Differentiation and proliferation potencies of human bone tissue-derived mesenchymal stromal cells (hBT-MSCs) after long-term cryopreservation －Comparison among cells stored for 1, 5, 10, 15, and 20 years.

INTRODUCTION: We investigated bone differentiation and proliferation potencies of human bone tissue-derived mesenchymal stromal cells (hBT-MSCs) after long-term cryopreservation. We determined the presence of any morphological and characteristic changes due to freezing to identify issues that need to be solved for future clinical applications. SUBJECTS AND METHODS: A total of 15 samples of hBT-MSCs that had been cryopreserved for different lengths of time, ranging from one year to 20 years (n = 3 each), were thawed and recultivated after being collected from excess iliac cancellous bone specimens of patients who underwent secondary alveolar bone grafting for cleft lip and palate in our department. We determined viability by observing calcein/EthD-stained cells under a confocal microscope, and the cell proliferation experiment was performed for one week using the Water Soluble Tetrazolium salts (WST) assay method. A confocal microscope was also used to identify any excessively accumulated senescence-associated growth factor SA-ßgal. Differentiation potency was assessed in the following three groups: bone differentiation, adipocyte differentiation, and nondifferentiation induction. We examined bone/adipocyte differentiation potencies using Alizarin Red staining, Ca quantitation, and Oil Red staining after continuously culturing cells for four weeks. RESULTS: Viability test results indicated that the proportion of viable cells decreased as the number of years of cryopreservation increased. The cell proliferation experiment showed that cells cryopreserved for a shorter duration multiplied exponentially. In the aging test, cells cryopreserved for ≥5 years showed similar positive reactions independent of the number of years of cryopreservation. In the cell proliferation test, there was no statistically significant difference between the years of cryopreserving. We compared bone differentiation and adipocyte differentiation ability with the non-induction group, and the induction group was confirmed to have a statistical advantage. However, there was no significant difference in the induction group pertaining to different ages. CONCLUSIONS: Samples cryopreserved for 20 years remained competent in bone and adipocyte differentiation. However, their differentiation direction tended to skew to either bone or adipocyte differentiation. Our results suggest that freezing does not accelerate aging, and samples cryopreserved for a long time are useful in future clinical applications.

Correction to: RNA-sequencing reveals positional memory of multipotent mesenchymal stromal cells from oral and maxillofacial tissue transcriptomes.

An amendment to this paper has been published and can be accessed via the original article.

RNA-sequencing reveals positional memory of multipotent mesenchymal stromal cells from oral and maxillofacial tissue transcriptomes.

BACKGROUND: Multipotent mesenchymal stromal cells (MSCs) can be isolated from numerous tissues and are attractive candidates for therapeutic clinical applications due to their immunomodulatory and pro-regenerative capacity. Although the minimum criteria for defining MSCs have been defined, their characteristics are known to vary depending on their tissue of origin. RESULTS: We isolated and characterized human MSCs from three different bones (ilium (I-MSCs), maxilla (Mx-MSCs) and mandible (Md-MSCs)) and proceeded with next generation RNA-sequencing. Furthermore, to investigate the gene expression profiles among other cell types, we obtained RNA-seq data of human embryonic stem cells (ESCs) and several types of MSCs (periodontal ligament-derived MSCs, bone marrow-derived MSCs, and ESCs-derived MSCs) from the Sequence Reads Archive and analyzed the transcriptome profile. We found that MSCs derived from tissues of the maxillofacial region, such as the jaw bone and periodontal ligament, were HOX-negative, while those derived from other tissues were HOX-positive. We also identified that MSX1, LHX8, and BARX1, an essential regulator of craniofacial development, were strongly expressed in maxillofacial tissue-derived MSCs. Although MSCs may be divided into two distinct groups, the cells originated from over the neck or not, on the basis of differences in gene expression profile, the expression patterns of all CD antigen genes were similar among different type of MSCs, except for ESCs. CONCLUSIONS: Our findings suggest that MSCs from different anatomical locations, despite meeting general characterization criteria, have remarkable differences in gene expression and positional memory. Although stromal cells from different anatomical sources are generally categorized as MSCs, their differentiation potential and biological functions vary. We suggested that MSCs may retain an original tissue memory about the developmental process, including gene expression profiles. This could have an important impact when choosing an appropriate cell source for regenerative therapy using MSCs.

