Exploring complications following cranioplasty after decompressive hemicraniectomy: A retrospective bicenter assessment of autologous, PMMA and CAD implants

Cranioplasty (CP) after decompressive hemicraniectomy (DHC) is a common neurosurgical procedure with a high complication rate. The best material for the repair of large cranial defects is unclear. The aim of this study was to evaluate different implant materials regarding surgery related complications after CP. Type of materials include the autologous bone flap (ABF), polymethylmethacrylate (PMMA), calcium phosphate reinforced with titanium mesh (CaP-Ti), polyetheretherketone (PEEK) and hydroxyapatite (HA). A retrospective, descriptive, observational bicenter study was performed, medical data of all patients who underwent CP after DHC between January 1st, 2016 and December 31st, 2022 were analyzed. Follow-up was until December 31st, 2023. 139 consecutive patients with a median age of 54 years who received either PMMA (56/139; 40.3%), PEEK (35/139; 25.2%), CaP-Ti (21/139; 15.1%), ABF (25/139; 18.0%) or HA (2/139; 1.4%) cranial implant after DHC were included in the study. Median time from DHC to CP was 117 days and median follow-up period was 43 months. Surgical site infection was the most frequent surgery-related complication (13.7%; 19/139). PEEK implants were mostly affected (28.6%; 10/35), followed by ABF (20%; 5/25), CaP-Ti implants (9.5%; 2/21) and PMMA implants (1.7%, 1/56). Explantation was necessary for 9 PEEK implants (25.7%; 9/35), 6 ABFs (24.0%; 6/25), 3 CaP-Ti implants (14.3%; 3/21) and 4 PMMA implants (7.1%; 4/56). Besides infection, a postoperative hematoma was the most common cause. Median surgical time was 106 min, neither longer surgical time nor use of anticoagulation were significantly related to higher infection rates (p = 0.547; p = 0.152 respectively). Ventriculoperitoneal shunt implantation prior to CP was noted in 33.8% (47/139) and not significantly associated with surgical related complications. Perioperative lumbar drainage, due to bulging brain, inserted in 38 patients (27.3%; 38/139) before surgery was protective when it comes to explantation of the implant (p = 0.035). Based on our results, CP is still related to a relatively high number of infections and further complications. Implant material seems to have a high effect on postoperative infections, since surgical time, anticoagulation therapy and hydrocephalus did not show a statistically significant effect on postoperative complications in this study. PEEK implants and ABFs seem to possess higher risk of postoperative infection. More biocompatible implants such as CaP-Ti might be beneficial. Further, prospective studies are necessary to answer this question.

POS0258 SAFETY AND IMMUNOGENICITY OF BNT162b2 mRNA COVID-19 VACCINE AMONG ADOLESCENTS WITH RHEUMATIC DISEASES TREATED WITH IMMUNOMODULATORY MEDICATIONS

Background

Adolescents with juvenile-onset autoimmune inflammatory rheumatic diseases (AIIRD) could be at risk for disease flare secondary to SARS-CoV-2 infection or to withholding anti-inflammatory therapy. While vaccination can protect against COVID-19, safety and immunogenicity data regarding anti-SARS-CoV-2 vaccines among adolescents with AIIRD are limited.

Objectives

This international, prospective, multicentre study evaluated the safety and immunogenicity of the BNT162b2 anti-SARS-CoV-2 vaccine among adolescents and young adults with juvenile-onset AIIRD, 80% of whom are on chronic immunomodulatory therapy.

Methods

Vaccine side effects, disease activity, and short-term efficacy were evaluated after 3 months in 91 patients. Anti-spike S1/S2 IgG antibody levels were evaluated in 37 patients and 22 controls, 2–9 weeks after the second dose.

Results

Ninety-one patients and 40 healthy controls were included. Safety profile was good, with 96.7% (n=88) of patients reporting mild or no side-effects, and no change in disease activity. However, 3 patients had transient acute symptoms: 2 following the first vaccination (renal failure and pulmonary haemorrhage) and 1 following the second dose (mild lupus flare vs. viral infection). Seropositivity rate was 97.3% in the AIIRD group compared with 100% among controls. However, anti-S1/S2 antibody titres were significantly lower in the AIIRD group compared with controls (242±136.4 vs. 387.8±57.3 BAU/ml, respectively; p<0.0001). No cases of COVID-19 were documented during the 3-month follow-up.

Conclusion

Vaccination of juvenile-onset AIIRD patients demonstrated good short-term safety and efficacy, high seropositivity rate, but lower anti-S1/S2 antibody titres compared to healthy controls. These results should encourage vaccination of adolescents with juvenile-onset AIIRD, even while on immunomodulation.

