Height Increase by your Extracellular Matrix

It was found that cell space affected cellular senescence.  Growth plates tend to be tightly packed against each other without sufficient Extracellular Matrix.  Dynamic compression of chondrocytes increases ECM matrix synthesis.  Although the amount of ECM decreases the response of cells to stimuli such as vibration.  Smoking in high doses decreases ECM synthesis(in low doses it may increase it).  Chondroitin and Glucosamine are two supplements involved in the ECM as is Hyaluronic Acid which is likely the most effective.  Also, inhibiting Smads 1/5/8 has been shown to enhance height growth whereas Smads 2/3 increase height(as a result of increasing Collagen Type II production).It's long been thought that chondrocyte hypertrophy plays the largest role in growing taller but what if the extracellular matrix is involved as well?  The ECM serves as an elastic substance that allows the bone to stretch and thus for us to increase our heights. 

Human growth plate contains aggrecan fragments that can be generated by m-calpain. 

"Growth plate is a cartilaginous structure responsible for longitudinal growth and calcification of long bones. Aggrecan is initially expressed within the growth plate but is lost during the course of calcification[Aggrecan is a member of the Chondroitin Sulfate Family]. Calcium-activated proteinases are believed to play a primary role in aggrecanolysis[lysis is a form of cell death]. In this study, m-calpain was shown to be expressed in a limited area of the growth cartilage at the lower hypertrophic zone. Confocal immunostaining demonstrated colocalization of m-calpain and the aggrecan product within the lower hypertrophic chondrocytes and in limited region of the pericellular matrix. Immunoblotting analysis identified anti-VPGVA-positive aggrecan product within the dissociative fractions of A1D1-A1D6 (densities 1.65, 1.56, 1.52, 1.47, 1.41, and 1.37 g/cm(3), respectively). These findings indicated that limited expression of m-calpain is colocalized with the appearance of calpain-related aggrecan products at the sites of aggrecanolysis and calcification, and suggested an important role of m-calpain in regulation of the growth plate process. The G1-G2-containing fragment of aggrecan remaining within the extracellular matrix (ECM) of the growth plate may contribute to the mechanical properties of the growth plate between the chondrocyte cell layers until bony replacement takes place."

The loss of aggrecan is important to chondrogenic differentiation into osteogenic cells. By increasing aggrecan levels it may be possible to elongate the period before osteogenic differentiation and thus grow taller for a longer period of time.

Sox9 is important in ECM formation. 

Identification of SOX9 interaction sites in the genome of chondrocytes.

"The transcription factor SOX9 is completely needed for chondrogenic differentiation and cartilage formation acting as a "master switch" in this differentiation. Heterozygous mutations in SOX9 cause campomelic dysplasia, a severe skeletal dysmorphology syndrome in humans characterized by a generalized hypoplasia of endochondral bones. To obtain insights into the logic used by SOX9 to control a network of target genes in chondrocytes, we performed a ChIP-on-chip experiment using SOX9 antibodies.

The ChIP DNA was hybridized to a microarray, which covered 80 genes, many of which are involved in chondrocyte differentiation. Hybridization peaks were detected in a series of cartilage extracellular matrix (ECM) genes including Col2a1, Col11a2, Aggrecan and Cdrap as well as in genes for specific transcription factors and signaling molecules. Our results also showed SOX9 interaction sites in genes that code for proteins that enhance the transcriptional activity of SOX9. Interestingly, a strong SOX9 signal was also observed in genes such as Col1a1 and Osx, whose expression is strongly down regulated in chondrocytes but is high in osteoblasts. In the Col2a1 gene, in addition to an interaction site on a previously identified enhancer in intron 1, another strong interaction site was seen in intron 6. This site is free of nucleosomes specifically in chondrocytes suggesting an important role of this site on Col2a1 transcription regulation by SOX9."

"Chondrogenesis is also controlled by a complex interplay of signaling molecules among which some target either the expression or the activity of SOX9. Whereas IL-1 and TNF α inhibit its expression, FGF signaling increases its expression and its activity; Wnt/β-catenin also inhibits its activity and expression, whereas PTHrP increases its activity."

Calcium has been shown to inhibit PTH and increase Beta-Catenin but calcium deficiency decreases height.  Beta Catenin also increases chondrocyte hypertrophy.  The negative height gaining aspects of Calcium must be outweighed by the positive.  CARM1 which disrupts the interaction of Sox9 with Beta-Catenin has been shown to result in you becoming taller.  So you need a precise blend of compounds to optimally grow taller.

LIPUS increases ECM related genes. 

Low-intensity pulsed ultrasound stimulates cell proliferation, proteoglycan synthesis and expression of growth factor-related genes in human nucleus pulposus cell line.

