Efficacy of Neonatal Porcine Bone Marrow-Derived Mesenchymal Stem Cell Xenotransplantation for the Therapy of Hind Limb Lymphedema in Mice.

Lymphedema is an intractable disease with few effective therapeutic options. Autologous mesenchymal stem cell (MSC) transplantation is a promising therapy for this disease. However, its use is limited by the cost and time for preparation. Recently, xenotransplantation of porcine MSCs has emerged as an alternative to autologous MSC transplantation. In this study, we aimed to clarify the usefulness of neonatal porcine bone marrow-derived MSC (NpBM-MSC) xenotransplantation for the treatment of lymphedema. One million NpBM-MSCs were xenotransplanted into the hind limbs of mice with severe lymphedema (MSC transplantation group). The therapeutic effects were assessed by measuring the femoral circumference, the volume of the hind limb, the number and diameter of lymphatic vessels in the hind limb, and lymphatic flow using a near-infrared fluorescence (NIRF) imaging system. We compared the effects using mice with lymphedema that did not undergo NpBM-MSC transplantation (negative control group). The condition of the transplanted NpBM-MSCs was also evaluated histologically. The femoral circumference and volume of the hind limb had been normalized by postoperative day (POD) 14 in the MSC transplantation group, but not in the negative control group (P = 0.041). NIRF imaging revealed that lymphatic flow had recovered in the MSC transplantation group by POD 14, as shown by an increase in luminance in the hind limb. Histological assessment also showed that the xenotransplantation of NpBM-MSC increased the proliferation of lymphatic vessels, but they had been rejected by POD 14. The xenotransplantation of NpBM-MSCs is an effective treatment for lymphedema, and this is mediated through the promotion of lymphangiogenesis.

Influence of relatively short-term culture on adult porcine islets for xenotransplantation.

Porcine islet xenotransplantation is a promising therapy for severe diabetes mellitus. Maintenance of the quality and quantity of porcine islets is important for the success of this treatment. Here, we aimed to elucidate the influence of relatively short-term (14 days) culture on adult porcine islets isolated from three micro-minipigs (P111, P112 and P121). Morphological characteristics of islets changed little after 14 days of culture. The viability of cultured islets was also maintained at a high level (> 80%). Furthermore, cultured islets exhibited similar glucose-stimulated insulin secretion and insulin content at Day 14 were preserved comparing with Day 1, while the expressions of Ins, Gcg and Sst were attenuated at Day 14. Xenotransplantation using diabetic nude mice showed no normalization of blood glucose but increased levels of plasma porcine C-peptide after the transplantation of 14 day cultured porcine islets. Histological assessment revealed that relatively short-term cultured porcine islets were successfully engrafted 56 days following transplantation. These data show that relatively short-term culture did not impair the quality of adult porcine islets in regard to function, morphology, and viability. Prevention of impairment of gene correlated with endocrine hormone is warranted for further improvement.

Safety and Potential Effect of Intrauterine Infusion of Autologous Adipose Tissue-Derived Regenerative Cells in Patients With Implantation Failure: A Pilot Study.

BACKGROUND: Implantation failure due to thin endometrium has emerged as a major cause of infertility. In this study, we aimed to assess the safety and preliminary efficacy of adipose tissue-derived regenerative cells (ADRCs), a source of adipose-derived stem cells, in infertility patients with implantation failure. METHODS: Five infertile women with implantation failure despite artificial reproductive technology were enrolled in this study and treated with ADRCs via the intrauterine route. The primary outcome was the incidence of adverse events. Additional outcomes were endometrial thickness after ADRC treatment and pregnancy success after embryo transfer. RESULTS: There were no adverse events in any patient. There was no elevation of white blood cell count, C-reactive protein, or D-dimer levels. There was a significant difference in endometrial thickness in the secretory phase before versus after intrauterine transplantation of ADRCs (3.8 ± 1.3 mm versus 8.8 ± 2.8 mm, respectively; p<0.05). A gestational sac and fetal heartbeat were detected on transvaginal ultrasound in two of five patients. CONCLUSION: Intrauterine infusion of autologous ADRCs is a simple and safe procedure that may ameliorate the endometrial microenvironment in infertile women with implantation failure.

