Xenogeneic transplantation of equine testicular cells into seminiferous tubules of immunocompetent rats

The objectives were to develop a transplantation assay for equine testicular cells using busulfan-treated prepubertal immunocompetent rats as recipients, and to determine if putative equine spermatogonial stem cells (SSCs) could be enriched by flow cytometric cell sorting (based on light scattering properties), thereby improving engraftment efficiency. Four weeks after transplantation of frozen/thawed PKH26-labeled equine testicular cells, 0.029 ± 0.045% (mean ± SD) of viable donor cells transplanted had engrafted. Donor cells were present in seminiferous tubules of all recipient rats forming chains, pairs, mesh structures, or clusters (with two to >30 cells/structure). Cells were localized to the basal compartment by the basement membrane. Although equine cells proliferated within rat seminiferous tubules, no donor-derived spermatogenesis was evident. Furthermore, there was no histologic evidence of acute cellular rejection. No fluorescent cells were present in control testes. When equine testicular cells were sorted based on light scattering properties, the percentage of transplanted donor cells that engrafted was higher after injection of cells from the small, low complexity fraction (II; 0.169 ± 0.099%) than from either the large, high complexity fraction (I; 0.046 ± 0.051%) or unsorted cells (0.009 ± 0.007%; P < 0.05). Seminiferous tubules of busulfan-treated prepubertal immunocompetent rats provided a suitable niche for engraftment and proliferation, but not differentiation, of equine testicular cells. Sorting equine testicular cells based on light scattering properties resulted in a 19-fold improvement in colonization efficiency by cells with high forward scatter and low side scatter, which may represent putative equine SSCs.     

Leydig cell involvement in the paracrine regulation of mast cells in the testicular interstitium of the rat

The accumulation of mast cells in the rat testicular interstitium was studied under different experimental conditions in order to correlate this accumulation with the alterations of specific testicular tissue compartments or cell types. Estrogen treatment was effective in inducing mast cell proliferation when administered on Day 1 or at higher doses at 10 days of age. Estrogens were ineffective beyond 20 days of age. Postnatal treatment of neonatal-estrogen-treated rats with FSH and LH prevented the appearance of mast cells. In contrast, treatment with the Leydig cell cytotoxic ethylene dimethane sulphonate (EDS) was effective in inducing mast cell accumulation only when administered to adult rats, inducing small numbers of mast cells at 45 days of age; it was ineffective on 30-day-old rats. Hypophysectomy alone did not determine the appearance of mast cells. However, when atrophic Leydig cells were destroyed with EDS, high numbers of mast cells accumulated in the testis. These results support the existence of Leydig cell-related inhibitory factors for mast cells in the rat testicular interstitium.     

Analysis of the progression of meiosis in dispersed rat testicular cells by flow cytofluorometry.

Initiation and progression of meiosis was followed in dispersed rat testicular cells by flow cytofluorometry and cytology. The DNA content of dissociated testicular cells of rats 6--30 days old, killed at daily intervals, was analysed by flow cytofluorometry using propidium iodide as a DNA-specific and quantitative fluorochrome. Testicular cells of a 6-day-old rat showed one peak of fluorescence. A second peak, at twice the modal channel number, appeared in testicular cells of 9-day-old animals. The number of cells under this peak increased progressively with age. A third peak, at half the channel number of the original one, appeared at 20 days and accounted for an increasing proportion of cells in testes taken from older rats. Cytological examination of the testicular tissue used for flow cytofluorometric analysis showed that preleptotene spermatocytes first appeared at 8 days after birth. Spermatids were first observed cytologically at 20 days after birth. The close temporal appearance of the fluorescence peaks with that of spermatocytes and spermatids, and the close association of the frequency of diploid and tetraploid cells as derived by flow cytofluorometry and cytology, indicated that the fluorescence peaks correspond--in order of increasing fluorescence--to spermatids, spermatogonia and somatic cells, and to spermatocytes. This conclusion was re-examined by analysing the ploidy levels of testicular cells of hypophysectomized or estradiol-treated by flow cytofluorodmetry. There was a loss of the haploid and tetraploid peaks subsequent to hypophysectomy. Estradiol dipropionate-treated rats, given weekly injections starting at 7 days of age, showed no appearance of the haploid peak and the regression of the tetraploid peak after an initial and transitory appearance. These results indicate that changes in ploidy levels that accompany the progression of meiosis in the testis were reflected in the sequential appearance of three fluorescence peaks as detected by flow cytofluorometry. The close correlation between the frequency of cell types as obtained by cytology and flow cytofluorometry indicates that the latter is a sensitive method for studying selected aspects of spermatogenesis in dissociated testicular cells.     