An in vitro long-term study of cryopreserved umbilical cord blood-derived platelet-rich plasma containing growth factors-PDGF-BB, TGF-ß, and VEGF.

PURPOSE: Umbilical cord blood-derived platelet-rich plasma (UCB-PRP) containing growth factors has attracted attention as a biomaterial useful for regenerative medicine. The osteoblastic differentiation of umbilical cord-derived mesenchymal stromal cells (UC-MSCs) can be induced by UCB-PRP. MATERIALS AND METHODS: Nine samples of UC and UCB were used to conduct an in vitro study that determined the contents of three growth factors (i.e., platelet-derived growth factor, transforming growth factor ß-1, and vascular endothelial growth factor) and that examined, by staining with Alizarin red, their ability to induce the osteoblastic differentiation of UC-MSCs at the baseline, 3 months, and 3 years of cryopreservation. RESULTS: The contents of growth factors in cryopreserved UCB-PRP were markedly elevated compared to those found in UCB at baseline. The samples of UCB that were added with cryopreserved UCB-PRP and those with bone morphogenetic protein-2 were stained granularly with Alizarin red, thus indicating the presence of calcium. The samples of UCB that were not added with UCB-PRP were not stained with Alizarin red. The above-mentioned contents and ability were maintained at 3 years of cryopreservation. Cryopreserved UCB-PRP possibly and advantageously induced the osteoblastic differentiation of UC-MSCs. CONCLUSION: The potential clinical application of cryopreserved UCB-PRP to regenerative medicine was suggested.

Vascular endothelial growth factor receptor 1 (VEGFR1) tyrosine kinase signaling facilitates granulation tissue formation with recruitment of VEGFR1+ cells from bone marrow.

Vascular endothelial growth factor (VEGF)-A facilitates wound healing. VEGF-A binds to VEGF receptor 1 (VEGFR1) and VEGFR2 and induces wound healing through the receptor's tyrosine kinase (TK) domain. During blood flow recovery and lung regeneration, expression of VEGFR1 is elevated. However, the precise mechanism of wound healing, especially granulation formation on VEGFR1, is not well understood. We hypothesized that VEGFR1-TK signaling induces wound healing by promoting granulation tissue formation. A surgical sponge implantation model was made by implanting a sponge disk into dorsal subcutaneous tissue of mice. Granulation formation was estimated from the weight of the sponge and the granulation area from the immunohistochemical analysis of collagen I. The expression of fibroblast markers was estimated from the expression of transforming growth factor-beta (TGF-ß) and cellular fibroblast growth factor-2 (FGF-2) using real-time PCR (polymerase chain reaction) and from the immunohistochemical analysis of S100A4. VEGFR1 TK knockout (TK-/-) mice exhibited suppressed granulation tissue formation compared to that in wild-type (WT) mice. Expression of FGF-2, TGF-ß, and VEGF-A was significantly suppressed in VEGFR1 TK-/- mice, and the accumulation of VEGFR1+ cells in granulation tissue was reduced in VEGFR1 TK-/- mice compared to that in WT mice. The numbers of VEGFR1+ cells and S100A4+ cells derived from bone marrow (BM) were higher in WT mice transplanted with green fluorescent protein (GFP) transgenic WT BM than in VEGFR1 TK-/- mice transplanted with GFP transgenic VEGFR1 TK-/- BM. These results indicated that VEGFR1-TK signaling induced the accumulation of BM-derived VEGFR1+ cells expressing F4/80 and S100A4 and contributed to granulation formation around the surgically implanted sponge area in a mouse model.

Vascular endothelial growth factor receptor-1 (VEGFR-1) signaling enhances angiogenesis in a surgical sponge model.