The porcine islet-derived organoid showed the characteristics as pancreatic duct.

Organoid is a tissue-engineered organ-like structure that resemble as an organ. Porcine islet-derived organoid might be used as an alternative donor of porcine islet xenotransplantation, a promising therapy for severe diabetes. In this study, we elucidated the characteristics of porcine islet organoids derived from porcine islets as a cell source for transplantation. Isolated porcine islets were 3D-cultured using growth factor-reduced matrigel in organoid culture medium consist of advanced DMEM/F12 with Wnt-3A, R-spondin, EGF, Noggin, IGF-1, bFGF, nicotinamide, B27, and some small molecules. Morphological and functional characteristics of islet organoids were evaluated in comparison with 2D-cultured islets in advanced DMEM/F12 medium. Relatively short-term (approximately 14 days)-cultured porcine islet organoids were enlarged and proliferated, but had an attenuated insulin-releasing function. Long-term (over a month)-cultured islet organoids could be passaged and cryopreserved. However, they showed pancreatic duct characteristics, including cystic induction, strong expression of Sox9, loss of PDX1 expression, and no insulin-releasing function. These findings were seen in long-term-cultured porcine islets. In conclusion, our porcine islet organoids showed the characteristics of pancreatic ducts. Further study is necessary for producing porcine islet-derived organoids having characteristics as islets.

Rescue of murine hind limb ischemia via angiogenesis and lymphangiogenesis promoted by cellular communication network factor 2.

Critical limb ischemia (CLI) is caused by severe arterial blockage with reduction of blood flow. The aim of this study was to determine whether therapeutic angiogenesis using cellular communication network factor 2 (CCN2) would be useful for treating CLI in an animal model. Recombinant CCN2 was administered intramuscularly to male C57BL/6J mice with hind limb ischemia. The therapeutic effect was evaluated by monitoring blood flow in the ischemic hind limb. In an in vivo assay, CCN2 restored blood flow in the ischemic hind limb by promoting both angiogenesis and lymphangiogenesis. VEGF-A and VEGF-C expression levels increased in the ischemic limb after treatment with CCN2. In an in vitro assay, CCN2 promoted proliferation of vascular and lymphatic endothelial cells, and it upregulated expression of Tgfb1 followed by expression of Vegfc and Vegfr3 in lymphatic endothelial cells under hypoxia. Suppression of Tgfb1 did not affect the activity of CCN2, activation of the TGF-ß/SMAD signaling pathway, or expression of Vegfr3 in lymphatic endothelial cells. In summary, treatment using recombinant CCN2 could be a promising therapeutic strategy for CLI.

Optimal temperature for the long-term culture of adult porcine islets for xenotransplantation.

Porcine islet xenotransplantation represents a promising therapy for severe diabetes mellitus. Long-term culture of porcine islets is a crucial challenge to permit the on-demand provision of islets. We aimed to identify the optimal temperature for the long-term culture of adult porcine islets for xenotransplantation. We evaluated the factors potentially influencing successful 28-day culture of islets at 24°C and 37°C, and found that culture at 37°C contributed to the stability of the morphology of the islets, the proliferation of islet cells, and the recovery of endocrine function, indicated by the expression of genes involved in pancreatic development, hormone production, and glucose-stimulated insulin secretion. These advantages may be provided by islet-derived CD146-positive stellate cells. The efficacy of xenotransplantation using islets cultured for a long time at 37°C was similar to that of overnight-cultured islets. In conclusion, 37°C might be a suitable temperature for the long-term culture of porcine islets, but further modifications will be required for successful xenotransplantation in a clinical setting.

Establishment of a Simple, Reproducible, and Long-lasting Hind Limb Animal Model of Lymphedema.

