Piera Smeriglio | Stanford University (original) (raw)

Papers by Piera Smeriglio

FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Jan 15, 2015

Understanding the regulation of the stem cell fate is fundamental for designing novel regenerativ... more Understanding the regulation of the stem cell fate is fundamental for designing novel regenerative medicine strategies. Previous studies have suggested that pharmacological treatments with small molecules provide a robust and reversible regulation of the stem cell program. Previously, we showed that treatment with a vanadium compound influences muscle cell fate in vitro. In this study, we demonstrate that treatment with the phosphotyrosine phosphatase inhibitor bisperoxovanadium (BpV) drives primary muscle cells to a poised stem cell stage, with enhanced function in muscle regeneration in vivo following transplantation into injured muscles. Importantly, BpV-treated cells displayed increased self-renewal potential in vivo and replenished the niche in both satellite and interstitial cell compartments. Moreover, we found that BpV treatment induces specific activating chromatin modifications at the promoter regions of genes associated with stem cell fate, including Sca-1 and Pw1. Thus, ...

Journal of visualized experiments : JoVE, 2015

Human articular cartilage is highly susceptible to damage and has limited self-repair and regener... more Human articular cartilage is highly susceptible to damage and has limited self-repair and regeneration potential. Cell-based strategies to engineer cartilage tissue offer a promising solution to repair articular cartilage. To select the optimal cell source for tissue repair, it is important to develop an appropriate culture platform to systematically examine the biological and biomechanical differences in the tissue-engineered cartilage by different cell sources. Here we applied a three-dimensional (3D) biomimetic hydrogel culture platform to systematically examine cartilage regeneration potential of juvenile, adult, and osteoarthritic (OA) chondrocytes. The 3D biomimetic hydrogel consisted of synthetic component poly(ethylene glycol) and bioactive component chondroitin sulfate, which provides a physiologically relevant microenvironment for in vitro culture of chondrocytes. In addition, the scaffold may be potentially used for cell delivery for cartilage repair in vivo. Cartilage ti...

Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, Jan 12, 2015

Regulation of gene expression changes during chondrogenic differentiation by DNA methylation and ... more Regulation of gene expression changes during chondrogenic differentiation by DNA methylation and demethylation is little understood. Methylated cytosines (5mC) are oxidized by the ten-eleven-translocation (TET) proteins to 5-hydroxymethylcytosines (5hmC), 5-formylcytosines (5fC) and 5-carboxylcytosines (5caC) eventually leading to a replacement by unmethylated cytosines (C) i.e. DNA demethylation. Additionally, 5hmC is stable and acts as an epigenetic mark by itself. Here, we report that global changes in 5hmC mark chondrogenic differentiation in vivo and in vitro. Tibia anlagen and growth plate analyses during limb development at mouse embryonic days E 11.5, 13.5 and 17.5 showed dynamic changes in 5hmC levels in the differentiating chondrocytes. A similar increase in 5hmC levels was observed in the ATDC5 chondroprogenitor cell line accompanied by increased expression of the TET proteins during in vitro differentiation. Loss of TET1 in ATDC5 decreased 5hmC levels and impaired differ...

We describe a new, simple immobilization protocol designed to induce muscle atrophy in lower hind... more We describe a new, simple immobilization protocol designed to induce muscle atrophy in lower hindlimb muscles in mice. Hindlimbs of C57BL6 mice were unilaterally immobilized for 7 days. Morphological analysis revealed that immobilization resulted in a significant reduction in muscle fiber size in both the extensor digitorum longus (EDL) and tibialis anterior (TA). By contrast, no significant changes in muscle fiber type content, as measured by NADH-TR staining, were detected. At the molecular level, expression of the muscle-specific ubiquitin ligases MAFbx/Atrogin-1 and MuRF1 genes was induced following immobilization in all the muscles examined. The characteristics of this model lend themselves to muscle atrophy research; its availability in mice may be instrumental for future studies on therapeutic interventions of muscle atrophy using transgenic and mutant mice strains. Skeletal muscle atrophy can be defined as a wasting or decrease in muscle mass as a result of surgery, immobili...

Arthritis & Rheumatology, 2013

Objective. To investigate the role of the newly discovered epigenetic mark 5-hydroxymethylcytosin... more Objective. To investigate the role of the newly discovered epigenetic mark 5-hydroxymethylcytosine (5hmC) and its regulators in altered gene expression in osteoarthritis (OA).

Tissue engineering. Part A, 2015

Regeneration of human articular cartilage is inherently limited and extensive efforts have focuse... more Regeneration of human articular cartilage is inherently limited and extensive efforts have focused on engineering the cartilage tissue. Various cellular sources have been studied for cartilage tissue engineering including adult chondrocytes, and embryonic or adult stem cells. Juvenile chondrocytes (from donors below 13 years of age) have recently been reported to be a promising cell source for cartilage regeneration. Previous studies have compared the potential of adult and juvenile chondrocytes or adult and osteoarthritic (OA) chondrocytes. To comprehensively characterize the comparative potential of young, old, and diseased chondrocytes, here we examined cartilage formation by juvenile, adult, and OA chondrocytes in three-dimensional (3D) biomimetic hydrogels composed of poly(ethylene glycol) and chondroitin sulfate. All three human articular chondrocytes were encapsulated in the 3D biomimetic hydrogels and cultured for 3 or 6 weeks to allow maturation and extracellular matrix for...

