Effect of macrophages on the differentiation of mouse induced pluripotent stem cells into hepatic progenitor cells / 临床肝胆病杂志

ObjectiveTo investigate the effect of macrophages (MCs) on the differentiation of mouse induced pluripotent stem cells (iPSCs) into hepatic progenitor cells (HPCs). MethodsA total of 24 C57BL/6N mice were used to obtain MCs by peritoneal irrigation, and the supernatant was collected to obtain the conditioned medium of MCs (MC-CDM). Activin A, bone morphogenetic protein 4, and fibroblast growth factor were used to induce the differentiation of mouse iPSCs into HPCs. The differentiation of HPCs were randomly divided into control group (normal medium) and experimental group (MC group; use of MC-CDM medium on day 5 of induction). Morphology, immunofluorescence assay, and Western blot were used to compare the morphology of HPCs and the expression of related proteins between the control group and the MC group. The t-test was used for comparison of continuous data between two groups. ResultsHPCs derived from iPSCs were established in vitro, and HPCs had the potential to differentiate into hepatocytes. Immunofluorescence assay showed that compared with the D12 control group, the D12 MC group had a significant increase in the protein expression of the HPC-specific protein CK19 (0.901±0.072 vs 0.686±0.097, t=-3.093, P＜0.05). Western blot showed that compared with the D12 control group, the D12 MC group had a significant increase in the protein expression of the HPC-related protein CK19 (1.922±0.103 vs 1.448±0.012, t =-7.881, P ＜005), as well as a significant increase in the protein expression of the autophagy-related protein LC3 (1.392±0.042 vs 1.101±0048, t =-5.978, P＜005). ConclusionMCs can promote the differentiation of mouse iPSCs into HPCs, possibly by increasing the autophagy level of HPCs.

Induced pluripotent stem cells: advances in research and application in dermatology / 中华皮肤科杂志

Induced pluripotent stem cells (iPSCs) are a kind of stem cells induced from somatic cells by reprogramming with some specific pluripotent transcription factors.Compared with traditional stem cells,iPSCs have many advantages,including a wide range of sources,the ability of totipotent differentiation,and less ethical and sourcing issues associated with embryonic stem cells which have been debated for a long time.In dermatology,iPSCs can be used to make regenerative skin,establish models of skin diseases,provide a new platform for studying the pathogenesis of skin diseases,and perform cell treatment or gene modification treatment for specific skin diseases.At present,the application value of iPSCs has been verified among animal models,and clinical trials are also under way.

Molecular and cellular mechanisms underlying the Stem Cell Educator therapy for the clinical treatment of diabetes / 中国医师杂志

Multiple immune dysfunctions and shortage of islet beta cells are two key issues for type 1 (T1D) and type 2 (T2D) diabetes.International multi-center clinical studies and basic research have demonstrated the safety and clinical efficacy of Stem Cell Educator therapy for the treatment of T1D and T2D.CB-SC display multiple immune modulations on T cells,regulatory T cells (Tregs),and monocytes through various molecular mechanisms,such as cell-cell contacting,releasing soluble factors,and correcting the autoimmune memory.Recently,we found that platelet-releasing mitochondria exhibit the immune modulation and can migrate to pancreatic islets and be taken up by islet beta cells,leading to the proliferation and enhancement of islet beta cell functions.These findings reveal new mechanisms underlying Stem Cell Educator therapy and open up new avenues to improve the treatment of diabetes in clinics.

GaAlAs laser pretreatment enhances the function of ADSCs in photoaging of the skin in rats / 中华医学美学美容杂志

Objective To investigate the effect of adipose-derived stem cells (ADSCs) on pho toaging skin after laser pretreatment with GaAlAs.Methods ADSCs were isolated from healthy wistar rats,ADSCs were isolated and cultured to establish an adipose-derived stem cell culture system.ADSCs were pretreated with GaAlAs laser at a wavelength of 650 nm 4 J/cm2.A rat model of pho toaging aging was established.Different doses of ADSCs and low energy laser ADSCs were pretreated with ADSCs for the treatment of photoaging skin,and the morphological changes of epidermis and dermis were observed before and after treatment with low energy laser pretreatment.Results When the concentration of ADSCs was 103/100 μl,there was no significant difference in epidermal thickness and dermal thickness between ADSCs treated group and GaAlAs pretreatment group (P＞0.05).The thickness of epidermis in the GaAlAs pretreatment group was significantly lower than that in the ADSCs group (P＜0.05) at 104/100 μl.When the concentration of ADSCs was 5 × 104/100 μl,the epidermal thickness of the GaAlAs pretreatment group decreased significantly and the thickness of the dermis increased significantly,which was significantly different from that of the ADSCs group (P ＜ 0.05).Conclusions GaAlAs laser pretreatment can enhance ADSCs anti-skin photoaging ability.

