Summary Purpose To determine whether a 6-day course of methylprednisolone (MP) improves outcome in patients with severe SARS-CoV‑2 (Corona Virus Disease 2019 [COVID-19]). Methods The study was a multicentric open-label trial of COVID-19 patients who were aged ≥ 18 years, receiving oxygen without mechanical ventilation, and with evidence of systemic inflammatory response who were assigned to standard of care (SOC) or SOC plus intravenous MP (40 mg bid for 3 days followed by 20 mg bid for 3 days). The primary outcome was a composite of death, admission to the intensive care unit, or requirement for noninvasive ventilation. Both intention-to-treat (ITT) and per protocol (PP) analyses were performed. Results A total of 91 patients were screened, and 64 were randomized (mean age70 ± 12 years). In the ITT analysis, 14 of 29 patients (48%) in the SOC group and 14 of 35 (40%) in the MP group suffered the composite endpoint (40% versus 20% in patients under 72 years and 67% versus 48% in those over 72 years; p = 0.25). In the PP analysis, patients on MP had a significantly lower risk of experiencing the composite endpoint (age-adjusted risk ratio 0.42; 95% confidence interval, CI 0.20–0.89; p = 0.043). Conclusion The planned sample size was not achieved, and our results should therefore be interpreted with caution. The use of MP had no significant effect on the primary endpoint in ITT analysis; however, the PP analysis showed a beneficial effect due to MP, which consistent with other published trials support the use of glucocorticoids in severe cases of COVID-19.

Sclerostin, encoded by the SOST gene, is a potent inhibitor of bone formation, produced by osteocytes, not by osteoblasts, but little is known about the molecular mechanisms controlling its expression. We aimed to test the hypothesis that epigenetic mechanisms, specifically DNA methylation, modulate SOST expression. We found two CpG‐rich regions in SOST: region 1, located in the proximal promoter, and region 2, around exon 1. qMSP and pyrosequencing analysis of DNA methylation showed that region 2 was largely methylated in all samples analyzed. In contrast, marked differences were observed in region 1. Whereas the CpG‐rich region 1 was hypermethylated in osteoblasts, this region was largely hypomethylated in microdissected human osteocytes. Bone lining cells showed a methylation profile between primary osteoblasts and osteocytes. Whereas SOST expression was detected at very low level or not at all by RT‐qPCR in several human osteoblastic and nonosteoblastic cell lines, and human primary osteoblasts under basal conditions, it was dramatically upregulated (up to 1300‐fold) by the demethylating agent AzadC. Experiments using reporter vectors demonstrated the functional importance of the region −581/+30 of the SOST gene, which contains the CpG‐rich region 1. In vitro methylation of this CpG‐island impaired nuclear protein binding and led to a 75 ± 12% inhibition of promoter activity. In addition, BMP‐2‐induced expression of SOST was markedly enhanced in cells demethylated by AzadC. Overall, these results strongly suggest that DNA methylation is involved in the regulation of SOST expression during osteoblast–osteocyte transition, presumably by preventing the binding of transcription factors to the proximal promoter. To our knowledge, our data provide first ever evidence of the involvement of DNA methylation in the regulation of SOST expression and may help to establish convenient experimental models for further studies of human sclerostin. © 2012 American Society for Bone and Mineral Research.

Osteoblasts are specialized cells that form new bone and also indirectly influence bone resorption by producing factors that modulate osteoclast differentiation. Although the methylation of CpG isl...

Sclerostin, encoded by the SOST gene, works as an inhibitor of the Wnt pathway and therefore is an important regulator of bone homeostasis. Due to its potent action as an inhibitor of bone formation, blocking sclerostin activity is the purpose of recently developed anti-osteoporotic treatments. Two bone-specific transcription factors, RUNX2 and OSX, have been shown to interact and co-ordinately regulate the expression of bone-specific genes. Although it has been recently shown that sclerostin is targeted by OSX in mice, there is currently no information of whether this is also the case in human cells. We have identified SP-protein family and AML1 consensus binding sequences at the human SOST promoter and have shown that OSX, together with RUNX2, binds to a specific region close to the transcription start site. Furthermore, we show that OSX and RUNX2 activate SOST expression in a co-ordinated manner in vitro and that SOST expression levels show a significant positive correlation with OSX/RUNX2 expression levels in human bone. We also confirmed previous results showing an association of several SOST/RUNX2 polymorphisms with bone mineral density.

Low serum levels of alkaline phosphatase (ALP) are a hallmark of hypophosphatasia. However, the clinical significance and the underlying genetics of low ALP in unselected populations are unclear. In order to clarify this issue, we performed a clinical, biochemical and genetic study of 42 individuals (age range 20-77yr) with unexplained low ALP levels. Nine had mild hyperphosphatemia and three had mild hypercalcemia. ALP levels were inversely correlated with serum calcium (r=-0.38, p=0.012), pyridoxal phosphate (PLP; r=-0.51, p=0.001) and urine phosphoethanolamine (PEA; r=-0.49, p=0.001). Although many subjects experienced minor complaints, such as mild musculoskeletal pain, none had major health problems. Mutations in ALPL were found in 21 subjects (50%), including six novel mutations. All but one, were heterozygous mutations. Missense mutations were the most common (present in 18 subjects; 86%) and the majority were predicted to have a damaging effect on protein activity. The presence of a mutated allele was associated with tooth loss (48% versus 12%; p=0.04), slightly lower levels of serum ALP (p=0.002), higher levels of PLP (p<0.0001) and PEA (p<0.0001), as well as mildly increased serum phosphate (p=0.03). Ten individuals (24%) had PLP levels above the reference range; all carried a mutated allele. One-half of adult individuals with unexplained low serum ALP carried an ALPL mutation. Although the associated clinical manifestations are usually mild, in approximately 50% of the cases, enzyme activity is low enough to cause substrate accumulation and may predispose to defects in calcified tissues.