References

[1]Fact sheet for healthcare providers administrating vaccine emergency use authorization (EUA) of the Pfizer-BioNTech COVID-19 vaccine to prevent coronavirus disease 2019 (COVID-19) for 12 years of age and older dilute before use for 12 years of age and old; Available from: www.cvdvaccine.com.

[2]Polack FP, Thomas SJ, Kitchin N, Absalon J, Gurtman A, Lockhart S, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Eng J Med 2020;383:2603–15. DOI: 10.1056/NEJMoa2034577

[3]Frenck RW, Klein NP, Kitchin N, Gurtman A, Absalon J, Lockhart S, et al. Safety, immunogenicity, and efficacy of the BNT162b2 Covid-19 vaccine in adolescents. N Eng J Med 2021;385:239–50.

[4]First COVID-19 vaccine approved for children aged 12 to 15 in EU | European Medicines Agency [Internet]. [cited 2022 Jan 3]. Available from: https://www.ema.europa.eu/en/news/first-covid-19-vaccine-approved-children-aged-12-15-eu

[5]FDA authorizes Pfizer-BioNTech COVID-19 vaccine for emergency use in children 5 through 11 Years of Age | FDA [Internet]. [cited 2022 Jan 1]. Available from: https://www.fda.gov/news-events/press-announcements/fda-authorizes-pfizer-biontech-covid-19-vaccine-emergency-use-children-5-through-11-years-age

[6]Woodworth KR, Moulia D, Collins JP, Hadler SC, Jones JM, Reddy SC, et al. The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Pfizer-BioNTech COVID-19 Vaccine in Children Aged 5–11 Years — United States, November 2021. MMWR Morbidity and Mortality Weekly Report [Internet]. 2021 Nov 12 [cited 2021 Dec 1];70(45):1579–83. Available from: https://www.cdc.gov/mmwr/volumes/70/wr/mm7045e1.htm

[7]Liguoro I, Pilotto C, Bonanni M, Ferrari ME, Pusiol A, Nocerino A, et al. SARS-COV-2 infection in children and newborns: a systematic review. Eur J Pediatr 2020;179:1029–46.

Acknowledgements

We thank the families and adolescents who participated in the study. We thank Mr. Yishai Friedlander, MPH, for performing the statistical analysis. We thank Faye Schreiber, MS, for editing the manuscript.

Disclosure of Interests

None declared

LB0003 IMMUNOGENICITY AND SAFETY OF THE BNT162b2 mRNA COVID-19 VACCINE IN ADULT PATIENTS WITH AUTOIMMUNE INFLAMMATORY RHEUMATIC DISEASES AND GENERAL POPULATION: A MULTICENTER STUDY

Background:

Vaccination represents a cornerstone in mastering the COVID-19 pandemic. Data on immunogenicity, efficacy, and safety of the novel BNT162b2 mRNA vaccine in patients with autoimmune inflammatory rheumatic diseases (AIIRD) are limited.

Objectives:

To investigate the immunogenicity, efficacy, and safety of the BNT162b2 mRNA vaccine in patients with AIIRD compared to the general population.

Methods:

A prospective multicenter study investigated immunogenicity, efficacy, and safety of the two-dose regimen BNT162b2 mRNA vaccine in adult patients with AIIRD including rheumatoid arthritis (RA), psoriatic arthritis (PsA), axial spondyloarthropathy (axSpA), systemic lupus erythematosus (SLE), connective tissues diseases (CTD), systemic vasculitides, and idiopathic inflammatory myositis (IIM), compared to control subjects without rheumatic diseases or immunosuppressive therapies. Serum IgG antibody levels against SARS-CoV-2 spike S1/S2 proteins were measured 2 - 6 weeks after the second vaccine dose. Seropositivity was defined as IgG ≥15 binding antibody units (BAU)/ml. Post-vaccination efficacy defined as post-vaccination COVID-19 infection and safety were assessed. Pre- and post- vaccination disease activity indices were assessed as appropriate for each disease.

Results:

A total of 686 AIIRD patients and 121 controls participated into the study. AIIRD patients were significantly older than controls, mean age±SD 56.76±14.88 vs 50.76±14.68, respectively, p<0.0001. A total of 95.2% (n=653) AIIRD patients were treated with immunomodulatory medications.

The seropositivity rate was 86% (n=590) in patients with AIIRD compared to 100% in controls (p <0.0001) The level of the S1/S2 antibodies was significantly reduced in AIIRD patients compared to controls (mean± SD 132.9±91.7 vs 218.6±82.06, P<0.0001). In patients with PsA, AxSpA, SLE, and LVV, the seropositive rate was above 90%. In RA, the seropositive rate was 82.1% and the lowest seropositive rate (<40%) was observed in patients with AAV and IIM.

