Bone marrow (BM)-derived mesenchymal stem cells (MSCs) represent a promising population for supporting new concepts in cellular therapy. This study was undertaken to assess the efficacy and feasibility of autologous BM-derived MSCs in the treatment of chronic nonhealing ulcers (diabetic foot ulcers and Buerger disease) of the lower extremities. A total of 24 patients with nonhealing ulcers of the lower limb were enrolled and randomized into implant and control groups. In the implant group, the patients received autologous cultured BM-derived MSCs along with standard wound dressing; the control group received only the standard wound dressing regimen, followed up for at least a 12-week period. Wound size, pain-free walking distance, and biochemical parameters were measured before therapy and at every 2-week interval following intervention. The implant group had significant improvement in pain-free walking distance and reduction in ulcer size as compared to those in the control group. In the implant group for Buerger disease, the ulcer area decreased from 5.04 ± 0.70 cm ² to 1.48 ± 0.56 cm ² ( p < 0.001), whereas the pain-free walking distance increased from 38.33 ± 17.68 m to 284.44 ± 212.12 m ( p < 0.001). In the diabetic foot ulcer group, the ulcer size decreased from 7.26 ± 1.41 cm ² to 2 ± 0.98 cm ² ( p < 0.001) at 12 weeks. Mononuclear cells were cultured for a minimum of five passages and characterized by cell-surface markers showing CD90 ⁺ , CD105 ⁺ , and CD34 ⁻ . There was no significant alteration in the biochemical parameters observed during the follow-up period, indicating normal liver and renal function following intervention. Biopsy microsection of implanted tissues showed development of dermal cells (mainly fibroblasts), including mature and immature inflammatory cells. The study indicates that autologous implantation of BM-derived MSCs in nonhealing ulcers accelerates the healing process and improves clinical parameters significantly.

Metformin, the first‐line drug to treat type 2 diabetes (T2D), inhibits mitochondrial glycerolphosphate dehydrogenase in the liver to suppress gluconeogenesis. However, the direct target and the underlying mechanisms by which metformin increases glucose uptake in peripheral tissues remain uncharacterized. Lipid phosphatase Src homology 2 domain‐containing inositol‐5‐phosphatase 2 (SHIP2) is upregulated in diabetic rodent models and suppresses insulin signaling by reducing Akt activation, leading to insulin resistance and diminished glucose uptake. Here, we demonstrate that metformin directly binds to and reduces the catalytic activity of the recombinant SHIP2 phosphatase domain in vitro . Metformin inhibits SHIP2 in cultured cells and in skeletal muscle and kidney of db/db mice. In SHIP2‐overexpressing myotubes, metformin ameliorates reduced glucose uptake by slowing down glucose transporter 4 endocytosis. SHIP2 overexpression reduces Akt activity and enhances podocyte apoptosis, and both are restored to normal levels by metformin. SHIP2 activity is elevated in glomeruli of patients with T2D receiving nonmetformin medication, but not in patients receiving metformin, compared with people without diabetes. Furthermore, podocyte loss in kidneys of metformin‐treated T2D patients is reduced compared with patients receiving nonmetformin medication. Our data unravel a novel molecular mechanism by which metformin enhances glucose uptake and acts renoprotectively by reducing SHIP2 activity.—Polianskyte‐Prause, Z., Tolvanen, T. A., Lindfors, S., Dumont, V., Van, M., Wang, H., Dash, S. N., Berg, M., Naams, J.‐B., Hautala, L. C., Nisen, H., Mirtti, T., Groop, P.‐H., Wähälä, K., Tienari, J., Lehtonen, S. Metformin increases glucose uptake and acts renoprotectively by reducing SHIP2 activity. FASEB J. 33, 2858–2869 (2019). www.fasebj.org

Human disease and biological practices are modelled in zebrafish (Danio rerio) at various phases of drug development as well as toxicity evaluation. The zebrafish is ideal forin vivopathological research and high-resolution investigation of disease progress. Zebrafish has an advantage over other mammalian models, it is cost-effective, it has external development and embryo transparency, easy to apply genetic manipulations, and open to both forward and reverse genetic techniques. Drug screening in zebrafish is suitable for target identification, illness modelling, high-throughput screening of compounds for inhibition or prevention of disease phenotypes and developing new drugs. Several drugs that have recently entered the clinic or clinical trials have their origins in zebrafish. The sophisticated screening methods used in zebrafish models are expected to play a significant role in advancing drug development programmes. This review highlights the current developments in drug discovery processes, including understanding the action of drugs in the context of disease and screening novel candidates in neurological diseases, cardiovascular diseases, glomerulopathies and cancer. Additionally, it summarizes the current techniques and approaches for the selection of small molecules and current technical limitations on the execution of zebrafish drug screening tests.