BACKGROUND: Vascular endothelial growth factor (VEGF)-A binds to both VEGF receptor (VEGFR)-1 and VEGFR-2, thereby promoting angiogenesis. It is widely accepted that VEGF-A, especially VEGFR-2, is a central player in angiogenesis, however the role of VEGFR-1 in angiogenesis remains unclear. The present study was conducted to examine the role of VEGFR-1 signaling in angiogenesis, using a quantitative in vivo angiogenesis model. METHODS: Polyurethane sponge disks were implanted into dorsal subcutaneous tissue of mice. Angiogenesis was estimated by determining the number of CD31(+) vessels by immunohistochemical analysis. The expression of pro-angiogenic factors was quantified by reverse transcription quantitative polymerase chain reaction. RESULTS: Compared to control IgG-treated mice, the number of CD31(+) vessels in the sponge implant was significantly suppressed in anti-VEGF-A neutralizing antibody-treated mice. CD31(+) vessel counts were suppressed in VEGFR-1 tyrosine kinase knockout (TKKO) mice, at the same level as in VEGFR-2 tyrosine kinase inhibitor (ZD6474)-treated mice compared to wild-type (WT) mice. The accumulation of VEGFR-1(+) cells in granulation tissue was significantly suppressed in VEGFR-1 TKKO mice compared to WT mice. In addition, expression of the pro-angiogenic growth factors, VEGF-A, matrix metalloproteinase-2, interleukin-6, and basic fibroblast growth factor in granulation tissue was suppressed in VEGFR-1 TKKO mice. A bone marrow (BM) transplantation experiment showed that the number of VEGFR-1(+) BM-derived cells and angiogenesis were significantly suppressed in VEGFR-1 TKKO mice transplanted with green fluorescent protein (GFP)(+) VEGFR-1 TKKO BM compared to WT mice transplanted with GFP(+) WT BM. CONCLUSIONS: These results suggest that the VEGFR-1 tyrosine kinase signaling has an effect on angiogenesis. A selective VEGFR-1 agonist/antagonist could be a candidate therapeutic agent to control angiogenesis with recruitment of BM cells.

Osteogenic potential of human umbilical cord-derived mesenchymal stromal cells cultured with umbilical cord blood-derived fibrin: a preliminary study.

This study examined the potential for osteogenesis via regenerative medicine using autologous tissues (umbilical cord (UC) and umbilical cord blood (UCB)) in nude mice. The study was designed to provide the three elements required for regenerative medicine (cell, scaffold, and growth factor) and autoserum for culture by means of autologous tissues. Mesenchymal stromal cells were obtained from UC (UC-MSCs). Fibrin, platelet-rich-plasma, and autoserum were obtained from UCB as scaffold, growth factor and serum for culture respectively. UC-MSCs were obtained from Wharton jelly and cultured with UCB-derived fibrin (UCB-fibrin) for 3-4 weeks to induce their differentiation into osteoblasts. They were implanted subcutaneously into the dorsum of male nude mice for 6 weeks prior to undergoing assessment. The assessments performed were haematoxylin and eosin, and alizarin red staining, immunohistochemical staining of human mitochondria, scanning electron microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry and real-time reverse transcriptase-polymerase chain reaction to assess the expressions of osteoblast markers. Consequently, the differentiation of UC-MSCs into osteoblasts and the production of hydroxyapatite were verified. This study suggested the possible formation of bone tissue using biomedical materials obtained from UC and UCB.

Osteogenic potential of human bone marrow-derived mesenchymal stromal cells cultured in autologous serum: a preliminary study.

PURPOSE: As part of the authors' research on potential osteogenesis by filling bone defects with human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) in patients with cleft lip and palate, they examined the cytoproliferative potential and cytobiological activity of hBM-MSCs in vitro and their osteogenic potential in vivo without performing osteoinduction. MATERIALS AND METHODS: The hBM-MSCs were collected from iliac cancellous bone and then used in primary culture, followed by 2 subcultures using an autologous serum (AS)-containing medium and a fetal bovine serum (FBS)-containing medium. Cytoproliferative potential and cytobiological activity as expressed by bone markers (alkaline phosphatase and osteocalcin) in hBM-MSCs cultured in the AS-containing medium (AS-cultured hBM-MSCs) and the FBS-containing medium (FBS-cultured hBM-MSCs) were examined in vitro, and the osteogenic potential of AS- and FBS-cultured hBM-MSCs was examined in mice. RESULTS: On day 6 of the second subculture, the number of hBM-MSCs per milliliter of specimen from 8 pediatric patients was significantly larger (P < .05) in FBS-cultured compared with AS-cultured hBM-MSCs. The alkaline phosphatase activity of hBM-MSCs was significantly greater (P < .05) when cultured in the AS-containing medium compared with the FBS-containing medium. The in vivo study showed the formation of an osteoid-like matrix rather than definite bone tissue. CONCLUSIONS: 1) FBS is appropriate for the cytoproliferation of hBM-MSCs; 2) the AS-containing medium is likely to have a good possibility of inducing the differentiation of hBM-MSCs; and 3) AS-cultured hBM-MSCs contain a group of cells that spontaneously differentiate into an osteoid-like matrix without performing osteoinduction.

