Selective Modulation of the BMP Signaling Pathway Has Distinct Effects on Long-Term In Vitro Maintenance of Primitive Hematopoietic Progenitors in Human Umbilical Cord Blood.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3162-3162
Author(s):  
Leah E. Colvin-Wanshura ◽  
Matthew S. Nelson ◽  
Elliot J. Stephenson ◽  
Shaukat A. Khan ◽  
Yonghong Xie ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Target Genes ◽  
Bmp Signaling ◽  
Hematopoietic Progenitors ◽  
Short Term ◽  
Term Survival ◽  
Selective Modulation ◽  
In Vitro Maintenance

Abstract Factors responsible for long-term survival and proliferation of human hematopoietic stem cells (hHSC), and their mechanisms of action, remain to be defined. We previously showed that specific O-sulfated heparan sulfate (OS-HS) improves human long-term culture initiating cell (LTC-IC) maintenance for up to 5 wks in vitro. This is related to the ability of OS-HS to bind to and modulate the activity of heparin-binding cytokines on primitive hematopoietic progenitors (PHP). Recent studies indicate that bone morphogenetic proteins (BMPs) influence the development of embryonic hematopoiesis and also augment short-term survival and proliferation of hHSC. Since HS may modulate BMP activity, we examined how combinations of OS-HS, BMPs and specific BMP antagonists influence PHP in umbilical cord blood (UCB). First, we confirmed by real-time quantitative RT-PCR (qRT-PCR) that UCB CD34+ and/or CD34+/CD38− cells (using linear mRNA amplification) constitutively express transcripts for BMP-4 and its inhibitor Chordin, BMP receptors BMPR-IA, BMPR-IB, BMPR-II, AcvR-II and AcvR-IIB, downstream signaling proteins SMAD-1 and -5, and target genes upregulated by BMPs including Inhibitors of DNA binding (Id) proteins 1–4, and determined their relative levels of expression. BMP-4 upregulated Id2 expression 17-fold, confirming that the BMP signaling pathway is functionally active in CD34+ cells. Next, we demonstrated that OS-HS may protect BMP-4 from its inhibitors, using Western immunoblotting of immunoprecipitated proteins to show that direct binding of the antagonist Chordin to BMP-4 is inhibited by OS-HS in a dose-dependent manner. Finally, we examined the effect of exogenous supplementation with 6 BMPs, or inhibition of endogenous BMPs by 7 antagonists, on short-term (2 wk) and long-term (5 wk) LTC-IC maintenance in UCB CD34+/CD38− cells cultured in presence of OS-HS, Flt3-ligand and thrombopoietin. Long-term LTC-IC maintenance was enhanced by BMP-4 (LTC-IC maintenance: 164 +/− 11% compared to culture without BMP-4; P=0.0001) but reduced by BMP-2 or BMP-7 (P<0.005), whereas BMP-3 had no effect. In combination, BMP-3, -4 and -7 offset each other, with no net effect on LTC-IC maintenance. The simultaneous presence of BMPs 2–7 was markedly inhibitory to both short-term (56 +/− 11%; P=0.0018) and long-term (38 +/− 11%; P=0.0024) LTC-IC maintenance. Inhibition of endogenous BMPs by Noggin (which antagonizes BMP-2, -4 and -7 and GDF-5) most effectively enhanced long-term LTC-IC maintenance (320 +/− 36%; P=0.0002). In contrast, other antagonists that inhibit different groups of BMPs did not enhance long-term LTC-IC maintenance. These results indicate that (a) the BMP signaling pathway is expressed and functionally active in human PHP, (b) different members of the BMP family have distinct stimulatory or inhibitory effects on long-term LTC-IC maintenance, (c) endogenously expressed BMPs are extremely important modulators of long-term PHP maintenance, and (d) the ability of OS-HS to augment long-term in vitro PHP maintenance may be related to its effect on endogenous BMP activity. Our data suggest that selective modulation of BMP signaling may be essential for achieving long-term in vitro maintenance of human PHP. Ongoing studies are investigating how OS-HS affects BMP signaling, and the downstream effects of these molecules on target genes that influence stem cell decisions and fate.

