Navigating the Genomic Landscape of Human Adipose Stem Cell-Derived β-Cells

Diabetes is a pandemic manifested through glucose dysregulation mediated by inadequate insulin secretion by beta cells. A beta cell replacement strategy would transform the treatment paradigm from pharmacologic glucose modulation to a genuine cure. Stem cells have emerged as a potential source for beta cell (β-cell) engineering. The detailed generation of functional β-cells from both embryonic and induced pluripotent stem cells has recently been described. Adult stem cells, including adipose derived, may also offer a therapeutic approach, but remain ill defined. In our study, we performed an in-depth assessment of insulin-producing beta cells generated from human adipose, irrespective of donor patient age, gender, and health status. Cellular transformation was confirmed using flow cytometry and single-cell imaging. Insulin secretion was observed with glucose stimulation and abrogated following palmitate exposure, a common free fatty acid implicated in human beta cell dysfunction. We used next-generation sequencing to explore gene expression changes before and after differentiation of patient-matched samples, which revealed more than 5,000 genes enriched. Adipose-derived beta cells displayed comparable gene expression to native β-cells. Pathway analysis demonstrated relevance to stem cell differentiation and pancreatic developmental processes, which are vital to cellular function, structural development, and regulation. We conclude that the functions associated with adipose derived beta cells are mediated through relevant changes in the transcriptome, which resemble those seen in native β-cell morphogenesis and maturation. Therefore, they may represent a viable option for the clinical translation of stem cell-based therapies in diabetes.

Computer-Aided Design and Manufacture of Intraoral Splints: A Potential Role in Cleft Care

BACKGROUND

Nasoalveolar molding is a nonsurgical modality for the treatment of cleft lip and palate that uses an intraoral splint to align the palatal shelves. Repeated impressions are needed for splint modification, each carrying risk of airway obstruction. Computer-aided design and manufacturing (CAD/CAM) has the ability to simplify the process. As a precursor to CAD/CAM splint fabrication, a proof-of-concept study was conducted to compare three-dimensional splints printed from alginate impressions versus digital scans. We hypothesized that intraoral digital scanning would compare favorably to alginate impressions for palate registration and subsequent splint manufacture, with decreased production times.

METHODS

Alginate and digital impressions were taken from 25 healthy teenage volunteers. Digital impressions were performed with a commercially available intraoral scanner. Plaster casts made from alginate impressions were converted to Standard Triangle Language files. Patient-specific matched scans were evaluated for total surface area with the concordance correlation coefficient. Acrylic palatal splints were three-dimensionally printed from inverse digital molds. Subjective appliance fit was assessed using a five-point scale.

RESULTS

A total of 23 participants were included. Most subjects preferred digital impression acquisition. Impression methods showed moderate agreement (concordance correlation coefficient 0.93). Subjects rated splints from digital impressions as having a more precise fit (4.4 versus 3.9). The digital approach decreased impression phase time by over 10-fold and overall production time by 28%.

CONCLUSIONS

CAD/CAM has evolved extensively over the past two decades and is now commonplace in medicine. However, its utility in cleft patients has not been fully realized. This pilot study demonstrated that CAD/CAM technologies may prove useful in patients requiring intraoral splints.

Differentiation of Adipose Tissue-Derived CD34+/CD31- Cells into Endothelial Cells In Vitro

In this study, CD34+/CD31- progenitor cells were isolated from the stromal vascular fraction (SVF) of adipose tissue using magnetic activated cell sorting. The endothelial differentiation capability of these cells in vitro was evaluated by culturing them in vascular endothelial growth factor (VEGF) induced medium for 14 days. Viability, proliferation, differentiation and tube formation of these cells were evaluated. Cell viability study revealed that both undifferentiated and endothelial differentiated cells remained healthy for 14 days. However, the proliferation rate was higher in undifferentiated cells compared to endothelial differentiated ones. Upregulation of endothelial characteristic genes (Von Willebrand Factor (vWF) and VE Cadherin) was observed in 2D culture. However, PECAM (CD31) was only found to be upregulated after the cells had formed tube-like structures in 3D Matrigel culture. These results indicate that adipose derived CD34+/CD31- cells when cultured in VEGF induced medium, are capable differentiation into endothelial-like lineages. Tube formation of the cells started 3h after seeding the cells on Matrigel and formed more stable and connected network 24 h post seeding in presence of VEGF.

