Association of blood n-3 fatty acid with bone mass and bone marrow TRAP-5b in the elderly with and without hip fracture.

The plasma n-3 fatty acid level was 26.2% lower in patients with osteoporotic hip fracture than in those with osteoarthritis. In all patients, n-3 fatty acid was positively associated with bone mineral density and inversely associated with tartrate-resistant acid phosphatase-5b level in bone marrow aspirates, reflecting the bone microenvironment. INTRODUCTION: Despite the potential beneficial role of n-3 fatty acid (FA) on bone metabolism, the specific mechanisms underlying these effects in humans remain unclear. Here, we assessed whether the plasma n-3 level, as an objective indicator of its status, is associated with osteoporosis-related phenotypes and bone-related markers in human bone marrow (BM) samples. METHODS: This was a case-control and cross-sectional study conducted in a clinical unit. n-3 FA in the blood and bone biochemical markers in the BM aspirates were measured by gas chromatography/mass spectrometry and immunoassay, respectively. BM fluids were collected from 72 patients who underwent hip surgery because of either osteoporotic hip fracture (HF; n = 28) or osteoarthritis (n = 44). RESULTS: After adjusting for confounders, patients with HF had 26.2% lower plasma n-3 levels than those with osteoarthritis (P = 0.006), and each standard deviation increment in plasma n-3 was associated with a multivariate-adjusted odds ratio of 0.40 for osteoporotic HF (P = 0.010). In multivariate analyses including all patients, a higher plasma n-3 level was associated with higher bone mass at the lumbar spine (ß = 0.615, P = 0.002) and total femur (ß = 0.244, P = 0.045). Interestingly, the plasma n-3 level was inversely associated with the tartrate-resistant acid phosphatase-5b level (ß = - 0.633, P = 0.023), but not with the bone-specific alkaline phosphatase level, in BM aspirates. CONCLUSIONS: These findings provide clinical evidence that n-3 FA is a potential inhibitor of osteoclastogenesis that favors human bone health.

Pine oil effects on chemical and thermal injury in mice and cultured mouse dorsal root ganglion neurons.

A commercial resin-based pine oil (PO) derived from Pinus palustris and Pinus elliottii was the major focus of this investigation. Extracts of pine resins, needles, and bark are folk medicines commonly used to treat skin ailments, including burns. The American Burn Association estimates that 500,000 people with burn injuries receive medical treatment each year; one-half of US burn victims are children, most with scald burns. This systematic study was initiated as follow-up to personal anecdotal evidence acquired over more than 10 years by MH Bhattacharyya regarding PO's efficacy for treating burns. The results demonstrate that PO counteracted dermal inflammation in both a mouse ear model of contact irritant-induced dermal inflammation and a second degree scald burn to the mouse paw. Furthermore, PO significantly counteracted the tactile allodynia and soft tissue injury caused by the scald burn. In mouse dorsal root ganglion neuronal cultures, PO added to the medium blocked adenosine triphosphate-activated, but not capsaicin-activated, pain pathways, demonstrating specificity. These results together support the hypothesis that a pine-oil-based treatment can be developed to provide effective in-home care for second degree burns.

Functional analysis of glucose-dependent insulinotropic polypeptide fusion proteins.

To generate functional fluorescently tagged glucose-dependent insulinotropic polypeptide (GIP), a series of GIP expression constructs were devised. These included G1 (complete preprohormone), G2 (lacking the C-terminal extension), G3 (lacking both N- and C-terminal extensions), G4 (G2 fused to green fluorescent protein, GFP), and G5 (G3 fused to GFP). Expression of G5 in bacteria generated immunopositive GIP together with GFP fluorescence, while G4 generated only fluorescence without immunoreactivity. Transfection of NIH3T3 cells with cDNAs of G1, G3, G5, but not G2, G4, and EGFP, resulted in immunologically detectable GIP formation, although fluorescence could be detected in the latter two. GIP as well as GIP-GFP secreted by NIH3T3 cells significantly stimulated intracellular cAMP accumulation and Ca(2+) mobilization in SaOS2 cells. The GIP receptor antagonist GIP(7-30) abolished these responses. These results suggest that a GIP-GFP fusion protein seven times larger than the native peptide retains function and may be used as an in vivo probe to detect GIP receptor distribution and to explore GIP's biological roles.

Overexpression of protein kinase C alpha and beta1 has distinct effects on bovine aortic endothelial cell growth.

Protein kinase C (PKC) plays an important role in the mitogenic response of endothelial cells to growth factors. PKC alpha and beta1 are the predominant classical isoforms expressed by bovine aortic endothelial cells (BAECs). The present studies were undertaken to elucidate the effect of PKC alpha and beta1 overexpression in BAEC growth. A series of BAEC lines that stably overexpress the full-length PKC alpha and beta1 cDNA were generated by using a replication-defective recombinant retrovirus. The level of PKC alpha and beta1 cDNA expression was determined by assaying for PKC alpha and beta1 mRNA transcripts. PKC alpha and beta1 protein levels were analysed by Western blotting. Functional analysis of these overexpressing lines was performed by measuring PKC activity and phorbol ester-binding assays. PKC alpha and beta1 overexpression had distinctive effects on BAEC growth and cell-cycle progression. Relative to untransfected BAECs and BAECs transfected with the viral vector alone, BAECs that overproduced PKC alpha exhibited reduced proliferation in vitro and increased accumulation of cells in the G2/M phase of the cell cycle. Growth inhibition was greater in cell lines overexpressing higher levels of PKC alpha. Conversely, a 5-fold greater increase in PKC beta1 activity promoted BAEC growth and shortened BAEC doubling time, whereas cells with a 2- to 4-fold increase in enzyme activity had growth profiles similar to those of both control groups. These results suggest that PKC alpha and beta1 overexpression has reciprocal effects on BAEC growth.