Anti-CD20 significantly impaired the vaccine’s immunogenicity, with the lowest seropositivity rate of 39%. The use of GC, mycophenolate mofetil (MMF), and abatacept was associated with a significantly lower rate of seropositivity (Figure 1). MTX significantly reduced the seropositivity in patients treated with MTX monotherapy and in combinations with other treatments (92% and 84%, respectively), although at a lesser magnitude than anti-CD20, MMF, and abatacept. More than 97% of patients treated with anti-cytokine therapies including TNFi, interleukin-17 and interleukin-6 inhibitors had an appropriate immunogenic response when used as monotherapy. The combination of TNFi with MTX significantly reduced the rate of seropositivity to 93%, p=0.04. Age over 65 years, a diagnosis of RA, IIM, ANCA-associated vascilitis, and treatment with GC, MMF, anti-CD20, and abatacept were associated with a reduced likelihood of seropositivity.

Figure 1.

Seropositivity rate by immunosuppressive treatment.

There were no post-vaccination symptomatic cases of COVID-19 among AIIRD patients and one mild case in the control group. Major adverse events in AIIRD patients included death (n=2) several weeks after the second vaccine dose, non-disseminated herpes zoster (n=6), uveitis (n=2), and pericarditis (n=1). Post-vaccination disease activity remained stable in the majority of patients.

Conclusion:

Vaccination with the BNTb262 vaccine resulted in an adequate immunogenic response with an acceptable safety profile in the majority of patients with AIIRD. Treatment with GC, rituximab, MMF, and abatacept may impair BNT162b2-induced immunogenicity. Postponing administration of rituximab, when clinically feasible, seems to be reasonable to improve vaccine-induced immunogenicity. Holding treatment with abatacept and MMF may be considered on an individual basis.

Disclosure of Interests:

None declared

Association of gastrointestinal events and osteoporosis treatment initiation in newly diagnosed osteoporotic Israeli women

BACKGROUND

The objective was to examine the association of gastrointestinal (GI) events and osteoporosis treatment initiation patterns among postmenopausal women following an osteoporosis diagnosis from an Israeli health plan.

METHODS

This retrospective analysis of claims records included women aged ≥ 55 years with ≥ 1 osteoporosis diagnosis (date of first diagnosis was index date). Osteoporosis treatment initiation was defined as use of osteoporosis therapy (oral bisphosphonates or other) during 12 months postindex. GI events (diagnosis of GI conditions) were reported for 12 months preindex and postindex (from index to treatment initiation or 1 year postindex, whichever occurred first). The association of postindex GI events (yes/no) with the initiation of osteoporosis treatment (yes/no) and with type of therapy initiated (oral bisphosphonate vs. other) were examined with logistic regression and Cox proportional hazard regression (as sensitivity analysis).

RESULTS

Among 30,788 eligible patients, 17.5% had preindex GI events and 13.0% had postindex GI events. About 70.6% of patients received no osteoporosis therapy within 1 year of diagnosis, 24.9% received oral bisphosphonates and 4.5% received other medications. Postindex GI events were associated with lower odds of osteoporosis medication initiation (85-86% reduced likelihood; p < 0.01). Upon treatment initiation, postindex GI was not significantly associated with the type of osteoporosis therapy initiated, controlling for baseline GI events and patient characteristics.

CONCLUSIONS

Among newly diagnosed osteoporotic women from a large Israeli health plan, 70.6% did not receive osteoporosis treatment within 1 year of diagnosis. The presence of GI events was associated with reduced likelihood of osteoporosis treatment initiation.

Calciotrophic hormones and hyperglycemia modulate vitamin D receptor and 25 hydroxyy vitamin D 1-α hydroxylase mRNA expression in human vascular smooth muscle cells

Estrogen receptors (ERα and ERβ), the vitamin D receptor (VDR) and 25 hydroxyy vitamin D 1-α hydroxylase (1OHase) mRNA are expressed in vascular smooth muscle cells (VSMC). In these cells estrogenic hormones modulate cell proliferation as measured by DNA synthesis (DNA). In the present study we determined whether or not the calciotrophic hormones PTH 1-34 (PTH) and less- calcemic vitamin D analog QW as well as hyperglycemia can regulate DNA synthesis and CK. E2 had a bimodal effect on VSMC DNA synthesis, such that proliferation was inhibited at 30nM but stimulated at 0.3nM. PTH at 50nM increased, whereas QW at 10nM inhibited DNA synthesis. Hyperglycemia inhibited the effects on high E2, QW and PTH on DNA only. Both QW and PTH increased ERα mRNA expression, but only PTH increased ERβ expression. Likewise, both PTH and QW stimulated VDR and 1OHase expression and activity. ERβ, VDR and 1OHase expression and activity were inhibited by hyperglycemia, but ERα expression was unaffected by hyperglycemia. In conclusion, calcitrophic hormones modify VSMC growth and concomitantly affect ER expression in these cells as well as the endogenous VSMC vitamin D system elements, including VDR and 1OHase. Some of the later changes may likely participate in growth effects. Of importance in the observation is that several regulatory effects are deranged in the presence of hyperglycemia, particularly the PTH- and vitamin D-dependent up regulation of VDR and 1OHase in these cells. The implications of these effects require further studies. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