Osteogenic potential of human umbilical cord-derived mesenchymal stromal cells cultured with umbilical cord blood-derived autoserum.

OBJECTIVE: Osteogenesis in the bone defect at the site of an alveolar cleft is important to enable patients with cleft lip and palate to acquire dental articulation. The presence of umbilical cord-derived mesenchymal stem cells has been reported. In this study, we used autoserum derived from the umbilical cord blood (UCB) of neonates in an attempt to examine the osteoblastic differentiation potential of umbilical cord-derived mesenchymal stromal cells (UC-MSCs) in nude mice. MATERIALS AND METHODS: UCB, hydroxyapatite, and rhBMP were used as the supply source of autoserum, scaffold, and osteoinductive growth factor, respectively. MSCs, obtained from Wharton's jelly and cultured for 3-4weeks to induce their differentiation into osteoblasts, were implanted subcutaneously into the dorsum of male nude mice for 6weeks before the assessment by real-time reverse transcriptase chain reaction of osteoblast marker expression. RESULTS: UCB-derived autoserum was a viable source for the culture and implantation of UC-MSCs. The osteoblastic differentiation potential of UC-MSCs was demonstrated in nude mice by performing immunohistochemical staining and by the presence of osteoblast marker expression. CONCLUSIONS: Our results confirm the osteogenic potential of UC-MSCs and provide basic evidence for the realization of regenerative medicine using autologous tissues.

Significance of CD271 in bone marrow mesenchymal stem cells--changes by cryopreservation.

In investigating the biological activities of bone marrow mesenchymal stem cells (BMMSCs), an important task is cell sorting of effective BMMSCs. In the present study, we examined the usefulness of CD271 as a cell surface marker of BMMSCs. Specifically, we investigated (1) CD271 expression before and after freezing, (2) difference between the CD271(+) and CD271(-) fractions regarding calcium formation level after bone differentiation, and (3) method of harvesting effective BMMSCs from marrow tissue. CD271 was partially expressed in cryopreserved BMMSCs (CBMMSCs). We used CD271 in separating CBMMSCs into different cell groups and compared the calcium formation levels between the CD271-expressed and CD271-nonexpressed groups. A significant amount of BMMSCs existed even in the CD271(-) fraction, and the calcium formation level was high in 4 of 5 CD271(-) fraction specimens. The same investigation was conducted on nonfrozen BMMSCs. No major difference was found in CD271 expression compared with CBMMSCs. However, the calcium formation level of the CD271(+) fraction was higher in 3 of 5 specimens. We presumed that CD271 expression might have been substantially changed during culture and cryopreservation. We compared the method of directly culturing bone marrow tissue and that of washing the sample before culture and confirmed that the calcium formation level of BMMSCs was higher when the marrow tissue was washed before culture.

Osteogenic potential of cryopreserved human bone marrow-derived mesenchymal stem cells cultured with autologous serum.

Secondary bone grafting in the alveolar cleft is one of the most important therapeutic modalities for patients with cleft lip and palate. However, in children, harvesting a sufficient amount of bone is difficult, and repeated operations are often required because deformation of the alveolar cleft may occur because of the grafted bone absorption and bone growth, which imposes a heavy burden on the patients. The burden may be reduced if the banking of human bone marrow-derived mesenchymal stem cells (MSCs) could be made possible, that is, if cryopreserved autologous MSCs, those that have been harvested from the patient's own bone marrow, could be cultured and expanded with the patient's own serum and can be thawed and cultivated for grafting at a later date. In the current study, a hybrid-type bone substitute was prepared by thawing and cultivating MSCs that have been cryopreserved for more than 3 months. The hybrid-type bone substitute was implanted subcutaneously in nude mice. At 6 and 9 weeks after grafting, the bone graft was removed, and the osteogenic potential of the cells cultured with autologous serum, as determined by alkaline phosphatase activity and alizarin red S staining, was compared with those cultured with fetal bovine serum. There was no significant difference in the osteogenic potential between MSCs cultured with autologous serum and those cultured with fetal bovine serum. The results suggest the possibility of artificial bone grafting using MSCs cultured with autologous serum and the banking of the cells.

