canals erode the non-mineralized cartilage matrix and thus give blood vessels and bone-forming cells access to the epiphysis for the subsequent development of the SOC. Canal formation is governed by several matrix metalloproteinases (MMPs) and, most notably, membrane-bound type-1 matrix metalloproteinase (MT1-MMP = MMP 14) is critical for this process. As a result, MT1-MMP−/−mice reveal a vascular defect accompanied by delayed ossification"<-so MT1-MMP may help you grow taller.

"In mice lacking both MMP 9 and MMP 13 epiphyseal development is affected"<-So MMP9 and 13 help with height as well.

As does VEGF...

"the establishment of the epiphyseal vascular network is triggered by the vascular endothelial growth factor (VEGF), and VEGF deficiency causes a delayed vascularization and formation of the SOC"

"Tartrate-resistant acid phosphatase activity type 5 (TRAP or Acp5) is an iron-containing enzyme that is found in humans and murine species. It occurs in diverse tissues including bone and cartilage . TRAP is, at first, synthesized as a latent proenzyme with low activity, and proteolytic processing generates two subunits of about 16 and 20–23 kDa with enhanced enzymatic activity. The cysteine proteinase cathepsin K has been suggested to be responsible for the proteolytic activation of TRAP. TRAP is highly expressed in chondroclasts as well as osteoclasts"

"chondroclasts attack the mineralized cartilage matrix whereas osteoclasts participate in the resorption of the mineralized bone matrix. TRAP prompts the dephosphorylation of bone matrix phosphoproteins like osteopontin and bone sialoprotein and was originally shown to be important for a normal endochondral bone formation"

"In long bones, the excavation of the epiphysis is mainly achieved by chondro/osteoclasts that bind to the substrate via their ruffled border. They create a highly acidic milieu, enabling disintegration and finally resorption of the mineralized cartilage and bone matrix. We could show that in Wt controls and TRAP−/− mice chondro/osteoclasts were formed to the same extent throughout development, hence the absence of TRAP did not impair their genesis. Moreover, their differentiation is normal, even though several ultrastructural subdomains are altered, resulting in a moderately reduced lysosomal degradation of the mineral crystallites compared to Wt littermates. Apart from TRAP, chondro/osteoclasts secrete tartrate-sensitive lysosomal acid phosphatase (LAP) during the resorptive process[so osteoclasts secrete LAP to compensate for the loss of TRAP but LAP is less effective at increasing height]. LAP mutants show almost no bone abnormalities but in LAP/TRAP doubly deficient mice, bone malformations are severe, and long bones are distinctly shorter compared to the TRAP knockouts. Furthermore, in the double knockout mice a distinct enlargement of the liver and spleen has been observed whereas hepatosplenomegaly has never been noted in LAP- and TRAP single knockout mice. This suggests that in distinct tissues the two phosphatases are capable to complement for each other thereby maintaining lysosomal function. We could demonstrate that after examination of a long postnatal period, epiphyseal excavation and bone formation was hardly impaired in the femur of mice lacking TRAP. Furthermore, trabeculation and reorganization of the articular cartilage layers was not altered in the knockouts. Thus, our data collectively indicate that the absence of TRAP does not affect marrow cavity formation, bone morphology and formation of the articular cartilage, and we suggest that LAP largely compensates for the loss of TRAP."

So if there are instances where LAP is being used over TRAP it may cause a loss of height.

So, it's likely that the proper paired activity of osteoblasts and osteoclasts are needed for proper height growth.  Things like Alendronate disrupt that homeostasis reduce height growth.  Similar disruption of that homeostasis with excessive osteoclasts is not likely to increase height either.  An increase in both osteoblasts/osteoclasts simultaneously may increase height.

Osteoclasts promote the formation of hematopoietic stem cell niches in the bone marrow.

"Formation of the hematopoietic stem cell (HSC) niche in bone marrow (BM) is tightly associated with endochondral ossification[endochondral ossification is required to form stem cell niches within the bone marrow]. We used the oc/oc mouse, a mouse model with impaired endochondral ossification caused by a loss of osteoclast (OCL) activity, to investigate the role of osteoblasts (OBLs) and OCLs in the HSC niche formation. The absence of OCL activity resulted in a defective HSC niche associated with an increased proportion of mesenchymal progenitors but reduced osteoblastic differentiation, leading to impaired HSC homing to the BM[so without osteoclasts there are more MSCs but they don't go to bone marrow]. Restoration of OCL activity reversed the defect in HSC niche formation. Our data demonstrate that OBLs are required for establishing HSC niches and that osteoblastic development is induced by OCLs."

