Contribution of photodynamic therapy in wound healing: A systematic review.

OBJECTIVE: We researched articles that used photodynamic therapy (PDT) for skin wound healing in humans. METHODS: The systematic review was conducted through scientific articles that investigated the action of PDT on wound healing in humans, published from July 2005 to March 2017, in the data bases PubMed and LILACS. RESULTS: The main types of wound described in selected articles in this review were chronic ulcer and non-melanoma skin cancer. For accomplishing the PDT, second generation of photosensitizing agents with laser or light emitting diode were used. The studies demonstrated that PDT contribute in several ways to the wound healing process: leading to cellular death; reducing or increasing inflammation; stimulating fibroblasts proliferation and, consequently, of collagen and elastin; raising transforming growth factor beta and metalloproteinases. Based on this, PDT provided good results in wound healing process, acting in several steps and accelerating tissue repair. CONCLUSIONS: PDT improved healing in many wound models in humans, revealing itself as a promising therapeutic modality for stimulating wound healing and remodelling.

Anti-nephrolithic potential of resveratrol via inhibition of ROS, MCP-1, hyaluronan and osteopontin in vitro and in vivo.

BACKGROUND: Though resveratrol is known to have anti-cancer, anti-diabetic, anti-oxidant and anti-inflammatory activities, the inhibitory mechanism of resveratrol in kidney stone formation has not been elucidated so far. METHOD: ELISA, flow cytometry, RT-PCR, and western blotting were performed. Human renal epithelial cells (HRCs) and rats with ethylene glycol (EG)-induced kidney stones were used. RESULTS: A wound healing assay revealed that resveratrol significantly inhibited the oxalate-mediated migration of HRCs, considering oxalate mediates kidney stone formation. Also, resveratrol suppressed the mRNA expression of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase subunits such as p22(phox) and p47(phox), monocyte chemoattractant protein 1 (MCP-1) and osteopontin (OPN) in oxalate-treated HRCs. Furthermore, western blotting showed that resveratrol downregulated the expression of MCP-1-related proteins including transforming growth factor(TGF-ß1), TGFR-I or II and hyaluronan in oxalate-treated HRCs. Consistently, resveratrol reduced oxalate-mediated production of reactive oxygen species (ROS) and malondialdehyde (MDA) in oxalate-treated HRCs, while the activities of anti-oxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were enhanced by resveratrol in HRCs and EG-treated kidneys of rats. Consistently, resveratrol significantly reduced the number of urine calcium oxalate crystals and serum MDA, and attenuated the expression of OPN and hyaluroran in EG-treated rats. CONCLUSIONS: Our findings suggest that resveratrol exerts anti-nephrolithic potential via inhibition of ROS, MCP-1 hyaluronan and OPN signaling.

Autocrine TGF-ß protects breast cancer cells from apoptosis through reduction of BH3-only protein, Bim.

Cancer cells undergo multi-step processes in obtaining the ability to metastasize, and are constantly exposed to signals that induce apoptosis. Acquisition of anti-apoptotic properties by cancer cells is important for metastasis, and recent studies suggest that transforming growth factor (TGF)-ß promotes the survival of certain types of cancer cells. Here, we found that in highly metastatic breast cancer cells, JygMC(A), JygMC(B) and 4T1, TGF-ß ligands were produced in autocrine fashion. Pharmacological inhibition of endogenous TGF-ß signalling by a TGF-ß type I receptor kinase inhibitor in serum-free conditions increased the expression of BH3-only protein, Bim (also known as Bcl2-like 11) in JygMC(A) and JygMC(B) cells, and caused apoptotic cell death. We also found that induction of Bim by TGF-ß was not observed in Foxc1 knocked-down cancer cells. These findings suggest that TGF-ß plays a crucial role in the regulation of survival of certain types of cancer cells through the TGF-ß-Foxc1-Bim pathway, and that specific inhibitors of TGF-ß signalling might be useful as apoptosis inducers in breast cancer cells.

Expression of transforming growth factors in hepatocellular carcinoma and its relations with clinicopathological parameters and prognosis.