Effect of prenatal treatment with busulfan on the hypothalamo-pituitary axis, genital tract and testicular histology of prepubertal male rats

Female Wistar rats were treated with busulfan or with solvent on Day 20 of pregnancy. Thirty male offspring of each group were killed at 38 days of age. In busulfan-treated rats, compared to controls, hypothalamic LH-RH content was decreased by 52%, whereas pituitary LH and FSH concentrations were increased by 60 and 43% respectively. Plasma LH and FSH were increased by 112 and 275% respectively. Prolactin concentrations were not changed, but plasma testosterone concentration was decreased by 48%. The total number of Leydig cells per testis was decreased by 52%, and LH binding sites per testis were decreased by 70%. The total number of Sertoli cells was decreased by 44%, while FSH binding sites per testis were decreased by 62%. Spermatogenesis was practically absent after prenatal exposure to busulfan. These data demonstrate that on Day 20 of pregnancy all the dividing cells in the fetal testes were depleted by an antimitotic treatment. The stimulation of the hypothalamo-pituitary axis could have been partly induced by the decrease in testosterone production, and by the aplasia of germ cells involving modifications of the remaining Sertoli and Leydig cells.     

Laminin expression during bone marrow mononuclear cell transplantation in hepatectomized rats

The adult bone marrow retains two populations of stem cells with emerging importance for the treatment of diverse liver diseases: hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). However, the mechanisms that control liver regeneration after bone marrow cell transplantation are still controversial. Liver regeneration after partial hepatectomy is a complex process that requires the proliferation of all hepatic cells. Growth factors, cytokines and extracellular matrix molecules are key elements in this process. Laminins are a family of extracellular matrix proteins with adhesive and chemotactic functions, expressed in the portal and centrolobular veins of the normal liver. The aim of this study was to investigate laminin expression during liver regeneration induced by partial hepatectomy followed by bone marrow mononuclear cell (BMMNC) transplantation. Rat BMMNCs were isolated by Ficoll-gradient centrifugation, stained with DAPI and injected into recently hepatectomyzed rats via the portal vein. Liver sections obtained 15 min, 1 day and 3 days after the surgery were immunolabeled with anti-rat CD34 and/or laminin primary antibodies and observed under a laser scanning confocal microscope. Results showed that 15 min after partial hepatectomy, a transplanted CD34+ HSC was found in contact with laminin, which was localized in the portal and centrolobular veins of rat livers. Furthermore, 1 and 3 days after hepatectomy, transplanted BMMNCs were found in the hepatic sinusoids expressing laminin. These results strongly suggest that laminin might be an important extracellular matrix component for bone marrow cell attachment and migration in the injured liver.     

Dye permeability and alkaline phosphatase activity of testicular capillaries in the postnatal rat

Summary Staining of testicular and epididymal tissues after intravenous, intraperitoneal or subcutaneous administration of a number of dyes was investigated in rats at different stages of postnatal development. After light green injections heavy staining of both testis and epididymis was visible to the naked eye in neonatal animals up to the age of 10 days, while in rats over 15 days old no appreciable staining of the testis could be seen, although the caput epididymis was strongly coloured. From 3–8 hours after subcutaneous acriflavine administration, the nuclei in the blood vessel walls of the testis, as well as the nuclei in the rete testis, tubuli efferentes and caput epididymis, fluoresced in all age groups. The nuclei of the interstitial and tubular cells were stained intensely until the age of 5 days. Thereafter the intensity gradually diminished until the age of 20 days, when no nuclear fluorescence was visible in the seminiferous tubules and even the interstitial nuclei fluoresced weakly or not at all.The histochemical alkaline phosphatase activity of the testicular capillaries was studied by Gomori's method, using fresh and postfixed cryostat sections from postnatal rat testes. The testicular capillaries exhibited appreciable activity at the age of 10 days.On the basis of the present and previous observations on the permeability of the testicular capillaries, the existence of a blood-testis barrier in the puberal and adult rat testis is suggested.Development of the blood-testis barrier and the alkaline phosphatase activity of the testicular capillaries are suggested to reflect general vascular maturation at the beginning of puberty in the rat.Supported by grants from Yrjö Jahnsson's Foundation and P. O. Klingendahl Foundation.     

