Geetanjali B. Tomar

Human gingiva-derived mesenchymal stem cells are superior to bone marrow-derived mesenchymal stem cells for cell therapy in regenerative medicine

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation into multiple cell lineages. Presently, bone marrow is considered as a prime source of MSCs; however, there are some drawbacks and limitations in use of these MSCs for cell therapy. In this study, we demonstrate that human gingival tissue-derived MSCs have several advantages over bone marrow-derived MSCs. Gingival MSCs are easy to isolate, homogenous and proliferate faster than bone marrow MSCs without any growth factor. Importantly, gingival MSCs display stable morphology and do not loose MSC characteristic at higher passages. In addition, gingival MSCs maintain normal karyotype and telomerase activity in long-term cultures, and are not tumorigenic. Thus, we reveal that human gingiva is a better source of MSCs than bone marrow, and large number of functionally competent clinical grade MSCs can be generated in short duration for cell therapy in regenerative medicine and tissue engineering.

Acellular Dermal Matrix Seeded With Autologous Gingival Fibroblasts for the Treatment of Gingival Recession: A Proof-of-Concept Study

BACKGROUND One of the most common esthetic concerns associated with periodontal tissues is gingival recession. There are multiple periodontal plastic surgery approaches documented in the literature for the treatment of such defects. With the tremendous advances being made in periodontal science and technology, tissue engineering could be considered among the latest exciting techniques for recession management. METHODS In this split-mouth, controlled, double-masked clinical case series, 20 sites from 10 patients with Miller Class I or II recessions affecting canines or premolars in the maxillary arch were selected. One tooth in each patient was randomized to receive either a subepithelial connective tissue graft (SCTG) (control group) or an acellular dermal matrix allograft (ADMA) seeded with autologous gingival fibroblasts (test group) under a coronally positioned flap. Clinical parameters, including recession depth, probing depth, clinical attachment level, width of keratinized tissue, attached gingiva, and plaque scores, were recorded by a calibrated examiner at baseline and 3 and 6 months. The inflammation of grafted sites was scored, and the healing time was calculated. The final esthetic outcome of treated sites was assessed by the root coverage esthetic score at the end of 6 months. RESULTS There were no significant differences between test and control sites for all measured clinical parameters. However, the test sites demonstrated less inflammation in the early postoperative period. CONCLUSION Within the limits of this case series, the results indicate that an ADMA seeded with autologous gingival fibroblasts by tissue-engineering technology may be explored as a substitute to an SCTG for the treatment of Miller Class I and II recession defects.

IL-3 Inhibits Human Osteoclastogenesis and Bone Resorption through Downregulation of c-Fms and Diverts the Cells to Dendritic Cell Lineage

IL-3 is an important cytokine that regulates hematopoiesis and functions as a link between the immune and the hematopoietic system. In this study, we investigated the role and mechanism of IL-3 action on human osteoclast formation and bone resorption using PBMCs. PBMCs differentiate into functional osteoclasts in the presence of M-CSF and receptor activator of NF-κB ligand as evaluated by 23c6 expression and bone resorption. We found that IL-3 dose-dependently inhibited formation of 23c6-positive osteoclasts, bone resorption and C-terminal telopeptide of type I collagen, a collagen degradation product. The inhibitory effect of IL-3 on bone resorption was irreversible. To investigate the mechanism of IL-3 action, we analyzed the effect of IL-3 on the receptor activator of NF-κB and c-Fms receptors and c-Fos, PU.1, NFAT cytoplasmic 1, and RelB transcription factors essential for osteoclastogenesis. IL-3 significantly inhibited c-Fms and downregulated both PU.1 and c-Fos at both mRNA and protein level. Furthermore, IL-3–treated cells showed increased expression of dendritic cell markers CD1a and CD80 and decreased expression of monocyte/macrophage marker CD14. Interestingly, IL-3 inhibited formation of human osteoclasts derived from blood monocytes and bone marrow cells of osteoporotic individuals. Thus, IL-3 may have therapeutic potential as an antiosteolytic agent in treatment of osteoporosis.

