Repurposing agricultural waste as low-cost cultured meat scaffolds

Growing meat in vitro using tissue engineering and bioproduction techniques (cellular agriculture) has become an increasingly promising solution to the global food security challenge. Our lab has established methods to cultivate bovine muscle tissue on decellularized plants, representing a viable low-cost, sustainable method to grow meat on edible scaffolds. Most work in this area has focused on the use of edible plant materials (i.e., spinach leaves, apple, broccoli) with inherent economic value. Harvest waste such as corn husk or jackfruit represent abundant sources of cellulose for scaffold production and may be a viable alternative. The present study aims to investigate production of cultured meat through tissue engineering and bioproduction on decellularized, edible samples of corn husk and jackfruit rind. Corn husks and jackfruit rinds were exposed to immersion decellularization. DNA quantification and histological analysis demonstrated sufficient decellularization (0.17 ± 0.06 and 0.07 ± 0.00 ug DNA/g tissue for corn husk and jackfruit rinds, respectively). Following decellularization, corn husk scaffold stiffnesses decreased from 56.67±16.71 MPa to 12.95±2.43 MPa in fiber-aligned direction, while jackfruit decreased from 7.54 ±2.42 MPa to 2.47±1.47 MPa. Seeded scaffolds with bovine satellite cells (BSCs) (11.45±2.24 ug/ul lysate/Gram) and avian (QM7s) (12.90±1.99 ug/ul lysate/Gram) demonstrated increased protein yields on jackfruit scaffolds. QM7 cultured on corn husk scaffolds yielded increased protein but PBSCs seeded on corn husks did not yield protein content higher than controls (QM7 on corn husk: 16.28±3.55, PBSCs on corn husks: 9.57±1.56 ug/ul lysate/Gram, control: 6.35±1.43 ug/ul lysate/Gram). Additionally, cell transfer from scaffold to scaffold (bead-to-bead transfer) was observed on corn husk scaffolds in a dynamic environment. These results suggest that decellularized harvest waste scaffolds may aid in realization of cultured meat products that will contribute to a more robust and environmentally sustainable food supply

Role of Schlafen 2 (SLFN2) in the Generation of Interferon α-induced Growth Inhibitory Responses*

The precise STAT-regulated gene targets that inhibit cell growth and generate the antitumor effects of Type I interferons (IFNs) remain unknown. We provide evidence that Type I IFNs regulate expression of Schlafens (SLFNs), a group of genes involved in the control of cell cycle progression and growth inhibitory responses. Using cells with targeted disruption of different STAT proteins and/or the p38 MAP kinase, we demonstrate that the IFN-dependent expression of distinct Schlafen genes is differentially regulated by STAT complexes and the p38 MAP kinase pathway. We also provide evidence for a key functional role of a member of the SLFN family, SLFN2, in the induction of the growth-suppressive effects of IFNs. This is shown in studies demonstrating that knockdown of SLFN2 enhances hematopoietic progenitor colony formation and reverses the growth-suppressive effects of IFNα on normal hematopoietic progenitors. Importantly, NIH3T3 or L929 cells with stable knockdown of SLFN2 form more colonies in soft agar, implicating this protein in the regulation of anchorage-independent growth. Altogether, our data implicate SLFN2 as a negative regulator of the metastatic and growth potential of malignant cells and strongly suggest a role for the SLFN family of proteins in the generation of the antiproliferative effects of Type I IFNs