BACKGROUND: Transforming growth factors (TGF)-beta1, TGF-betaR2 and Smad4 belong to the TGF family, and play important roles in carcinogenesis and the development of carcinoma, especially hepatocellular carcinoma (HCC). TGF-beta1 is a multipotent polypeptide, which inhibits the growth of epithelial cells including hepatoma cell lines and hepatocytes by inducing apoptosis. TGF-betaR2 forms a heterodimeric complex upon binding to TGF-beta, and then generates the first step in the signal transduction pathway leading to growth inhibition in coordination with the type 1 receptor. Smad4 protein is an important mediator in the TGF-beta signaling pathway, and negatively regulates the growth of epithelial cells. This study aimed to detect the expression of TGF-beta1, TGF-betaR2 and Smad4 in HCCs and their adjacent normal tissues, while assessing its relations with the clinicopathological parameters of HCC. METHODS: Forty-seven HCC specimens and their adjacent normal tissues were obtained surgically at the Affiliated Hospital of Medical College, Qingdao University. The expression of TGF-beta1, TGF-betaR2 and Smad4 was separately detected by immunohistochemistry in all HCC specimens and their adjacent normal tissues, and its relations with the clinicopathological parameters of HCC were assessed. RESULTS: The positive expression of TGF-beta1 was 72.34% in the HCC specimens, which was higher than that in the adjacent normal tissues (P<0.001). The positive expression of Smad4 and TGF-betaR2 was 34.04% and 59.57% respectively in the carcinoma specimens. The expression of TGF-beta1, TGF-betaR2 and Smad4 was significantly higher in groups with a tumor embolus of the portal vein, integrity of the amicula, and Edmondson's III-IV than that in other groups, but it was not related to tumor size (P<0.05). CONCLUSIONS: TGF-beta1 may play an important role in the occurrence and development of HCC. Combined detection of TGF-beta1, TGF-betaR2 and Smad4 may be useful for the determination of the degree of malignancy and the prognosis of HCC.

Antisense extracellular signal-regulated kinase-2 gene therapy inhibits platelet-derived growth factor-induced proliferation, migration and transforming growth factor-beta(1) expression in vascular smooth muscle cells and attenuates transplant vasculopathy.

Platelet-derived growth factor-BB (PDGF-BB) enables vascular smooth muscle cells (VSMCs) to proliferate, migrate and secrete connective tissue matrix, which are critical events in transplant vasculopathy. However, little is known about the intracellular pathways that mediate these biologic responses of VSMCs. Extracellular signal-regulated kinase (ERK) pathway plays a major role in cellular responses and vascular diseases. In this study, we observed that the inhibition of ERK2 activity by recombinant adenovirus encoding antisense ERK2 (Adanti-ERK2) significantly suppressed the proliferation, converting of cell cycle from G(1) phase to S phase and directed migration, and partially abrogated transforming growth factor-beta(1) (TGF-beta(1)) expression in VSMCs stimulated with PDGF-BB. Ex vivo gene transfer of Adanti-ERK2 into rat aortic allograft attenuated chronic transplant vasculopathy by the inhibition of VSMC proliferation and migration. In conclusion, ERK2 is involved in PDGF-BB-induced VSMCs proliferation, migration and TGF-beta(1) expression and may be a potential therapeutic target for transplant vasculopathy.

Ascorbic acid induces apoptosis in adult T-cell leukemia.

BACKGROUND: Adult T-cell leukemia (ATL) is an acute malignancy of activated T-cells caused by the human T-cell lymphotrophic virus type-1 (HTLV-1). MATERIALS AND METHODS: The effects of non-cytotoxic concentrations of ascorbic acid (AA) were evaluated against HTLV-1 positive and negative cells. The effect of AA on apoptosis and proliferation was evaluated by cell cycle analysis. The role of p53, p21 Bax and Bcl-2a on cell cycle modulation and apoptosis was also assessed. The anti-proliferative effects were tested by determining the changes in the expression of transforming growth factors (TGF-alpha, TGF-beta1 and TGF-beta2). RESULTS: Ascorbic acid was found to reduce the proliferation of cells and induce apoptosis by the modulation of p53, p21, Bcl-2 and Bax. CONCLUSION: The results of this study show the anti-proliferative effects of AA against leukemic cells.

Characterization of the functional and growth properties of cell lines established from ileal and rectal carcinoid tumors.

Carcinoids of the intestine are the most common gastrointestinal carcinoid tumors. Therapeutic options to treat patients with these tumors are limited. There are very few ileal carcinoid cell lines available for in vitro studies to analyze new drugs that could be effective in treating patients with metastatic tumors. A replication defective recombinant adenovirus with an SV40 early T-antigen insert was used to infect two intestinal carcinoid tumors to create carcinoid cell lines. The cell lines were studied by cell culture, reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry. Both cell lines expressed SV40 large T antigen and receptors for TGFbeta1, TGFbeta2, EGFR, and somatostatin receptors. Treatment with TGFbeta1 led to growth inhibition and increased apoptosis in the cultured cells. Octreotide inhibited cell growth of both cell lines while stimulating apoptosis. Treatment of the HC45 cells with gefitinib also inhibited cell growth in a concentration-dependent manner. TGFbeta treatment stimulated chromogranin A expression while expression of two other granins, chromogranin B and 7B2, did not change significantly. RNA profiling of cells treated with TGFbeta1 showed increased expression of vitamin D3 receptor. This finding was validated by real-time quantitative polymerase chain reaction, Western blotting, and immunohistochemistry. These results indicate that these carcinoid cell lines can be used to study the proliferative and apoptotic mechanisms involved in intestinal carcinoid tumor growth regulation.

L-selectin and intercellular adhesion molecule-1 regulate the development of Concanavalin A-induced liver injury.

Concanavalin A (Con A)-induced hepatitis is a model for human T cell-mediated hepatitis. We evaluated the role of L-selectin and intercellular adhesion molecule-1 (ICAM-1) in this model by injecting Con A intravenously in mice lacking L-selectin (L-selectin-/-), ICAM-1 (ICAM-1-/-), or both (L-selectin/ICAM-1-/-). Blood and liver samples were collected 0, 8, 24, and 48 h after Con A treatment. Increases in plasma transaminase levels, which peaked 8 h after injection, were reduced significantly in L-selectin-/-, ICAM-1-/-, and L-selectin/ICAM-1-/- mice compared with wild-type mice. Liver necrosis was more strongly inhibited in ICAM-1-/- mice than in L-selectin-/- mice but was most prominently reduced in L-selectin/ICAM-1-/- mice, in parallel with decreased plasma transaminase levels. The reduced severity of hepatitis in the mutant mice correlated with decreases in numbers of liver CD4+ T cells but not numbers of CD8+ T cells or neutrophils. Following Con A treatment, L-selectin deficiency reduced liver mRNA expression of tumor necrosis factor-alpha, and ICAM-1 deficiency reduced expression of interleukin-4. By contrast, reductions in liver macrophage inhibitor protein-1alpha mRNA occurred in all mutant mice. These results indicate that L-selectin and ICAM-1 contribute cooperatively to the development of Con A-induced hepatitis by regulating leukocyte infiltration and subsequent cytokine production.

[Progress in gene therapy of liver cirrhosis].

Liver cirrhosis is a common progressive pathological lesion in the late stage of chronic liver disease, which is characterized by disorganization of normal hepatic structure of regenerative nodules and hyperplasia of fibrotic tissues. In recent years, with the development of molecular biology, the molecular mechanisms underlying liver cirrhosis has been revealed more and more, which makes the therapy at the gene level possible. The ideal strategy for the treatment of liver cirrhosis should include prevention of fibrogenesis, stimulation of hepatocyte proliferation and reorganization of the liver architecture. Several gene therapy approaches for treatment of liver cirrhosis have been developed by transfer of some genes of cytokines and enzymes (e.g. HGF, TGF beta 1R, MMPs). These gene therapies can inhibit fibrogenesis and hepatocyte apoptosis and also produce resolution of fibrosis in the cirrhotic liver. Thus, gene therapy may be potentially useful for the treatment of liver cirrhosis, which is otherwise fatal and untreatable by conventional therapy.

[Growth factor and regeneration of intervertebral disc].

OBJECTIVE: To review research progress of the relation between growth factor and repair of intervertebral disc. METHODS: The recent articles on growth factor and repair of intervertebral disc were extensively reviewed. The expression of growth factor in intervertebral disc and the effect of growth factor on disc cells were investigated. RESULTS: Some growth factors play roles in the development and degeneration of intervertebral disc. Exogenous growth factor can increase proliferation of disc cells and production of proteoglycans and collagens. Gene of growth factor can be transferred to intervertebral disc cell by adenovirus. CONCLUSION: Growth factor plays an important role in the regulation of development and degeneration of interertebral disc. The above results show that the feasibility of usage of growth factor in the treatment of disc degeneration and in repair and reconstruction of disc.

