LncRNA TP53TG1 Promotes the Growth and Migration of Hepatocellular Carcinoma Cells via Activation of ERK Signaling.

Long non-coding RNA (lncRNA) TP53 target 1 (TP53TG1) was discovered as a TP53 target gene. TP53TG1 has been reported as having dual roles by exerting tumor-suppressive and oncogenic activities that vary depending on the cancer type. Yet, the role of TP53TG1 in hepatocellular carcinoma (HCC) is not fully understood. In this study, we performed both gain- and loss-of-function studies to determine the biological role of TP53TG1 in HCC. We found that the knockdown of TP53 in HCC cells caused the upregulation of TP53TG1. Furthermore, we found that the knockdown of TP53TG1 not only suppressed HCC cell proliferation and migration, but also reduced intrinsic ERK signaling. In contrast, the overexpression of TP53TG1 increased ERK activation and enhanced HCC proliferation. In conclusion, our study reveals an oncogenic role of TP53TG1 in HCC, which provides a novel insight into the cell-type-specific function of TP53TG1 in HCC.

Beverage ethanol exposures among infants reported to United States poison control centers.

BACKGROUND: Case studies and small series have demonstrated that beverage ethanol may pose a serious poisoning hazard to infants. Intoxicated infants may not present with the classic signs or symptoms of ethanol poisoning. The objective of this study was to describe the epidemiology of beverage ethanol exposures among infants reported to the United States poison control centers. METHODS: Data from the National Poison Data System were retrospectively analyzed for infants <12 months of age who were exposed to beverage ethanol from 2009-2018. RESULTS: Over the 10-year study period, 1,818 infant exposures to beverage ethanol were reported. Most exposures were single substance (95.2%), and the most common route of exposure was ingestion (n = 1,738). Infants 9-11 months were the most commonly exposed age group subset (45.3%). The annual number and rate of alcoholic beverage exposure increased by 37.5% and 42.9%, respectively, from 2009 to 2018. Of the 563 infants evaluated at a healthcare facility, 38% of exposures were hospitalized. Infants 0-5 months of age had higher odds of being admitted to a non-critical (OR: 2.35, 95% CI: 1.41-3.92) or critical care unit (OR: 2.39; 95% CI: 1.50-3.79) compared to infants 6-11 months of age. Infants 0-5 months of age were more likely to (OR: 4.65; 95% CI: 3.18-6.79) experience a serious outcome compared to infants ages 6-11 months. Five fatalities in infants <6 months old were documented. An in-depth case review identified improper storage and subsequent formula preparation with beverage ethanol as a common exposure mechanism. CONCLUSIONS: Beverage ethanol exposures among infants are associated with hospitalization, serious clinical effects, and mortality. Infants may present with atypical signs and symptoms of intoxication, requiring a high index of suspicion. Opportunities exist to reduce exposures by addressing improper storage of beverage alcohols.

Three dimensional extrusion printing induces polymer molecule alignment and cell organization within engineered cartilage.

Proper cell-material interactions are critical to remain cell function and thus successful tissue regeneration. Many fabrication processes have been developed to create microenvironments to control cell attachment and organization on a three-dimensional (3D) scaffold. However, these approaches often involve heavy engineering and only the surface layer can be patterned. We found that 3D extrusion based printing at high temperature and pressure will result an aligned effect on the polymer molecules, and this molecular arrangement will further induce the cell alignment and different differentiation capacities. In particular, articular cartilage tissue is known to have zonal collagen fiber and cell orientation to support different functions, where collagen fibers and chondrocytes align parallel, randomly, and perpendicular, respectively, to the surface of the joint. Therefore, cell alignment was evaluated in a cartilage model in this study. We used small angle X-ray scattering analysis to substantiate the polymer molecule alignment phenomenon. The cellular response was evaluated both in vitro and in vivo. Seeded mesenchymal stem cells (MSCs) showed different morphology and orientation on scaffolds, as a combined result of polymer molecule alignment and printed scaffold patterns. Gene expression results showed improved superficial zonal chondrogenic marker expression in parallel-aligned group. The cell alignment was successfully maintained in the animal model after 7 days with distinct MSC morphology between the casted and parallel printed scaffolds. This 3D printing induced polymer and cell alignment will have a significant impact on developing scaffold with controlled cell-material interactions for complex tissue engineering while avoiding complicated surface treatment, and therefore provides new concept for effective tissue repairing in future clinical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2190-2199, 2018.