Novel mutations of the HOXD13 gene in hand and foot malformations.

Homeobox genes encode a set of transcription factors of fundamental importance for body patterning during embryogenesis. Hoxa9-a13 and Hoxd9-d13 play an especially important part in vertebrate limb development. Synpolydactyly (SPD) is characterized by various malformations of the limbs. The expansion of the polyalanine tract in 1OXD13 is one of its major causes. Recently, there have been many analysis studies of HOXD13 in patients with SPD and limb malformations. We analyzed HOXD13 in 100 patients with limb malformations, which affects the limbs in the distal parts of the metacarpal and/or metatarsal bones. Seven mutations in the coding region and two mutations in the 5'-untranslated region were identified. All were novel mutations. In this study, the mutations were located upstream in the homeobox. Thus, translation of the homeobox was affected by upstream mutations. Consequently, this suggested the possibility that abnormalities in the hands and feet could be caused by novel HOXD13 gene mutations.

The effect of preoperative use of an orthopedic plate on articulatory function in children with cleft lip and palate.

OBJECTIVE: To evaluate the effect of preoperative use of an orthopedic plate (OP) on postoperative articulatory function in children with cleft lip and palate. SUBJECTS: The subjects had complete unilateral or bilateral cleft lip and palate and were scheduled for a one-stage palatoplasty. MAIN OUTCOME MEASURES: Tongue movements during sucking were analyzed by ultrasonography. Postoperative articulatory behavior was also assessed at 5 years 4 months of age. RESULTS: There was an excessive downward excursion of the rear portion of the tongue during sucking regardless of the use or nonuse of the OP. This indicated that infants with cleft palate could not create negative pressure in the oral cavity, even with the OP. However, the OP appeared effective for preventing irregular movements of the tongue during sucking. The proportion of subjects obtaining excellent articulation was significantly higher in the group using the OP until palatoplasty than in the group who did not continue using the OP. The proportion of subjects with disturbed articulatory function in the latter group was comparable with that in the control group, who never used the OP. CONCLUSIONS: Continuous use of the OP up to the time of palatoplasty appeared to be effective for the postoperative articulatory function in children with complete cleft lip and palate. Inhibiting irregular movements of the tongue, the OP might assist in preventing "palatalized articulation."

Oral-facial-digital syndrome type II (Mohr syndrome): clinical and genetic manifestations.

The oral-facial-digital syndromes (OFDS) represent a heterogenous group of disorders characterized by oral malformation, facial anomalies, and digital anomalies. Type II OFDS was reported by Mohr in 1941. Mohr syndrome is an autosomal recessive inherited disease characterized by median cleft lip, poly lobed tongue, absence of medial incisors, and polydactyly of hands and feet. Some other different expressive types of OFDS cases have been reported, and identified with 11 different clinical entities up to the present. Until now, only three cases of OFDS II in Japanese patients have been detected except for our patient. At this time, we observed a Japanese patient of Mohr syndrome with median cleft lip and tongue, hypertrophied frenula, absence of left medial incisor, and bilateral bifidity of great toe. Lip and tongue plasty was performed at 7 months after birth and toe plasty was done at 11 months with good results.

A case of a Japanese patient with cleidocranial dysplasia possessing a mutation of CBFA1 gene.

Cleidocranial dysplasia (CCD) is an autosomal dominant human bone disease characterized by hypoplastic or aplastic clavicles, wide cranial sutures, supernumerary teeth, short stature, and other skeletal disorders. Recently, various mutations of the core binding factor (CBFA1) gene have been detected in CCD patients. The CBFA1 gene is a member of the runt family of transcription factors. We experienced one Japanese case of CCD with open sutures, hypoplasia of clavicles and brachydactyly, combined with atlant-axis dislocation. We performed the sequence analysis of the CBFA1 gene and detected a missense mutation of R225W in exon 3.