Previously claimed male germline stem cells from porcine testis are actually progenitor Leydig cells

Abstract

BackgroundMale germline stem cells (mGSCs) offer great promise in regenerative medicine and animal breeding due to their capacity to maintain self-renewal and to transmit genetic information to the next generation following spermatogenesis. Human testis-derived embryonic stem cell-like cells have been shown to possess potential of mesenchymal progenitors, but there remains confusion about the characteristics and origin of porcine testis-derived stem cells.MethodsPorcine testis-derived stem cells were obtained from primary testicular cultures of 5-day old piglets, and selectively expanded using culture conditions for long-term culture and induction differentiation. The stem cell properties of porcine testis-derived stem cells were subsequently assessed by determining the expression of pluripotency-associated markers, alkaline phosphatase (AP) activity, and capacity for sperm and multilineage differentiation in vitro. The gene expression profile was compared via microarray analysis.ResultsWe identified two different types of testis-derived stem cells (termed as C1 and C2 here) during porcine testicular cell culture. The gene expression microarray analysis showed that the transcriptome profile of C1 and C2 differed significantly from each other. The C1 appeared to be morphologically similar to the previously described mouse mGSCs, expressed pluripotency- and germ cell-associated markers, maintained the paternal imprinted pattern of H19, displayed alkaline phosphatase activity, and could differentiate into sperm. Together, these data suggest that C1 represent the porcine mGSC population. Conversely, the C2 appeared similar to the previously described porcine mGSCs with three-dimensional morphology, abundantly expressed Leydig cell lineage and mesenchymal cell-specific markers, and could differentiate into testosterone-producing Leydig cells, suggesting that they are progenitor Leydig cells (PLCs).ConclusionCollectively, we have established the expected characteristics and markers of authentic porcine mGSCs (C1). We found for the first time that, the C2, equivalent to previously claimed porcine mGSCs, are actually progenitor Leydig cells (PLCs). These findings provide new insights into the discrepancies among previous reports and future identification and analyses of testis-derived stem cells.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0931-0) contains supplementary material, which is available to authorized users.

Bone morphogenetic protein 9 induces osteogenic differentiation of germ cell 1 spermatogonial cells

“…Further, MSC-to-osteoblast transition is driven by BMP9, the most potent osteogenesis-inducing BMP signal in vitro and in vivo [21,22,73]. MSCs originating from the mesoderm can be isolated from different tissues [5,74,75,76,77]. Indeed, pluripotent stem cells isolated from testis are similar to MSCs, as demonstrated by gene expression profiling studies [5,77].…”

“…Indeed, pluripotent stem cells isolated from testis are similar to MSCs, as demonstrated by gene expression profiling studies [5,77]. MSCs can be derived from the testis [5,8,74]. Though it is possible to differentiate bone tissue from MSCs, few studies have examined BMP9-induced osteogenesis of testis-derived MSCs.…”

Investigation Into the Relationship Between Sperm Cysteine-Rich Secretory Protein 2 (CRISP2) and Sperm Fertilizing Ability and Fertility of Boars

“…To evaluate the distribution of CRISP2 in the sperm before and after capacitation, immunofluorescence detection was performed as previously described (21). The sperm before and after in vitro capacitation were fixed with 4% paraformaldehyde for 20 min, washed three times with PBS, permeabilized with 0.5% Triton-100 for 10 min, and blocked in 1% BSA (Sigma) for 30 min.…”