造血干细胞移植条件对小鼠造血重建的影响

通过同种基因型小鼠构建造血干细胞移植模型,将预处理的全骨髓单个核细胞或c-Kit⁺造血干细胞移植至致死剂量照射的受体小鼠体内,动态监测移植2～16周后受体小鼠体内供体来源细胞造血重建以及嵌合情况,以期揭示不同群体的供体细胞以及预处理等因素对小鼠造血干细胞移植后造血重建的影响。实验结果显示,移植后早期(2周)全骨髓单个核细胞组髓系比例要高于c-Kit⁺细胞移植组,但全骨髓移植组受体小鼠呈现出较大的移植后不良反应,出现脱毛、食欲不振以及体重减轻的症状。c-Kit⁺细胞移植组在淋系重建上要早于全骨髓移植组,供体细胞的嵌合植入也早于全骨髓移植组,但两组实验组最终均能完成造血重建过程。实验结果表明c-Kit⁺细胞移植组在移植后能够较快地实现供体细胞植入,进而开始造血重建,且c-Kit⁺细胞移植组的不良反应要低于全骨髓移植组。结果说明在整体造血重建效果上c-Kit⁺细胞移植组要优于全骨髓移植组。     

Electron microscopy of isolated rat testicular cells grown in vitro

Summary Suspensions of viable testicular cells obtained from two groups of rats (one group treated for ten days with 50 I. U. of serum gonadotropins (HCG) daily; one group not previously treated) were cultured for ten days. Numerous cells adhered to the glass to form a confluent monolayer and remained in good condition after ten days. This monolayer contained two cell types identified by electron microscopy: fibroblastic cells and Leydig cells. The relative proportion by which these two cells contributed to the monolayer was related to the condition of the donor when the culture was initiated. Fibroblastic cells were more abundant when the animal was not previously treated with HCG. However Leydig cells almost exclusively formed the monolayer when cultures were begun with testicular cells of HCG-treated rats. Gonadotropins on the other hand did not seem capable of acting in vitro.     

Comparison of various kinds of bone marrow stem cells for the repair of infarcted myocardium: single clonally purified non-hematopoietic mesenchymal stem cells serve as a superior source

A variety of adult stem cells have been used to transplant into the infarcted (MI) heart, however, comparative studies are lacking to show more suitable source of cells for transplantation. We have identified a single non-hematopoietic mesenchymal stem cell subpopulation (snMSCs) isolated from human bone marrow and clonally purified, that over 99% of them expressed MSC marker proteins and cardiomyocyte marker proteins when induction in vitro. We also compared the effects of the snMSCs with unpurified MSC (uMSCs), mononuclear cells (BMMNCs), or peripheral blood mononuclear cells (PBMNCs) on myocardial repair after induction of MI in rats. Ninety days later, we observed a better cardiac function assessed by ejection fraction, fraction of shortening and lung wet/dry weight ratios, less remodeling of left ventricle (LV), lower collagen density in the LV, and more vessels in the ischemic wall in the snMSCs transplantation group than in other cell-transplanted groups. Furthermore, the transplanted cells expressing cardiomyocyte specific proteins or vascular endothelial cell marker proteins were more in the snMSCs group than in other ones. We conclude that transplantation with single clonally purified MSCs seems to be more beneficial to the cardiac repair than with other stem cells after MI.     

Modulation of testicular functions by testicular opioid peptides.