Effects of GnRH analogues, 'add-back' steroid therapy, antiestrogen and antiprogestins on leiomyoma and myometrial smooth muscle cell growth and transforming growth factor-beta expression.

The objective of this study was to elucidate the biological significance of GnRH and antiprogestins and antiestrogen in leiomyoma and their interactions with ovarian steroid 'add-back' therapy. Leiomyoma and myometrial smooth muscle cells (LSMC and MSMC) were isolated and exposed to GnRH agonist (leuprolide acetate, LA), 17beta-estradiol (E2), medroxyprogesterone acetate (MPA), GnRH antagonist (Antide), estrogen antagonist, ICI182780 (Fulvestrant) and progesterone antagonists RU486 (Mifepristone) and ZK98299 (Onapristone) and combinations thereof. The rate of DNA synthesis, cell proliferation and transforming growth factor-beta (TGF-beta) expression were then determined. In both cell types, we found that in a dose-dependent manner, LA inhibited, whereas E2, MPA and the combination of E2 + MPA stimulated, the rate of DNA synthesis in these cells. Antide reversed the inhibitory effect of LA, while LA partly inhibited the stimulatory effect of the steroids. In addition, RU486, ICI182780 and ZK98299 at 0.1 micro mol/l or higher doses inhibited the rate of DNA synthesis and partly reversed the effects of E2 and/or MPA. We also found that LSMC expressed elevated levels of TGF-beta1 compared with MSMC. In both cell types, the effects of LA, E2, MPA, RU, ZK and ICI and combinations thereof on TGF-beta1 production were reflective of their effects on DNA synthesis. In line with this, TGF-beta1 was found to stimulate DNA synthesis and the E2-, TGF-beta1- or E2 + TGF-beta1-induced DNA synthesis was found to be inhibited by TGF-beta1 neutralizing antibodies and/or LA. In conclusion, the results provide further evidence that GnRH agonist- and RU486-induced leiomyoma regression is mediated in part through an interactive mechanism that results in altered cell growth and suppression of TGF-beta production.

Activation of a meiotic checkpoint during Drosophila oogenesis regulates the translation of Gurken through Chk2/Mnk.

BACKGROUND: During Drosophila oogenesis, unrepaired double-strand DNA breaks activate a mei-41-dependent meiotic checkpoint, which couples the progression through meiosis to specific developmental processes. This checkpoint affects the accumulation of Gurken protein, a transforming growth factor alpha-like signaling molecule, as well as the morphology of the oocyte nucleus. However, the components of this checkpoint in flies have not been completely elucidated. RESULTS: We show that a mutation in the Drosophila Chk2 homolog (DmChk2/Mnk) suppresses the defects in the translation of gurken mRNA and also the defects in oocyte nuclear morphology. We also found that DmChk2 is phosphorylated in a mei-41-dependent pathway. Analysis of the meiotic cell cycle progression shows that the Drosophila Chk2 homolog is not required during early meiotic prophase, as has been observed for Chk2 in C. elegans. We demonstrate that the activation of the meiotic checkpoint affects Dwee1 localization and is associated with DmChk2-dependent posttranslational modification of Dwee1. We suggest that Dwee1 has a role in the meiotic checkpoint that regulates the meiotic cell cycle, but not the translation of gurken mRNA. In addition, we found that p53 and mus304, the Drosophila ATR-IP homolog, are not required for the patterning defects caused by the meiotic DNA repair mutations. CONCLUSIONS: DmChk2 is a transducer of the meiotic checkpoint in flies that is activated by unrepaired double-strand DNA breaks. Activation of DmChk2 in this specific checkpoint affects a cell cycle regulator as well as mRNA translation.

[Effects of androgen and estrogen on the expressions of basic fibroblast growth factor, transforming growth factor and smoothelin].

OBJECTIVE: To study effects of androgen and estrogen on the expressions of basic fibroblast growth factor (bFGF) and transforming growth factor beta2 (TGFbeta2) in cultured human prostatic stromal cells. METHODS: Human prostatic stromal cells obtained from 11 patients with benign prostatic hypertrophy (BPH) were cultured and stimulated with dihydrotestosterone (DHT) and estradiol (E2). The expressions of bFGF and TGFbeta2 mRNA along with smoothelin mRNA were observed with reverse transcriptase-polymerase chain reaction. RESULTS: DHT significantly upregulated bFGF expression, and E2 enhanced TGFbeta2 and smoothelin expressions. A positive correlation between expressions of TGFbeta2 and smoothelin was observed. CONCLUSION: DHT can induce bFGF expression and E2 promotes TGFbeta2 expression, and the transformation toward smooth muscle cells induced by E(2) may involve the action of TGFbeta2.