IL-3 Attenuates Collagen-Induced Arthritis by Modulating the Development of Foxp3+ Regulatory T Cells

IL-3, a cytokine secreted by Th cells, functions as a link between the immune and the hematopoietic system. We previously demonstrated the potent inhibitory role of IL-3 on osteoclastogenesis, pathological bone resorption, and inflammatory arthritis. In this study, we investigated the novel role of IL-3 in development of regulatory T (Treg) cells. We found that IL-3 in a dose-dependent manner increases the percentage of Foxp3+ Treg cells indirectly through secretion of IL-2 by non-Treg cells. These IL-3–expanded Treg cells are competent in suppressing effector T cell proliferation. Interestingly, IL-3 treatment significantly reduces the severity of arthritis and restores the loss of Foxp3+ Treg cells in thymus, lymph nodes, and spleen in collagen-induced arthritis mice. Most significantly, we show that IL-3 decreases the production of proinflammatory cytokines IL-6, IL-17A, TNF-α, and IL-1 and increases the production of anti-inflammatory cytokines IFN-γ and IL-10 in collagen-induced arthritis mice. Thus, to our knowledge, we provide the first evidence that IL-3 play an important role in modulation of Treg cell development in both in vitro and in vivo conditions, and we suggest its therapeutic potential in the treatment of rheumatoid arthritis and other autoimmune diseases.

IL-3 promotes osteoblast differentiation and bone formation in human mesenchymal stem cells.

IL-3 is an important cytokine that regulates hematopoiesis. We have previously demonstrated that IL-3 is a potent inhibitor of osteoclastogenesis and bone resorption. In the present study, we have investigated the role of IL-3 on human osteoblast differentiation and bone formation. We found that IL-3 in a dose-dependent manner increases osteoblast differentiation and matrix mineralization in human mesenchymal stem cells (MSCs). IL-3 significantly enhances the expression of osteoblast specific genes such as alkaline phosphatase, collagen type-I, osteocalcin and osteopontin; and Runx-2 and osterix transcription factors. Moreover, IL-3 induces the expression of bone morphogenetic protein-2 (BMP-2), and activates smad1/5/8. IL-3 enhances osteoblast differentiation and BMP-2 secretion through JAK/STAT pathway. Interestingly, IL-3 promotes in vivo bone regeneration ability of MSCs. Thus, we reveal for the first time that IL-3 enhances human osteoblast differentiation and bone formation in both in vitro and in vivo conditions, and suggest its therapeutic potential for bone formation in important bone diseases.

Novel platinum-palladium bimetallic nanoparticles synthesized by Dioscorea bulbifera: anticancer and antioxidant activities

Medicinal plants serve as rich sources of diverse bioactive phytochemicals that might even take part in bioreduction and stabilization of phytogenic nanoparticles with immense therapeutic properties. Herein, we report for the first time the rapid efficient synthesis of novel platinum–palladium bimetallic nanoparticles (Pt–PdNPs) along with individual platinum (PtNPs) and palladium (PdNPs) nanoparticles using a medicinal plant, Dioscorea bulbifera tuber extract (DBTE). High-resolution transmission electron microscopy revealed monodispersed PtNPs of size 2–5 nm, while PdNPs and Pt–PdNPs between 10 and 25 nm. Energy dispersive spectroscopy analysis confirmed 30.88%±1.73% elemental Pt and 68.96%±1.48% elemental Pd in the bimetallic nanoparticles. Fourier transform infrared spectra indicated strong peaks at 3,373 cm−1, attributed to hydroxyl group of polyphenolic compounds in DBTE that might play a key role in bioreduction in addition to the sharp peaks at 2,937, 1,647, 1,518, and 1,024 cm−1, associated with C–H stretching, N–H bending in primary amines, N–O stretching in nitro group, and C–C stretch, respectively. Anticancer activity against HeLa cells showed that Pt–PdNPs exhibited more pronounced cell death of 74.25% compared to individual PtNPs (12.6%) or PdNPs (33.15%). Further, Pt–PdNPs showed an enhanced scavenging activity against 2,2-diphenyl-1-picrylhydrazyl, superoxide, nitric oxide, and hydroxyl radicals.

Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis.

IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-kappaB (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

Lactobacillus acidophilus inhibits bone loss and increases bone heterogeneity in osteoporotic mice via modulating Treg-Th17 cell balance

Osteoporosis is one of the most important but often neglected bone disease associated with aging and postmenopausal condition leading to bone loss and fragility. Probiotics have been associated with various immunomodulatory properties and have the potential to ameliorate several inflammatory conditions including osteoporosis. Lactobacillus acidophilus (LA) was selected as probiotic of choice in our present study due its common availability and established immunomodulatory properties. In the present study, we report for the first time that administration of LA in ovariectomized (ovx) mice enhances both trabecular and cortical bone microarchitecture along with increasing the mineral density and heterogeneity of bones. This effect of LA administration is due to its immunomodulatory effect on host immune system. LA thus skews the Treg-Th17 cell balance by inhibiting osteoclastogenic Th17 cells and promoting anti-osteoclastogenic Treg cells in ovx mice. LA administration also suppressed expression of osteoclastogenic factors (IL-6, IL-17, TNF-α and RANKL) and increased expression of anti-osteoclastogenic factors (IL-10, IFN-γ). Taken together the present study for the first time clearly demonstrates the therapeutic potential of LA as an osteo-protective agent in enhancing bone health (via tweaking Treg-Th17 cell balance) in postmenopausal osteoporosis.

Probiotics and Bone Health: It takes GUTS to Improve Bone Density

Probiotics are a class of symbiotic bacteria whose administration in adequate amount provides health benefits to the host by altering the composition of gut microbiota. The gut microbiota is known to regulate both the host immune system and metabolism, leading to increased bone mass by inhibiting bone resorption. Ovariectomy induced estrogen deficiency which mimics postmenopausal osteoporosis in women leads to enhanced bone inflammation and resorption. Recently it has been reported that different strains of bacteria (e.g. Lactobacillus, Bifidobacteria etc.), have important role in gut-bone regulation in ovariectomized mouse. Thus administration of probiotics can open up new avenues in treatment of various inflammatory bone conditions such as osteoporosis and rheumatoid arthritis by modulating the delicate balance between the gut microbiota and immune system.

Gloriosa superba Mediated Synthesis of Silver and Gold Nanoparticles forAnticancer Applications

Designing of novel environmentally benign route for synthesis of nanoparticles is a prerequisite for developing nanomedicine. Medicinal plants serve as rich source of diverse phytochemicals which not only synthesizes but also stabilizes the bioreduced nanoparticles. Herein we report for the first time the anticancer activity of gold and silver nanoparticles synthesized employing Gloriosa superba tuber extract. The synthesis was found to be rapid and efficient which completed within 5 h. Optimum concentration of AgNO3 was found to be 3 mM for synthesis of AgNPs while for AuNPs it was found to be 4 mM. Higher temperature facilitated the biosynthesis process, optimum being 50°C. High resolution transmission electron microscopy revealed that the AgNPs were smaller in a range from 3 to 20 nm, majority being spherical in shape. AuNPs were of exotic shapes like spheres, triangles and hexagons that varied in size from 20 to 120 nm. Elemental gold and silver were confirmed in the AuNPs and AgNPs, respectively using energy dispersive spectroscopy and X-ray diffraction spectroscopy. Fourier transform infrared spectroscopy indicated a broad peak from 3300 to 3500 cm-1 in all the three spectra was attributed to O-H group of phenols/alcohol, which could be a component of the GSTE that might play a critical role in synthesis and stabilization. Biochemical analysis showed the presence of phenolics, starch, reducing sugars, ascorbic acid and citric acid. Gas chromatography-mass spectroscopy indicated that the most predominant compounds found in GSTE, were phenol, 3-methoxy-(C7H8O2), salicyl alcohol (C7H8O2), benzoic acid, 2-hydroxy-6-methoxy-(C8H8O4) and asarone (C12H16O3). AgNPs exhibited 42.04 ± 1.87% anticancer activity while AuNPs showed only 35.59 ± 4.1%. A synergistic antiproliferative activity up to 58.48 ± 1.71% was observed on combination of both which was confirmed by flow cytometry and confocal microscopy.