New vitamin D less-calcemic analog affect human bone cell line and cultured vascular smooth muscle cells similar to other less-calcemic analogs

Primary cultures of human bone and vascular cells respond to vitamin D treatment by modulation of cell proliferation measured by DNA synthesis (DNA) and energy metabolism measured by creatine kinase specific activity (CK) via binding to vitamin D receptors (VDR) which are expressed in these cells. Vitamin D compounds also modulate the response to estradiol-17β (E₂) and the expression mRNAs of estrogen receptors (ERα and ERβ), VDR, 25-hydroxy vitamin D₃ 1-α hydroxylase (1OHase) and lipoxygenases (12LO and 15LO). We now compared our newly synthesized analog: 1α,25-dihydroxy-9-methylene-19-norvitamin D₃ JK152 (JK), on bone and vascular cells compared to other analogs. Human bone cell line SaOS₂ respond to JK by increased DNA and stimulated CK dose-dependently, similar to the less-calcemic analogs CB 1093 (CB) and EB 1089 (EB). JK also up-regulated the response to E₂ in terms of DNA and CK. JK inhibited DNA synthesis and increased CK in primary human vascular smooth muscle cells (VSMC) dose-dependently similar to EB and CB. JK up regulated the response to E₂ in terms of CK with no effect on DNA. JK similar to CB and EB stimulated mRNA expression of VDR and ERα, 12LO and 15LO, with no effect on ERβ and 1OHase mRNA expression in SaOS₂ measured by real time PCR. Similar treatments of VSMC with JK, CB and EB stimulated 12LO and 15LO, VDR and ERα mRNA expression with no effect on ERβ and 1OHase mRNA expression. The results presented here demonstrate that the new vitamin D less-calcemic analog JK is similar to other analogs in its effects on human cultured cells and therefore may be used in combined hormone replacement treatment (HRT) both in vitro and in vivo.

Vitamin D less-calcemic analog modulates the expression of estrogen receptors, vitamin D receptor and 1α-hydroxylase 25-hydroxy vitamin D in human thyroid cancer cell lines

Estrogen receptors (ERs) are expressed in various "non-reproductive" cancer cell types. Some cancer types express 1α-hydroxylase 25-hydroxy vitamin D (1OHase) whose product, 1,25(OH)2D3 can retard cancer cell proliferation. Thyroid carcinoma cell growth is apparently promoted by estrogens, but whether or not this interaction is modified by vitamin D metabolites/analogs is presently unknown. Here we assessed the effect of a less calcemic vitamin D analog [JK 1624 F2-2 (JKF)] in three human thyroid cancer cell lines: ARO (anaplastic carcinoma), NPA (papillary carcinoma) and MRO (follicular carcinoma). (1) All cell lines expressed both ERα and ERβ, vitamin D receptor (VDR) and 1OHase mRNA quantified by Real Time PCR. There was a general abundance of ERβ over ERα expression, such that the ratio of ERβ to ERα mRNA was >1000:1, 228:1 and 7.7:1 in ARO, MRO and NPA cells, respectively. (2) JKF up regulated ERβ expression in ARO (by 110±15%) and MRO (by 280±10%) but down regulated ERβ in NPA cells (by 40±15%). The expression of VDR was up regulated by JKF in NPA (21±6%), down regulated in ARO (-24±7%) and not affected in MRO. (3) All three human thyroid cancer cell lines were found to express 1OHase, which was up regulated by JKF in MRO (350±25%) and NPA (35±8%) but down regulated in ARO (-20±5%). This is the first report to describe direct regulation of VDR and 1OHase expression by a vitamin D analog in human thyroid cancer cells. A functional role for the vitamin D system in human thyroid cancer is suggested by the finding that the vitamin D analog can affect ERs expression which is in turn involved in estrogen-induced cell growth in an ER-type specific manner in these cells.

