The generation of loads in excess of the osteogenic threshold by physical movement.

“stresses in bones in excess of the osteogenic threshold will stimulate bone growth; however, protocols for the generation of these stresses had not been established. Two trial movements were examined in the study: the plié and a movement requiring the subject to move a leg sequentially to 45° displaced positions – the star excursion balance test. Using inverse dynamics and an optimisation approach, the loads in the muscles crossing the hip and knee joints and the corresponding joint contact forces were calculated. It was found that the osteogenic threshold was exceeded in both these trials identifying them as suitable exercises in the maintenance of bone health. In the order of increasing bone load at the hip, and hence increasing bone growth stimulation, are the following demi plié, star excursion balance test with maximum reach criterion, grande plié and star excursion balance test with maximum speed criterion. In the order of increasing bone load at the knee are demi plié, grande plié, star excursion balance test with maximum reach criterion and star excursion balance test with maximum speed criterion. However, due to the high loads encountered, these exercises are not recommended for subjects with advanced osteoporosis although the boundary between therapeutic bone loading leading to increase in bone mineral density and loads capable of causing fracture is unclear.”

“BMD fracture thresholds:110 mg/cm^3 in the distal femur and 70 mg/cm^3 in the proximal tibia”

“threshold of stress at which bone growth is stimulated corresponding to a stress of approximately 20MPa, which for a bone’s Young’s modulus of 20 GPa is 1000me.”

“As the lever arm at which the muscles act at the joint is typically relatively small compared to the segment length to which they are attached, the loads in the muscles and hence the compressive forces in the joint and bone can be very large”

“during a quasi-static rise from a deep squat, the tibio-femoral joint forces were 5.5–6.6 times the body weight.”

“a hip joint contact force of 2.38 times body weight occurred while walking at 4 km/h, 2.51 times body weight during stair ascent and 2.60 times body weight during stair descent.”

The star excursiion balance test generated a force around 6 times bodyweight in the knee.

If we understand how biomechanical bone formation is induced from mesenchymal stem cells we can induce new bone growth to reinvigorate longitudinal growth.

A computational model of clavicle bone formation: A mechano-biochemical hypothesis.

“Clavicle development arises from mesenchymal cells condensed as a cord extending from the acromion towards the sternal primordium. First two primary ossification centers form, extending to develop the body of the clavicle through intramembranous ossification. However, at its ends this same bone also displays endochondral ossification.  [These] embryological events [occur in] two serial phases: first formation of an ossified matrix by intramembranous ossification based on three factors: systemic, local biochemical, and mechanical factors. After this initial phase expansion of the ossified matrix follows with mesenchymal cell differentiation into chondrocytes for posterior endochondral ossification. Our model provides strong evidence for clavicle formation integrating molecules and mechanical stimuli through partial differentiation equations using finite element analysis.”

“areas of low octahedral shear stress and high hydrostatic stress promote bone formation by endochondral ossification. On the contrary, areas of octahedral shear stress result directly in osteogenic induction.”

“hydrostatic stress promotes mesenchymal cell into a cartilaginous differentiation pathway, whereas octahedral shear stress stimulates mesenchymal cells to differentiate into bone.”

Modeling of signaling pathways in chondrocytes based on phosphoproteomic and cytokine release data.

“The signaling pathways downstream 78 receptors of interest are interrogated. On the phosphoproteomic level, 17 key phosphoproteins are measured upon stimulation with single treatments of 78 ligands. On the cytokine release level, 55 cytokines are measured in the supernatant upon stimulation with the same treatments. Using an Integer Linear Programming formulation, the proteomic data is combined with a priori knowledge of proteins’ connectivity to construct a mechanistic model, predictive of signal transduction in chondrocytes.
We were able to validate previous findings regarding major players of cartilage homeostasis and inflammation (E.g. IL1B, TNF, EGF, TGFA, INS, IGF1 and IL6). Moreover, we studied pro-inammatory mediators (IL1B and TNF) together with pro-growth signals for investigating their role in chondrocytes hypertrophy and highlighted the role of underreported players such as INHBA, DEFB1, CXCL1 and Flagellin, and uncovered the way they cross-react in the phosphoproteomic level.”