"Low-intensity pulsed ultrasound (LIPUS) stimulation has been shown to effect differentiation and activation of human chondrocytes. A study involving stimulation of rabbit disc cells with LIPUS revealed upregulation of cell proliferation and proteoglycan (PG) synthesis. However, the effect of LIPUS on human nucleus pulposus cells has not been investigated. In the present study, therefore, we investigated whether LIPUS stimulation of a human nucleus pulposus cell line[the cells in the intervertebral disc that affect disc height, so you should also be able to grow taller that way but the affects on matrix synthesis should be applicable to other chondrocyte matrix production namely growth plates] (HNPSV-1) exerted a positive effect on cellular activity. HNPSV-1 cells were encapsulated in 1.2% sodium alginate solution at 1x10(5) cells/ml and cultured at 10 beads/well in 6-well plates. The cells were stimulated for 20 min each day using a LIPUS generator, and the effects of LIPUS were evaluated by measuring DNA and PG synthesis. Furthermore, mRNA expression was analyzed by cDNA microarray using total RNA extracted from the cultured cells. Our study revealed no significant difference in cell proliferation between the control and the ultrasound treated groups. However, PG production was significantly upregulated in HNPSV cells stimulated at intensities of 15, 30, 60, and 120 mW/cm(2) compared with the control. The results of cDNA array showed that LIPUS significantly stimulated the gene expression of growth factors and their receptors (BMP2, FGF7, TGFbetaR1 EGFRF1, VEGF). These findings suggest that LIPUS stimulation upregulates PG production in human nucleus pulposus cells by the enhancement of several matrix-related genes including growth factor-related genes."

So LIPUS may be able to increase height by increasing ECM in growth plate cells and by directly increasing the height of the intervertebral discs.

The periosteum may be important in ECM function as well... 

Development of bone and cartilage in tissue-engineered human middle phalanx models.

"Human middle phalanges were tissue-engineered with midshaft scaffolds of poly(L-lactide-epsilon-caprolactone) [P(LA-CL)], hydroxyapatite-P(LA-CL), or beta-tricalcium phosphate-P(LA-CL) and end plate scaffolds of bovine chondrocyte-seeded polyglycolic acid. Midshafts were either wrapped with bovine periosteum or left uncovered. Constructs implanted in nude mice for up to 20 weeks were examined for cartilage and bone development as well as gene expression and protein secretion, which are important in extracellular matrix (ECM) formation and mineralization. Harvested 10- and 20-week constructs without periosteum maintained end plate cartilage but no growth plate formation. They also consisted of chondrocytes secreting type II collagen and proteoglycan, and they were composed of midshaft regions devoid of bone. In all periosteum-wrapped constructs at like times, end plate scaffolds held chondrocytes elaborating type II collagen and proteoglycan and cartilage growth plates resembling normal tissue. Chondrocyte gene expression of type II collagen, aggrecan, and bone sialoprotein varied depending on midshaft composition, presence of periosteum, and length of implantation time. Periosteum produced additional cells, ECM, and mineral formation within the different midshaft scaffolds. Periosteum thus induces midshaft development and mediates chondrocyte gene expression and growth plate formation in cartilage regions of phalanges. This work is important for understanding developmental principles of tissue-engineered phalanges and by extension those of normal growth plate cartilage and bone."

So things that are anabolic to the periosteum may have additional affects on ECM and cartilagenous growth plates in such a way as to increase height.  Although, sprinters who generate a lot of shear strain on the periosteum were not found to be taller than non-sprinters(in fact they were a little bit shorter).  But this could be due to the fact that perhaps shorter individuals prefer running.

The Extracellular Matrix also provides cues for height growth, remember that Type I Collagen is essential for chondrogenic differentiation of stem cells(Type I Collagen is a huge part of bone tissue):

Mesenchymal Stem Cells Sense Three Dimensional Type I Collagen through Discoidin Domain Receptor 1.

"The extracellular matrix provides structural and organizational cues for tissue development and defines and maintains cellular phenotype during cell fate determination. Multipotent mesenchymal stem cells use this matrix to tightly regulate the balance between their differentiation potential and self-renewal in the native niche. When understood, the mechanisms that govern cell-matrix crosstalk during differentiation will allow for efficient engineering of natural and synthetic matrices to specifically direct and maintain stem cell phenotype. This work identifies the discoidin domain receptor 1 (DDR1), a collagen activated receptor tyrosine kinase, as a potential link through which stem cells sense and respond to the 3D organization of their extracellular matrix microenvironment. DDR1 is dependent upon both the structure and proteolytic state of its collagen ligand and is specifically expressed and localized in three dimensional type I collagen culture. Inhibition of DDR1 expression results in decreased osteogenic potential, increased cell spreading, stress fiber formation and ERK1/2 phosphorylation. Additionally, loss of DDR1 activity alters the cell-mediated organization of the naïve type I collagen matrix. Taken together, these results demonstrate a role for DDR1 in the stem cell response to and interaction with three dimensional type I collagen. Dynamic changes in cell shape in 3D culture and the tuning of the local ECM microstructure, directs crosstalk between DDR1 and two dimensional mechanisms of osteogenesis that can alter their traditional roles."