Background: Lymphedema is an intractable disease for which there is currently no established curative therapy. A reliable and long-lasting lymphedema model is essential for development of better treatments. In this study, we aimed to establish a simple, reproducible and long-lasting mouse model of lymphedema. Methods: Our model is characterized by a combination of a circumferential skin incision in the femoral region, complete dissection of regional lymph nodes, and ablation of the inguinal route in the femoral region. The characteristics of the lymphedema were evaluated and compared with those of two other models. One of these models involved dissection of the subiliac, popliteal, and sciatic lymph nodes (model A) and the other excision of the subiliac, popliteal, and sciatic lymph nodes with cauterization of lymphatic vessels and closure without a skin excision (model B). Results: Although the lymphedema in models A and B resolved spontaneously, that in the new model lasted for a month with increases in femoral circumference and hind limb volume, thickening of the skin, especially subcutaneous tissue, and congestion of peripheral lymphatic vessels. Furthermore, this model could be used for assessing the therapeutic effects of syngeneic mesenchymal stem cell transplantation. The average operation time for the new model was 14.4 ±â€…1.3 minutes. Conclusion: Long-lasting lymphedema can be achieved by our new model, making it suitable for assessing therapies for lymphedema.

Elevation in white blood cell count and development of hyper LDL cholesterolemia.

To investigate the relationship between white blood cell (WBC) count and incidence of hyper-low-density lipoprotein (LDL) cholesterolemia in a population-based longitudinal study. This is a retrospective study using data of annual health check-ups for residents of Iki City, Japan. A total of 3312 residents (≥ 30 years) without hyper-LDL cholesterolemia at baseline were included in this analysis. Primary outcome was incidence of hyper-LDL cholesterolemia (LDL cholesterol levels ≥ 3.62 mmol/L and/or use of lipid lowering drugs). During follow-up (average 4.6 years), 698 participants development of hyper-LDL cholesterolemia (incidence 46.8 per 1000 person-years). Higher incidence of hyper-LDL cholesterolemia was observed among participants with higher leukocyte count (1st quartile group: 38.5, 2nd quartile group: 47.7, 3rd quartile group: 47.3, and 4th quartile group: 52.4 per 1,000 person-years, P = 0.012 for trend). Statistically significant relation was observed even after adjustment for age, gender, smoking, alcohol intake, leisure-time exercise, obesity, hypertension and diabetes: hazard ratio 1.24 (95% confidence interval 0.99 to 1.54) for 2nd quartile group, 1.29 (1.03-1.62) for 3rd quartile group and 1.39 (1.10-1.75) for 4th quartile group, compared with 1st quartile group (P for trend = 0.006). Increased WBC count was related to incidence of hyper-LDL cholesterolemia in general Japanese population.

Differentiation of human adipose tissue-derived mesenchymal stromal cells into steroidogenic cells by adenovirus-mediated overexpression of NR5A1 and implantation into adrenal insufficient mice.

BACKGROUND AIMS: Cell therapy for adrenal insufficiency is a potential method for physiological glucocorticoid and mineralocorticoid replacement. We have previously shown that mouse mesenchymal stromal cells (MSCs) differentiated into steroidogenic cells by the viral vector-mediated overexpression of nuclear receptor subfamily 5 group A member 1 (NR5A1), an essential regulator of steroidogenesis, and their implantation extended the survival of bilateral adrenalectomized (bADX) mice. METHODS: In this study, we examined the capability of NR5A1-induced steroidogenic cells prepared from human adipose tissue-derived MSCs (MSC [AT]) and the therapeutic effect of the implantation of human NR5A1-induced steroidogenic cells into immunodeficient bADX mice. RESULTS: Human NR5A1-induced steroidogenic cells secreted adrenal and gonadal steroids and exhibited responsiveness to adrenocorticotropic hormone and angiotensin II in vitro. In vivo, the survival time of bADX mice implanted with NR5A1-induced steroidogenic cells was significantly prolonged compared with that of bADX mice implanted with control MSC (AT). Serum cortisol levels, which indicate hormone secretion from the graft, were detected in bADX mice implanted with steroidogenic cells. CONCLUSIONS: This is the first report to demonstrate steroid replacement by the implantation of steroid-producing cells derived from human MSC (AT). These results indicate the potential of human MSC (AT) to be a source of steroid hormone-producing cells.