HOXA10 Affects the Fate of Hematopoietic Progenitors and Stem Cells in a Concentration Dependent Manner.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3550-3550 ◽  
Author(s):  
Ann C.M. Brun ◽  
Mattias Magnusson ◽  
Noriko Miyake ◽  
Eva Nilsson ◽  
Jon Mar Björnsson3 ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Cells ◽  
Fold Increase ◽  
Dependent Manner ◽  
Hematopoietic Progenitors ◽  
Short Term ◽  
Cells Cultured

Abstract Several studies have demonstrated that homeobox (Hox) genes are involved in the regulation of hematopoietic stem cells (HSC), and overexpression with retroviral vectors containing HOXB4 generate increased numbers of repopulating stem cells in vitro, but may also perturb differentiation of hematopoietic cells when the concentration of HOXB4 is very high. HOXA10 is expressed in primitive hematopoietic cells and myeloid progenitors. To study the effect of this gene we generated an inducible system based on a tetracycline transactivator, controlling the expression of HOXA10, aiming to study how different concentrations of HOXA10 affect the fate of hematopoietic progenitors and stem cells. We mated our tetO-HOXA10 mouse with the Rosa26rtTA strain, allowing activation of HOXA10 in all hematopoietic tissues after administration of doxycycline. Mice were born at normal ratios with no hematopoietic pathology. Inducible bone marrow was harvest and cultured for 12 days in 6 different concentrations of doxycyclin, revealing an increased proliferation at low concentrations, but a decline in proliferation capacity with higher concentrations. To verify that hematopoietic progenitors were affected, a CFU-GM colony assay was performed on cells cultured for 12 days, showing a two fold increase in the number of CFU-GM formed from the highly proliferating cells compared to wt and uninduced HOXA10 cells (p = 0.01). To study the effect of HOXA10 in more primitive cells, sorted inducible HOXA10 lin−, Sca1+, c-kit+ (LSK) cells were cultured for 13 days in different concentrations of doxycyclin. Lower concentrations of doxycyclin resulted in increased proliferation, while increasing concentrations resulted in decreased proliferation. Furthermore, using Q-RT-PCR, we found that the expression of HOXA10 was directly proportional to the concentration of doxycycline and no leakiness was detected in the uninduced LSK cells. The cultured cells were transplanted in a competitive setting into lethally irradiated mice to evaluate the repopulating ability of the expanded cells. Three weeks post BMT (short-term repopulation), intermediate levels of HOXA10 (0.08–0.2 mg/ml doxycyclin) resulted in a three-fold increase in repopulating capacity of the HOXA10 LSK cells whereas uninduced and higher levels of HOXA10 resulted in decreased reconstitution compared with fresh LSK cells (fresh LSK = 100%, intermediate: 313±182%, high: 45±35%, uninduced 35±33%, n=7 p< 0.01). However, sixteen weeks after transplantation we found that cells cultured for 13 days at intermediate levels of HOXA10 (0.08–0.2 mg/ml doxycyclin) preserved the stem cell reconstitution capacity compared to fresh LSK cells (fresh LSK = 100%, 0.2 mg/ml 153±82% n=7). Furthermore, uninduced LSK cells and higher levels of HOXA10 resulted in a 3 fold lower long-term reconstitution compared to Fresh LSK cells (0 mg/ml 34±32 %, high HOXA10 9±8% significant to both fresh cells and cells cultured in 0.2 mg/ml, p<0.003, n=7). These findings show that intermediate expression of HOXA10 can increase the short-term HSCs repopulating potential and can maintain the long-term repopulating stem cells for up to 13 days of in vitro culture. These results suggest that HOXA10 plays an important role in the regulation of HSCs and indicate that the effect of HOXA10 on stem cell fate decisions is dependent on the level of HOXA10 expression.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

Human thymic epithelial cells maintain long-term survival of clonogenic myeloid and erythroid progenitor cells in vitro

2000 ◽  
Vol 111 (1) ◽  
pp. 363-370 ◽  
Author(s):  
Katsuto Takenaka ◽  
Mine Harada ◽  
Tomoaki Fujisaki ◽  
Koji Nagafuji ◽  
Shinichi Mizuno ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Progenitor Cells ◽  
Thymic Epithelial Cells ◽  
Erythroid Progenitor ◽  
Term Survival ◽  
Long Term Survival ◽  
Erythroid Progenitor Cells

Short-term weight loss after hospitalization predicts long-term survival in patients with chronic heart failure