Advances in research and application of liver organoids / 临床肝胆病杂志

Liver diseases significantly affect human health. Classic research models cannot maintain hepatocyte polarity for a long time and have a different genetic background from normal human hepatocytes, which limits the research on the physiological functions of hepatocytes and the mechanisms of related diseases. The latest liver organoid technology can obtain liver organoids with partial liver structure by reprogrammed induced pluripotent stem cells or in vitro culture of liver biopsy tissue and maintain long-term proliferation and genetic stability, and therefore, it is expected to become a powerful tool for disease modelling, drug screening, and cell therapy. This article mainly reviews the research and application of liver organoids in recent years.

Advances in the research of the application of induced pluripotent stem cells in tissue engineering skin as seed cells / 中华烧伤杂志

Tissue engineering skin has a wide application prospect on the clinical treatment of all sorts of skin defect, especially large area burn. The shortage of seed cells and their function improvement are the main problems in this field. The existing seed cells of tissue engineering skin are difficult to meet the needs of clinical application due to the limitations of acquisition, proliferation, and aging. Subsequently, the generation of induced pluripotent stem cells (iPSCs) provides a safe and efficient cell source for tissue engineering skin. Our article focuses on the origin of iPSCs and its characteristics of differentiating into keratinocytes, fibroblasts, melanocytes, vascular smooth muscle cells, nerve cells, and hair follicle, and discusses the main problems and prospects of iPSCs in establishment of tissue engineering skin and application in wound repair.

Leukemia propagating cells in Philadelphia chromosome-positive ALL: a resistant phenotype with an adverse prognosis

BACKGROUND: Targeted therapy has revolutionized the management of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL); however, relapse still occurs because of the presence of quiescent stem cells, termed leukemia propagating cells (LPCs). This study aimed to assess the phenotypic diversity of LPCs in adult patients with Ph+ B-Acute ALL (B-ALL) and to assess its prognostic impact. METHODS: Seventy adults with newly diagnosed Ph+ B-ALL were recruited at the Mansoura Oncology Center. Multiparameter flow cytometry studies of mononuclear blast cells for cluster of differentiation (CD)34, CD38, and CD58 were performed. RESULTS: Seventeen patients had blasts with the pattern of LPCs (CD34+CD38−CD58−), while 53 cases had other diverse phenotypic patterns. The rate of complete response was significantly lower in patients with the LPC phenotype (47% vs. 81%, P=0.006). The median time to achieve a complete response was prolonged in patients with the CD34+CD38−CD58− phenotype (48 vs. 32 days, P=0.016). The three-year overall survival was significantly lower in patients with the CD34+CD38−CD58− phenotype (37% vs. 55% respectively, P=0.028). Multivariate analysis showed that the CD34+CD38− CD58− phenotype was an independent risk factor for overall survival. CONCLUSION: The presence of CD34+CD38−CD58− LPCs at diagnosis allows rapid identification of higher risk patients. Risk stratification of these patients is needed to further guide therapy and develop effective LPCs-targeted therapy to improve treatment outcome.

The Therapeutic Effect of Human Embryonic Stem Cell-Derived Multipotent Mesenchymal Stem Cells on Chemical-Induced Cystitis in Rats / 대한배뇨장애요실금학회지