The possible physiological role of testicular opioid peptides in the control of testicular functions has been studied. In neonatal rats intratesticular administration of opiate receptor antagonists (naloxone, nalmefene) stimulates Sertoli cell proliferation and secretion. Both in adult and neonatal rats local injection of the testis with opiate receptor antagonists or with beta-endorphin antiserum results in a decrease in steroidogenesis in long-term studies. Treatment of neonatal testis with an enkephalin analogue induces a short-term suppression of testosterone secretion. Further studies were carried out to investigate whether the above described local effects of opiate agonist or antagonist on testicular function are under the regulatory control of testicular nerves. Partial denervation of the testis was performed by testicular injection of 6-hydroxydopamine (a neurotoxin degenerating sympathetic neural structures) or by vasectomy (cutting the inferior spermatic nerve). If testicular administration of opioid agonist or antagonist was combined with partial denervation of the testis, the effects of pharmacological agents influencing testicular opioid level were not evident. The data indicate that opioid peptides synthesized in the testis are components of the intratesticular regulatory system and that local opioid actions are modulated by testicular nerves.     

Effect of mononuclear phagocytes on the differentiation of syngeneic, allogeneic and xenogeneic hematopoietic stem cells

The colony formation in spleen of lethally irradiated syngeneic or hybrid recipients was studied after transplantation of bone marrow cells, with or without macrophages from lymph nodules or from peritoneal cavity of mice, cells of macrophage-like cell line J-774, and monocytes from peripheral blood of healthy donors. The direction of stem cell differentiations in the presence of all the types of mononuclear phagocytes was seen to change from mainly erythroid to mainly myeloid one. The ratio of erythroid to myeloid colonies became equal to 0.5-0.9 instead of 2.0, when bone marrow cells were injected with equivalent quantity of mononuclear phagocytes. This new regulatory function of mononuclear phagocytes is discussed.     

Prolongation of skin allograft survival after neonatal injection of donor bone marrow and epidermal cells

Composite-tissue (e.g., hand allograft) allotransplantation is currently limited by the need for immunosuppression to prevent graft rejection. Inducing a state of tolerance in the recipient could potentially eliminate the need for immunosuppression but requires reprogramming of the immunological repertoire of the recipient. Skin is the most antigenic tissue in the body and is consistently refractory to tolerance induction regimens using bone marrow transplantation alone. It was hypothesized that tolerance to skin allografts could be induced in rats by injecting epidermal cells with bone marrow cells during the first 24 hours of life of the recipients. Brown Norway rats (RT1n) served as donors for the epidermal cells, bone marrow cells, and skin grafts. Epidermal cells were injected intraperitoneally and bone marrow cells were injected intravenously into Lewis (RT1l) newborn recipient rats. In control groups, recipients received saline solution with no cells (group I, n = 12), bone marrow cells only (group II, n = 15), or epidermal cells only (group III, n = 15). In the experimental group (group IV, n = 18), recipients received epidermal and bone marrow cells simultaneously. Skin grafts were transplanted from Brown Norway (RT1n) rats to the Lewis (RT1l) rats 8 weeks after cell injections. Skin grafts survived an average of 8.5 days in group I (10 grafts), 9.2 days in group II (12 grafts), and 12 days in group III (14 grafts). Grafts survived 15.5 days (8 to 26 days) in group IV (15 grafts). The difference was statistically significant (p < 0.05). Hair growth was observed in some accepted grafts in group IV but never in the control groups. This is the first report of prolonged survival of skin allografts in a rat model after epidermal and bone marrow cell injections. Survival prolongation was achieved across a major immunological barrier, without irradiation, myeloablation, or immunosuppression. It is concluded that the presentation of skin-specific antigens generated a temporary state of tolerance to the skin in the recipients that could have delayed the rejection of skin allografts.     