Mutual interaction of special phytoestrogenic compounds, their synthetic carboxy-derivatives and the less-calcemic vitamin D analog activities in human derived female cultured osteoblasts

Cultured female-derived human bone cells (hObs) responded by different parameters to different phytoestrogenic and vitamin D compounds. Pre- and post-menopausal hObs express ERα and ERβ mRNA with higher abundance of ERα. Pre-treatment with the less-calcemic vitamin D analog JKF 1624F(2)-2 (JKF) upregulated responsiveness to estrogens via modulation of ERs expression. These estrogenic compounds induce the expression and activity of 25 hydroxy-vitamin D(3)-1α hydroxylase (1OHase). We now analyzed the effects of carboxy-genistein (cG), carboxy-biocainin A (cBA) and carboxy-daidzein (cD), of BA, D or G and of licorice derived compounds glabridin (Glb) and glabrene (Gla) and estradiol-17β (E(2)) on DNA synthesis, creatine kinase specific activity (CK), intracellular and membranal E(2) binding and their modulations by JKF in hObs. We also analyzed modulation by phytoestrogenic compounds of 1OHase mRNA expression and activity. We showed that: (1) all compounds stimulated DNA synthesis and CK. (2) JKF and all estrogenic compounds modulated ERα and ERβ mRNA expression. (3) Pre-treatment with JKF increased DNA synthesis and CK responses only to E(2), D, G and Gla. (4) JKF increased the intracellular competitive binding only of E(2), D and G. (5) JKF abolished the membranal binding of all protein-bound estrogens. (6) JKF and all estrogenic compounds except the protein-bound ones up-regulated 1OHase expression and activity. In conclusion phytoestrogens and their analogs increase DNA synthesis and CK, and lead to increased production of 1,25(OH)(2)D(3) in hObs, while pre-treatment with JKF modulates the effect of estrogenic compounds via regulation of ERs mRNA expression in a yet unclear mechanism.

Anti-thyroid cancer properties of a novel isoflavone derivative, 7-(O)-carboxymethyl daidzein conjugated to N-t-Boc-hexylenediamine in vitro and in vivo

The incidence of thyroid cancer is up to 3 folds higher in women than in men, suggesting that estrogenic effects may be involved in the pathogenesis of this malignancy. Here, we explore whether or not human thyroid cancer cell growth can be curbed by a novel isoflavone derivative generated in our laboratory, the N-t-Boc-hexylenediamine derivative of 7-(O)-carboxymethyl daidzein (cD-tboc). With the exception of the follicular cancer cell line WRO, estrogen receptor (ER)α mRNA was only marginally expressed in cell lines derived from papillary (NPA), follicular (MRO), anaplastic thyroid carcinoma (ARO) such that the expression of estrogen receptor (ER) βmRNA was more abundant than that of ERα mRNA in these cell types. Estradiol-17β (E2; 0.03-300nmol/l) per se increased proliferation in all four cell-types. The ERβ-specific agonist DPN increased [(3)H]-thymidine incorporation in all four thyroid cancer cell lines, whereas the ERα-specific agonist PPT increased growth only in NPA and WRO. By contrast, cD-tboc, derived from the weak estrogen daidzein, did not cause cell growth and dose-dependently diminished cell growth in all four cell lines via apoptosis and not necrosis, as detected by the release of histone-DNA fragments. The cytotoxic growth inhibitory effect of cD-tboc in these cells was modulated by E2 and the general caspase inhibitor Z-VAD-FMK, and the magnitude of this salvage was cell type-and dose-dependent. When nude mice carrying ARO thyroid xenografts were treated with cD-tboc, tumor volume decreased significantly, and no apparent toxicity was observed. These results suggest that cD-tboc may be a promising agent for therapy of thyroid carcinoma either alone or in combination with existing cytotoxic drugs.

The effects of estrogen receptors α- and β-specific agonists and antagonists on cell proliferation and energy metabolism in human bone cell line

In cultured human osteoblasts estradiol-17β (E2) modulated DNA synthesis, the specific activity of creatine kinase BB (CK), 12 and 15 lipoxygenase (LO) mRNA expression and formation of 12- and 15-hydroxyeicosatetraenoic acid (HETE). We now investigate the response of human bone cell line (SaOS2) to phytoestrogens and estrogen receptors (ER)-specific agonists and antagonists. Treatment of SaSO2 with E2, 2,3-bis (4-hydroxyphenyl)-propionitrile (DPN; ERβ-specific agonist), 4,4',4″-[4-propyl-(1H)-pyrazol-1,3,5-triyl] tris-phenol (PPT; ERα-specific agonist), biochainin A (BA), daidzein (D), genistein (G) and raloxifene (Ral) showed increased DNA synthesis and CK. Ral inhibited completely all stimulations except DPN and to some extent D. The ERα-specific antagonist methyl-piperidino-pyrazole (MPP) and the ERβ-specific antagonist 4-[2-phenyl-5,7-bis (tri-fluoro-methyl) pyrazolo [1,5-a]pyrimidin-3-yl] phenol (PTHPP) inhibited DNA synthesis, CK and reactive oxygen species (ROS) formation induced by estrogens according to their receptors affinity. The LO inhibitor baicaleine inhibited only E2, DPN and G's effects. E2 and Ral unlike all other compounds had no effect on ERα mRNA expression, while ERβ mRNA expression was stimulated by all compounds. All compounds modulated the expression of 12LO and 15LO mRNA, except E2, PPT and Ral for 12LO, and 12- and 15-HETE productions and stimulated ROS formation which was inhibited by NADPH oxidase inhibitors diphenyleneiodonium chloride (DPI) and N-acetyl cysteine and the estrogen inhibitor ICI. DPI did not affect hormonal-induced DNA and CK. In conclusion, we provide evidence for the separation of mediation via ERα and ERβ pathways in the effects of estrogenic compounds on osteoblasts, but the role of LO/HETE/ROS is unclear.