"Signaling through Jagged 1 (Jag-1) on OBLs and its receptor Notch on HSCs is involved in the expansion of the HSC pool, and signaling through stromal Angiopoietin 1 (Ang-1) and its receptor Tie-2 on HSCs is involved in maintaining HSC quiescence in the niche"

"OBLs and mesenchymal cells also express osteopontin (OPN), which is a negative regulator of HSC pool size that inhibits HSC proliferation, promotes HSC apoptosis, and affects the expression of Jag-1 and Ang-1 by stromal cells"<-Maybe inhibiting osteopontin will help you grow taller?

"Stromal-derived factor-1 (SDF-1), which is produced by mesenchymal cells and OBLs, is the major chemoattractant for many hematopoietic progenitors, including HSCs"<-maybe we can induce expression of SDF-1 to where we want the growth plate to be to grow taller in that specific area?

"Coupling factors such as insulin-like growth factor, basic fibroblast growth factor, TGF-β, bone morphogenetic proteins, and platelet-derived growth factor are released from the bone matrix during bone resorption and are known to induce bone formation, thereby coupling bone resorption and formation "<-Many of these factors are pro-chondrogenic.

"osteoclasts recruit osteoblasts to sites of bone remodelling by mobilizing chemotactic proteins from matrix and direct secretion of such proteins that attract osteoblast precursors. Thus, anti-resorptive agents, such as the cathepsin K inhibitor odanacatib, that dampen osteoclast function but not number may also preserve osteoblast recruitment by preserving the bone resorptive cell."

"Evidence exists that osteoclasts recruit osteoblasts to sites of bone remodelling by two distinct mechanisms. The first is mobilization and activation of bone-residing growth factors such as TGFβ and IGF-I. These proteins, in turn, target mesenchymal stem cells that are osteoblast precursors and recruit them to sites of remodelling where they undergo differentiation into mature bone-forming cells. The other mechanism whereby osteoclasts recruit osteoblasts is by direct secretion of chemotactic molecules independent of bone degradation. CTHRC1 has recently been identified as one such molecule. Thus osteoclasts promote bone formation by mobilizing matrix-residing growth factors and by direct secretion of molecules such as CTHCR1, both of which recruit osteoblast precursors."

Conclusion:  Height Increase Methods that involve suppressing osteoclast activity will not increase height.  Osteoclasts are an important part of the process of growing taller.  Ensuring proper function of insulin receptor substrate-1 and peroxisome profilerator-activated receptor in children can increase final adult stature.


  1. Hi...sorry to be a pain, but i have a lot of long did it take you to gain .5"? How would you know where the upper part of the femur begins? Is it ok if you perform lsjl on the lower end of the femur instead of the upper end? Are you measuring your self at the same times of the day? Also, what is your routine for the spine? Thanks for you time.

  2. I measure myself after the gym. No routine for the spine. I haven't seen any femur gains yet. I do both upper and lower parts of the femur as I'm still refining the technique.

  3. I am going to start the dumbbell version of LSJL soon.

    22 pound dumbbell on my ankles, 2 minutes per side, so 8 minutes per day.

    I don't think my growth plates have fused so this might boost the growth.

    I will measure my height increase by having my tibia and femur at a 90 degree angle and then measure the length from the floor to the top of my knee.

    Anything I should add to this?

  4. I'm starting to get bruises after I tap my ankles is this normal? How much pain do u feel doing this?

  5. Bruises don't matter. What matters is damage to tendons and ligaments which is minimal for the ankle. Your skin can turn totally black and you will heal just fine. I feel some pain. You are trying to cause microfractures in the trabecular bone to release those stem cells.

    If you feel severe pain in your tendons or ligaments that is cause for concern but redness is not as the skin heals very effectively.

  6. Looks good Alex, it'll be great having data from someone whose growth plates aren't "fused"!