造血干细胞辐射损伤和修复的研究Ⅳ.——苯甲酸雌二醇对小鼠造血干细胞辐射损伤和修复的影响

小鼠于照前7天由肌内注射苯甲酸雌二醇,根据骨髓粒系祖细胞(CFU-D),内源性脾结节(CFU-S),以及骨髓细胞分裂指数和染色体畸变率的改变,探讨其对受照射小鼠造血功能的影响。在照射后的早期,不论CFU-D的数量或染色体畸变率,用药与对照组之间均未见有差异,而在照射后的第3、5、9天,给药组CFU-D的产率均比不用药的对照组有明显提高,而且,骨髓细胞分裂指数在照后3～5天亦高于对照组。上述结果提示,苯甲酸雌二醇的辐射防护作用主要不在减轻造血干细胞的辐射损伤,而与促进残存干细胞增殖有关。     

Interaction of inhibitor and stimulator in the regulation of CFU-S proliferation

An inhibitor and stimulator of CFU-S proliferation can be obtained from haemopoietic tissue containing, respectively, relatively quiescent CFU-S (e.g. normal bone marrow) and proliferating CFU-S (e.g. regenerating bone marrow). In this paper we explore the capacity for inhibitor and stimulator production in relation to changes in the proliferative status of the CFU-S and their mode of interaction. The increase in proliferative activity of CFU-S following a concentrated regime of phenylhydrazine injections is paralleled by an increase in the capacity for stimulator production and a decrease in the capacity for inhibitor production. These processes are reversed as the normal low proliferative activity returns. Using density fractionated marrow populations, dose-response measurements show that while inhibitor- and stimulator-producing cells persist throughout the changes in CFU-S proliferation, their magnitude of factor production moderates in relation to those changes. The inhibitor and stimulator are not mutually destructive: the two factors retain their activities after co-incubation and re-separation. On the other hand, the presence of either factor blocks the synthesis of the other by the appropriate producer cells. A model for the regulation of CFU-S proliferation by the inhibitor and stimulator is thus suggested in which the relative spatial distributions of CFU-S in a microenvironment containing inhibitor- and stimulator-producing cells are an important feature. It also implies the existence of a signal from the CFU-S compartment which determines the appropriate inhibitor or stimulator production.     

The CFU-S redistribution in spontaneous AKR leukemia

The number of bone marrow CFU-S decreases at the terminal stage of spontaneous AKR leukemia. This decrease is compensated by an increase of CFU-S in the spleen, lymph nodes, liver and thymus. Thus, the overall CFU-S number is basically equivalent to that found in normal mice. We take this as evidence of a spatial redistribution of CFU-S in AKR leukemia.     

Inhibitory effects of 5-azapyrimidine nucleosides on cellular immunity

The effect of 5-azacytidine (5-AzCR) and 5-aza-deoxycytidine (5-AzCdR) on the survival of skin grafts in mice and rats, the action of these drugs on regional GVH reaction, as well as the formation of haemopoietic colonies (CFU-5) in the spleen were studied. Both drugs prolonged the life span of skin grafts when administered 24 hr before transplantation, or on the 4th post-transplantation day. However, they were little effective when injected 24 hr after skin grafting, or after induction of the regional GVHR. Following intraperitoneal administration, they inhibited CFU-5 formation. Two-hour incubation in vitro of cells with 5-AzCR significantly reduced their GVH reactivity and capacity to form CFU-5; 5-AzCdR under the same conditions was ineffective.     