Vitamin D metabolites and analogs induce lipoxygenase mRNA expression and activity as well as reactive oxygen species (ROS) production in human bone cell line

Vitamin D metabolites and its less-calcemic analogs (vitamin D compounds) are beneficial for bone and modulate cell growth and energy metabolism. We now analyze whether 25(OH)D(3) (25D), 1,25(OH)(2)D(3) (1,25D), 24,25(OH)(2)D(3) (24,25D), JKF1624F(2)-2 (JKF) or QW1624F(2)-2 (QW) regulate lipooxygenase (LO) mRNA expression and its products; hydroxyl-eicosatetraenoic acid (12 and 15HETE) formation, as well as reactive oxygen species (ROS) production in human bone cell line (SaOS2) and their interplay with modulation of cell proliferation and energy metabolism. All compounds except 25D increased 12LO mRNA expression and modulated 12 and 15HETE production whereas ROS production was increased by all compounds, and inhibited by NADPH oxidase inhibitors diphenyleneiodonium (DPI) and N-acetylcysteine (NAc). Baicaleine (baic) the inhibitor of 12 and 15LO activity blocked only slightly the stimulation of DNA synthesis by all compounds, whereas DPI inhibited almost completely the stimulation of DNA and CK by all compounds. Treatments of cells with 12 or 15HETE increased DNA synthesis and CK that were only slightly inhibited by DPI. These results indicate that vitamin D compounds increased oxidative stress in osteoblasts in part via induction of LO expression and activity. The increased ROS production mediates partially elevated cell proliferation and energy metabolism, whereas the LO mediation is not essential. This new feature of vitamin D compounds is mediated by intracellular and/or membranal binding sites and its potential hazard could lead to damage due to increased lipid oxidation, although the transient mediation of ROS in cell proliferation is beneficial to bone growth in a yet unknown mechanism.

DT56a (Femarelle), contrary to estradiol-17β, is effective in human derived female osteoblasts in hyperglycemic condition

We have reported previously, that female-derived cultured osteoblasts (hObs) responded to DT56a (Femarelle) measured by the stimulation of creatine kinase specific activity (CK), which is a marker for hormone responsiveness and (3)[H] thymidine incorporation into DNA (DNA synthesis). Since the skeletal protective effects of estrogens are not discernable in hyperglycemic diabetic women, we sought to analyze the effect of estrogenic compounds on CK and DNA synthesis in hObs when grown in high glucose concentration (HG). Cells were grown either in normal glucose (NG) (4.5g/L; 22mM) or HG (9.0g/L; 44mM) for 7 days. HG increased constitutive CK but, the response of CK activity and DNA synthesis to estradiol-17β (E(2)) treatment was reduced. In contrary, DT56a was found to be active (as measured by CK activity and DNA synthesis) in both NG and HG. HG decreases the hormonal responsiveness and might block important effects of estrogenic compounds, most likely contributing to their decreased skeletal preserving properties in hyperglycemic women. In hObs from post-menopausal women grown in HG, ERs mRNA expressions were unchanged. On the other hand, in hObs from pre-menopausal women HG increased ERs mRNA expressions. Since DT56a unlike E(2) is active in HG environment as well as in normal glucose, it may be an effective bone restoring agent in diabetic post-menopausal women.

Vitamin D analogs induce lipoxygenase mRNA expression and activity as well as reactive oxygen species (ROS) production in human bone cells

Vitamin D metabolites or its less-calcemic analogs (JKF or QW) are beneficial for bone biology. We analyzed whether or not 25(OH)D3 (25), 1,25(OH)2D3 (1,25), JKF or QW regulate lipooxygenase (LO) enzymes expression and their products hydroxyeicosatetraenoic acid (12 and 15 HETE) formation as well as reactive oxygen species (ROS) production in human bone cell lines (SaOS2 and hFOB) and primary cultured human bone cells (Obs) from males or females. All compounds except 25 increased LOs mRNA expression and HETE production in female or male Obs. ROS formation was induced by JKF and QW in both cell lines, and was inhibited by different inhibitors. Baicalein (baic) an inhibitor of 12 and 15 LO activity, inhibited partially ROS formation by JKF or QW in SaSO2 and hFOB. JKF-stimulated DNA synthesis in female Obs was inhibited by baic but unchanged by addition of HETE or HETE with baic. These results indicate that vitamin D increased oxidative stress in bone cells is in part via induction of LO expression and activity. This new feature of vitamin D is probably mediated by intracellular and/or membranal receptors and its potential hazard could lead to potential damage due to increased lipid oxidation.