“up-regulation of the SOX9 transcription factor induced by TGFB or FGF stimulation leads to collagen synthesis. On the other hand, over-activation of NFKB induced by several pathways (E.g. Inflammation related pathways or bone development processes leads to the release of MMPs and collagen degradation.”

” a large number of stimuli raised a significant response in chondrocytes, activating at least one phosphoprotein signal. As positive control observations, well known players such as IL1B, TNF, EGF, TGFA, INS, IGF1 and IL6{up in LSJL} responded as expected from previous studies. The pro-inflammatory mediators IL1B and TNF activated IKB, HSP27{note this is reduced by Lithium}, MAPK14 (p38) and JUN{up in LSJL}, already known to promote inflammation in cartilage, together with pro-growth signals such as CREB, ERK, GSK3, IRS1 and MAP2K1 (MEK12), validating their role in chondrocyte hypertrophy”

” pro-growth stimuli such as EGF, TGFA and INS activated only anabolic pathways, leaving inflammation related signals unaffected.”

Stimuli also found to affect chondrocytes include “INHBA (Inhibin beta A), ADIPOQ (Adiponectin), DEFB1 (Defensin beta 1), BTC (Betacellulin){up in LSJL}, CXCL1{highly upregulated by LSJL}, HBEGF{up}, IL19, CXCL10, ODN2006 (TLR9 ligand), NOG (Noggin) and Flagellin.”

“Major inflammatory mediators such as IL1B and TNF, signal through their receptors to IKB, MAPK14, HSP27 and JUN. IL1B also activates CREB and MAP2K1 (growth related signals) via TRAF6″

” Pro-growth stimuli such as TGFA, BTC, EGF, IGF1, INS and FGF2 signal through GRB2 to SOS, RAS and from there either to MAP2K1 (MEK12) via RAF1, or signal through PI3K to AKT and to CREB. IL6 activates mostly STAT3 via JAK1.”

“CXCL1, a small cytokine of the CXC family, binds to CXCR2 and activates RPS6KA1. HBEGF, a ligand of the EGFR, signals via the same pathways as EGF, BTC and TGFA. DEFB1, a TLR ligand, signals through TLR4 to RAC1 and from there to the MAPKs and finally activates HSP27 demonstrating pro-inflammatory action. Flagellin, also a TLR ligand, signals through TLR5 to MYD88 and then merges with the IL1 pathway activating major inflammatory signals, CREB and MAP2K1. INHBA, a ligand of the TGFBR, signals via the MAPKs to activate JNK and P53.”

Since drinking water contains Arsenic and Fluoride which can affect gene expression, it’s conceivable that drinking water could affect height growth.

Arsenic and fluoride co-exposure affects the expression of apoptotic and inflammatory genes and proteins in mononuclear cells from children.

“Humans may be exposed to arsenic (As) and fluoride (F) through water consumption.  Herein, the expression of cIAP-1, XIAP, TNF-α, ENA-78[also known as CXCL5 which is downregulated by LSJL], survivin, CD25, and CD40 was evaluated by RT-PCR. Additionally, the surface expression of CD25, CD40, and CD40L on peripheral blood mononuclear cells were analyzed by flow cytometry, and TNF-α was measured by western blotting. This study examined 72 children 6-12 years old who were chronically exposed to As (154.2μg/L) and F (5.3mg/L) in drinking water and in food cooked with the same water. The urine concentrations of As (6.9 to122.4μg/L) were positively correlated with the urine concentrations of F (1.0 to 8.8mg/L). The CD25 gene expression levels and urine concentrations of As and F were negatively correlated, though the CD40 expression levels were negatively correlated only with the As concentration. Age and height influenced the expression of cIAP-1, whereas XIAP expression was correlated only with age. Additionally, there was a lower percentage of CD25- and CD40-positive cells in the group of 6- to 8-year-old children exposed to the highest concentrations of both As and F when compared to the 9- to 12-year-old group (CD25: 0.7±0.8 vs. 1.1±0.9. CD40: 16.0±7.0 vs. 21.8±5.8). PHA-stimulated lymphocytes did not show any changes in the induction of CD25, CD69, or CD95. In summary, high concentrations of As and F alter the expression patterns of CD25 and CD40 at both the genetic and protein levels. These changes could decrease immune responses in children exposed to As and F.”

