Hen Yu Liu

Tissue-engineered intervertebral disc and chondrogenesis using human nucleus pulposus regulated through TGF-β1 in platelet-rich plasma

Human intervertebral disc (IVD) degeneration often initiated from the human nucleus pulposus (hNP) with aging leading to IVD destruction and extracellular matrix (ECM) depletion. Previously, we have successfully employed transforming growth factor‐β1 (TGF‐β1) to promote chondrogenesis of mesenchymal progenitor cells (MPCs) and immortalized human mesenchymal stem cells. In this study, we examine the role of TGF‐β1 in platelet‐rich plasma (PRP) on disc regeneration, including proliferation, redifferentiation, and the reconstitution of tissue‐engineered NP. hNP cells were isolated from volunteers with different ages and cultured in the presence of PRP. We found that the most effective concentration for hNP proliferation was 1 ng/ml TGF‐β1 in PRP, which was further applied in the following experiments. hNP cell proliferation in all age groups were increased time‐dependently by PRP and cell morphologies showed aggregation. The mRNA of Sox9, type II collagen, and aggrecan were all significantly upregulated by PRP through RT‐PCR. Glycosaminoglycan (GAG) accumulation reached the highest value at day 7 and continued to day 9 culture. PRP promoted NP regeneration via the Smad pathway was also determined and highly activated p‐Smad2/3 at 30 min and continuously sustained to 120 min. Immunostaining of type II collagen indicates that PRP participates in chondrogenesis of tissue‐engineered NP with collagen scaffolds. We concluded that growth factors in PRP can effectively react as a growth factor cocktail to induce hNP proliferation and differentiation, and also promote tissue‐engineered NP formation. These findings are the first to demonstrate that PRP might be a therapeutic candidate for prevention of disc degeneration. J. Cell. Physiol. 209: 744–754, 2006.

Intervertebral disc regeneration in an ex vivo culture system using mesenchymal stem cells and platelet-rich plasma

An ex vivo degenerative intervertebral disc (IVD) organ culture system was established for the screening of disc regeneration agents. Its application was demonstrated by a stem cell and growth factor-based therapeutic approach for the amelioration of IVD. An ex vivo culture system using chymopapain to partially digest nucleus proposus tissue was established to mimic human IVD degeneration. This system was then used for the evaluation of different therapeutic regimens including: mesenchymal stem cell derived from eGFP-transgenic porcine (MSC-GFP), platelet-rich plasma (PRP) and MSC-GFP/PRP combined treatment, and confirmed in in vivo animal model. Chondrogenic-specific gene products including Col II and aggrecan were found upregulated and chondrogenic matrix deposition increased, as evident by sustained fluorescent signals over 4 weeks, in the MSC-GFP implanted group. Previously, we demonstrated in vitro stage-specific chondrogenesis of MSC by chondrocytic commitment. These same molecules upregulated for chondrogenesis were also observed in MSC-GFP group. PRP that has been shown to promote nucleus pulposus (NP) regeneration also resulted in significant increased levels of mRNA involved in chondrogenesis and matrices accumulation. The ex vivo IVD regeneration results were repeated and supported by in vivo porcine degenerative system. Moreover, the disc height index (DHI) was significantly increased in both in vivo MSC-GFP and PRP regeneration groups. Unexpectedly, the MSC-GFP/PRP combined therapy demonstrated an inclination towards osteogenesis in ex vivo system. The ex vivo degenerative IVD culture system described in this study could serve as an alternative and more accessible model over large animal model. This system also provides a high-throughput platform for screening therapeutic agents for IVD regeneration.

The balance between adipogenesis and osteogenesis in bone regeneration by platelet-rich plasma for age-related osteoporosis

The aim of this study was to develop a new diagnostic and therapeutic approach for the treatment of osteoporosis. Previously, we demonstrated that intraosseous transplantation of platelet-rich plasma (PRP) treated-osteoblast-like cells into ovariectomized senescence-accelerated mice (OVX-SAMP8) prevented the development of osteoporosis. In continuation, we aimed to explore the complex etiology of osteoporosis using this platform. An inverse relationship between bone marrow adipogenesis and osteogenesis has been suggested in the development of osteoporosis but the underlying mechanisms remain poorly described. To address these issues, we used PRP to inhibit adipocyte differentiation by promoting osteoblastic differentiation in adipocytes. In addition, a positive correlation between an increase in bone marrow adipocytes and bone loss was established. We assessed this relationship using an osteoporotic animal disease model which consisted of young (for prevention) and old (for treatment) OVX-SAMP8 mice. This animal model demonstrated that PRP treatment mainly exerted its action via promoting bone regeneration but also appeared to suppress adipogenesis within the marrow. The findings and methodology of this study could potentially be applied in the prevention and treatment of osteoporosis.

