MicroRNA-149 suppresses osteogenic differentiation of mesenchymal stem cells via inhibition of AKT1-dependent Twist1 phosphorylation

Osteogenic differentiation is a vital process for growth, repair, and remodeling of bones. Accumulating evidence have suggested that microRNAs (miRNAs or miRs) play a crucial role in osteogenic differentiation of mesenchymal stem cells (MSCs). Hence, the current study set out to elucidate the role of miR-149 in osteogenic differentiation of MSCs and the underlying mechanism. First, rat models of bone differentiation were established using the Masquelet-induced membrane technique, and MSCs were isolated. The expression of miR-149 and AKT1 in the rats and cells was detected with RT-qPCR and western blot analysis. The relationships among miR-149, AKT1, and Twist1 were further predicted by online bioinformatics prediction and verified using dual luciferase reporter gene assay. Alteration of miR-149, AKT1, or Twist1 was performed to further explore their effect on osteogenic differentiation of MSCs. miR-149 was poorly expressed in the process of osteogenic differentiation of MSCs, while AKT1 was highly expressed. miR-149 negatively regulated the expression of AKT1, which in turn diminished the protein levels of Twist1 and promoted the phosphorylation levels of Twist1. Lastly, miR-149 acted as an inhibitor of osteogenic differentiation of MSCs, which could be reversed by AKT1. To sum up, miR-149 silencing promoted osteogenic differentiation of MSCs by enhancing Twist1 degradation through AKT1 upregulation, representing a new method for bone repair treatment.

Hard and soft tissue augmentation of vertical ridge defects with the “hard top double membrane technique”: introduction of a new technique and a case report

<abstract> <p>Vertical ridge defects (VRD) of the jaws often require both bone and keratinized mucosa (KM) reconstruction. A new staged procedure is proposed to restore both hard and soft tissues in the VRD through a case report. A patient required the lower right second premolar and first molar rehabilitation. The first surgery aimed to restore the bone architecture through the use of a titanium reinforced dense-PTFE (TR-dPTFE) membrane, positioned and stabilized on top of tenting screws. This membrane didn't cover the whole defect, it just created an hard top that avoided the collapse of a collagen membrane that was placed over it. This resorbable membrane was stabilized with tacks and covered the whole defect, protecting a mixture of autogenous bone and porcine xenograft both lingually and buccally. The second surgery was performed after a 5 month healing time either to remove the tenting screws and the TR-dPTFE membrane, and to augment KM with a gingival graft harvested from the palate. Both regenerated hard and soft tissues were left to mature for 7 months before the third surgery. In this last stage implants insertion and healing abutments application were carried out in a straightforward way, since bone and KM had been previously restored. Two bone samples, harvested for histologic evaluation, stated a great amount of new bone formation. This new approach allowed inserting implants in matured and stable regenerated bone and augmented KM, avoiding the hard and soft tissue loss around implant neck that can affect the VRD treatments during healing.</p> </abstract>

Water Quality Analyses: Evidence from River Gashua and Some Selected Groundwater Sources in Gashua, Nigeria

The interface between surface water and groundwater is becoming more complex owing to the effects of climate change and anthropogenic activities these days. In this study, the physicochemical; pH, color, electrical conductivity, total dissolved solids, and turbidity while bacteriological parameters; total and fecal coliform of water samples from River Gashua and its surrounding wells in Gashua local government area of Yobe State were assessed. All the physicochemical parameters were analyzed using water quality standards. Fecal and total coliforms were assayed using the filter membrane technique. The results obtained from the physicochemical parameters of Boreholes (BH1, BH2, and BH3) and hand pump wells (HPW1, HPW2, and HPW3) are within the World Health Organization (WHO) standards. However, the river (R) water sample was found to have a high concentration in total dissolved solids, turbidity, and color than permissible standards. Bacteriological analysis revealed the presence of total and fecal coliform in the water samples; R, BH2, BH3, HPW1, HPW2, and HPW3. The findings indicate that there is a need to protect the quality of the river system. Therefore, it is recommended that government and other stakeholders should take appropriate and corrective actions to avert the continuous discharge of waste products into the river. Again, Yobe State Ministry of Environment should ensure that all public boreholes are routinely subjected to appropriate water assays to ascertain their suitability for human consumption.

Is the bioactivity of induced membranes time dependent?

Purpose The induced membrane technique (IMT) is a two-stage surgical procedure for reconstruction of bone defects. Bone grafting (second stage of IMT) is recommend after 4–8 weeks assuming the highest bioactivity of IMs. However, larger studies concerning the biology and maturation of IMs and a potential time dependency of the bioactivity are missing. Therefore, aim of this study was the time-dependent structural and cellular characterization of cement spacer IMs concomitantly to an analysis of membrane bioactivity. Methods IMs from 60 patients (35–82 years) were obtained at different maturation stages (1–16 weeks). IMs were studied by histology and co-culture with mesenchymal stem cells (MSC). IM lysates were analyzed by ELISA and protein microarray. Results Increasing vascularization and fibrosis were found in membranes older than 4 and 7 weeks, respectively. MSC grew out from all membranes and all membranes enhanced proliferation of cultured MSC. Osteocalcin and osteopontin (in membrane lysates or induced in MSC by membrane tissue) were found over all time points without significant differences. In contrast to alkaline phosphatase activity, increasing levels of osteoprotegerin were found in membranes. Conclusion The histological structure of IMs changes during growth and maturation, however, biologically active MSC and factors related to osteogenesis are found over all time points with minor changes. Thus, membranes older than 8 weeks exert regenerative capacities comparable to the younger ones. The postulated narrow time frame of 4–8 weeks until bone grafting can be questioned and surgeons may choose timing for the second operation more independently and based on other clinical factors.

Forward Osmosis: An Approach to Reclaim Dairy Waste Stream Whey

Recognizing the issues with conventional water resources and stricter wastewater effluent disposal standards, the treatment and recovery from wastewater are gaining impetus. The dairy industry consumes a substantial amount of water and generates a massive quantity of wastewater annually. Whey, which is about 94% water, is a waste stream produced in the dairy industry during the manufacture of cheese, paneer, yogurt, etc. Although various wastewater treatment technologies are available in the market, membrane technologies are considered the most advanced and reliable ones, but they are expensive. In recent years, Forward Osmosis (FO) is looked upon as a potential alternative to these costly and energy intensive pressure driven membrane processes. FO works on the principle of natural osmotic pressure where energy is just required to lift the solutions. The present lab-scale study investigates the partial reclamation of water from whey using FO technology. The Continuous Single Pass (CSP) and Recirculation mode (RC) study is conducted using high osmotic pressure (π = 375 bar at 298K) saturated aqueous(aq.) NaCl as the draw solution. The aq. NaCl solution is a potential brine stream in the dairy industry and finds applications in the manufacture of paneer, butter, cheese and ice cream eliminating the need for draw regeneration. The back diffusion study of the Hollow Fibre Forward Osmosis (HFFO) membrane revealed about 0.82% back diffusion of solute. The maximum water recovery of ~ 56% is achieved in CSP mode while 57.6% is achieved for RC mode with Feed/Draw ratio of 4.5:1. For F/D of 10:1, the maximum permeate flux of ~ 8.7 kg m− 2 h− 1 is observed for the CSP mode of operation for 10 minutes of study. Thus, FO is an efficient membrane technique that eliminates the need for draw regeneration and can be applied in the dairy industry.