In vitro induction of CFU-S proliferation by a non viral splenic activity from myeloproliferative sarcoma virus infected mice

The myeloproliferative sarcoma virus (MPSV) induces a myeloproliferative syndrome in DBA/2 mice. It is characterized by a considerable increase in the number (100-fold) and in the concentration (10-fold) of pluripotent hematopoietic stem cells detected in vivo (CFU-S) in the spleens of infected animals. Prior studies have shown the presence of a mixed-colony promoting activity (MPA) in neoplastic spleens. In the presence of a small quantity of erythropoietin, MPA induces the proliferation and differentiation of pluripotent hematopoietic stem cells, detected in vitro (Mix-CFU). We tested the effect of factors produced by neoplastic spleen cells on the proliferation of day 10 CFU-S and their entry into the cell cycle. This was done by comparing the number of day 10 CFU-S present in suspensions of normal bone marrow cells incubated for 2 days on agar underlays containing cells from either normal or neoplastic spleens. Our results show the existence of an activity secreted by cells from the spleens of MPSV-infected animals which starts CFU-S cycling and which is physically distinct from MPSV. The presence of this activity, whose identity with MPA remains to be proven, would enable us to explain the proliferation of CFU-S in the course of the disease.     

Comparative ability of early and late CFU-S to recover after sublethal radiation damage

Laboratory of Development Biology, Tbilisi University. (Presented by Academician of the Academy of Medical Sciences of the USSR M. M. Khananashvili). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 105, No. 5, pp. 597–599, May, 1988.     

小鼠颌下腺组织培养上清液对造血干细胞和骨髓细胞增殖影响的实验研究

本实验采用脾集落形成法和流式细胞术等技术,研究了小鼠颌下腺组织培养上清液（ＳＧＣＭ）对造血干细胞和骨髓细胞增殖的影响。结果表明：正常雄性和雌性ＳＧＣＭ对小鼠造血干细胞增殖和分化有明显促进作用：ＳＧＣＭ能能效促进小鼠骨髓细胞（ＢＭＣ）由相对静止期（Ｇ０／Ｇ１）进行增殖活跃期（Ｓ＋Ｇ２／Ｍ）,并能提高骨髓有核细胞数。研究提示,正常小鼠颌下腺可能通过分泌造血生长因子样物质促进小鼠造血干细胞增殖和全化并加     

Studies on the self-renewal ability of CFU-S which have been serially transferred in long-term culture or in vivo

The progressive decline in the repopulating ability of bone marrow serially-transferred through a succession of recipients is well documented. A similar series of transfers onto successive long-term culture adherent layers has been carried out using as 'donor' cells both adherent layer cells and cells from the culture supernatant. For as long as the in vitro serial transfer regime can be maintained the decline in self-renewal ability ('quality') of the CFU-S parallels the similar decline observed in vivo and occurs irrespective of the quality of CFU-S transferred. In both the in vivo and in vitro transfer regimes there is little or no loss of quality of CFU-S as a result of one 'transfer' although there may be a reduction in the total numbers of CFU-S in the mouse. However, a second and third transfer in vivo or in vitro leads to a rapid decline in the quality (self-renewal ability) of the CFU-S. Furthermore, despite the fact that the cells are transferred in vitro to a new adherent layer there is no recovery of the quality lost in the second transfer of the CFU-S. This fact implies that self-renewal potential of the CFU-S is a property intrinsic to the cell. The data presented here appear to exclude mitotic history and proliferative stress as factors determining the loss of self-renewal in CFU-S. They also fail to implicate stromal involvement in the decline. It may be that the dilution of an accessory cell or simply the disaggregation of the marrow may be major factors. The work presented indicates that the loss of self-renewal and repopulating ability of haemopoietic stem cells as a result of marrow transplantation may be studied using the long-term marrow culture and yield results relevant to in vivo marrow transplantation.     

60Coγ射线一次和分次照射的生物效应

小鼠受⁶⁰Coγ射线一次(12.90×10^-2C/kg)和分次(2.58×10^-2C/kg连续5天)照射, 停照曰2天两组股骨骨髓多能造血=干细胞CFU—S数明显低于正常对照组, 两分次照射明显高于一次照射组, 其恢复前者也较后者快, 分次照射组骨髓基质功能的损伤也轻于一次照射组；两组小肠粘膜上皮细胞与正常对照组照比无明显差异；孕鼠分次照射后出生3个月的兄性仔鼠的睾丸提伤从多以此照射组。