Project description:Purpose: Transvaginal meshes for the treatment of Pelvic Organ Prolapse (POP) have been associated with severe adverse events and have been banned for clinical use in many countries. We recently reported the design of degradable poly (L-lactic acid)-co-poly (e-caprolactone) nanofibrous mesh (P nanomesh) bioengineered with endometrial mesenchymal stem/stromal cells (eMSC) for POP repair. We showed that such bioengineered meshes had high tissue integration as well as immunomodulatory effects in vivo. This study aimed to determine the key molecular players enabling eMSC- based foreign body response modulation. Methods: SUSD2+ eMSC were purified from single cell suspensions obtained from endometrial biopsies from cycling women by magnetic bead sorting. Electrospun P nanomeshes with and without eMSC were implanted in a NSG mouse skin wound repair model for 1 and 6 weeks. Quantitative PCR was used to assess the expression of extracellular matrix (ECM), cell adhesion, angiogenesis and inflammation genes as log2 fold changes compared to sham controls. Histology and immunostaining was used to visualize the ECM, blood vessels and multinucleated foreign body giant cells around implants. Results: Bioengineered P nanomesh/ eMSC constructs explanted after 6 weeks showed significant increase in 35 genes associated with ECM, ECM regulation, cell adhesion angiogenesis and immune response in comparison to P nanomesh alone. In the absence of eMSC, acute inflammatory genes were significantly elevated at 1 week. However, in presence of eMSC, there was an increased expression of anti-inflammatory genes including Mrc1 and Arg1 by 6 weeks. There was formation of multinucleated foreign body giant cells around both implants at 6 weeks that expressed CD206, a M2 macrophage marker. Conclusion: This study reveals that eMSC modulate the foreign body response to degradable P nanomeshes in vivo by altering the expression profile of mouse genes. eMSC reduce acute inflammatory and increase ECM synthesis, angiogenesis and anti-inflammatory gene expression at 6 weeks while forming newly synthesized collagen within the nanomeshes and neo-vasculature in close proximity. From a tissue engineering perspective, this is a hallmark of a highly successful implant, suggesting significant potential as alternative surgical constructs for the treatment of POP.
Project description:To analyze gene expression pattern in response to nitric oxde in Saccharomyces cerevisiae, we performed microarray analysis using yeast cells treated with a nitric oxide donor S-nitroso-N-acetyl-DL-penicillamine (SNAP). S. cerevisiae S288c strain was cultured in synthetic dextrose (SD) minimal medium up to log phase (OD600 = 1), and then treated with 100 micro molar of SNAP for 10, 30, or 60 min. After treatment with SNAP, cells were disrupted adn total RNA was extracted. We commissioned following experiments to BIO MATRIX RESEARCH Inc.
Project description:We identify the cis and trans determinants of nucleosome positioning using a functional evolutionary approach involving S. cerevisiae strains containing large genomic regions from other yeast species. In a foreign species, nucleosome depletion at promoters is maintained over poly(dA:dT) tracts, whereas internucleosome spacing and all other aspects of nucleosome positioning tested are not. Interestingly, the locations of the +1 nucleosome and RNA start sites shift in concert. Strikingly, in a foreign species, nucleosome-depleted regions occur fortuitously in coding regions, and they often act as promoters that are associated with a positioned nucleosome array linked to the length of the transcription unit. nucleosome mapping for 3 strains bearing yeast artificial chromosomes from Kluyveromyces lactis and 2 strains with Debaryomyces hansenii artificial chromosomes in Saccharomyces cerevisiae
Project description:Silicone-based medical devices are widely used in chronic implants and are generally perceived to be safe. However, immune-related complications including malignancies have recently been linked to textured breast implants. Here, we examine the influence of clinically approved breast implants surface features on host immune responses. Prosthetics with surface roughness of 0, 4, and 90 (Ra) were implanted in mammary fat pads of mice for 2 weeks and cells adjacent to the resulting tissue capsules were evaluated for foreign body immune responses using single-cell RNA-seq. Our findings identify a unique and finely tuned surface topography that is capable of modulating implant immunity to suppress foreign body response.
Project description:Foreign body reaction is one of the most important limiting factors to the clinical translation of implantable bioelectronics. The experiment compares the process of foreign body reaction, following the implantation of a silicon device in a mouse peripheral nerve, to that of peripheral nerve injury, following nerve crushing. Both processes are also compared to a naïve peripheral nerve from an uninjured mouse. The endpoints are day 1, 4, 7, 14 and 28 days.
