Hydrogen sulfide (H2S) is a gasotransmitter known to regulate bone formation and bone mass in unperturbed mice. However, it is presently unknown whether H2S plays a role in pathologic bone loss. Here we show that ovariectomy (ovx), a model of postmenopausal bone loss, decreases serum H2S levels and the bone marrow (BM) levels of two key H2S-generating enzymes, cystathione β-synthase (CBS) and cystathione γ-lyase (CSE). Treatment with the H2S-donor GYY4137 (GYY) normalizes serum H2S in ovx mice, increases bone formation, and completely prevents the loss of trabecular bone induced by ovx. Mechanistic studies revealed that GYY increases murine osteoblastogenesis by activating Wnt signaling through increased production of the Wnt ligands Wnt16, Wnt2b, Wnt6, and Wnt10b in the BM. Moreover, in vitro treatment with 17β-estradiol upregulates the expression of CBS and CSE in human BM stromal cells (hSCs), whereas an H2S-releasing drug induces osteogenic differentiation of hSCs. In summary, regulation of H2S levels is a novel mechanism by which estrogen stimulates osteoblastogenesis and bone formation in mice and human cells. Blunted production of H2S contributes to ovx-induced bone loss in mice by limiting the compensatory increase in bone formation elicited by ovx. Restoration of H2S levels is a potential novel therapeutic approach for postmenopausal osteoporosis.

BackgroundThe aim of the study was to characterize synovial cells from OA synovium with low-grade and moderate-grade synovitis and to define the role of synovial macrophages in cell culture.MethodsSynovial tissue explants were analyzed for the expression of typical markers of synovial fibroblasts (SF), synovial macrophages (SM) and endothelial cells. Synovial cells at passage 1 (p.1) and 5 (p.5) were analyzed for different phenotypical markers by flow cytometric analysis, inflammatory factors by multiplex immunoassay, anabolic and degradative factors by qRT-PCR. P.1 and p.5 synovial cells as different cell models were co-cultured with adipose stem cells (ASC) to define SM effects.ResultsSynovial tissue showed a higher percentage of CD68 marker in moderate compared with low-grade synovitis. Isolated synovial cells at p.1 were positive to typical markers of SM (CD14, CD16, CD68, CD80 and CD163) and SF (CD55, CD73, CD90, CD105, CD106), whereas p.5 synovial cells were positive only to SF markers and showed a higher percentage of CD55 and CD106. At p.1 synovial cells released a significantly higher amount of all inflammatory (IL6, CXCL8, CCL2, CCL3, CCL5) and some anabolic (IL10) factors than those of p.5. Moreover, p.1 synovial cells also expressed a higher amount of some degradative factors (MMP13, S100A8, S100A9) than p.5 synovial cells. Co-culture experiments showed that the amount of SM in p.1 synovial cells differently induced or down-modulated some of the inflammatory (IL6, CXCL8, CCL2, CCL3, CCL5) and degradative factors (ADAMTS5, MMP13, S100A8, S100A9).ConclusionsWe found that p.1 (mix of SM and SF) and p.5 (only SF) synovial cells represent two cell models that effectively reproduce the low- or moderate-grade synovitis environment. The presence of SM in culture specifically induces the modulation of the different factors analyzed, confirming that SM are key effector cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-016-0983-4) contains supplementary material, which is available to authorized users.

We demonstrated that ASC are responsible for the switching of activated-M1-like inflammatory macrophages to a M2-like phenotype, mainly through PGE2. This evidenced that activated-M1-like macrophages may represent a relevant cell model to test the efficacy/potency of ASC and suggests a specific role of ASC as important determinants in therapeutic dampening of synovial inflammation in OA.

