Alcian blue/alizarin red staining of cartilage and bone of short-tailed fruit bat (Carollia perspicillata)

Resveratrol increases nucleus pulposus matrix synthesis through activating the PI3K/Akt signaling pathway under mechanical compression in a disc organ culture

Disc nucleus pulposus (NP) matrix homeostasis is important for normal disc function. Mechanical overloading seriously decreases matrix synthesis and increases matrix degradation. The present study aims to investigate the effects of resveratrol on disc NP matrix homeostasis under a relatively high-magnitude mechanical compression and the potential mechanism underlying this process. Porcine discs were perfusion-cultured and subjected to a relatively high-magnitude mechanical compression (1.3 MPa at a frequency of 1.0 Hz for 2 h once per day) for 7 days in a mechanically active bioreactor. The non-compressed discs were used as controls. Resveratrol was added along with culture medium to observe the effects of resveratrol on NP matrix synthesis under mechanical load respectively. NP matrix synthesis was evaluated by histology, biochemical content (glycosaminoglycan (GAG) and hydroxyproline (HYP)), and expression of matrix macromolecules (aggrecan and collagen II). Results showed that this high-magnitude mechanical compression significantly decreased NP matrix content, indicated by the decreased staining intensity of Alcian Blue and biochemical content (GAG and HYP), and the down-regulated expression of NP matrix macromolecules (aggrecan and collagen II). Further analysis indicated that resveratrol partly stimulated NP matrix synthesis and increased activity of the PI3K/Akt pathway in a dose-dependent manner under mechanical compression. Together, resveratrol is beneficial for disc NP matrix synthesis under mechanical overloading, and the activation of the PI3K/Akt pathway may participate in this regulatory process. Resveratrol may be promising to regenerate mechanical overloading-induced disc degeneration.

Propagation and differentiation of human Wharton's jelly stem cells on three-dimensional nanofibrous scaffolds

Stem cells isolated from the Wharton's jelly of the human umbilical cord (hWJSCs) are unique compared to other stem cell types as they lie in between embryonic stem cells (ESCs) and adult mesenchymal stem cells (MSCs) on the developmental map and share stemness markers of ESCs and MSCs. Yet, they do not induce tumorigenesis and are hypoimmunogenic and proliferative and fresh cell numbers can be harvested painlessly in abundance from discarded umbilical cords. Additionally, they secrete important soluble bioactive molecules from the interleukin and cell adhesion family, hyaluronic acid, collagen, glycosoaminoglycans, and chondroitin sulfate. Many of these molecules are involved in bone, cartilage, and joint repair. It has also been shown that hWJSCs attach, proliferate, and differentiate efficiently in the stem cell niches of three-dimensional matrices, particularly nanofibrous scaffolds. Thus, tissue constructs made up of hWJSCs and biodegradable nanofibrous scaffolds will facilitate clinical translation and improved functional outcome for arthritis, bone, and cartilage diseases. When applied in vivo, the hWJSCs from the tissue construct may improve repair either by differentiating into new chondrocytes or osteocytes and/or release of important factors that favor repair through paracrine functions. The nanofibrous scaffold is expected to provide the architecture and niches for the hWJSCs to perform and will later biodegrade encouraging engraftment. This chapter provides a step-by-step protocol for the preparation of such tissue constructs involving hWJSCs and nanofibrous scaffolds. The methodology also includes the targeted in vitro differentiation of the hWJSCs to osteogenic and chondrogenic lineages when attached to the nanofibrous scaffolds.

The short-tailed fruit bat Carollia perspicillata: a model for studies in reproduction and development

Carollia perspicillata has proven to be a valuable laboratory model for studies in reproduction and development. We present here an overview of the care and handling of Carollia in captivity and discuss some pertinent studies in reproductive biology. Finally, we describe various features of the genome and some of the genetic manipulations that are now possible.