Procedure of Adult Porcine Islet Isolation.

Islet transplantation is a useful therapeutic choice for severe diabetes mellitus; however, limited donor supplies have interfered with the use of this treatment. Therefore, the establishment of alternative donor sources and engineered tissue, which enables to produce appropriate insulin for controlling blood glucose, is an important challenge. The adult pig is a promising and feasible donor source and materials for the engineered tissue for the clinical setting among various candidates. The recent progress of gene-editing technology contributes to possible clinical porcine xenotransplantation, including porcine islet xenotransplantation. For the success of future clinical porcine islet xenotransplantation, establishing an islet isolation technique for acquiring adequate, good-quality porcine islets is equally important to use a gene-edited pig. However, the characteristics of porcine islets are different from other species; therefore, establishing a suitable technique for porcine islets is challenging. Impact statement Recent technological progress promotes the feasibility of xenotransplantation, including islet xenotransplantation, for clinical setting. Adult pig is a promising and feasible donor source for islet xenotransplantation and engineered tissue, which enables to control blood glucose in recipients. It is important to acquire porcine islets in good qualities for the promotion, however, establishing a technique for adult porcine islet isolation is important but challenging because of the vulnerability of adult porcine islets. Deciding the proper timing of stopping pancreatic digestion is one of the important factors for obtaining adult porcine islets in good quality.

Serum triglyceride levels and incidence of hypertension in a general Japanese population: ISSA-CKD study.

The aim of this study was to clarify the relationship between fasting and nonfasting serum triglyceride (TG) levels and the incidence of hypertension in a general Japanese population. We conducted a population-based retrospective cohort study using annual health check-up data of residents of Iki City, Nagasaki Prefecture, Japan. A total of 3202 participants without hypertension at baseline were included in the present analysis. TG levels were classified as quartile 1 (<0.82 mmol/L), quartile 2 (0.83-1.13 mmol/L), quartile 3 (1.14-1.70 mmol/L) and quartile 4 (≥1.71 mmol/L) for men, and as quartile 1 (<0.70 mmol/L), quartile 2 (0.71-0.96 mmol/L), quartile 3 (0.97-1.34 mmol/L) and quartile 4 (≥1.35 mmol/L) for women. The outcome was incident hypertension. During an average follow-up of 4.4 years, 983 participants developed hypertension, according to the Cox proportional hazards model. The annual incidence of hypertension increased with an elevation in TG levels for men (5.88% in quartile 1, 8.30% in quartile 2, 7.62% in quartile 3, and 9.82% in quartile 4). This association was significant, even after adjustment for other risk factors: hazard ratio 1.41 [95% CI 1.07-1.85] for quartile 2, 1.30 [0.99-1.71] for quartile 3, and 1.59 [1.22-2.08] for quartile 4 compared with quartile 1 (p = 0.041 for trend). In contrast, there was no clear association between serum TG levels and the incidence of hypertension after adjustment for confounding factors among women (p = 0.240 for trend). High levels of serum TG were associated with the future incidence of hypertension in a general population of Japanese men but were not associated with that in women. Casual serum triglyceride levels and incidence of hypertension in a general Japanese population: ISSA-CKD study.

Induction of potassium channel regulator KCNE4 in a submandibular lymph node metastasis model.

Cancer cells often metastasize to the lymph nodes (LNs) before disseminating throughout the body. Clinically, LN metastasis correlates with poor prognosis and influences treatment options. Many studies have shown that cancer cells communicate with immune and stromal cells to prepare a suitable niche for metastasis. In this study, mice were injected with B16-F10 murine melanoma cells to generate a tongue submandibular lymph node (SLN) metastasis model in which genes of interest could be investigated. Microarray analyses were performed on SLNs, identifying 162 upregulated genes, some of which are known metastasis genes. Among these upregulated genes, Kcne4, Slc7a11, Fscn1, and Gadd45b were not associated with metastasis, and increased expression of Kcne4 and Slc7a11 was confirmed by real-time PCR and immunohistochemistry. The roles of KCNE4 in chemokine production and cell adhesion were examined using primary lymphatic endothelial cells, and demonstrated that Ccl17 and Ccl19, which are involved in melanoma metastasis, were upregulated by KCNE4, as well as Mmp3 matrix metalloproteinase. Expression of KCNE4 was detected in human LNs with metastatic melanoma. In conclusion, we found that LN metastatic melanoma induces KCNE4 expression in the endothelium of LNs.