3D Printing Bioactive PLGA Scaffolds Using DMSO as a Removable Solvent.

Present bioprinting techniques lack the methodology to print with bioactive materials that retain their biological functionalities. This constraint is due to the fact that extrusion-based printing of synthetic polymers is commonly performed at very high temperatures in order to achieve desired mechanical properties and printing resolutions. Consequently, current methodology prevents printing scaffolds embedded with bioactive molecules, such as growth factors. With the wide use of mesenchymal stem cells (MSCs) in regenerative medicine research, the integration of growth factors into 3D printed scaffolds is critical because it can allow for inducible MSC differentiation. We have successfully incorporated growth factors into extrusion printed poly (lactic-co-glycolic acid) (PLGA) scaffolds by introducing dimethyl sulfoxide (DMSO) for low temperature printing. Mechanical testing results demonstrated significantly different compressive and tensile properties for PLGA scaffold printed with or without DMSO. In particular, the PLGA-DMSO scaffold displayed a highly stretchable feature compared to the regular PLGA scaffold. The cellular response of growth factor introduction was evaluated in vitro using human mesenchymal stem cells (hMSCs). By evaporating the DMSO after printing, we ensured that there was no cytotoxic effect on seeded hMSCs. The addition of lineage specific growth factors led to increased expression of corresponding genetic markers for chondrogenesis, osteogenesis, and adipogenesis. We concluded that the use of DMSO for 3D printed scaffold fabrication with bioactive items is a revolutionary methodology in advancing regenerative medicine. The incorporation of bioactive molecules opens pathways to more therapeutic uses for 3D printing in treating damaged or deteriorating native tissue.

3D printing PLGA: a quantitative examination of the effects of polymer composition and printing parameters on print resolution.

In the past few decades, 3D printing has played a significant role in fabricating scaffolds with consistent, complex structure that meet patient-specific needs in future clinical applications. Although many studies have contributed to this emerging field of additive manufacturing, which includes material development and computer-aided scaffold design, current quantitative analyses do not correlate material properties, printing parameters, and printing outcomes to a great extent. A model that correlates these properties has tremendous potential to standardize 3D printing for tissue engineering and biomaterial science. In this study, we printed poly(lactic-co-glycolic acid) (PLGA) utilizing a direct melt extrusion technique without additional ingredients. We investigated PLGA with various lactic acid:glycolic acid (LA:GA) molecular weight ratios and end caps to demonstrate the dependence of the extrusion process on the polymer composition. Micro-computed tomography was then used to evaluate printed scaffolds containing different LA:GA ratios, composed of different fiber patterns, and processed under different printing conditions. We built a statistical model to reveal the correlation and predominant factors that determine printing precision. Our model showed a strong linear relationship between the actual and predicted precision under different combinations of printing conditions and material compositions. This quantitative examination establishes a significant foreground to 3D print biomaterials following a systematic fabrication procedure. Additionally, our proposed statistical models can be applied to couple specific biomaterials and 3D printing applications for patient implants with particular requirements.

Effect of Dynamic Culture and Periodic Compression on Human Mesenchymal Stem Cell Proliferation and Chondrogenesis.

We have recently developed a bioreactor that can apply both shear and compressive forces to engineered tissues in dynamic culture. In our system, alginate hydrogel beads with encapsulated human mesenchymal stem cells (hMSCs) were cultured under different dynamic conditions while subjected to periodic, compressive force. A customized pressure sensor was developed to track the pressure fluctuations when shear forces and compressive forces were applied. Compared to static culture, dynamic culture can maintain a higher cell population throughout the study. With the application of only shear stress, qRT-PCR and immunohistochemistry revealed that hMSCs experienced less chondrogenic differentiation than the static group. The second study showed that chondrogenic differentiation was enhanced by additional mechanical compression. After 14 days, alcian blue staining showed more extracellular matrix formed in the compression group. The upregulation of the positive chondrogenic markers such as Sox 9, aggrecan, and type II collagen were demonstrated by qPCR. Our bioreactor provides a novel approach to apply mechanical forces to engineered cartilage. Results suggest that a combination of dynamic culture with proper mechanical stimulation may promote efficient progenitor cell expansion in vitro, thereby allowing the culture of clinically relevant articular chondrocytes for the treatment of articular cartilage defects.