PURPOSE: To evaluate the therapeutic effect of human embryonic stem cell (hESC)-derived multipotent mesenchymal stem cells (M-MSCs) on ketamine-induced cystitis (KC) in rats. METHODS: To induce KC, 10-week-old female rats were injected with 25-mg/kg ketamine hydrochloride twice weekly for 12 weeks. In the sham group, phosphate buffered saline (PBS) was injected instead of ketamine. One week after the final injection of ketamine, the indicated doses (0.25, 0.5, and 1×106 cells) of M-MSCs (KC+M-MSC group) or PBS vehicle (KC group) were directly injected into the bladder wall. One week after M-MSC injection, the therapeutic outcomes were evaluated via cystometry, histological analyses, and measurement of gene expression. Next, we compared the efficacy of M-MSCs at a low dose (1×105 cells) to that of an identical dose of adult bone marrow (BM)-derived MSCs. RESULTS: Rats in the KC group exhibited increased voiding frequency and reduced bladder capacity compared to rats of the sham group. However, these parameters recovered after transplantation of M-MSCs at all doses tested. KC bladders exhibited markedly increased mast cell infiltration, apoptosis, and tissue fibrosis. Administration of M-MSCs significantly reversed these characteristic histological alterations. Gene expression analyses indicated that several genes associated with tissue fibrosis were markedly upregulated in KC bladders. However the expression of these genes was significantly suppressed by the administration of M-MSCs. Importantly, M-MSCs ameliorated bladder deterioration in KC rats after injection of a low dose (1×105) of cells, at which point BM-derived MSCs did not substantially improve bladder function. CONCLUSIONS: This study demonstrates for the first time the therapeutic efficacy of hESC-derived M-MSCs on KC in rats. M-MSCs restored bladder function more effectively than did BM-derived MSCs, protecting against abnormal changes including mast cell infiltration, apoptosis and fibrotic damage.

Comparative study of proliferative and periodontal differentiation propensity of induced pluripotent stem cells at different passages / 北京大学学报(医学版)

Objective:To compare the proliferative and periodontal specific differentiation abilities of induced pluripotent stem cells (iPSCs) at different passages,and to investigate whether long term culturing would have a negative influence on their proliferation and specific differentiation capacity,thus providing a theoretical basis for further in-depth research on periodontal regeneration and the possible clinical applications of iPSCs.Methods:IPSCs derived from human gingival fibroblasts at passages 5,10,15 and 20 were recovered and cultured in vitro.Their morphology and proliferation rates were observed respectively.We further induced the iPSCs at different passages toward periodontal tissue under the treatment of growth/differentiation factor-5 (GDF-5) for 14 days through the EB routine,then compared the periodontal differentiation propensities between the different passages of iPSCs by detecting their calcified nodules formation by Alizarin red staining and assaying their relative periodontal tissue related marker expressions by qRT-PCR and immunofluorescence staining,including bone related markers:osteocalcin (OCN),bone sialoprotein (BSP);periodontal ligament related markers:periostin,vimentin;and cementum related markers:cementum attachment protein (CAP),cementum protein 1 (CEMP1).The untreated spontaneous differentiation groups were set as negative controls respectively.Results:iPSCs at different passages all showed a high proliferative capacity when cultured in vitro and turned into a spindlelike shape similar to fibroblasts upon periodontal specific differentiation.All iPSCs formed typical calcified nodules upon GDF-5 induction by Alizarin red staining in comparison to their untreated controls.The relative calcium deposition at all passages had been significantly upgraded under the treatment of GDF-5 (P5:t =2.125,P =0.003;P10:t =2.246,P =0.021;P15:t =3.754,P =0.004;P20:t =3.933,P =0.002),but no significant difference in their calcium deposition were detected within passages 5,10,15 and 20 (periodontal differentiation:F =2.365,P =0.109;spontaneously differentiation:F =2.901,P =0.067).Periodontal tissue related marker expressions of iPSCs at all passages had also been significandy upgraded under the treatment of GDF-5 (P ＜ 0.05),but still,no significant difference in their expression levels of periodontal tissue related proteins were detected within passages (BSP:F =0.926 7,P=0.450;vimentin:F=0.917 1,P=0.455;CEMP1:F=2.129,P=0.1367).Conclusion:Our results preliminarily confirmed that long term culturing won't influence the proliferation capacity and periodontal specific differentiation propensity of iPSCs,as they can still proliferate and differentiate toward periodontal cells with high efficiency upon growth factor induction after continuous passaging.Therefore,iPSCs could be recognized as a promising cell source for future possible application in periodontal tissue regeneration.