So proper DDR1 signaling is essential for height growth and for LSJL.

"Changes in cell shape, cytoskeletal tension and tissue geometry influence cell fate decisions[lateral joint loading influences the last two by tension against the actin cytoskeleton and bone deformation, it possibly influences cell shape by dynamic compression of chondrocytes]. Cell shape controls two dimensional (2D) cell behavior through alteration of internal cytoskeletal tension"

The spatial properties of the ECM also play a role in cell fate.  This is a problem for height growth post puberty but not an insurmountable one.  Of course, this is the factors that affect cells on two planes whereas within the bone there are three.

"Cell-mediated reorganization of the ECM requires adhesion, secretion, degradation and assembly of the proteins within that matrix. DDR1 and integrins are responsible for the upregulation of matrix metalloproteinases (MMPs) in response to collagen adhesion that mediate the cellular remodeling response."

DDR upregulates MMPs.  So, even if post-fusion there is no cartilagenous template.  DDR1 may allow for the formation of new cartilage canals to form new ones.

"Geometric control of cell shape by changing ECM dynamics alters intracellular distances. Spatial restriction, in this way, can force crosstalk between pathways that would not cross in a planar cell."

Cellular Compression alters intracellular distances that changes cross talk dynamics.  Lateral Joint Loading may alter both intracellular and intercellular distances.

ECM Stiffness Primes the TGFβ Pathway to Promote Chondrocyte Differentiation.

"Cells encounter physical cues such as extracellular matrix (ECM) stiffness in a microenvironment replete with biochemical cues.  Here we investigate mechanisms by which chondrocytes generate an integrated response to ECM stiffness and TGFβ, a potent agonist of chondrocyte differentiation. Primary murine chondrocytes and ATDC5 cells grown on 0.5 MPa substrates deposit more proteoglycan and express more Sox9, Col2α1, and aggrecan mRNA relative to cells exposed to substrates of any other stiffness. The chondroinductive effect of this discrete stiffness, which falls within the range reported for articular cartilage, requires the stiffness-sensitive induction of TGFβ1. Smad3 phosphorylation, nuclear localization, and transcriptional activity are specifically increased in cells grown on 0.5 MPa substrates. ECM stiffness also primes cells for a synergistic response, such that the combination of ECM stiffness and exogenous TGFβ induce chondrocyte gene expression more robustly than either cue alone through a p38 MAPK-dependent mechanism. In this way, the ECM stiffness primes the TGFβ pathway to efficiently promote chondrocyte differentiation. This work reveals novel mechanisms by which cells integrate physical and biochemical cues to exert a coordinated response to their unique cellular microenvironment."

What's the stiffness of the adult epiphyseal bone marrow?

Growth and differentiation of pre-chondrogenic cells on bioactive self-assembled peptide nanofibers.

"Sulfated glycosaminoglycan molecules are vital constituents of both developing and mature cartilage extracellular matrix. The interplay between regulator proteins and glycosaminoglycan molecules has an essential role in coordinating differentiation, expansion and patterning during cartilage development. We exploited the functional role of extracellular matrix on chondrogenic differentiation by imitating extracellular matrix both chemically by imparting functional groups of native glycosaminoglycans, and structurally through peptide nanofiber network. For this purpose, sulfonate, carboxylate and hydroxyl groups were incorporated on self-assembled peptide nanofibers. When ATDC5 cells were cultured on functional peptide nanofibers, they rapidly aggregated in insulin-free medium and formed cartilage-like nodules and deposited sulfated glycosaminoglycans. Collagen II and aggrecan gene expressions were significantly enhanced which indicated the remarkable bioactive role of this nanofiber system on chondrogenic differentiation. Glycosaminoglycan mimetic peptide nanofiber system provides a promising platform for cartilage regeneration."

"Perlecan, a heparan sulfate proteoglycan, functions as a growth factor reservoir, thereby increasing local concentration of growth factors"  It also helps trigger chondrocyte differentiation.

"proteoglycans are highly negatively charged biomacromolecules in cartilage extracellular matrix. The carboxylate and sulfate groups on proteoglycans provide fixed negative charge to extracellular matrix and each proteoglycan-associated negative charge requires a mobile counter ion to maintain tissue electroneutrality."

"The mobile counter ions (e.g. Na+) coming from outside of the tissue result in drawing of water into the tissue and high swelling pressure."

"NF 4[the most chondrogenic group] was composed of mainly E-PA and SO3-PA that bring carboxylate, hydroxyl and sulfonate groups together at proper ratio."

So how to grow taller via the ECM:

• Periosteum 
• LIPUS 
• SOX9
• ECM may help control the differentiation of stem cells and thus may help them to undergo a chondrogenic lineage, DDR1 helps the cells interact with the ECM
• Supplements that increase ECM formation or decrease ECM degradation(some degradation is needed for proper modeling)