“Studies of As-exposed populations have demonstrated unusual gene expression profiles for cell cycle control-related factors, transcription factors, and inflammatory molecules”

“Using microarrays, our group determined that the IL-6, IL-1β, TNF-α, TGF-β, CD40, IL-2RA, CD40L, CD25, ENA78, SURVIVIN, XIAP, and IAP-1 genes are differentially expressed in adults chronically exposed to high concentrations of As (22.5–148.9 μg/L) and F (2.3–5.4 mg/L) compared to the control group (As: 0.3–1.4 μg/L; F: 0.1–0.7 mg/L)”<-Not strong height altering genes except possibly TGF-Beta.

“cIAP-1 expression was positively correlated with age and height”<-Can clAP-1(also known as clasp1) affect height?

XIAP and TNFalpha were also associated with height but not above statistical significance but closer than the rest of the genes.  p<0.15.  TNFalpha definitely affects height but there is it is likely that there’s an optimal quantity of TNFalpha for height growth rather than it just being good or bad.

This study could link Clasp1 to height growth:

Association of TALS developmental disorder with defect in minor splicing component U4atac snRNA.

“The spliceosome, a ribonucleoprotein complex that includes proteins and small nuclear RNAs (snRNAs), catalyzes RNA splicing through intron excision and exon ligation to produce mature messenger RNAs, which, in turn serve as templates for protein translation. We identified four point mutations in the U4atac snRNA component of the minor spliceosome in patients with brain and bone malformations and unexplained postnatal death [microcephalic osteodysplastic primordial dwarfism type 1 (MOPD 1) or Taybi-Linder syndrome (TALS); Mendelian Inheritance in Man ID no. 210710]. Expression of a subgroup of genes, possibly linked to the disease phenotype, and minor intron splicing were affected in cell lines derived from TALS patients. Our findings demonstrate a crucial role of the minor spliceosome component U4atac snRNA in early human development and postnatal survival.”

” The TALS phenotype includes marked intrauterine and postnatal growth retardation; short, bowed long bones with severe delay in epiphyseal maturation”

“The U4atac snRNA is located within intron 2 of the CLASP1 gene, –682 base pairs (bp) to –556 bp upstream of exon 3. Because of this, TALS mutations could, in theory, alter CLASP1 splicing and/or expression. In silico splice site predictions, real time–quantitative polymerase chain reaction (RT-qPCR) analysis of CLASP1 mRNA levels, and an RT-PCR study of CLASP1 exon 3 splicing in TALS patients revealed no effects of TALS mutations on CLASP1 expression or splicing”

However, the study seems to show a lack of connection of CLASP1 to dwarfism.

Can Idursulfase affect normal individuals who want to grow taller?

The Effect of Recombinant Human Iduronate-2-Sulfatase (Idursulfase) on Growth in Young Patients with Mucopolysaccharidosis Type II.

“Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is an X-linked, recessive, lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase. Early bone involvement leads to decreased growth velocity and short stature in nearly all patients. [We] investigate the effects of enzyme replacement therapy (ERT) with idursulfase (Elaprase) on growth in young patients with mucopolysaccharidosis type II. Analysis of longitudinal anthropometric data of MPS II patients (group 1, n = 13) who started ERT before 6 years of age (range from 3 months to 6 years, mean 3.6 years, median 4 years) was performed and then compared with retrospective analysis of data for MPS II patients naïve to ERT (group 2, n = 50). Patients in group 1 received intravenous idursulfase at a standard dose of 0.58 mg/kg weekly for 52-288 weeks. The course of average growth curve for group 1 was very similar to growth pattern in group 2. The average value of body height in subsequent years in group 1 was a little greater than in group 2, however, the difference was not statistically significant. In studied patients with MPS II, idursulfase did not appear to alter the growth patterns. ”

So idursulfase therapy only seems to have an impact when used before 6 years of age.

“Mucopolysaccharidosis type II (MPS II, Hunter syndrome, OMIM# 309900) is caused by the deficiency of the enzyme iduronate-2-sulfatase (I2S; EC 3.1.6.13) that is responsible for breaking down heparan and dermatan sulfate (HS and DS) within the cells”

I don’t think idursulfase will have an impact on “normal” individuals.  And it’s only having above a certain threshold of the enzyme affects height.

