Mesenchymal Cells are a Promising -But Still Unsatisfying- Anti- Inflammatory Therapeutic Strategy for Osteoarthritis: A Narrative Review.

Osteoarthritis (OA) is a chronic disease with both degenerative and inflammatory characteristics, affecting the osteochondral unit with the involvement of cartilage, subchondral bone and periarticular tissues. OA can produce chronic pain with neuropathic and inflammatory characteristics, leading to an increased disability. OA is secondary to many predisposing factors where the inflammatory process plays a key role. To manage OA, it would seem logical to block the factors influencing the inflammatory process at different levels, T lymphocytes, neutrophils, and the balance between phenotype-1 macrophages (M1, pro-inflammatory) and phenotype-2 macrophages (M2 anti-inflammatory), the managing cells. The efforts to repair and rebuild the lost cartilage and the attempts to implant autologous or heterologous material, with or without growth factors and the administration of drugs or the use of medical devices, have failed their objective. TNF-alpha and IL-1 inhibitors can only have a transient effect on pain; intra-articular oxidized Low-Density Lipoproteins are able to stimulate the activation of M2, while growth factors need to be better investigated. Also, intra-articular injections of mesenchymal stem cells (MSC) can inhibit the proliferation of T-lymphocytes, leading to cartilage repair and to osteophytes inhibition thanks to the release of exosomes, nanosized particles which are the active components. Gut microbiota has a potential role in the development of OA and could be able to influence the response to therapeutic agents.

Role of the Osteochondral Unit in the Pathogenesis of Osteoarthritis: Focus on the Potential Use of Clodronate.

Osteoarthritis (OA) is a chronic disease characterized by inflammation and progressive deterioration of the joint. The etiology of OA includes genetic, phlogistic, dismetabolic and mechanical factors. Historically, cartilage was considered the target of the disease and therapy was aimed at protecting and lubricating the articular cartilage. The osteochondral unit is composed of articular cartilage, calcified cartilage, and subchondral and trabecular bone, which work synergistically to support the functional loading of the joint. Numerous studies today show that OA involves the osteochondral unit, with the participation therefore of the bone in the starting and progression of the disease, which is associated with chondropathy. Cytokines involved in the process leading to cartilage damage are also mediators of subchondral bone edema. Therefore, OA therapy must be based on the use of painkillers and bisphosphonates for both the control of osteometabolic damage and its analgesic activity. Monitoring of the disease of the osteochondral unit must be extensive, since bone marrow edema can be considered as a marker of the evolution of OA. In the present review, we discuss some of the pathogenetic mechanisms associated with osteoarthritis, with a particular focus on the osteochondral unit and the use of clodronate.

Double-blind, placebo-controlled, multiple-ascending-dose study on the pharmacodynamics of ABIO-08/01, a new CNS drug with potential anxiolytic activity. 1. EEG mapping, psychometric and tolerability findings.

In a double-blind, placebo-controlled, multiple-ascending-dose study, the encephalotropic and psychotropic properties of ABIO-08/01, a new potentially anxiolytic and nootropic isoxazoline, were studied in 16 young healthy males. In a randomized nonbalanced phase 1 study, they received 3 oral drug doses (10, 20, 40 mg) and placebo for 7 days (washout period 8 days). EEG mapping and psychometry were carried out at hours 0, 1, 6 of day 1 (acute effect) and day 5 (subacute and superimposed effects). MANOVA/ Hotelling T(2) test demonstrated significant central effects of ABIO-08/01 versus placebo after acute, subacute and superimposed administration of all doses in the resting, vigilance-controlled and eyes-open EEG. Univariate analysis revealed activating patterns in the resting EEG (40 mg > 20 mg > 10 mg), and sedative patterns in the eyes-open EEG (10 mg > 20 mg > 40 mg). In the vigilance-controlled EEG, 40 mg of ABIO-08/01 induced activating patterns, whereas 10 mg induced sedative patterns. Concerning psychometry, ABIO-08/01 improved concentration (40 mg > 20 mg > 10 mg; activating effect) and deteriorated well-being (10 mg > 20 mg > 40 mg; sedative effect). Ten milligrams also improved reaction time performance and psychomotor activity. ABIO-08/01 is well-tolerated and is of interest in anxiety disorders.

Double-blind, placebo-controlled, multiple-ascending-dose study on the effects of ABIO-08/01, a novel anxiolytic drug, on perception and cognition, utilizing event-related potential mapping and low-resolution brain electromagnetic tomography.

Early pharmacological studies in animals demonstrated that ABIO-08/01, a new isoxazoline, exerted anxiolytic and anticonvulsant, but also cognition-enhancing properties. Thus, the aim of the present double-blind, placebo-controlled multiple-ascending-dose study was to investigate the effect of the new compound on event-related potentials (ERPs). In a randomized ascending-dose design for phase-1 studies, 16 young healthy male subjects aged 30.2 +/- 5.7 years received three ascending drug doses (10, 20, and 40 mg) and placebo for 7 days, with a washout period of 8 days in between. Auditory ERPs were recorded pre-dose and 2 h post-dose on days 1 (acute effect) and 5 (subacute and absolute superimposed effect). Descriptive statistics with one confirmatory statement on P300 latency demonstrated a significant shortening after acute, subacute, and superimposed administration of 40 mg ABIO-08/01. While ERP amplitudes showed only minor effects, low-resolution brain electromagnetic tomography (LORETA) demonstrated that ABIO-08/01 promotes more efficient information processing by reallocating perceptual and cognitive ERP resources. Thus, our ERP studies confirm early pharmacological findings in animals of a cognition-enhancing effect of ABIO-08/01, which is interesting in the context of the anxiolytic mode of action of the compound as its CNS effects are quite different from those of anxiolytic sedatives, such as benzodiazepines.