The influence of transplanted culture of bone marrow stromal cells on reparative osteohistogenesis in parietal bone defect

Recently the problem connected with transplantation of bone marrow stromal cells for optimization of reparative osteogenesis is very actively studied. However, the objective methods allowing to observe the behavior of transplanted cells in a bone wound and to estimate character of regenerative osteogenesis after cell transplantation are used in an insufficient measure in both experimental and clinical researches. The aim of this study is to clarify the fate of stromal cells in a bone wound and to investigate the influence of bone marrow stromal cells on the process ofposttraumatic osteogenesis after cell transplantation in parietal bone defect. The experiments were carried out on 38 rabbits with artificially made parietal bone defect (diameter 1.0 cmm). The rabbits were divided into three groups: the first group was a control one; the rabbits of the second group were injected autogenic cultivated bone marrow stromal cells (10(6)); the rabbits of the third group were injected with autogenic cultivated bone marrow stromal cells (10(6)) in collagn gel. The methods of light and fluorescent microscopy, histomorphometry and statistical treatment of the data were used to estimate the results. The obtained data showed that transplanted cells were viable at least during 18 days after transplantation and efficiently took part in the reparative process. The transplantation of cultivated bone marrow stromal cells in collagen gel caused 30% increase in the part of bone tissue in the bone regenerate tissue in comparison with control after 120 days.     

Regulation of testicular and Sertoli cell gamma-glutamyl transpeptidase by follicle-stimulating hormone

Hormonal deprivation achieved by hypophysectomy or gonadotropin-releasing hormone (GnRH)-antagonist treatment of immature rats resulted in markedly lower testicular gamma-glutamyl transpeptidase (GGT) activity than in the testes of age-matched controls. When begun 15 days after hypophysectomy, follicle-stimulating hormone (FSH) treatment significantly increased testicular GGT above that in testes from hypophysectomized controls in a time- and dose-dependent manner. In contrast, testosterone propionate had only a small effect. Testicular GGT was higher in adult hypophysectomized rats treated with FSH from the time of surgery than in untreated hypophysectomized rats; testosterone propionate treatment had no effect. GGT activity in Sertoli cells isolated from GnRH antagonist-treated or hypophysectomized immature rats was also lower than in cells from control rats. FSH treatment from the day of hypophysectomy resulted in Sertoli cell GGT values equivalent to those from intact controls. These data indicate that FSH regulates GGT activity in rat testis and Sertoli cells.     

粒细胞集落刺激因子对失代偿期肝硬化患者骨髓干细胞的动员效果及安全性观察

目的观察失代偿期肝硬化患者行自体骨髓干细胞移植前粒细胞集落刺激因子（G-CSF）对骨髓干细胞的动员效果及安全性。方法在51例失代偿期肝硬化患者行自体骨髓干细胞经肝动脉移植术前,连续2 d给予G-CSF 4μg/（kg·d）动员骨髓干细胞。抽取骨髓的当日化验血常规、肝肾功等指标;从患者髂后上棘抽取骨髓150-200 ml,分离收集骨髓单个核细胞并计数,应用流式细胞仪检测CD34＋细胞并计数,观察应用G-CSF期间不良反应的类型和发生率。患者治疗前后比较采用配对t检验进行统计学分析。结果G-CSF皮下注射后,外周血白细胞由术前（3.31±0.96）×10^9/L升至（11.35±1.92）×10^9/L（P〈0.01）,骨髓单个核细胞数（1.91±0.83）×10^9/kg,CD34＋细胞为（2.02±1.29）×10^7/kg;患者皮下注射后,发热率17.6﹪,体温最高38℃,停药后降至正常;腹部胀痛3例,四肢皮肤散发皮疹2例,均未给予特殊处理,2-3 d后恢复正常。结论给予G-CSF皮下注射后提取骨髓干细胞移植治疗失代偿期肝硬化的是一种临床确切有效的、安全的干细胞动员方法。     

Effects of testosterone on testicular inhibin and fluid production in intact and hypophysectomized adult rats

Rats were given s.c. implants of high (HT) or low (LT) doses of testosterone and 10 days later hypophysectomy or sham-operation was performed. The rats were killed after 50 days. Unilateral efferent duct ligation was performed 16 h before death to measure seminiferous tubule fluid production and the increment in testicular inhibin values (inhibin production). Inhibin levels in testis cytosols were measured by a pituitary cell culture bioassay. The LT implants maintained serum testosterone at control values and decreased testicular weight whereas HT implants raised serum testosterone 3-fold and maintained testicular weight at 75-85% of pretreatment levels. In intact rats, LT implants caused no change in testicular inhibin content but decreased inhibin production; no significant changes occurred with HT implants. After hypophysectomy both values were significantly suppressed and could not be maintained by HT or LT implants. However, the HT implants partly restored inhibin production despite their inability to influence testicular inhibin content. In contrast, tubule fluid production depended mainly on intratesticular testosterone levels and occurred normally in intact or hypophysectomized rats with HT but not LT implants. These results indicate that inhibin and seminiferous tubule fluid production, both functions of the Sertoli cell, are under different hormonal control. The maintenance of inhibin production by the testis requires the support of pituitary hormones, presumably FSH, while seminiferous tubule fluid production requires testosterone, presumably through LH stimulation of Leydig cells. These findings are consistent with the hypothesis that inhibin is produced in response to trophic stimulation by FSH.     

