Establishment of embryonic stem cell (ESC) lines has been successful in mouse and human, but not in farm animals. Development of direct reprogramming technology offers an alternative approach for generation of pluripotent stem cells, applicable also in farm animals. Induced pluripotent stem cells (iPSCs) represent practically limitless, ethically acceptable, individuum-specific source of pluripotent cells that can be generated from different types of somatic cells. iPSCs can differentiate to all cell types of an organism’s body and have a tremendous potential for numerous applications in medicine, agriculture, and biotechnology. However, molecular mechanisms behind the reprogramming process remain largely unknown and hamper generation of bona fide iPSCs and their use in human clinical practice. Large animal models are essential to expand the knowledge obtained on rodents and facilitate development and validation of transplantation therapies in preclinical studies. Additionally, transgenic animals with special traits could be generated from genetically modified pluripotent cells, using advanced reproduction techniques. Despite their applicative potential, it seems that iPSCs in farm animals haven’t received the deserved attention. The aim of this review was to provide a systematic overview on iPSC generation in the most important mammalian farm animal species (cattle, pig, horse, sheep, goat, and rabbit), compare protein sequence similarity of pluripotency-related transcription factors in different species, and discuss potential uses of farm animal iPSCs. Literature mining revealed 32 studies, describing iPSC generation in pig (13 studies), cattle (5), horse (5), sheep (4), goat (3), and rabbit (2) that are summarized in a concise, tabular format.
COBISS.SI-ID: 3700616
Primary mammary epithelial cell cultures were established from mammary tissue of lactating and non-lactating goats to assess the expression of beta-casein (CSN2) in vitro. Primary cell cultures were established by enzymatic digestion of mammary tissue and characterized using antibodies against cytokeratin 14, cytokeratin 18, and vimentin. The established primary cell lines in the second passage were grown in basal medium on plastic and in hormone-supplemented (lactogenic) medium on plastic and on an extracellular matrix-covered surface, respectively. CSN2 gene expression was evaluated using quantitative reverse transcription PCR. The presence of CSN2 transcripts was detected in all samples, including cells originating from non-lactating goat, grown in basal medium. The presence of CSN2 protein was confirmed using immunofluorescence. Response to the hormonal treatment and cell morphology differed between the cell lines and treatments. In 2 cell lines supplemented with lactogenic hormones in the medium, CSN2 expression was increased, while CSN2 levels in one of the cell lines remained constant, regardless of the treatment. Addition of extracellular matrix showed positive effects on CSN2 transcription activity in 1 of the cell lines, while in the other 2 showed no statistically significant effects. CSN2 expression appeared to depend on subtle differences in physiological state of the starting tissue material, growth conditions, cell types present in the culture, and methods used for cell culture establishment. Further studies are necessary to identify factors that determine hormone-responsiveness and transcriptional activity of milk protein genes in goat primary mammary cell cultures.
COBISS.SI-ID: 3540360
The exact role and sensitivity of cells to estrogen and progesterone, mediated through the steroid receptors, during lactation is not known. Expression of estrogen receptor 1 (ESR1) and progesterone receptor (PGR) was quantified in mammary tissue-derived primary goat mammary epithelial cells (pgMECs) to determine the influence of donor tissue physiology (lactating and juvenile) and cell culture growth conditions (basal and lactogenic) on ESR1 and PGR expression in the derived cells. Relative mRNA levels for both receptors were the highest in cell lines derived from mammary tissue of juvenile goats. Maintaining pgMECs in lactogenic conditions resulted in up-regulation of ESR1 (1.36 to 12.35-fold) and in down-regulation of PGR (-2.53 to -3.62-fold), compared to basal conditions. Based on western blotting analysis we suggest that the differences in mRNA expression are translated to the protein level. We suggest that differential expression in lactating conditions is correlated with terminal differentiation of the pgMECs. Double immunostainings showed that ER-α positive cells do not exclusively belong to the luminal lineage and that ER-α and PR can be expressed individually or co-expressed in the pgMECs. The derived primary cultures/lines in early passages are hormone-responsive and represent a useful surrogate for mammary tissue in research experiments.