Application of swine iPS cell transplantation in porcine myocardial infarction model / 中国医师杂志

Objective To observe the therapeutic effect of porcine myocardium against porcine myocardial infarction (MI) by porcine myocardial infarction model with connexin-43/zonula occludens-1 (CX43/ZO-1) double gene induced pluripotent stem cells (iPS) transplantation.Methods Porcine myocardial infarction model was established by balloon occlusion.One week later,1640 culture medium,CX43 gene ips cells and CX43/ZO-1 gene ips cells were injected into the different coronary arteries.After 3 months,electron microscopy and color Doppler ultrasonography were used to evaluate the curative effect.Results Compared to ips group of CX43 and 1640 culture group,in CX43/ZO-1 gene ips group,electron microscope showed a large number of island-like cardiomyocytes,blood vessels and intact intercalated discs in the infarct area and normal myocardial junction area structure,color Doppler echocardiography showed left ventricular end diastolic diameter reduced,and ejection fraction was significantly increased (P ＜ 0.05).Conclusions Transfection of CX43/ZO-1 double gene ips cells can promote cardiomyocyte regeneration and cardiac function recovery in porcine myocardial infarction model.

Immune modulation by mouse lymphocytes co-culturedwith cord blood-derived multipotent stem cells in Alzheimer's disease model mice / 基础医学与临床

Objective To investigate the immune modulation effect of lymphocytes co-cultured with human cord blood derived-multipotent stem cells(CB-SCs) and to explore their therapeutic potential for Alzheimer's Disease (AD) model mice.Methods CB-SCs were isolated from human cord blood.Lymphocytes were isolated from spleens of AD model mice.The lymphocytes were co-cultured with CB-SCs or cultured alone for 72 h.AD model mice were divided into experimental group and control group randomly,and then the experimental group mice were administrated with lymphocytes co-cultured with CB-SCs and control group were administrated with lymphocytes cultured alone by caudal vein injection.Then,the behavior experiment was carried out.The CD4+CD25+Foxp3+Tregswere detected by flow cytometry.The protein expression of TNF-αand IL-10 in peripheral blood was detected by ELISA,The mRNA expression of TNF-α and IL-10 in brain tissue was detected by PCR.The amyloid-β(Aβ)plaques were detected by immunohistochemistry.Results 1)There was spatial learning and memory improvement on experimental group.2)The Aβ plaques of experimental group decreased.3)The percentage of CD4+CD25+Foxp3+Tregs in peripheral blood and IL-10 level in plasma were higher in experimental group(P<0.05).The pro-inflammatory cytokines,TNF-α level in plasma of experimental group was lower than that in the control group(P<0.001).4)The mRNA expression of IL-10 in brain was higher in experimental group as compared to those in the control group(P<0.05),and the mRNA expression of TNF-α of experimental group was lower than that in the control group(P<0.05).Conclusions The lymphocytes co-cultured with CB-SCs have immunotherapeutic effect in AD model mice,which is mainly displayed with increased proportion of Tregs and enhanced anti-inflammatory function of Tregs.

Generation of pluripotent stem cells using non-integrated approach in human azoospermia patients / 天津医药

Objective To establish induced pluripotent stem cells (iPSCs) in patients with azoospermia by non-integrated approach. Methods Using the commercially available serum-free medium (TeSR?2) and embryonic stem cell culture medium (Stem Adhere? Defined Matrix) to define the culture system, the iPSCs were established by using non-integrated Sendai virus infection in peripheral blood mononuclear cells of azoospermia patients. The immunofluorescence, karyotype analysis, embryoid body differentiation and teratoma formation were used to identify pluripotency, karyotype and differentiation ability of iPSCs. Results The established iPSCs showed the characteristics of human embryonic stem cells. Immunofluorescence analysis showed that octamer-binding transcription factor 4 (OCT4), SRY-related-box protein-2 (SOX2), stage-specific embryonic antigen-4 (SSEA-4) and tumor rejection antigen-1-60 (TRA-1-60) were positive for the expression of stem cell pluripotency markers. Karyotype analysis showed that they had normal karyotype. In addition, embryoid body and teratoma tests showed that the iPSCs had the ability to differentiate into three germ layers in vitro and in vivo. Conclusion The induction of pluripotent stem cell line is successfully constructed by non-integrated approach in azoospermia patients.