Significance of germ cells for the expression of testicular endocrine function in rats

Germ-cell depletion was induced in rats by busulphan administration during the fetal period (Group B). Although a sigmoidal increase of serum testosterone concentration was observed 1 h after the administration of graded doses of hCG (0.3-15.0 i.u./100 g body weight) in intact rats and those in Group B, a shift in the dose-response curve to the right was observed in the latter, suggesting that the sensitivity of testicular response to gonadotrophin was lower in germ cell-depleted rats. However, since the sensitivity was almost identical for both groups of rats for isolated Leydig cells incubated in vitro for 3 h with hCG (0.5-312.5 i.u./ml), the intrinsic nature of the cells was not affected in Group B rats. When the responses of testicular tissue blocks were examined in the in-vitro incubation system, reduced sensitivity reappeared for those from Group B rats, and the presence of testicular tissue components including seminiferous tubules was considered to be responsible for the difference in Leydig cell sensitivity between intact rats and those exposed to busulphan. By the combination of in-vivo and in-vitro experiments, we have demonstrated that germ cells are involved in the endocrine function of the testis.     

Time course of the differentiation of granulated metrial gland cells in chimeric mice

Granulated metrial gland (GMG) cell differentiation was examined in deciduomata in lethally irradiated mice which had been reconstituted with rat bone marrow. The time at which the bone marrow reconstitution was carried out was varied in relation to the time of initiating the decidual reaction. GMG cells were examined at various times after bone marrow transplantation to determine whether they had the morphology which characterised them as being derived from host or donor stem cells. Differentiation of donor type GMG cells was seen within the first week after transplantation and occurred even when the bone marrow was transplanted two days after initiating the decidual response.     

In vitro differentiation of reprogrammed murine somatic cells into hepatic precursor cells

Recently, a new approach to reprogram somatic cells into pluripotent stem cells was shown by fusion of somatic cells with embryonic stem (ES) cells, which results in a tetraploid karyotype. Normal hepatocytes are often polyploid, so we decided to investigate the differentiation potential of fusion hybrids into hepatic cells. We chose toxic milk mice (a model of Wilson's disease) and performed initial transplantation experiments using this potential cell therapy approach. Mononuclear bone marrow cells from Rosa26 mice were fused with OG2 (Oct4-GFP transgenic) ES cells. Unfused ES cells were eliminated by selection with G418 for OG2-Rosa26 hybrids and fusion-derived colonies could be subcloned. Using an endodermal differentiation protocol, hepatic precursor cells could be generated. After FACS depletion of contaminating Oct4-GFP-positive cells, the hepatic precursor cells were transplanted into immunosuppressed toxic milk mice by intrasplenic injection. However, five out of eight mice showed teratoma formation within 3-6 weeks after transplantation in the spleen and liver. In conclusion, a hepatic precursor cell type was achieved from mononuclear bone marrow cell-ES cell hybrids and preliminary transplantation experiments confirmed engraftment, but also showed teratoma formation, which needs to be excluded by using more stringent purification strategies.     

Therapeutic angiogenesis for severe ischemic heart diseases by autologous bone marrow cells transplantation

Conventional therapies for severe ischemic heart disease are limited in applicability. While several angiogenesis researches have shown novel efficacy, safety and feasibility for clinical use, recently we have started the clinical trial of a sole cell therapy using autologous bone marrow mononuclear cells transplantation targeted into ischemic hibernating myocardium. Here, we review the background of bone marrow cell research and introduce therapeutic angiogenesis for severe ischemic heart disease by autologous bone marrow cells transplantation.