Synergistic anabolic actions of hyaluronic acid and platelet-rich plasma on cartilage regeneration in osteoarthritis therapy

Osteoarthritis (OA) is a common disease associated with tissue inflammation, physical disability and imbalanced homeostasis in cartilage. For advanced treatments, biological approaches are currently focused on tissue regeneration and anti-inflammation. This study was undertaken to evaluate the therapeutic efficacies of hyaluronic acid (HA) and platelet-rich plasma (PRP) (HA+PRP) on OA. Articular chondrocytes were obtained from five OA patients. The optimal HA and PRP concentrations were evaluated by MTT assay. The expressions of chondrogenic and inflammatory genes were analyzed by RT-PCR. Signaling pathway was examined by immunoblotting and the expressions of OA pathology-related chemokines and cytokines was demonstrated by real-time PCR-based SuperArray. The therapeutic efficacies of HA+PRP were then demonstrated in 3D arthritic neo-cartilage and ACLT-OA model. Here we showed that HA+PRP could greatly retrieve pro-inflammatory cytokines-reduced articular chondrocytes proliferation and chondrogenic phenotypes, the mechanism of which involve the sequential activation of specific receptors CD44 and TGF-βRII, downstream mediators Smad2/3 and Erk1/2, and the chondrogenic transcription factor SOX9. The real-time PCR-based SuperArray results also indicated that OA pathology-related chemokines and cytokines could be efficiently suppressed by HA+PRP. Moreover, the cartilaginous ECM could be retrieved from inflammation-induced degradation by HA+PRP in both 2D monolayer and 3D neo-cartilage model. Finally, the intra-articular injection of HA+PRP could strongly rescue the meniscus tear and cartilage breakdown and then decrease OA-related immune cells. The combination of HA+PRP can synergistically promote cartilage regeneration and inhibit OA inflammation. This study might offer an advanced and alternative OA treatment based on detailed regenerative mechanisms.

The effect of diminished osteogenic signals on reduced osteoporosis recovery in aged mice and the potential therapeutic use of adipose-derived stem cells

Adipose-derived stem cells (ADSCs) have been shown to be pluoripotent and explored for their usage in tissue engineering. Previously, we have established a cell-based approach comprised of platelet-enriched plasma and osteo-progenitor cells for treating osteoporosis in an ovariectomized-senescence-accelerated mice (OVX-SAMP8) model. In the present study, we intend to explore the feasibility of using ADSCs as a cell-based therapeutic approach for treating osteoporosis, and to examine the effects of aging on the pluoripotency of ADSCs and the efficiency of bone formation both in vitro and in vivo. Flow cytometry was used to characterize ADSCs isolated from young and aged female SAMP8 mice and showed that the highly positive expression of surface markers such as CD44 and CD105 and negative for CD34 and CD45. Therefore, to compare the aging effects on the growth kinetics and differentiation potential of young and aged ADSCs, we found that there was a significant decline in both the proliferation rate (approximately 13.3%) and osteo-differentiation potential in aged ADSC. Subsequently, young and aged ADSCs were transplanted into the bone marrow of osteoporotic mice (OVX-SAMP8) to evaluate their bone formation ability. ADSC transplants were shown effective in restoring bone mineral density in the right/left knees, femurs and spine, 4 months post-transplantation; mice which received young ADSC transplants showed significantly higher bone regeneration (an average of 24.3% of improved BMD) over those received aged ADSCs. In conclusion, these findings showed that aging impedes osteoporosis-ameliorating potential of ADSC by diminishing osteogenic signal, and that ADSC could be used as a potential cell-based therapy for osteoporosis.

Transplantation of Embryonic Fibroblasts Treated with Platelet-Rich Plasma Induces Osteogenesis in SAMP8 Mice Monitored by Molecular Imaging

The aim of this study was to develop a cell-based bone-regeneration approach evaluated by molecular imaging and immunohistochemistry. Methods: Genetically modified NIH3T3 embryonic fibroblasts carrying enhanced green fluorescent protein (NIH3T3-G) were predifferentiated into osteoblastlike cells using platelet-rich plasma (PRP) medium, followed by intraosseous transplantation into ovariectomized senescence-accelerated mouse prone substrain 8 (OVX-SAMP8 mice). Results: PRP-conditioned NIH3T3-G (PRP/NIH3T3-G) engraftment prevented the development of osteoporosis. Molecular imaging and immunohistochemistry demonstrated the migration of NIH3T3-G cells from the implantation site throughout the skeleton. In situ analyses revealed coexpression of osteopontin and green fluorescent protein in the newly formed bone tissue, demonstrating that the transplant restored the bone trabecular architecture and mineral density in treated OVX-SAMP8 mice. Interestingly, the life span of OVX-SAMP8 mice receiving PRP/NIH3T3-G transplantation was significantly prolonged and similar to that of the congenic senescence-resistant strain of mice. Conclusion: This unique and yet simple approach could potentially be applied to the treatment of senile postmenopausal osteoporosis and perhaps inborn genetic syndromes associated with accelerated aging, such as Hutchinson–Gilford progeria syndrome, and for the prolongation of life expectancy in general.