Lipoxygenase-derived metabolites are regulators of peroxisome proliferator-activated receptor gamma-2 expression in human vascular smooth muscle cells

BACKGROUND

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the nuclear receptor family that has been implicated in cell differentiation and proliferation, glucose metabolism, macrophage development, and inflammatory responses. PPAR-gamma can be activated by a range of synthetic substances and also by products of lipid oxidation such as oxidized low-density lipoprotein, 13-hydroxyoctadecadienoic acid (13-HODE) and 15-hydroxyeicosatetraenoic acid (15-HETE). Since 12- and 15-lipoxygenase (12- and 15-LO) are expressed in human vascular smooth muscle cells (VSMCs), we set out to investigate the possible relation between PPAR-gamma and LO system in these cells.

METHODS

In vitro experiments in human VSMC using standard methods.

RESULTS

The LO products, 12-HETE (10(-7) mol/l), 15-HETE (10(-7) mol/l) and 13-HODE (10(-7) mol//l) increased the expression of PPAR-gamma-2 messenger RNA (mRNA) in VSMC (by 100, 50, and 100%, respectively. Rosiglitazone (1-10 micromol/l) was found to upregulate both the mRNA expression of two LO enzymes, platelet-type 12-lipoxygenase (12-LO; +70%) and 15-lipoxygenase type 2 (15-LO; +60%), and the secretion of their eicosanoid products 12- and 15-HETE. In addition, rosiglitazone-induced a threefold increase in PPAR-gamma-2 mRNA expressions and modest 50% rise in PPAR-gamma-1 mRNA expression. The effect of rosiglitazone on PPAR-gamma-2 could be entirely blocked by the LO inhibitor baicalein and restored by the addition of exogenous 12-HETE.

CONCLUSIONS

These results suggest a novel amplification cycle in which PPAR-gamma activation induces production of 12- and 15-LO-derived metabolites which in turn feed back to upregulate PPAR-gamma-2's own expression. The implications of this link in VSMC pathophysiology remain to be elucidated.

Membranal effects of phytoestrogens and carboxy derivatives of phytoestrogens on human vascular and bone cells: new insights based on studies with carboxy-biochanin A

Estradiol-17beta (E2) and some phytoestrogens induce a biphasic effect on DNA synthesis in cultured human vascular smooth muscle cells (VSMC), i.e., stimulation at low concentrations and inhibition at high concentrations. These compounds also increase the specific activity of creatine kinase (CK) as well as intracellular Ca2+ concentration in both VSMC and human female-derived cultured bone cells (OBs), and stimulate ERK1/2 phosphorylation in VSMC. At least some of these effects are exerted via membranal binding sites (mER), as would appear from observations that protein-bound, membrane impermeant estrogenic complexes can mimic the effect of E2 on DNA synthesis, intracellular Ca2+ concentration and MAPK, but not on CK activity. We now extend these studies by examining the effects of a novel carboxy-derivative of biochanin A, 6-carboxy-biochanin A (cBA) in VSMC and human osteoblasts in culture. cBA increased DNA synthesis in VSMC in a dose-dependent manner and was able to maintain this effect when linked to a cell membrane impermeable protein. In VSMC both cBA and estradiol, in their free or protein-bound forms induced a steep and immediate rise in intracellular calcium. Both the free and protein-bound conjugates of cBA and estradiol increased net MAPK-kinase activity. Neither the stimulatory effect of cBA nor the inhibitory effect of estradiol on DNA synthesis in VSMC could be shown in the presence of the MAPK-kinase inhibitor UO126. The presence of membrane binding sites for both estradiol and cBA was supported by direct visualization, using fluorescence labeling of their respective protein conjugates, E2-BSA and cBA-ovalbumin. Furthermore, these presumed membrane ER for estradiol and cBA were co-localized. In cultured human osteoblasts, cBA stimulated CK activity in a dose related fashion, which paralleled the increase in CK induced by estradiol per se, confirming the estrogenic properties of cBA in human bone cells. Both the free and protein-bound forms of cBA elicited immediate and substantial increments in intracellular Ca2+, similar to, but usually larger than the responses elicited by estradiol per se. cBA also increased ERalpha and suppressed ERbeta mRNA expression in human osteoblasts. Cultured human osteoblasts also harbor membrane binding sites for protein-bound form of cG, which are co-localized with the binding sites for protein-bound estradiol. The extent to which these properties of the novel synthetic phytoestrogen derivatives may be utilized to avert human vascular and/or bone disease requires further study.