Bioprinting functional tissues

Despite the numerous lives that have been saved since the first successful procedure in 1954, organ transplant has several shortcomings which prevent it from becoming a more comprehensive solution for medical care than it is today. There is a considerable shortage of organ donors, leading to patient death in many cases. In addition, patients require lifelong immunosuppression to prevent graft rejection postoperatively. With such issues in mind, recent research has focused on possible solutions for the lack of access to donor organs and rejections, with the possibility of using the patient's own cells and tissues for treatment showing enormous potential. Three-dimensional (3D) bioprinting is a rapidly emerging technology, which holds great promise for fabrication of functional tissues and organs. Bioprinting offers the means of utilizing a patient's cells to design and fabricate constructs for replacement of diseased tissues and organs. It enables the precise positioning of cells and biologics in an automated and high throughput manner. Several studies have shown the promise of 3D bioprinting. However, many problems must be overcome before the generation of functional tissues with biologically-relevant scale is possible. Specific focus on the functionality of bioprinted tissues is required prior to clinical translation. In this perspective, this paper discusses the challenges of functionalization of bioprinted tissue under eight dimensions: biomimicry, cell density, vascularization, innervation, heterogeneity, engraftment, mechanics, and tissue-specific function, and strives to inform the reader with directions in bioprinting complex and volumetric tissues. STATEMENT OF SIGNIFICANCE: With thousands of patients dying each year waiting for an organ transplant, bioprinted tissues and organs show the potential to eliminate this ever-increasing organ shortage crisis. However, this potential can only be realized by better understanding the functionality of the organ and developing the ability to translate this to the bioprinting methodologies. Considering the rate at which the field is currently expanding, it is reasonable to expect bioprinting to become an integral component of regenerative medicine. For this purpose, this paper discusses several factors that are critical for printing functional tissues including cell density, vascularization, innervation, heterogeneity, engraftment, mechanics, and tissue-specific function, and inform the reader with future directions in bioprinting complex and volumetric tissues.

Non-coding RNAs in Various Stages of Liver Disease Leading to Hepatocellular Carcinoma: Differential Expression of miRNAs, piRNAs, lncRNAs, circRNAs, and sno/mt-RNAs

Hepatocellular carcinoma (HCC) was the fifth leading cause of cancer death in men and eighth leading cause of death in women in the United States in 2017. In our study, we sought to identify sncRNAs in various stages of development of HCC. We obtained publicly available small RNA-seq data derived from patients with cirrhosis (n = 14), low-grade dysplastic nodules (LGDN, n = 9), high grade dysplastic nodules (HGDN, n = 6), early hepatocellular carcinoma (eHCC, n = 6), and advanced hepatocellular carcinoma (HCC, n = 20), along with healthy liver tissue samples (n = 9). All samples were analyzed for various types of non-coding RNAs using PartekFlow software. We remapped small RNA-seq to miRBase to obtain differential expressions of miRNAs and found 87 in cirrhosis, 106 in LGDN, 59 in HGDN, 80 in eHCC, and 133 in HCC. Pathway analysis of miRNAs obtained from diseased samples compared to normal samples showed signaling pathways in the microRNA dependent EMT, CD44, and others. Additionally, we analyzed the data sets for piRNAs, lncRNAs, circRNAs, and sno/mt-RNAs. We validated the in silico data using human HCC samples with NanoString miRNA global expression. Our results suggest that publically available data is a valuable resource for sncRNA identification in HCC progression (FDR set to <0.05 for all samples) and that a data mining approach is useful for biomarker development.

Small Non-coding RNA Abundance in Adrenocortical Carcinoma: A Footprint of a Rare Cancer

BACKGROUND: Adrenocortical carcinoma (ACC) is a relatively rare, but aggressive type of cancer, which affects both children and adults. OBJECTIVE: Small non-coding RNAs (sncRNAs) play important roles and may serve as biomarkers for disease diagnosis, prognosis and treatment. METHODS: In our study, we sought to identify sncRNAs associated with malignant adrenal tumors. We obtained publicly available, small RNA sequencing data derived from 45 ACC and 30 benign tumors arising from the cortex of the adrenal gland, adrenocortical adenomas (ACA), and compared their sncRNA expression profiles. RESULTS: First, we remapped small RNA-seq to miRBase version 21 to check expression of miRNAs and found 147 miRNAs were aberrantly expressed (p<0.05) in ACC samples compared to ACA samples. Pathway analysis of differentially expressed miRNAs revealed p53 signaling pathways to be profoundly affected in ACC samples. Further examination for other types of small RNAs revealed 16 piRNAs, 48 lncRNAs and 19 sn/snoRNAs identified in ACC samples. Conclusions: Our data analysis suggests that publically available resources can be mined for biomarker development and improvements in-patient care; however, further research must be performed to correlate tumor grade with gene expression.

Concise Review: Bioprinting of Stem Cells for Transplantable Tissue Fabrication

Bioprinting is a quickly progressing technology, which holds the potential to generate replacement tissues and organs. Stem cells offer several advantages over differentiated cells for use as starting materials, including the potential for autologous tissue and differentiation into multiple cell lines. The three most commonly used stem cells are embryonic, induced pluripotent, and adult stem cells. Cells are combined with various natural and synthetic materials to form bioinks, which are used to fabricate scaffold‐based or scaffold‐free constructs. Computer aided design technology is combined with various bioprinting modalities including droplet‐, extrusion‐, or laser‐based bioprinting to create tissue constructs. Each bioink and modality has its own advantages and disadvantages. Various materials and techniques are combined to maximize the benefits. Researchers have been successful in bioprinting cartilage, bone, cardiac, nervous, liver, and vascular tissues. However, a major limitation to clinical translation is building large‐scale vascularized constructs. Many challenges must be overcome before this technology is used routinely in a clinical setting. Stem Cells Translational Medicine2017;6:1940–1948