Potential Osteoporosis Recovery by Deep Sea Water through Bone Regeneration in SAMP8 Mice

The aim of this study is to examine the therapeutic potential of deep sea water (DSW) on osteoporosis. Previously, we have established the ovariectomized senescence-accelerated mice (OVX-SAMP8) and demonstrated strong recovery of osteoporosis by stem cell and platelet-rich plasma (PRP). Deep sea water at hardness (HD) 1000 showed significant increase in proliferation of osteoblastic cell (MC3T3) by MTT assay. For in vivo animal study, bone mineral density (BMD) was strongly enhanced followed by the significantly increased trabecular numbers through micro-CT examination after a 4-month deep sea water treatment, and biochemistry analysis showed that serum alkaline phosphatase (ALP) activity was decreased. For stage-specific osteogenesis, bone marrow-derived stromal cells (BMSCs) were harvested and examined. Deep sea water-treated BMSCs showed stronger osteogenic differentiation such as BMP2, RUNX2, OPN, and OCN, and enhanced colony forming abilities, compared to the control group. Interestingly, most untreated OVX-SAMP8 mice died around 10 months; however, approximately 57% of DSW-treated groups lived up to 16.6 months, a life expectancy similar to the previously reported life expectancy for SAMR1 24 months. The results demonstrated the regenerative potentials of deep sea water on osteogenesis, showing that deep sea water could potentially be applied in osteoporosis therapy as a complementary and alternative medicine (CAM).

Delayed animal aging through the recovery of stem cell senescence by platelet rich plasma.

Aging is related to loss of functional stem cell accompanying loss of tissue and organ regeneration potentials. Previously, we demonstrated that the life span of ovariectomy-senescence accelerated mice (OVX-SAMP8) was significantly prolonged and similar to that of the congenic senescence-resistant strain of mice after platelet rich plasma (PRP)/embryonic fibroblast transplantation. The aim of this study is to investigate the potential of PRP for recovering cellular potential from senescence and then delaying animal aging. We first examined whether stem cells would be senescent in aged mice compared to young mice. Primary adipose derived stem cells (ADSCs) and bone marrow derived stem cells (BMSCs) were harvested from young and aged mice, and found that cell senescence was strongly correlated to animal aging. Subsequently, we demonstrated that PRP could recover cell potential from senescence, such as promote cell growth (cell proliferation and colony formation), increase osteogenesis, decrease adipogenesis, restore cell senescence related markers and resist the oxidative stress in stem cells from aged mice. The results also showed that PRP treatment in aged mice could delay mice aging as indicated by survival, body weight and aging phenotypes (behavior and gross morphology) in term of recovering the cellular potential of their stem cells compared to the results on aged control mice. In conclusion these findings showed that PRP has potential to delay aging through the recovery of stem cell senescence and could be used as an alternative medicine for tissue regeneration and future rejuvenation.

Osteoporosis Recovery by Antrodia camphorata Alcohol Extracts through Bone Regeneration in SAMP8 Mice

Antrodia camphorata has previously demonstrated the efficacy in treating cancer and anti-inflammation. In this study, we are the first to evaluate Antrodia camphorata alcohol extract (ACAE) for osteoporosis recovery in vitro with preosteoblast cells (MC3T3-E1) and in vivo with an osteoporosis mouse model established in our previous studies, ovariectomized senescence accelerated mice (OVX-SAMP8). Our results demonstrated that ACAE treatment was slightly cytotoxic to preosteoblast at 25 μg/mL, by which the osteogenic gene expression (RUNX2, OPN, and OCN) was significantly upregulated with an increased ratio of OPG to RANKL, indicating maintenance of the bone matrix through inhibition of osteoclastic pathway. Additionally, evaluation by Alizarin Red S staining showed increased mineralization in ACAE-treated preosteoblasts. For in vivo study, our results indicated that ACAE inhibits bone loss and significantly increases percentage bone volume, trabecular bone number, and bone mineral density in OVX-SAMP8 mice treated with ACAE. Collectively, in vitro and in vivo results showed that ACAE could promote osteogenesis and prevent bone loss and should be considered an evidence-based complementary and alternative medicine for osteoporosis therapy through the maintenance of bone health.

The potential use of platelet-rich plasma to reconstruct the microtia chondrocyte in human auricular cartilage regeneration

Microtia is characterized as an incomplete auricular development and surgical reconstruction for microtia is still limited even with emerging developments. This study aimed to apply bionanomaterials (PRP/collagen scaffold) for human auricular neocartilage reconstruction by using microtia chondrocytes. The results showed that PRP (TGF-β1 750 pg/mL and 1 ng/mL) increased cell viability of microtia chondrocytes during in vitro 9-day cultures. Additionally, chondrogenic-specific mRNA of Aggrecan and type II collagen (Col II) was significantly and continuously expressed with PRP treatment during the 21-day in vitro expansion. Tissue engineering of auricular neocartilage was performed by seeding microtia chondrocytes in bionanomaterials (PRP/collagen scaffold) 3-dimensional (3D) cultures. Immunohistochemistry (IHC) of Col II showed intensive signals between cells and matrix after 4-week cultures. Conclusion. Our results demonstrated that PRP promotes proliferation and redifferentiation of microtia chondrocytes and provides regenerative potentials in auricular neocartilage reconstruction.