Xenotransplantation of neonatal porcine bone marrow-derived mesenchymal stem cells improves diabetic wound healing by promoting angiogenesis and lymphangiogenesis.

BACKGROUND: Some clinical trials have shown the usefulness of stem cell therapy for diabetic foot ulcers. However, the donor supply is limited, and the process is time consuming and expensive. This study assessed the therapeutic effects of neonatal porcine bone marrow-derived mesenchymal stem cell (npBM-MSC) xenotransplantation using diabetic wound model mice. METHODS: All layers of back skin were removed from streptozotocin-induced diabetic mice. In the npBM-MSCs group, npBM-MSCs were transplanted to the wound, and syngeneic mouse bone marrow-derived mesenchymal stem cells (mBM-MSCs) were transplanted to the wound in the mBM-MSCs group. The control group comprised diabetic mice that did not receive cellular therapy. The therapeutic effects of the transplantation were evaluated according to the rate of wound closure and the promotion of neovascularization in the wound. RESULTS: The wound closure rate was significantly improved in the npBM-MSCs group compared with the control group (p < .001 at postoperative day [POD] 4 and p < .01 at POD 7) and mBM-MSCs groups (p < .05 at POD 4). Prominent promotion of both angiogenesis and lymphangiogenesis was observed in the npBM-MSCs group. Furthermore, the expression of murine Prox1 and both porcine and murine Vegfs and Tgfb1 in the wounds was enhanced until POD 4 by npBM-MSCs transplantation. The amounts of vascular endothelial growth factor (VEGF) A, VEGFC, and transforming growth factor ß1 secreted from npBM-MSCs were higher than those from mBM-MSCs (p < .05). CONCLUSION: Xenotransplantation of npBM-MSCs improved diabetic wound healing by promoting both angiogenesis and lymphangiogenesis.

Possibility of adiponectin use to improve islet transplantation outcomes.

Although islet transplantation (ITx) is a promising therapy for severe diabetes mellitus, further advancements are necessary. Adiponectin, an adipokine that regulates lipid and glucose metabolism, exerts favorable effects on islets, such as reinforcement of the insulin-releasing function. This study evaluated the possibility of adiponectin use to improve ITx outcomes. We treated mouse islets with 10 µg/mL recombinant mouse adiponectin by overnight culture and then assessed the insulin-releasing, angiogenic, and adhesion functions of the islets. Furthermore, 80 syngeneic islet equivalents with or without adiponectin treatment were transplanted into the renal subcapsular space of diabetic mice. In in vitro assessment, released insulin at high glucose stimulation, insulin content, and expressions of vascular endothelial growth factor and integrin ß1 were improved in adiponectin-treated islets. Furthermore, adiponectin treatment improved the therapeutic effect of ITx on blood glucose levels and promoted angiogenesis of the transplanted islets. However, the therapeutic effect was not pronounced in glucose tolerance test results. In conclusion, adiponectin treatment had preferable effects in the insulin-releasing, angiogenic, and adhesion functions of islets and contributed to the improvement of ITx. The future use of adiponectin treatment in clinical settings to improve ITx outcomes should be investigated.

CCN2-induced lymphangiogenesis is mediated by the integrin αvß5-ERK pathway and regulated by DUSP6.

