RESUMEN
INTRODUCTION: AHSG, a serum glycoprotein with recognized anti-calcification activity, has also been suggested to modulate both bone formation and resorption. Though the bulk of AHSG is mostly synthesized in the liver, it has been claimed that also bone cells might produce it. However, the extent of the bone AHSG production and the potential controlling factors remain to be definitively proven. A relevant number of studies support the notion that FGF23, a bone-derived hormone, not only regulates the most important mineral metabolism (MM) related factors (phosphate, parathyroid hormone, vitamin D, etc.), but might be also involved in cardiovascular (CV) outcome, both in chronic kidney disease (CKD) patients and in the general population. Furthermore, in addition to some direct autocrine and paracrine effects in bone, FGF23 has been suggested to interact with AHSG. In this study we investigated if AHSG is really produced by bone cells, and if its bone production is related and/or controlled by FGF23, using cultured bone cells, according to a new method recently published by our group. RESULTS: Our data show that AHSG is consistently produced in osteocytes and to a far lesser extent in osteoblasts. Both FGF23 addition to the culture medium and its over-expression in osteocytes were associated with a consistent increase of both AHSG mRNA and protein, while FGF23 silencing was followed by opposite effects. Though most of these results were largely affected by the blockage of FGF23 receptors, the role of these receptors in the different experimental sets is still not completely clarified. In addition, we found that FGF23 and AHSG proteins co-localized both in cytoplasm and nucleus, which suggests a possible reciprocal interactivity. CONCLUSIONS: Our data not only confirm that AHSG is produced in bone, mainly in osteocytes, but show for the first time that its production is modulated by FGF23. Since both proteins play important roles in the bone and cardiovascular pathology, these results add new pieces to the puzzling relationship between bone and vascular pathology, in particular in CKD patients, prompting future investigations in this field.
Asunto(s)
Factores de Crecimiento de Fibroblastos/metabolismo , Osteocitos/metabolismo , alfa-2-Glicoproteína-HS/biosíntesis , Animales , Bovinos , Células Cultivadas , Medios de Cultivo , Factor-23 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/genética , Técnica del Anticuerpo Fluorescente , Regulación de la Expresión Génica/efectos de los fármacos , Silenciador del Gen/efectos de los fármacos , Humanos , Masculino , Ratones Endogámicos BALB C , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteocitos/efectos de los fármacos , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas Recombinantes/farmacología , Tibia/efectos de los fármacos , Tibia/metabolismo , Factores de Tiempo , alfa-2-Glicoproteína-HS/genéticaRESUMEN
BACKGROUND: Donovanosis is a chronic bacterial illness, progressive and indolent, which normally attacks the skin and mucous membranes in the genital and perigenital regions. CASE: An 18-year-old pregnant female presented with large, hypertrophic lesions in the ano-genital region. HIV serology was negative. Pap smear revealed a CIN 1 associated with HPV infection. Biopsy yielded macrophages laden with Gram-negative Donovan bodies. SUMMARY AND CONCLUSION: A diagnosis of vulvar and perianal donovanosis was reached; the patient decided to terminate the pregnancy and was treated with azithromycin, which led to clinical resolution.