Umbilical cord blood pluripotent stem cell immune education treatment for juvenile type 1 diabetes / 中国医师杂志

Type 1 diabetes is a autoimmune disease that occurs under the influence of both genetic predisposition and environmental factors,mediated mainly by T lymphocytes with various kinds of other involved immune cells.The autoimmune attacks eventually lead to the islet beta cell destruction and insulin insufficiency.Multiple fundamental studies and clinical trials have revealed that umbilical cord blood pluripotent stem cells have the potential to help restore immune balance,induce immune tolerance,stop the autoimmune attacks against beta cells,and promote beta cell regeneration in type 1 diabetes mellitus (T1DM),by means of cell to cell contact and soluble cytokine secretion.For the past few years,the National Clinical Research Center for Metabolic Diseases of Second Xiangya Hospital has been leading the research on stem cell education therapy and has performed the therapy for 35 juvenile type 1 diabetes patients from China and foreign countries,introducing a novel treatment for T1DM.

Study on PHBHHx co-cultured with mouse induced pluripotent stem cells for use as myocardial patches in vitro / 中华胸心血管外科杂志

Objective To study the effect of polymer material on adhesion , proliferation and differentiation of mouse in-duced pluripotent stem cells via co-culturing in vitro, to find a suitable polymeric biomaterials for miPSCs attachment , prolifera-tion and differentiation , forming myocardial patches as a new repair method for myocardial infarction .Methods miPSCs were recovered, passaged and cultured with PHBHHx two-dimension films and PHBHHx three-dimension films together.The mor-phology of miPSCs attached on the films was visualized under scanning electron microscope ( SEM) .The mouse induced pluri-potent stem cells were induced by differentiation medium that containing vitamin C .Control group did not add any inducer.The survival and differentiation of miPSCs were observed through immunofluorescence and flow cytometry .Results MiPSCs can grow, proliferate and differentiate on PHBHHx films both two-dimension and three-dimension.Vitamin C, as a favourable in-ducer, can markedly improve the efficiency of miPSCs differentiation of cardiomyocytes on PHBHHx films .Immunofluorescence results demonstrated positive cTnT expression.Flow cytometry measured cTnT expression: Vitamin C inducer group(47.54 ± 1.46)%>without any inducer group(7.02 ±0.95)%(PPHBHHx two-dimensional films(53.31 ±1.41)%>traditional cell culture(47.54 ±1.46)%(P<0.05).Conclusion iPSCs can ad-here, survive and differentiate on the PHBHHx film.Vitamin C, as a favourable inducer, can markedly improve the efficiency of miPSCs differentiation of cardiomyocytes .Relative to PHBHHx two-dimensional film culture and traditional culture , the three-dimensional PHBHHx film culture has a great advantage in the process of miPSCs differentiating into myocardial cells .

Studies on the long non-coding RNA during the reprogramming of human pluripotent stem cells / 天津医药

Objective To investigate the changes and roles of the long non-coding RNA (IncRNA)during the reprogramming of human induced pluripotent stem cells. Methods Agilent Human lncRNA (4 × 180K) chip was used to check the expression of lncRNA in somatic cells, induced pluripotent stem cells and embryonic stem cells. Compared with differentially expressed lncRNA in somatic cells and induced pluripotent stem cells, lncRNA was selected that may play an important role during the reprogramming of human pluripotent stem cells. Results The lncRNA expression profiles in induced pluripotent stem cells were similar to embryonic stem cells, but were different from the somatic cells. A total of 3 156 differentially expressed lncRNAs were found between stem cells and somatic cells by cluster analysis, and 222 differentially expressed lncRNAs were found during the reprogramming process of human pluripotent stem cells by biological analysis. Conclusion lncRNA may play an important role in reprogramming process of human pluripotent stem.

Induced pluripotent stem cells in bone tissue regeneration：how to achieve clinical application in orthopedic surgery as soon as possible? / 中国组织工程研究

BACKGROUND:Biomaterial combined with stem cels is revealing a bright future in bone tissue regeneration in orthopedic surgery. Induced pluripotent stem cels have better cel sources and characteristic, which have become a hotspot of stem cel field. OBJECTIVE:To review the research history, preparation method, cel characteristics of induced pluripotent stem cels and the research developments in orthopeadic surgery so far. METHODS:A computer-based search of CNKI and PubMed was performed for articles about induced pluripotent stem cels and their applications in the field of orthopeadic surgery published from 1999 to 2014. Typical and creative research achievements were enroled in result analysis. RESULTS AND CONCLUSION: Studies have shown that induced pluripotent stem cels have a potential application prospect in bone tissue regeneration, and they also show a satisfying biocompatibility with various scaffold materials, in which, the induced pluripotent stem cels can maintain a good osteogenetic potential. Detection methods and smal-molecule compounds have been discovered gradualy for cartilage regeneration. But how to effectively induce the chondrogenic differentiation of induced pluripotent stem cels and to realize the clinical applications need further research.