Lymphangiogenesis is essential for the development of the lymphatic system and is important for physiological processes such as homeostasis, metabolism and immunity. Cellular communication network factor 2 (CCN2, also known as CTGF), is a modular and matricellular protein and a well-known angiogenic factor in physiological and pathological angiogenesis. However, its roles in lymphangiogenesis and intracellular signaling in lymphatic endothelial cells (LECs) remain unclear. Here, we investigated the effects of CCN2 on lymphangiogenesis. In in vivo Matrigel plug assays, exogenous CCN2 increased the number of Podoplanin-positive vessels. Subsequently, we found that CCN2 induced phosphorylation of ERK in primary cultured LECs, which was almost completely inhibited by the blockade of integrin αvß5 and partially decreased by the blockade of integrin αvß3. CCN2 promoted direct binding of ERK to dual-specific phosphatase 6 (DUSP6), which regulated the activation of excess ERK by dephosphorylating ERK. In vitro, CCN2 promoted tube formation in LECs, while suppression of Dusp6 further increased tube formation. In vivo, immunohistochemistry also detected ERK phosphorylation and DUSP6 expression in Podoplanin-positive cells on CCN2-supplemented Matrigel. These results indicated that CCN2 promotes lymphangiogenesis by enhancing integrin αvß5-mediated phosphorylation of ERK and demonstrated that DUSP6 is a negative regulator of excessive lymphangiogenesis by CCN2.

Therapeutic effects of acylated ghrelin-specific receptor GHS-R1a antagonist in islet transplantation.

Islet transplantation is a type of cellular replacement therapy for severe diabetes that is limited by compromising effect on engrafted islets. Trials aiming to improve the function of transplanted islets have also been challenging. This study attempted to elucidate whether regulation of growth hormone secretagogue receptor-1a (GHS-R1a), one of the ghrelin receptors, improve the therapeutic effects of islet transplantation using [D-Lys3]-GHRP-6 (DLS), a specific GHS-R1a antagonist. The therapeutic effects of DLS were assessed in terms of the expression/production of endocrine genes/proteins, insulin-releasing function under glucose stimulation of mouse islets, and outcomes of syngeneic murine islet transplantation with systemic DLS administration. DLS treatment promoted insulin production and suppressed somatostatin production, suggesting that cancelation of the binding between ghrelin and GHS-R1a on ß or δ cells improved insulin expression. DLS also promoted the glucose-dependent insulin-releasing function of ß cells. However, the therapeutic effect of DLS in islet transplantation was fractional. In conclusion, the GHS-R1a antagonist showed preferable effects in improving the therapeutic outcomes of islet transplantation, including the promotion of insulin-releasing function.

Behavioral profile in a Dctn1G71A knock-in mouse model of Perry disease.

Perry disease (Perry syndrome) is a rare, rapidly progressive, autosomal dominant neurodegenerative disease characterized by parkinsonism, depression/apathy, weight loss, and respiratory symptoms including central hypoventilation. It is caused by missense mutations (e.g. p.G71A) in the DCTN1 gene. We previously generated transgenic mice that expressed human DCTN1G71A mutant protein under the control of Thy1 promoter. These mice exhibited apathy-like behavior and parkinsonism. However, it is possible that this phenotype was due to a gene-dosage imbalance or transgene insertion position. To circumvent these potential caveats, we have generated a knock-in mouse model carrying a p.G71A mutation in Dctn1. Heterozygous Dctn1G71A and wild-type littermates were subjected to a battery of behavioral analyses. Furthermore, immunohistochemistry for tyrosine hydroxylase (TH) was performed on brain sections of these mice, and TH signal intensity in substantia nigral neurons was quantified. Dctn1G71A mice were immobile for longer than wild-type mice of the same age and sex in the tail-suspension test, revealing depressive characteristics. In addition, the beam-walking test and pole test detected motor deficits in Dctn1G71A female mice. Finally, immunostaining revealed a decrease in TH immunoreactivity in neurons of the substantia nigra in the Dctn1G71A mice. Collectively, heterozygous Dctn1G71A mice showed depression-like behavior, motor deficits, and a functional reduction in substantia nigral neurons, as judged by TH immunostaining, thereby exhibiting multiple features of Perry disease. Hence, this mouse model will be useful in elucidating pathological mechanisms of Perry disease and for developing novel therapeutic strategies against it.