2006 ◽  
Vol 31 (03) ◽  
Author(s):  
M Lainscak ◽  
S von Haehling ◽  
A Sandek ◽  
I Keber ◽  
M Kerbev ◽  
...  
Keyword(s):  
Heart Failure ◽  
Weight Loss ◽  
Chronic Heart Failure ◽  
Short Term ◽  
Term Survival ◽  
Long Term Survival

scholarly journals Parenteral Nutrition and Oxidant Load in Neonates

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2631
Author(s):  
Kandeepan Karthigesu ◽  
Robert F. Bertolo ◽  
Robert J. Brown
Keyword(s):  
Parenteral Nutrition ◽  
Storage Temperature ◽  
Oral Feeding ◽  
Published Data ◽  
Short Term ◽  
Antioxidant Defences ◽  
Term Survival ◽  
Nutrient Sources ◽  
Short Term Survival

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

scholarly journals MODL-16. ABEMACICLIB, A SELECTIVE CDK4/6 INHIBITOR, RESTRICTS GROWTH OF PEDIATRIC GLIAL-LINEAGE TUMORS IN VITRO AND IN VIVO

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii414-iii414
Author(s):  
Muh-Lii Liang ◽  
Tsung-Han Hsieh ◽  
Tai-Tong Wong
Keyword(s):  
Dna Repair ◽  
Therapeutic Strategy ◽  
Target Genes ◽  
Rna Seq ◽  
Downstream Target ◽  
Rb Phosphorylation ◽  
Glial Lineage

Abstract BACKGROUND Glial-lineage tumors constitute a heterogeneous group of neoplasms, comprising gliomas, oligodendrogliomas, and ependymomas, which account for 40%–50% of all pediatric central nervous system tumors. Advances in modern neuro-oncological therapeutics are aimed at improving neoadjuvant chemotherapy and deferring radiotherapy because radiation exposure may cause long-term side effects on the developing brain in young children. Despite aggressive treatment, more than half the high-grade gliomas (pHGGs) and one-third of ependymomas exhibit recurrence within 2 years of initial treatment. METHODS By using integrated bioinformatics and through experimental validation, we found that at least one gene among CCND1, CDK4, and CDK6 was overexpressed in pHGGs and ependymomas. RESULTS The use of abemaciclib, a highly selective CDK4/6 inhibitor, effectively inhibited cell proliferation and reduced the expression of cell cycle–related and DNA repair–related gene expression, which was determined through RNA-seq analysis. The efficiency of abemaciclib was validated in vitro in pHGGs and ependymoma cells and in vivo by using subcutaneously implanted ependymoma cells from patient-derived xenograft (PDX) in mouse models. Abemaciclib demonstrated the suppression of RB phosphorylation, downstream target genes of E2F, G2M checkpoint, and DNA repair, resulting in tumor suppression. CONCLUSION Abemaciclib showed encouraging results in preclinical pediatric glial-lineage tumors models and represented a potential therapeutic strategy for treating challenging tumors in children.

An oncology clinical trial design with randomization adaptive to both short- and long-term responses

2017 ◽  
Vol 28 (7) ◽  
pp. 2015-2031 ◽  
Author(s):  
Hao Liu ◽  
Xiao Lin ◽  
Xuelin Huang
Keyword(s):  
Trial Design ◽  
Clinical Trial Design ◽  
Therapeutic Benefit ◽  
Survival Outcome ◽  
Operating Characteristics ◽  
Short Term ◽  
Term Survival ◽  
Long Term Survival ◽  
Term Response

In oncology clinical trials, both short-term response and long-term survival are important. We propose an urn-based adaptive randomization design to incorporate both of these two outcomes. While short-term response can update the randomization probability quickly to benefit the trial participants, long-term survival outcome can also change the randomization to favor the treatment arm with definitive therapeutic benefit. Using generalized Friedman’s urn, we derive an explicit formula for the limiting distribution of the number of subjects assigned to each arm. With prior or hypothetical knowledge on treatment effects, this formula can be used to guide the selection of parameters for the proposed design to achieve desirable patient number ratios between different treatment arms, and thus optimize the operating characteristics of the trial design. Simulation studies show that the proposed design successfully assign more patients to the treatment arms with either better short-term tumor response or long-term survival outcome or both.

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