Tissue Engineering Part A, 2014

Regeneration of human cartilage is inherently inefficient. Current cell-based approaches for cart... more Regeneration of human cartilage is inherently inefficient. Current cell-based approaches for cartilage repair, including autologous chondrocytes, are limited by the paucity of cells, associated donor site morbidity, and generation of functionally inferior fibrocartilage rather than articular cartilage. Upon investigating the role of collagen VI (Col VI), a major component of the chondrocyte pericellular matrix (PCM), we observe that soluble Col VI stimulates chondrocyte proliferation. Interestingly, both adult and osteoarthritis chondrocytes respond to soluble Col VI in a similar manner. The proliferative effect is, however, strictly due to the soluble Col VI as no proliferation is observed upon exposure of chondrocytes to immobilized Col VI. Upon short Col VI treatment in 2D monolayer culture, chondrocytes maintain high expression of characteristic chondrocyte markers like Col2a1, agc, and Sox9 whereas the expression of the fibrocartilage marker Collagen I (Col I) and of the hypertrophy marker Collagen X (Col X) is minimal. Additionally, Col VI-expanded chondrocytes show a similar potential to untreated chondrocytes in engineering cartilage in 3D biomimetic hydrogel constructs. Our study has, therefore, identified soluble Col VI as a biologic that can be useful for the expansion and utilization of scarce sources of chondrocytes, potentially for autologous chondrocyte implantation. Additionally, our results underscore the importance of further investigating the changes in chondrocyte PCM with age and disease and the subsequent effects on chondrocyte growth and function.

Proceedings of the National Academy of Sciences, 2011

A variety of markers are invaluable for identifying and purifying stem/progenitor cells. Here we ... more A variety of markers are invaluable for identifying and purifying stem/progenitor cells. Here we report the generation of a murine reporter line driven by Pw1 that reveals cycling and quiescent progenitor/stem cells in all adult tissues thus far examined, including the intestine, blood, testis, central nervous system, bone, skeletal muscle, and skin. Neurospheres generated from the adult PW1-reporter mouse show near 100% reporter-gene expression following a single passage. Furthermore, epidermal stem cells can be purified solely on the basis of reporter-gene expression. These cells are clonogenic, repopulate the epidermal stem-cell niches, and give rise to new hair follicles. Finally, we demonstrate that only PW1 reporter-expressing epidermal cells give rise to follicles that are capable of self-renewal following injury. Our data demonstrate that PW1 serves as an invaluable marker for competent self-renewing stem cells in a wide array of adult tissues, and the PW1-reporter mouse serves as a tool for rapid stem cell isolation and characterization. bulge | subgranular zone | subventricular zone | crypt | regeneration

Pflügers Archiv - European Journal of Physiology, 2014

In skeletal muscle, the resting chloride conductance (gCl), due to the ClC-1 chloride channel, co... more In skeletal muscle, the resting chloride conductance (gCl), due to the ClC-1 chloride channel, controls the sarcolemma electrical stability. Indeed, loss-of-function mutations in ClC-1 gene are responsible of myotonia congenita. The ClC-1 channel can be phosphorylated and inactivated by protein kinases C (PKC), but the relative contribution of each PKC isoforms is unknown. Here, we investigated on the role of PKCθ in the regulation of ClC-1 channel expression and activity in fast-and slow-twitch muscles of mouse models lacking PKCθ. Electrophysiological studies showed an increase of gCl in the PKCθ-null mice with respect to wild type. Muscle excitability was reduced accordingly. However, the expression of the ClC-1 channel, evaluated by qRT-PCR, was not modified in PKCθ-null muscles suggesting that PKCθ affects the ClC-1 activity. Pharmacological studies demonstrated that although PKCθ appreciably modulates gCl, other isoforms are still active and concur to this role. The modification of gCl in PKCθ-null muscles has caused adaptation of the expression of phenotypespecific genes, such as calcineurin and myocyte enhancer factor-2, supporting the role of PKCθ also in the settings of muscle phenotype. Importantly, the lack of PKCθ has prevented the aging-related reduction of gCl, suggesting that its modulation may represent a new strategy to contrast the aging process.

Molecular Biology of the Cell, 2011

FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Jan 24, 2015

Regeneration of human cartilage is inherently inefficient; an abundant autologous source, such as... more Regeneration of human cartilage is inherently inefficient; an abundant autologous source, such as human induced pluripotent stem cells (hiPSCs), is therefore attractive for engineering cartilage. We report a growth factor-based protocol for differentiating hiPSCs into articular-like chondrocytes (hiChondrocytes) within 2 weeks, with an overall efficiency >90%. The hiChondrocytes are stable and comparable to adult articular chondrocytes in global gene expression, extracellular matrix production, and ability to generate cartilage tissue in vitro and in immune-deficient mice. Molecular characterization identified an early SRY (sex-determining region Y) box (Sox)9(low) cluster of differentiation (CD)44(low)CD140(low) prechondrogenic population during hiPSC differentiation. In addition, 2 distinct Sox9-regulated gene networks were identified in the Sox9(low) and Sox9(high) populations providing novel molecular insights into chondrogenic fate commitment and differentiation. Our finding...