Fat-Covered Islet Transplantation using Epididymal White Adipose Tissue.

Islet transplantation is a cellular replacement therapy for severe diabetes mellitus. The intraperitoneal cavity is typically the transplant site for this procedure. However, intraperitoneal islet transplantation has some limitations, including poor transplant efficacy, difficult graft detection ability, and a lack of graftectomy capability for post-transplant analysis. In this paper, "fat-covered islet transplantation", an intraperitoneal islet transplantation method that utilizes epididymal white adipose tissue, is used to assess the therapeutic effects of bioengineered islets. The simplicity of the method lies in the seeding of islets onto epididymal white adipose tissue and using the tissue to cover the islets. While this method can be categorized as an intraperitoneal islet transplantation technique, it shares characteristics with intra-adipose tissue islet transplantation. The fat-covered islet transplantation method demonstrates more robust therapeutic effects than intra-adipose tissue islet transplantation, however, including the improvement of blood glucose and plasma insulin levels and the potential for graft removal. We recommend the adoption of this method for assessing the mechanisms of islet engraftment into white adipose tissue and the therapeutic effects of bioengineered islets.

Lymphangiogenesis and angiogenesis rescue murine ischemic hindlimb via transient receptor potential vanilloid 4.

In this study, we assessed the regulation of transient receptor potential vanilloid 4 (TRPV4) promoting lymphangio/angiogenesis to improve the ischemic hindlimb animal model, and revealed that (1) a TRPV4 agonist improved the blood flow of ischemic hindlimbs by inducing both angiogenesis and lymphangiogenesis; (2) excessive TRPV4 expression was detected on lymphatic endothelial cells (LECs) in the ischemic hindlimb; and (3) hypoxic conditions promoted Ca2+ influx into LECs via TRPV4. It is considered that the upregulation of both lymphatic and blood vessels by activating TRPV4 would be a promising therapeutic strategy for peripheral artery disease.

Xenotransplantation of neonatal porcine bone marrow-derived mesenchymal stem cells improves murine hind limb ischemia through lymphangiogenesis and angiogenesis.

BACKGROUND: The clinical utility of stem cell therapy for peripheral artery disease has not been fully discussed, and one obstacle is limited donor supplies. In this study, we attempted to rescue mouse ischemic hind limb by xenotransplantation of neonatal porcine bone marrow-derived mesenchymal stem cells (npBM-MSCs). METHODS: Neonatal porcine bone marrow-derived mesenchymal stem cells were transplanted to ischemic hind limbs of male C57BL/6J mice (npBM-MSCs group). Mice with syngeneic transplantation of mouse BM-MSCs (mBM-MSCs group) were also prepared for comparison. The angiogenic effects were evaluated by recovery of blood flow on laser Doppler imaging, histologic findings, and genetic and protein levels of angiogenic factors. RESULTS: Regarding laser Doppler assessments, blood flow in the hind limb was rapidly recovered in the npBM-MSCs group, compared with that in the mBM-MSCs group (P = .016). Compared with the mBM-MSCs group, the npBM-MSCs group had early and prominent lymphangiogenesis [P < .05 on both post-operative days (PODs) 3 and 7] but had similar angiogenesis. Regarding genomic assessments, xenotransplantation of npBM-MSCs enhanced the expressions of both porcine and murine Vegfc in the hind limbs by POD 3. Interestingly, the level of murine Vegfc expression was significantly higher in the npBM-MSCs group than in the mBM-MSCs group on PODs 3 and 7 (P < .001 for both). Furthermore, the secreted VEGFC protein level was higher from npBM-MSCs than from mBM-MSCs (P < .001). CONCLUSION: Xenotransplantation of npBM-MSCs contributed to the improvement of hind limb ischemia by both angiogenesis and lymphangiogenesis, especially promotion of the latter. npBM-MSCs may provide an alternative to autologous and allogeneic MSCs for stem cell therapy of critical limb ischemia.