Mesenchymal stem cells (MSCs) hold great promise for therapeutic application in non-healing ulcers and tissue regeneration because of their multi-lineage differentiation potential. MSCs delivered may migrate to the sites of injury and improve wound healing by stimulating angiogenesis and promoting revascularization. The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide. It is associated with peripheral neuropathy and peripheral arterial occlusive disease (PAOD), which predispose patients to develop non-healing foot ulcers following minor trauma. A high rate of amputation exists among diabetic patients due to non-healing foot ulcers, which are a significant burden for the society despite new therapeutic protocols developed. In recent years, stem cell transplantation has been considered as a new therapeutic option for diabetic foot ulcers (DFUs). The regeneration potential of MSCs has been demonstrated in the experimental and clinical trials. Here we review the potential efficacy and systematic use of MSCs for the treatment of non-healing DFUs, current advances, MSC delivery systems, and possible options to enhance the therapeutic potential of stem cell for wound healing.

Myofibrils made up of actin, myosin, and associated proteins generate the contractile force in muscle, and, consequently, mutations in these proteins may lead to heart failure. Septins are a conserved family of small GTPases that associate with actin filaments, microtubules, and cellular membranes. Despite the importance of septins in cytoskeleton organization, their role in cardiomyocyte organization and function is poorly characterized. Here, we show that septin 7 is expressed in both embryonic and adult zebrafish hearts and elucidate the physiological significance of sept7b, the zebrafish ortholog of human septin 7, in the heart in embryonic and larval zebrafish. Knockdown of sept7b reduced F-actin and α-cardiac actin expression in the heart and caused disorganization of actin filaments. Electron microscopy of sept7b-depleted larvae showed disorganization of heart myofibrils and partial detachment from Z-disks. Functional studies revealed that knockdown of sept7b leads to reduced ventricular dimensions, contractility, and cardiac output. Furthermore, we found that depletion of sept7b diminished the expression of retinaldehyde dehydrogenase 2, which catalyzes the synthesis of retinoic acid necessary for heart morphogenesis. We further observed that the sept7b and retinoic acid signaling pathways converge to regulate cardiac function. Together, these results specify an essential role for sept7b in the contractile function of the heart. NEW & NOTEWORTHY Knockdown of the zebrafish ortholog of human septin 7 (sept7b) destabilizes cardiac actin and reduces ventricular dimensions, contractility, and cardiac output in larval zebrafish, indicating that sept7b is essential for cardiac function. We further found that sept7b and retinoic acid signaling pathways converge to regulate cardiac function. These data prompt further studies defining the role of sept7b in cardiomyopathies.

The adapter protein CD2-associated protein (CD2AP) functions in various signaling and vesicle trafficking pathways, including endosomal sorting and/or trafficking and degradation pathways. Here, we investigated the role of CD2AP in insulin-dependent glucose transporter 4 (Glut4, also known as SLC2A4) trafficking and glucose uptake. Glucose uptake was attenuated in CD2AP−/− podocytes compared with wild-type podocytes in the basal state, and CD2AP−/− podocytes failed to increase glucose uptake in response to insulin. Live-cell imaging revealed dynamic trafficking of HA–Glut4–GFP in wild-type podocytes, whereas in CD2AP−/− podocytes, HA–Glut4–GFP clustered perinuclearly. In subcellular membrane fractionations, CD2AP co-fractionated with Glut4, IRAP (also known as LNPEP) and sortilin, constituents of Glut4 storage vesicles (GSVs). We further found that CD2AP forms a complex with GGA2, a clathrin adaptor, which sorts Glut4 to GSVs, suggesting a role for CD2AP in this process. We also found that CD2AP forms a complex with clathrin and connects clathrin to actin in the perinuclear region. Furthermore, clathrin recycling back to trans-Golgi membranes from the vesicular fraction containing GSVs was defective in the absence of CD2AP. This leads to reduced insulin-stimulated trafficking of GSVs and attenuated glucose uptake into CD2AP−/− podocytes.