Further studies on the early protective responses of pigs following immunisation with high potency foot and mouth disease vaccine.

The ability of an emergency oil adjuvanted foot-and-mouth disease (FMD) vaccine to elicit early protective immunity in pigs against direct contact homologous challenge was examined. All vaccinates showed reduced viraemia and shedding of FMDV, and certain animals were protected, showing no clinical signs. IL-6, IL-8 and IL-12 were consistently detected in challenged animals that had been vaccinated. Other cytokines--IL-1, IL-2, TNF, TGF and interferons--were not detected. This demonstrates that the vaccine did not induce a systemic inflammatory response, nor a systemic elevation of T lymphocyte activity. Although the IL-6 and IL-8 did not relate to protection, IL-12 production was highest in the protected vaccinated pigs. Thus, the induction of monocytic cell activity, demonstrable by the production of IL-6, IL-8 and IL-12, appears to play a critical role in FMDV emergency vaccine induction of the innate immune defences which relate to early protection against FMD. The possible modes of defence in which such cytokine activity would be involved are discussed.

The phosphodiesterase inhibitor, pentoxifylline, alters rat intestinal epithelial cell proliferation via changes in the expression of transforming growth factors.

BACKGROUND: Phosphodiesterase (PDE) inhibitors, among which pentoxifylline (PTX), are candidate molecules for the treatment of TNF-alpha-dependent inflammatory diseases. Based on the controversial effects of PTX observed in experimentally-induced colitis, the aim of this work was to analyse its influence on intestinal epithelial cell proliferation and growth factor expression using the well-established IEC18 cell line. METHODS: The effects of PTX, and of an activation (addition of dibutyryl-cAMP, db-cAMP) or inhibition (by a specific cAMP-protein kinase inhibitor, PKI) of the cAMP pathway, were examined after 3 days of culture. The IEC18 cell proliferation and [3H] thymidine incorporation, as well as the expression of TGF-alpha, TGF-beta1 and -beta2 mRNAs, were analysed in basal culture conditions and in the presence of the pro-inflammatory cytokine, TNF-alpha. RESULTS: PTX, like exogenous db-cAMP, inhibited in a dose-dependent manner the basal and TNF-alpha-modulated IEC18 cell proliferation; this effect was partly prevented by PKI. We confirmed that PTX induced a dose-related increase in intracellular cAMP. Concomitantly, the expression of TGF-alpha mRNA dropped and that of TGF-beta2 increased. Addition of db-cAMP instead of PTX also decreased TGF-alpha mRNA, but did not change TGF-beta2 transcripts. The decrease in the expression of TGF-alpha mRNA caused by PTX and db-cAMP was completely abolished by PKI; in contrast, TGF-beta2 remained unaltered. Yet, anti-TGF-beta2 antibodies partially restored the PTX-inhibited cell proliferation. CONCLUSION: The phosphodiesterase inhibitor, PTX, inhibits IEC18 cell proliferation via a differential modulation of TGF-alpha and TGF-beta2 expression. The drop in TGF-alpha mRNA is related to increasing intracellular cAMP, whereas the effect upon TGF-beta2 appears cAMP-independent.

Functioning of the Drosophila orb gene in gurken mRNA localization and translation.

The orb gene encodes an RNA recognition motif (RRM)-type RNA-binding protein that is a member of the cytoplasmic polyadenylation element binding protein (CPEB) family of translational regulators. Early in oogenesis, orb is required for the formation and initial differentiation of the egg chamber, while later in oogenesis it functions in the determination of the dorsoventral (DV) and anteroposterior axes of egg and embryo. In the studies reported here, we have examined the role of the orb gene in the gurken (grk)-Drosophila epidermal growth factor receptor (DER) signaling pathway. During the previtellogenic stages of oogenesis, the grk-DER signaling pathway defines the posterior pole of the oocyte by specifying posterior follicle cell identity. This is accomplished through the localized expression of Grk at the very posterior of the oocyte. Later in oogenesis, the grk-DER pathway is used to establish the DV axis. Grk protein synthesized at the dorsal anterior corner of the oocyte signals dorsal fate to the overlying follicle cell epithelium. We show that orb functions in both the early and late grk-DER signaling pathways, and in each case is required for the localized expression of Grk protein. We have found that orb is also required to promote the synthesis of a key component of the DV polarity pathway, K(10). Finally, we present evidence that Orb protein expression during the mid- to late stages of oogenesis is, in turn, negatively regulated by K(10).