Stem cell transplantation for diabetic nephropathy:possibility, feasibility and application / 中国组织工程研究

BACKGROUND:To control blood glucose, blood pressure, blood lipids and inhibit the rennin-angiotensin system is the main idea focused on the treatment of diabetic nephropathy, but the curative effect is unsatisfactory. Hemodialysis and kidney transplantation are suitable for serious cases, however, which is restricted because of the limited source of kidneys and high cost. Regenerative medicine research based on stem cells brings a new hope for treatment of diabetic nephropathy. OBJECTIVE:To comprehensively analyze the mechanism underlying different sources of stem cells for treatment of diabetic nephropathy and the clinical implications. METHODS:Papers addressing stem cells for the treatment of diabetic nephropathy were retrieved by computer in CNKI database and PubMed database from January 2005 to August 2013 with the key words“embryonic stem cells, bone marrow mesenchymal stem cells, induced pluripotent stem cells, diabetic nephropathyin Chinese and English. Papers published recently or in journals with high impact factor were selected. A total of 60 papers were included for review. RESULTS AND CONCLUSION:Embryonic stem cells, bone marrow mesenchymal stem cells, induced pluripotent stem cells have the potential to differentiate into renal histiocytes. A large numbers of experimental studies have shown that stem cells transplantation has a positive effect on recovery of injured kidney. Stem celltransplantation can provide a novel therapy for diabetic nephropathy.

Immunoregulatory effect of multipotent stem cells in liver injury and repair / 临床肝胆病杂志

Immunological imbalance is the foundation for the development of liver damage or fibrosis.Therefore,the treatment of liver disea-ses not only relies on regenerative medicine for cellular replacement,but also depends on immunoregulation.The immunological basis of liver injury and repair,the immunological basis of multipotent stem cells for allograft,and the research advances in the immunoregulatory effect of stem cells in the treatment of liver diseases demonstrated that multipotent stem cells,especially mesenchymal stem cells,have low immuno-genicity and cause immunosuppression,with the immunological basis of allograft;in addition,they can improve the local immune microenvi-ronment of the liver by immunoregulation to reduce the liver injury caused by immune response.It is suggested that multipotent stem cells, which meet the requirements of cellular replacement and immunoregulation in the liver,will become an ideal treatment of liver diseases.

Research for induced pluripotent stem cells in cardiovascular area / 心血管康复医学杂志

Induced pluripotent stem cells (iPSCs)are pluripotent stem cells obtained through transduction of specific transcription factors and reprogramming of human and animal somatic cells,Which are similar to embryonic stem cells.The iPSCs possesses characteristics of unlimited proliferation,self-reneWal and multi-differentiation.This arti-cle mainly summarized current research condition,application value and prospects of iPSCs in cardiovascular area, and its defect in application of current stage.

Proliferative Effect of Aqueous Extracts ofParquetina Nigrescens on HaemopoieticMultipotent Stem Cells in Irradiated Guinea Pigs.

Patients suffer a decrease in haemopoietic stem cells as a consequence of disease, radiation or chemotherapy. Radiotherapy and chemotherapy are common therapeutic modalities for cancer, leukemia, and lymphoma. Unfortunately, these therapies are not tumor-specific. Normal tissues, particularly the bone marrow (BM), are extremely vulnerable to cytotoxicity caused by these therapies. Antidotes are required for the untoward side effects of these therapies. Although a lot of potential better treatments are currently being developed, few research studies have investigated the proliferative effect of plant extracts which may modulate stem cells self-renewal and differentiation. However, in recent years there has been an upsurge of interest on the effects of various dietary insufficiencies on haemopoietic and immune responses (Sanberg et al., 2006). Other investigators have recently reported that dietary fatty acids, particularly oleic acid and linoleic acid, actively promote the proliferation of haemopoietic stem cells (Sanberg et al., 2006) as well as modulate the self-renewal of intestinal epithelial cells. This study was done to determine the potential proliferative effect of Parquetina nigrescens on haemopoietic multipotent stem cells in irradiated guinea pigs bone marrow. The study shows that the plant has positive proliferative effects on haemopoietic multipotent stem cells. The proliferative effect correlates with the concentration of the P. nigrescens.