Wnt signaling affects both bone modeling, which occurs during development, and bone remodeling, which is a lifelong process involving tissue renewal. Wnt signals are especially known to affect the differentiation of osteoblasts. In this review, we summarize recent advances in understanding the mechanisms of Wnt signaling, which is divided into two major branches: the canonical pathway and the noncanonical pathway. The canonical pathway is also called the Wnt/β-catenin pathway. There are two major noncanonical pathways: the Wnt-planar cell polarity pathway (Wnt-PCP pathway) and the Wnt-calcium pathway (Wnt-Ca2+ pathway). This review also discusses how Wnt ligands, receptors, intracellular effectors, transcription factors, and antagonists affect both the bone modeling and bone remodeling processes. We also review the role of Wnt ligands, receptors, intracellular effectors, transcription factors, and antagonists in bone as demonstrated in mouse models. Disrupted Wnt signaling is linked to several bone diseases, including osteoporosis, van Buchem disease, and sclerosteosis. Studying the mechanism of Wnt signaling and its interactions with other signaling pathways in bone will provide potential therapeutic targets to treat these bone diseases.

The depressions in RBC, WBC, and neutrophils observed in this study are not only exposure dependent, but also significantly different in the lowest exposed group (at or below 0.25 ppm) compared with unexposed subjects. The results of the present study appear to suggest that lymphocytes may not be more sensitive to chronic benzene exposure than neutrophils.

The aim of the present study was to determine whether early weaning-induced growth retardation could be attenuated by increased consumption of methionine as DL-methionine (DLM) or DL-2-hydroxy-4-methylthiobutyrate (HMTBA) in both lactating sows and weaned piglets. Therefore, diets containing DLM and HMTBA at 25 % of the total sulphur-containing amino acids (AA) present in the control (CON) diet were fed to lactating sows and weaned piglets and their responses were evaluated. Compared with the CON dietfed sows, the HMTBA diet-fed sows exhibited a tendency (P, 0·10) towards higher plasma taurine concentrations and the DLM dietfed sows had higher (P,0·05) plasma taurine concentrations, but lower (P, 0·05) isoleucine concentrations. Suckling piglets in the HMTBA treatment group had higher (P,0·05) intestinal reduced glutathione (GSH) content, lower (P,0·05) oxidised glutathione (GSSG):GSH ratio, and higher (P, 0·05) plasma cysteine and glutathione peroxidase (GPx) activity than those in the CON and DLM treatment groups. The feed intake (P, 0·05) and body weight of piglets averaged across post-weaning (PW) days were higher (P, 0·05) in the HMTBA treatment group than in the DLM treatment group and were higher (P, 0·05) and tended (P, 0·10) to be higher, respectively, in the HMTBA treatment group than in the CON treatment group. Increased (P,0·05) GSSG content and GSSG:GSH ratio and down-regulated (P,0·05) expression of nutrient transport genes were observed in the jejunum of piglets on PW day 7 than on PW day 0. On PW day 14, the HMTBA diet-fed piglets had higher (P, 0·05) intestinal GSH content than the CON diet-fed piglets and higher (P,0·05) plasma GPx activity, villus height and goblet cell numbers than the CON diet-and DLM diet-fed piglets. In conclusion, early weaning-induced growth retardation appears to be attenuated through changes in plasma AA profiles and elevation of growth performance and intestinal antioxidant capacity in piglets following increased consumption of methionine as HMTBA.