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Sulforaphane (SFN) is one of most important dietary constituents of broccoli (Brassica oleracea) and other cruciferous vegetables, which have been reported to exhibit health benefits, including prevention and therapy of cancer, such as colorectal carcinoma (CRC). The objective of this study was to determine whether the anticancer effect of SFN on colon cancer HT-29 cell line could be improved by the combined treatment with molecules inhibiting microRNAs (miRNAs) involved in CRC. As miRNA inhibiting molecules we focused on peptide-nucleic acids (PNAs). As miRNA to be targeted, miR-15b-5p was selected on the basis of several information present in the literature and confirming that miR-15b-5p is overexpressed in colon cancer patients, and that its targeting decreases cell migration and metastasis in colorectal cancer. In this article, we described for the first time the efficacy of targeting miR-15b-5p by using a PNA against miR-15b-5p (R8-PNA-a15b), functionalized with an octoarginine peptide (R8) for maximizing cellular uptake. The miR-15b-5p downregulation in the colon cancer HT-29 cell line was associated with inhibition of in vitro cell growth and activation of the proapoptotic pathway, demonstrated by a sharp increase of late apoptotic cells in HT-29treated cell populations. A second conclusion of this study is that the R8-PNA-a15b might be proposed in ''combo-therapy'' associated with SFN. To our knowledge, no report is available in the literature on a combination between SFN and miRNA-targeting molecules. Our data demonstrate that this combined treatment leads to a very high proportion of apoptotic HT-29 cells (over 85%), a value higher than the sum of the values of apoptotic cells obtained after singularly administered regents (either SFN or R8-PNA-a15b).

Background A key clinical feature of COVID-19 is a deep inflammatory state known as “cytokine storm” and characterized by high expression of several cytokines, chemokines and growth factors, including IL-6 and IL-8. A direct consequence of this inflammatory state in the lungs is the Acute Respiratory Distress Syndrome (ARDS), frequently observed in severe COVID-19 patients. Cytokine storm is associated with severe forms of COVID-19 and poor prognosis for COVID-19 patients. Sulforaphane (SFN), one of the main components of Brassica oleraceae L. ( Brassicaceae or Cruciferae ), is known to possess anti-inflammatory effects in tissues from several organs, among which joints, kidneys and lungs. Purpose The objective of the present study was to determine whether SFN is able to inhibit IL-6 and IL-8, two key molecules involved in the COVID-19 cytokine storm. Methods The effects of SFN were studied in vitro on bronchial epithelial IB3-1 cells exposed to the SARS-CoV-2 Spike protein (S-protein). The anti-inflammatory activity of SFN on IL-6 and IL-8 expression has been evaluated by RT-qPCR and Bio-Plex analysis. Results In our study SFN inhibits, in cultured IB3-1 bronchial cells, the gene expression of IL-6 and IL-8 induced by SARS-CoV-2. This represents the proof-of-principle that SFN may modulate the release of some key proteins of the COVID-19 cytokine storm. Conclusion The control of the cytokine storm is one of the major issues in the management of COVID-19 patients. Our study demonstrates that SFN can be employed in protocols useful to control hyperinflammatory state associated with SARS-CoV-2 infection.

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The importance of hydrogen sulfide (H2S) in the regulation of multiple physiological functions has been clearly recognized in the over 20 years since it was first identified as a novel gasotransmitter. In bone tissue H2S exerts a cytoprotective effect and promotes bone formation. Just recently, the scientific community has begun to appreciate its role as a therapeutic agent in bone pathologies. Pharmacological administration of H2S achieved encouraging results in preclinical studies in the treatment of systemic bone diseases, such as osteoporosis; however, a local delivery of H2S at sites of bone damage may provide additional opportunities of treatment. Here, we highlight how H2S stimulates multiple signaling pathways involved in various stages of the processes of bone repair. Moreover, we discuss how material science and chemistry have recently developed biomaterials and H2S-donors with improved features, laying the ground for the development of H2S-releasing devices for bone regenerative medicine. This review is intended to give a state-of-the-art description of the pro-regenerative properties of H2S, with a focus on bone tissue, and to discuss the potential of H2S-releasing scaffolds as a support for bone repair.