Diseased Primary Cell

Research on disease is often limited by access to patients and availability of diseased tissues. The 'disease models' can help overcome these problems by examining diseases in the laboratory. One way to simplify the complexity of a disease is to analyze individual cell or groups of cells instead of observing a complex tissues or the whole body. Diseased primary cells are new source of cells that can be used as disease models, which are otherwise difficult to explore. The disease model makes it possible to conduct a closer and more extensive scientific investigation of the diseases. They also allow experiments to be repeated many times, which is absolutely necessary for results to be considered trustworthy.

Diseased Human Bronchial Epithelial Cells (HBECs) and Asthma

Asthma is a chronic respiratory disease characterized by recurrent exacerbations. One feature of asthma (especially severe asthma) is airway remodelling, that is, an increase in smooth muscle mass, fibrosis, and excessive mucus production. The epithelium plays a key role in the development of airway remodelling and inflammation as it is the primary barrier to environmental exposures.

The use of primary cells and cell lines in vitro models is essential for understanding the function of the epithelium relevant to asthma. Primary human bronchial epithelial cells (HBECs) can be cultured at air-liquid interface (ALI) using defined medium to drive the differentiated phenotype. Primary HBECs from asthma and non-asthma subjects have been compared in a number of studies to investigate the intrinsic differences in the asthmatic epithelium. Epithelial cells from asthma patients display differential expression of genes associated with inflammation, repair, and remodelling and have been shown to differ from normal cells during culture including increased proliferation and slower repair of mechanical wounds. Several groups have cultured asthmatic epithelial cells in ALI, exhibiting a poorly differentiated phenotype, that is, an increase in the number of basal cells or a decrease in tight junction formation, as well as differing responses to stimuli such as cigarette smoke, mechanical wounding, and viral infections.

These data suggest that bronchial epithelial cells may be an effective drug target for asthma. HBECs culture models can be used for drug development to assess the direct effects of potential drugs on cell function and signaling as well as drug uptake and metabolism.

Diseased Preadipocytes and Type 2 Diabetes (T2D)

The incidence of obesity is rising sharply in almost all societies of the world, and with it come important pathological consequences such as type 2 diabetes mellitus. By 2030, the global incidence of type 2 diabetes is projected to double to 350 million and the expenditure attributed to diabetes estimated to reach $132 billion in the United States alone.

Deterioration of the adipogenic potential of preadipocytes may contribute to adipose tissue dysfunction in obesity and type 2 diabetes (T2D). We hypothesised that preadipocytes from obese humans with or without type 2 diabetes (T2D) exhibit distinct epigenomes and transcriptomic responses to differentiation in culture. The transcriptomic profile of visceral adipose tissue preadipocytes collected from lean, obese and obese with T2D was assessed throughout in vitro differentiation using RNA-sequencing. Reduced Representation Bisulfite Sequencing was used to establish the genome-wide DNA methylation profile of human preadipocytes and 3T3-L1 preadipocytes. The results showed that preadipocytes from all obese subjects (Obese + Obese T2D) were transcriptionally different in response to differentiation compared to those of Lean, preadipocytes from Obese T2D showed impaired insulin signaling and a further transcriptomic shift towards altered adipocyte function.

The above data suggests that preadipocytes from obese humans are epigenetically reprogrammed. Reconstructing the epigenome of preadipocytes can be used as a therapeutic option to ameliorate adipose tissue biology in T2D.