Carboxy derivatives of isoflavones as affinity carriers for cytotoxic drug targeting in adrenocortical H295R carcinoma cells

Carboxy derivatives of isoflavones that exhibit oestrogenic/anti-oestrogenic properties were used as carriers for affinity drug targeting to H295R adrenocortical carcinoma cells that express transcripts of oestrogen receptor (ER) alpha and beta. These derivatives were prepared by introducing a carboxymethyl group at the 6-position of genistein and of biochanin A, yielding 6CG and 6CB respectively. In transactivation assays, 6CG displayed mixed agonist/antagonist activity for ERalpha, whereas 6CB displayed only weak antagonist activity. Low concentrations of oestrogen, 6CG and 6CB were capable of inducing proliferation in H295R cells and of stimulating creatine kinase (CK) specific activity, suggesting that these cells were sensitive to oestrogenic compounds. In in vivo experiments, both 6CG and 6CB were capable of inhibiting oestrogen-induced CK specific activity in rat tIssues. For affinity drug targeting, the cytotoxic drug daunomycin was coupled to 6CB and 6CG, yielding 6CB-Dau and 6CG-Dau respectively. These conjugates were tested for their antiproliferative ability to inhibit DNA synthesis as assessed by incorporation of [(3)H]thymidine in H295R cells. A dose-dependent cytoxicity was observed with both conjugates. At 0.3-3 nM, both conjugates were 10 to 30 times more potent than daunomycin. At 30 nM these conjugates were two to three times more potent than daunomycin. At concentrations ranging between 300 and 3000 nM, no difference in cytotoxicity was observed between the conjugates and daunomycin. When the cells were treated over a wide range of concentrations with a combination of 6CG plus daunomycin, the observed cytotoxicity was less than with daunomycin alone. When non-transformed rat enterocytes, which do not express ER, were treated with 6CG-Dau or daunomycin, the antiproliferative effect of 6CG-Dau was the same as that of daunomycin over the concentration range tested. These pilot studies suggest that the ready availability of oestrogenic binding sites in H295R cells can be exploited for site-directed chemotherapy.

A novel form of platelet-type 12-lipoxygenase mRNA in human vascular smooth muscle cells

The lipoxygenase pathway has been implicated in the growth, migration, and contraction of vascular smooth muscle cells (VSMCs). However, the precise type of lipoxygenase present in the vascular wall has not been characterized. In this study, we used a specific reverse-transcriptase polymerase chain reaction method with 2 sets of specific primers on total RNA and polyA (+)RNA of normal human VSMCs prepared from umbilical artery. Two forms of platelet-type 12-lipoxygenase mRNA were present in human VSMCs: the already published form cloned from human erythroleukemia cells and a variant form of platelet-type 12-lipoxygenase, which includes 2 additional sequences consistent with the 2 introns (D and E). This novel form of 12-lipoxygenase poly A (+)RNA was downregulated by lipopolysaccharide (10 ug/ml) and upregulated by epidermal growth factor (100 ng/ml) but was not affected by angiotensin II (10(-7) mol/l). We developed a rabbit anti-human platelet-type 12-lipoxygenase polyclonal antibody directed against a 24-amino acid peptide encoded within exon 4. Western immunoblotting of protein extracted from VSMCs and umbilical artery and platelet extract with this antibody showed a coordinate 110-kDa protein and the already-described 70-kDa band detected in platelets and cord homogenate. Another 120-kDa protein was consistently detected in cord extracts but not in platelet or VSMC homogenates. The immunohistochemistry study performed with the same antibody showed extensive cytoplasmic staining of VSMCs. The specific role of these different forms of platelet-type 12-lipoxygenase is subject to further investigation.

Image vividness as a psychophysiological regulator in Posttraumatic Stress Disorder

This study examined the relationship between image vividness and psychophysiological responses to trauma-related stimuli in participants with Posttraumatic Stress Disorder (PTSD). An auditory stimulus related to a shared trauma was presented to participants with and without PTSD and physiological parameters (heart rate and blood pressure) were measured concurrently. A negative correlation was noted in the PTSD group between image vividness and the level of physiological response. When the PTSD group was divided into high and low vividness, the physiological response was higher than that of the non-PTSD controls only when image vividness was low. The results are discussed in the context of Lang' s theoretical model, emphasizing the role of image vividness in the mediation and regulation of psychophysiology.