A key theory behind LSJL is the use of hydrostatic pressure to induces mesenchymal stem cells into chondrocytes to form new growth plates.  Hydrostatic Pressure alters the expression of some of the genes altered by LSJL.  Although, there are many genes not shared which is not surprising considering that LSJL exerts other forces than hydrostatic pressure and the microenvironment is different between the rat bone and the cell lines used.  Hydrostatic pressure is one of the most consistent stimuli in inducing neo chondroinduction.

Hydrostatic pressure decreases membrane fluidity and lipid desaturase expression in chondrocyte progenitor cells.

“Membrane biomechanical properties are critical in modulating nutrient and metabolite exchange as well as signal transduction. Biological membranes are predominantly composed of lipids, cholesterol and proteins, and their fluidity is tightly regulated by cholesterol and lipid desaturases. To determine whether such membrane fluidity regulation occurred in mammalian cells under pressure, we investigated the effects of pressure on membrane lipid order of mouse chondrogenic ATDC5 cells and desaturase gene expression. Hydrostatic pressure linearly increased membrane lipid packing and simultaneously repressed lipid desaturase gene expression. We also showed that cholesterol mimicked and cholesterol depletion reversed those effects, suggesting that desaturase gene expression was controlled by the membrane physical state itself. This study demonstrates a new effect of hydrostatic pressure on mammalian cells and may help to identify the molecular mechanisms involved in hydrostatic pressure sensing in chondrocytes. ”

“Hydrostatic pressure (HP) is known to reduce lipid membrane fluidity. High HP triggers an adaptive mechanism, during which membrane fluidity is increased by raising the proportion of unsaturated fatty acids.”

“TDC5 cells responded to the change in their membrane fluidity under pressure by modulating the expression of Fads1, Fads2, Scd1 or Scd2. 10 or 20 MPa did indeed significantly inhibit the expression of all four genes after 24 h, while 5 MPa also significantly decreased Fads1 and Scd1 expression.”<-None of the genes were directly altered over significance by LSJL.  The genes were measured one hour after loading so it’s possible that the genes returned to baseline after one hour.

With this  data it’s easy to see why there was no change in gene expression level by LSJL as most of the repression of these genes occurred after 6 or 24 hours under hydrostatic pressure.

“MβCD increased ATDC5 membrane fluidity (laurdan GP values respectively increased and decreased under cholesterol and MβCD treatment”

“Similar to HP, cholesterol increased laurdan GP and significantly inhibited Fads1 and Fads2 expression. By contrast, MβCD[methyl-β-cyclodextrin], which decreased laurdan GP, significantly increased the expression of all four desaturase genes. Together, this suggests that membrane fluidity itself may be the general modulator of desaturase gene expression.”<-Cholesterol has been implicated in controlling endochondral bone growth before.

“the beneficial effects of loading on cartilage are mediated by the transcription factor CITED2, which represses cartilage degradation by the matrix metalloproteinase MMP1.”

“In the human hip joint, loads typically reach 10 MPa during normal activity, with peaks of up to 18 MPa. Considering that interstitial fluid pressure supports about 70 to 90% of the applied load, HP within the cartilage can be expected to regularly exceed 7 MPa and peak at around 16 MPa. 20 MPa is therefore a relatively high pressure”

“How HP is actually sensed by the cell remains poorly understood, but the link between HP and cholesterol suggests at least two hypotheses: both HP and cholesterol may converge on the SREBP pathway, cholesterol by affecting SREBP maturation via SCAP, HP by affecting the membrane fluidity of the endoplasmic reticulum, where non-activated SREBPs reside and which is more sensitive to HP than the plasma membrane; the mechanosensing mechanism of HP could also reside in cholesterol-rich domains like lipid rafts or caveolae”

“membranes rich in unsaturated fatty acids may be compressible enough to deform significantly, and trigger signaling events, even under relatively small pressures. Finally, the plasma membrane is supported by the cytoskeleton, which is mostly incompressible; it is possible that pressurization of the compressible intracellular fluid leads to large deformations in membrane domains unsupported by the cytoskeleton, the change in bulk volume being focused onto a small membrane area.”