Using bispecific antibodies in forced degradation studies to analyze the structure-function relationships of symmetrically and asymmetrically modified antibodies.

Forced degradation experiments of monoclonal antibodies (mAbs) aid in the identification of critical quality attributes (CQAs) by studying the impact of post-translational modifications (PTMs), such as oxidation, deamidation, glycation, and isomerization, on biological functions. Structure-function characterization of mAbs can be used to identify the PTM CQAs and develop appropriate analytical and process controls. However, the interpretation of forced degradation results can be complicated because samples may contain mixtures of asymmetrically and symmetrically modified mAbs with one or two modified chains.

Engineering human renal epithelial cells for transplantation in regenerative medicine.

Cellular transplantation may treat several human diseases by replacing damaged cells and/or providing a local source of trophic factors promoting regeneration. We utilized human renal epithelial cells (hRECs) isolated from cadaveric donors as a cell model. For efficacious implementation of hRECs for treatment of kidney diseases, we evaluated a novel encapsulation strategy for immunoisolation of hRECs and lentiviral transduction of the Green Fluorescent Protein (GFP) as model gene for genetic engineering of hRECs to secrete desired trophic factors.

Three-dimensional lung tumor microenvironment modulates therapeutic compound responsiveness in vitro--implication for drug development.

Three-dimensional (3D) cell culture is gaining acceptance in response to the need for cellular models that better mimic physiologic tissues. Spheroids are one such 3D model where clusters of cells will undergo self-assembly to form viable, 3D tumor-like structures. However, to date little is known about how spheroid biology compares to that of the more traditional and widely utilized 2D monolayer cultures.

A human in vitro model that mimics the renal proximal tubule.

Human in vitro-manufactured tissue and organ models can serve as powerful enabling tools for the exploration of fundamental questions regarding cell, matrix, and developmental biology in addition to the study of drug delivery dynamics and kinetics. To date, the development of a human model of the renal proximal tubule (PT) has been hindered by the lack of an appropriate cell source and scaffolds that allow epithelial monolayer formation and maintenance. Using extracellular matrices or matrix proteins, an in vivo-mimicking environment can be created that allows epithelial cells to exhibit their typical phenotype and functionality.

Regulation of the human SOX9 promoter by Sp1 and CREB.

The transcription factor SOX9 is essential for multiple steps during skeletal development, including mesenchymal cell chondrogenesis and endochondral bone formation. We recently reported that the human SOX9 proximal promoter region is regulated by the CCAAT-binding factor through two CCAAT boxes located within 100 bp of the transcriptional start site. Here we report that the human SOX9 proximal promoter is also regulated by the cyclic-AMP response element binding protein (CREB) and Sp1.