Bone and bone marrow interactions: hematological activity of osteoblastic growth peptide (OGP)-derived carboxy-terminal pentapeptide. II. Action on human hematopoietic stem cells.

Osteogenic growth peptide (OGP) is a peptide exerting regulatory effects on the bone and on bone marrow. The carboxy-terminal pentapeptide (OGP10-14) is the biologically active portion of OGP. We evaluated OGP10-14 hematopoietic activity performing colony-forming tests on human stem cells derived by bone marrow, peripheral blood and cord blood. Granulocyte-macrophage colony-forming unit (CFU) were significantly increased in OGP10-14-treated samples, while granulocyte-erythrocyte-monocyte-megakaryocyte CFU and burst-forming unit (BFU) erythroid were increased only in the cord blood test.Moreover, OGP10-14 preserves stem cells self renewal potential in long-term culture (LTC) initiating cells and acts directly on CD34+ enriched cells or by increasing activity of stem cell factor (SCF) and granulocyte-megakaryocyte colony-stimulating factor.

Bone and bone-marrow interactions: haematological activity of osteoblastic growth peptide (OGP)-derived carboxy-terminal pentapeptide. Mobilizing properties on white blood cells and peripheral blood stem cells in mice.

Osteogenic growth peptide (OGP) increases blood and bone marrow cellularity in mice, and enhances engraftment of bone marrow transplant. Carboxy-terminal pentapeptide (OGP10-14) holds several properties of full-length polypeptide. We evaluated whether synthetic OGP-derived pentapeptide (sOGP10-14) has some activity on peripheral blood cell recovery after cyclophosphamide-induced aplasia, and on stem cell mobilization. Peripheral blood stem cell (PBSC) mobilization was evaluated by administering granulocyte-colony stimulating factor (G-CSF) or sOGP10-14 after cyclophosphamide (CTX) injection. Haematological parameters and CD34/Sca-1 positive cells were sequentially evaluated. Colony-forming tests were performed in bone marrow cells from CTX-, G-CSF- and sOGP10-14-treated mice. sOGP10-14 was able to enhance band cells and monocyte recovery after cyclophosphamide administration. White blood cell (WBC) counts reached the maximum peak by day +10 but, on day +7, a significant recovery was already detected in sOGP10-14 treated mice. On day +10 the WBC increase in sOGP10-14-treated mice was comparable to that found in G-CSF treated ones. Moreover, CD34/Sca-1 positive early precursors were significantly mobilized by sOGP10-14 compared to the control group. In sOGP10-14-treated mice, the colony-forming unit-granulocyte-macrophage-megakaryocyte (GEMM-CFU) and burst-forming unit-erythroid (BFU-E) were significantly increased in bone marrow cells in comparison to mice treated with CTX only. These results suggest a central role of sOGP10-14 in bone and bone marrow interaction, and a possible role of sOGP10-14 as a mobilizing agent.

Osteogenic growth peptide effects on primary human osteoblast cultures: potential relevance for the treatment of glucocorticoid-induced osteoporosis.

The osteogenic growth peptide (OGP) is a naturally occurring tetradecapeptide that has attracted considerable clinical interest as a bone anabolic agent and hematopoietic stimulator. In vivo studies on animals have demonstrated that the synthetic peptide OGP (10-14), reproducing the OGP C-terminal active portion [H-Tyr-Gly-Phe-Gly-Gly-OH] increases bone formation, trabecular bone density and fracture healing. In vitro studies performed on cellular systems based on osteoblastic-like cell lines or mouse stromal cells, have demonstrated that OGP (10-14) increases osteoblast proliferation, alkaline phosphatase (ALKP) activity and matrix synthesis and mineralization. In view of a potential application of OGP (10-14) in clinical therapy, we have tested different concentrations of OGP (10-14) on primary human osteoblast (hOB) cultures. We have observed significant increases of hOB proliferation (+35%), ALKP activity (+60%), osteocalcin secretion (+50%), and mineralized nodules formation (+49%). Our experimental model based on mature hOBs was used to investigate if OGP (10-14) could prevent the effects on bone loss induced by sustained glucocorticoid (GC) treatments. A strong decrease in bone formation has been attributed to the effects of GCs on osteoblastogenesis and osteocyte apoptosis, while an increase in bone resorption was due to a transient osteoblastic stimulation, mediated by the OPG/RANKL/RANK system, of osteoclasts recruitment and activation. Moreover, GCs act on hOBs decreasing the release of osteoprotegerin (OPG) a regulator of the RANKL/RANK interaction. Here, we provide evidences that OGP (10-14) inhibits hOB apoptosis induced by an excess of dexamethasone (-48% of apoptotic cells). Furthermore, we show that OGP (10-14) can increase OPG secretion (+20%) and can restore the altered expression of OPG induced by GCs to physiological levels. Our results support the employment of OGP (10-14) in clinical trials addressed to the treatment of different bone remodeling alterations including the GC-induced osteoporosis.