| 1. |
- Hagforsen, Eva, et al.
(författare)
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Women with palmoplantar pustulosis have disturbed calcium homeostasis and a high prevalence of diabetes mellitus and psychiatric disorders : a case-control study
- 2005
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Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 85:3, s. 225-232
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Tidskriftsartikel (refereegranskat)abstract
- Palmoplantar pustulosis is characterized by pustule formation in the acrosyringium. Nearly 50% of palmoplantar pustulosis sera produce immunofluorescence of the palmar papillary endothelium from healthy subjects, but also of the endothelium of normal parathyroid gland. With a case-control design the levels of calcium and parathyroid hormone in serum were measured in 60 women with palmoplantar pustulosis and 154 randomly selected population-based control women. One-third of the controls had been smokers, whereas 95% of the cases were or had been smokers. Mean age-adjusted serum calcium was increased in the patients compared with the controls (2.43 vs 2.36 mmol/l; p<0.0001), whereas the parathyroid hormone concentration was suppressed (23.2 vs 31.1 ng/l; p<0.0001). The plasma levels of parathyroid hormone-related protein were normal in patients but there was a strong expression of this protein in the acrosyringium both in palmoplantar pustulosis and control skin. As even a marginal elevation of serum calcium is associated with an increased risk for diabetes, cardiovascular disease and psychiatric disease, we analysed the risk for these disorders in palmoplantar pustulosis patients compared with that in the control group. Both diabetes mellitus and psychiatric disorders were associated with palmoplantar pustulosis with an odds ratio of 8.7 (95% CI 3.3-22.8) and 5.6 (95% CI 2.2-14.4), respectively. Palmoplantar pustulosis is a complex disease with an increased risk for several non-dermatological disorders. The role of the mildly increased serum calcium for the high risk for diabetes and depression deserves to be studied.
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| 2. |
- Lagumdzija, Alena
(författare)
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The effects of some peptide hormones on osteoblast-like cells : with specific focus on oxytocin and vasopressin
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The nonapeptides oxytocin (OXT) and vasopressin (AVP) are mainly produced in the hypothalamus and released into the circulation through the neurohypophysis. Recently, an OXT-receptor was demonstrated in human osteoblast-like (hOB) cells, and it has been suggested that patients with central diabetes insipidus (deficiency of AVP) have decreased bone mass. Insulin-like growth factor-I (IGF-I), parathyroid hormone (PM), and PTH-related protein (PTHrP) are hormones that have known anabolic effects on bone metabolism. These hormones, as well as AVP, increase the production of nitric oxide (NO) from endothelial cells. NO is also produced in osteoblasts (OB) and participates in the regulation of bone metabolism. One of the aims of the present studies was to investigate the effects of OXT and AVP on OBlike cells. Primary cultures of human OB-like (hOB) cells were prepared from trabecular bone material obtained during knee- and hip-joint replacement surgery. An osteosarcoma cell line (SaOS-2) was used as well. A second aim was to evaluate whether NO was involved in the effects of AVP, IGF-I and PTH/PTHrP For this purpose, bone marrow cells with an OB-phenotype derived from endothelial nitric oxide synthase knockout (eNOSKO) mice and their wild type (WT) counterparts were studied. OXT and AVP increased the proliferation and protein synthesis of OB-like cells. The effects were found in concentrations close to physiological (10- 100 pmol/l) and were abolished by an OXT- and V 1-receptor antagonist or a proteinkinase C inhibitor, respectively. These findings indicate that the effects of OXT and AVP were mediated through receptors specific to these peptides. In addition, the expression of mRNA for the V 1 a-receptor in hOB cells was demonstrated by RT-PCR. OXT and AVP decreased the production of interleukin-6 from h0B cells and AVP decreased the production of macrophage colony-stimulating factor (MCSF) as well. Neither AVP nor IGF-I induced an increase in cell proliferation in OB-like cells derived from eNOSKO mice, whereas an increase in cell proliferation could be demonstrated in cells derived from WT mice, as well as in cells from eNOSKO mice incubated with an NO donor, SNAP. Thus NO might be involved in the effects of AVP and IGF-I on OB-like cells. In contrast, the increase in cell proliferation in response to PTH and PTHrP seemed to be independent of NO synthesis, since PTH and PTHrP increased cell proliferation in cells from both WT and eNOSKO mice. In conclusion, OXT and AVP increased proliferation of OB-like cells and for the first time mRNA for an AVP-receptor was demonstrated in h0B cells. It is likely that OXT and AVP also may be of importance for bone metabolism in vivo. These peptides or their analogues may, in the future, be used therapeutically for the prevention of osteopenia or the treatment of osteoporosis.
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| 3. |
- Tsai, Jon A., et al.
(författare)
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Albumin-bound lipids induce free cytoplasmic calcium oscillations in human osteoblast-like cells
- 2007
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Ingår i: Cell Biochemistry and Function. - : Wiley. - 0263-6484 .- 1099-0844. ; 25:3, s. 245-249
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Tidskriftsartikel (refereegranskat)abstract
- [Ca2+](i) oscillations were found in human osteoblast-like cells (hOB cells) exposed to high-lipid bovine serum albumin (BSA), but not when exposed to low-lipid BSA. These [Ca2+](i) oscillations were inhibited by heptanol and suramin, which implies that gap junctions and purinergic signalling may be important for these [Ca2+](i) oscillations. The high-lipid BSA preparation that was used contains arachidonic acid. [Ca2+](i) oscillations could be induced by low lipid albumin with arachidonic acid added. The albumin-bound lipids were also important for osteoblast growth since DNA synthesis and the total cell protein content was higher in hOB cells exposed to high-lipid BSA. The effect of arachidonic acid on hOB cell proliferation was bone-donor dependent; both stimulatory and inhibitory effects were observed. The physiological importance of albumin-bound lipids is unclear; given that albumin has only minimal contact with osteoblasts under normal conditions. Only when bone capillaries are disrupted, e.g. during a fracture, would significant amounts of albumin reach osteoblasts. Albumin-bound lipids could therefore contribute to stimulation of osteoblast proliferation during fracture healing.
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