Divergence of the inflammatory response in two types of chickens.

We compared inflammatory responses to lipopolysaccharide (LPS) injection in laying type (Brown Nick) to broiler type (Avian x Avian) chicks. Rectal temperature was measured at 0, 1, 2, 4, 6, 12, and 24h after LPS injection (0, 0.1, 0.3, 0.6, 1, 2.5, or 5mg/kg bw). In layers, rectal temperature increased from 41.31+/-0.19 degrees C to a maximum 42.27+/-0.41 degrees C at 4h after 1mg/kg LPS. Relative to layers, the febrile response in broilers was considerably lower, delayed in onset, and required higher levels of LPS (5mg/kg). Proliferation of spleen cells from un-injected chicks in response to LPS, PHA, and Con A was evaluated in vitro. IFNgamma, TGFbeta(2), MGF and IL-1beta relative to beta-actin mRNA expression were analyzed in spleen cells stimulated with LPS. Splenocytes from layers had a higher proliferative response to LPS (P=0.045), but lower proliferative response to PHA (P=0.004) and Con A (P=0.004) than broilers. Expression of mRNA for MGF, IL-1beta and IFNgamma was lower in broilers than in layers (P<0.001). Reduced production of the pro-inflammatory cytokines in broilers could have resulted from the observed increased production of the immunosuppressive cytokine TGFbeta(2.) These differences in cytokine expression may explain the blunted febrile response in broilers compared to layers. Because the acute phase response of inflammation causes decreased food intake, the blunted inflammatory response of broilers may permit faster growth.

A role for the DP subunit of the E2F transcription factor in axis determination during Drosophila oogenesis.

The E2F family of transcription factors contributes to cell cycle control by regulating the transcription of DNA replication factors. Functional 'E2F' is a DNA-binding heterodimer composed of E2F and DP proteins. Drosophila contains two E2F genes (dE2F, dE2F2) and one DP gene (dDP). Mutation of either dE2F or dDP eliminates G(1)-S transcription of known replication factors during embryogenesis and compromises DNA replication. However, the analysis of these mutant phenotypes is complicated by the perdurance of maternally supplied gene function. To address this and to further analyze the role of E2F transcription factors in development we have phenotypically characterized mitotic clones of dDP mutant cells in the female germline. Our analysis indicates that dDP is required for several essential processes during oogenesis. In a fraction of the mutant egg chambers the germ cells execute one extra round of mitosis, suggesting that in this tissue dDP is uniquely utilized for cell cycle arrest rather than cell cycle progression. Mutation of dDP in the germline also prevents nurse cell cytoplasm transfer to the oocyte, resulting in a 'dumpless' phenotype that blocks oocyte development. This phenotype likely results from both disruption of the actin cytoskeleton and a failure of nurse cell apoptosis, each of which are required for normal cytoplasmic transfer. Lastly, we found that dDP is required for the establishment of the dorsal-ventral axis, as loss of dDP function prevents the localized expression of the EGFR ligand Gurken in the oocyte, which initiates dorsal-ventral polarity in the egg chamber. Thus we have uncovered new functions for E2F transcription factors during development, including an unexpected role in pattern formation.

[The mechanism of bone formation promoted by mechano-electrical environments--current studies on local bone factors].

The mechanism for promoting bone formation under the mechanical and the electromagnetical fields stimulation is not yet quite clear. In recent years, it has been found the mechanical and electromagnetical environments may induce the osteogenic cells to produce some local bone factors, such as prostaglandin E2(PGE2), insultine-like growth factors-II (IGF-II), bone morphogenetic protein (BMP) and transforming growth factor beta (TGF-beta). These factors play an important role in bone formation and remodeling. This article introduces current studies on some of these local bone factors under the stimulation of the mechanical and electromagnetical environments.