Comparative transcriptomic analysis of human mesenchymal stem cells derived from dental pulp and adipose tissues.

Objective: Mesenchymal stem cells (MSCs) have been isolated from various human tissues. Although they share cardinal stem cell features of self-renewal and multi-potency, they also seem to possess distinct characteristics depending on the tissue types they originated from. When developing stem cell-based therapies, MSCs with the most desirable characteristics should be chosen. However, our knowledge on tissue type-specific characteristics of MSCs is limited. Here, we comparatively studied the gene expression profiles of MSCs from different tissue types, and predicted target diseases suitable for each type of MSCs. Methods: We harvested MSCs from human dental pulp and adipose tissue specimens and subjected them to gene expression microarray analysis. Characteristic gene expression signatures of the MSCs from each tissue type were identified using gene-annotation enrichment analysis. Results: Dental pulp-derived MSCs exhibited gene expression signatures of neuronal growth, while adipose tissue-derived MSCs exhibited signatures of angiogenesis and hair growth. MSCs from each tissue type expressed a discrete set of genes encoding secretory peptides, which may function as paracrine factors. Conclusions: MSCs derived from different tissue types demonstrated distinct gene expression signatures, which are suggestive of target diseases in clinical applications of the MSCs and stem cell-conditioned media. By expanding the analysis to MSCs from a wide range of tissue types, and by employing multiple omics approaches, a catalogue of MSCs and therapeutic targets can be generated.

Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro.

The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and ß-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin.

Relationship between plasma progesterone concentration and number of conceptuses and their growth in superovulated cattle.

Elevated concentrations of circulating progesterone (P4) in the immediate post-ovulation period are associated with advancement of conceptus elongation in cattle. Superovulated (SOV) cattle have not only elevated plasma P4 concentrations but also multiple embryos in the uterus because of the formation of multiple corpora lutea. We examined the relationship between plasma P4 concentration and uterine glucose level in the immediate post-ovulation period and the presence and growth of multiple conceptuses in SOV cattle. SOV cattle were artificially inseminated with frozen-thawed semen at standing estrus (day 0), and the conceptuses were recovered by nonsurgical flushing of the uterus on day 13. In the SOV cattle, there were quadratic relationships between plasma P4 concentration on days 4, 5 and 7 and conceptus length and between number of conceptuses in the uterus and conceptus length. These results suggest that conceptus growth in SOV cattle is regulated by both systemic P4 level and number of conceptuses and that there are ranges of plasma P4 concentrations and numbers of conceptuses in the uterus that are suitable for conceptus growth and development. Plasma P4 concentrations on days 5 and 7, but not the numbers of conceptuses, were quadratically correlated with uterine glucose levels on day 13 in SOV cattle. In addition, conceptus length was positively correlated with uterine glucose level in SOV cattle. Accordingly, regardless of the number of conceptuses in the uterus, the plasma P4 concentration was well correlated with the regulation of conceptus growth via changes in uterine glucose levels in SOV cattle.

Effect of maternal age on mitochondrial DNA copy number, ATP content and IVF outcome of bovine oocytes.

The primary aim of the present study was to examine the effect of maternal age (in months) on mitochondrial DNA copy number (Mt number), ATP content and IVF outcome of bovine oocytes. We also compared the Mt number of oocytes with fertilisation outcome and ATP content. Oocytes were collected from cows aged 20-204 months and the Mt number was determined by real-time polymerase chain reaction. The Mt number in immature and mature oocytes was determined to be 368,118 and 807,794, respectively; the ATP content in these oocytes was 1.2 and 2.0 pM, respectively. Both Mt number and ATP content increased during oocyte maturation. However, after 90 months of age, the Mt number of mature oocytes decreased with increasing maternal age, whereas the ATP content of mature oocytes was positively correlated with maternal age (P<0.01); there was no obvious relationship observed between Mt number and ATP content. Furthermore, maternal age was positively correlated with the abnormal fertilisation rate (P<0.01). Mt number and fertilisation outcome were unrelated, but the nature of this relationship differed between young (21-89 months) and old (>89 months) cows. Thus, we conclude that Mt number, the ATP content and fertilisation outcome of bovine oocytes are affected by maternal age.

Effect of N-acetyl-D-glucosamine on bovine sperm-oocyte interactions.

N-Acetyl-D-glucosamine (GlcNAc) is a major component of glycosaminoglycan, which is involved in sperm-oocyte interactions. We examined the effect of adding GlcNAc and other monosaccharides, D-mannose and D-fucose, to the in vitro fertilization (IVF) medium on bovine sperm-oocyte interactions. In medium in which sperm and a zona pellucida (ZP) were co-incubated with monosaccharides for 5 min, addition of GlcNAc (5 or 25 mM) significantly reduced the number of sperm that attached to the ZP. Pretreatment of gametes with GlcNAc (5 mM) prior to co-incubation also suppressed sperm-ZP attachment. Addition of GlcNAc (5 or 25 mM) to the medium in which sperm and a ZP were co-incubated for 5 h, however, significantly increased the number of sperm binding to and penetrating the ZP in a concentration-related manner. The other monosaccharides, D-fucose and D-mannose, did not have this effect. Supplementation of the sperm-oocyte co-incubation medium with 5 mM GlcNAc also enhanced the rate of polyspermic fertilization. When the ZPs were removed from the oocytes, GlcNAc did not affect the fertilization rate. Furthermore, incubation of sperm with 5 mM GlcNAc induced sperm membrane destabilization and an acrosome reaction, as evidenced by the hypo-osmotic swelling test and fluorescein isothiocyanate-labeled peanut agglutinin/propidium iodide (FITC-PNA/PI) staining. Finally, GlcNAc suppressed ZP hardening following fertilization, as determined by measuring the time required for pronase to dissolve the ZP. In conclusion, supplementation of IVF medium with GlcNAc has various effects on sperm-oocyte interactions including suppression of initial attachment, induction of sperm membrane destabilization and acrosome reaction, increase in the number of sperm secondarily bound to and penetrating the ZP, suppression of ZP hardening following sperm-oocyte co-incubation and increase in the rate of polyspermic fertilization.