Sex and Sex Hormones in Tissue Homeostasis

Women are not small men. Sex-specific differences do not only affect the classical target organs of sexual differentiation and reproduction, but have been found to involve most, if not all the organs and tissues in the body. One of the consequences of this dimorphism is that diseases manifest in a sex- and gender-specific way. Key to maintenance of a healthy state is functioning tissue able to cope with insults. Regulated death of damaged cells and replacement with new cells by proliferation is a prerequisite for maintaining tissue function taking place at different pace in the different organs. The intent of this chapter is to review current evidence for sex-specific differences in tissue homeostasis focusing on the variability of hormone exposure characteristic for the female reproductive life stages

Human Platelet Lysates Successfully Replace Fetal Bovine Serum in Adipose-Derived Adult Stem Cell Culture

Fetal bovine serum (FBS) is still the gold standard as a cell culture medium additive due to its high level of growth stimulatory factors. Although supplementation of growth media with FBS is common practice in cell and tissue culture, FBS bears a number of disadvantages and its use has been questioned recently: (1) an ill-defined medium supplement, (2) qualitative and quantitative batch-to-batch variations, and (3) animal welfare concerns regarding the harvest of bovine fetal blood.Recently, we were able to show the capacity of human platelet α-granule lysates to replace FBS in a variety of human and animal cell culture systems. Thus, lysates of human donor platelets may become a valuable non animal-derived substitute for FBS in cultures of mammalian cells and in human and animal stem cell technology.Stem cells may become the future for human-based alternative to animal testing, in vitro toxicology, and drug safety assessment. New stem cell-based test systems are continuously established, and their performance under animal-derived component free culture conditions has to be defined in prevalidation and validation studies. In order to accomplish these tasks, adipose-derived mesenchymal stem cells (ADSC) were expanded in media supplemented with platelet lysates. Proliferation assays by resazurin and WST-8 compared with direct cell counting confirmed the growth promoting effect of platelet lysate, comparable to high FBS. Furthermore, we established culture conditions that ADSC kept their undifferentiated state as determined by CD73, CD90 and CD105 expression and the lack of negative marker CD45. Preliminary tests whether ADSC can be differentiated towards adipogenic, osteogenic, or chondrogenic phenotypes under platelet lysate supplemented growth conditions were also successful

Human Platelet Lysates Promote the Differentiation Potential of Adipose-Derived Adult Stem Cell Cultures

Adipose tissue from liposuction is a rich source for human mesenchymal stem cells. This type of adult stem cell is ethically acceptable, that paved the way for research on their potential use in regenerative medicine. However, any clinical application of adult stem cells is impeded by the use of FBS as an animal-derived growth supplement. In addition, stem cell cultures gained importance as innovative human-based alternative to animal testing, in vitro toxicology, drug testing and safety assessment. Thus, animal-derived component-free culture protocols are mandatory for a successful application of human stem cell-based testing systems under humanized conditions.Recently, we succeeded in using human platelet lysates (PL) as a serum alternative in the cell culture of a number of human and animal cell lines, and human mesenchymal stem cells. PL were prepared as cell-free extracts from activated donor thrombocytes.The minimal criteria defining multipotent mesenchymal cells are (1) the capacity to adhere to plastic, (2) the expression of specific surface antigens (e.g. CD73, CD90, CD105) for undifferentiated state, and (3) the potential of the cells to differentiate into the adipogenic, chondrogenic and osteogenic lineage. In the present study, adipose-derived stem cells (ADSC) were used as cell model. ADSC were maintained under PL or FBS and then switched to the respective media to induce mesodermal differentiation. Differentiation endpoints were assessed by phase-contrast microscopy and by histochemical staining: (1) lipid droplets in adipocytes were stained by Oil red O, (2) proteoglycans in chondrogenic spheroids were detected by toluidineblue, and fine structure of spheroids was monitored by scanning electron microscopy, and (3) calcium deposits in differentiated osteoblasts were stained with silver nitrate (von Kossa staining). Adipogenic differentiation was further confirmed by quantitative real-time PCR of selected marker genes (PREF1 vs. FABP4). There were no differences between FBS- and PL-grown ADSC, indicative for retention of the differentiation potential of ADSC under animal-derived component-free culture conditions in PL-supplemented culture media. The degree of adipogenic and osteogenic differentiation was even more pronounced under PL compared to FBS

Good Cell Culture Practice (GCCP) - eine Initiative zur Standardisierung und Qualitaetssicherung von in vitro Arbeiten. Die Etablierung einer ECVAM Task Force.

Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra