Proliferation Of Bone Marrow Cells Research Articles

Immunomodulatory Activity of the Marine Sponge, Haliclona (Soestella) sp. (Haplosclerida: Chalinidae), from Sri Lanka in Wistar Albino Rats: Immunosuppression and Th1-Skewed Cytokine Response.

Natural secondary metabolites of sponges of the genus Haliclona are associated with an array of biological activity with therapeutic usage. We investigated the immunopharmacological properties of a presumably novel marine sponge species from Sri Lanka, Haliclona (Soestella) sp. Sponge material was collected from southern Sri Lanka by scuba diving. Sponge identification was based on spicule and skeleton morphology using light microscopy. Selected in vivo and ex vivo tests investigated nonfunctional and functional immunomodulatory activity of the Haliclona (Soestella) sp. crude extract (HSCE) in the Wistar rat model. Compared to the controls, rats orally gavaged daily for 14 consecutive days with 15 mg/kg dose of the HSCE manifested a significant reduction of immune cell counts of total WBCs (by 17%; p < 0.01), lymphocytes (38%), platelets (52%), splenocytes (20%), and bone marrow cells (BMC; 60%) (p < 0.001), with a concurrent increase in the neutrophil : lymphocyte ratio (p < 0.05); RBC counts abated by 53% (p < 0.001). A significant reduction of the splenosomatic index was evident with the 10 and 15 mg/kg doses (p < 0.001). Rat plasma TNF-α cytokine level was augmented by tenfold (p < 0.001), IL-6 level by twofold (p < 0.01) with the 15 mg/kg HSCE treatment, while IL-10 was detectable in rat plasma only with this treatment; the corresponding Th1 : Th2 cytokine ratio (TNF-α : IL-10) was indicative of an unequivocal Th1-skewed cytokine response (p < 0.01). Ex vivo bone marrow cell and splenocyte proliferation were significantly and dose dependently impaired by HSCE (IC50 0.719 and 0.931 μg/mL, respectively; p < 0.05). Subacute toxicity testing established that HSCE was devoid of general toxic, hepatotoxic, and nephrotoxic effects. In conclusion, HSCE was orally active, nontoxic, and effectively suppressed nonfunctional and functional immunological parameters of Wistar rats, suggestive of the potential use of the HSCE as an immunosuppressant drug lead.

Eflapegrastim's enhancement of efficacy compared with pegfilgrastim in neutropenic rats supports potential for same-day dosing

Eflapegrastim (Rolontis) is a long-acting granulocyte colony-stimulating factor (G-CSF) with an IgG4 Fc fragment and short polyethylene glycol linker. Current G-CSF products are administered 24 hours after chemotherapy. The present study compares the duration of neutropenia (DN) with eflapegrastim or pegfilgrastim at 0, 2, 5, or 24 hours post chemotherapy. Eflapegrastim was evaluated by G-CSF receptor binding and bone marrow cell proliferation assays in vitro. Eflapegrastim-Fc component binding to Fcγ receptors C1q and FcRn was assessed by enzyme-linked immunosorbent assay. Neutropenia was induced in rats via intraperitoneal cyclophosphamide or docetaxel/cyclophosphamide. Rats received chemotherapy followed by vehicle, pegfilgrastim, or eflapegrastim at 2, 5, or 24 hours. The difference in DN after treatment was assessed. In vitro binding to G-CSF receptor of both agents was similar. Binding to FcRn and no binding to Fcγ receptors or C1q were observed with eflapegrastim. Studies in chemotherapy-induced neutropenic rats revealed shorter DN with eflapegrastim versus pegfilgrastim. Increased levels of G-CSF in serum and marrow were observed in groups treated with eflapegrastim versus those treated with pegfilgrastim. Although eflapegrastim and pegfilgrastim have similar in vitro binding affinity, the Fc fragment in eflapegrastim increases the uptake into bone marrow, resulting in increased therapeutic potential for chemotherapy-induced neutropenia. Eflapegrastim's greater marrow resident time provided a pharmacodynamic advantage over pegfilgrastim, translating into shortened duration of neutropenia. Our findings support eflapegrastim same-day administration with chemotherapy, warranting further evaluation in patients undergoing myelosuppressive chemotherapy.

Enhanced Intestinal Immune Response in Mice after Oral Administration of Korea Red Ginseng-Derived Polysaccharide.

(1) Background: The immunostimulatory role of the polysaccharide fraction (KRG-P) of Korea red ginseng (KRG) was studied in cells. However, its immunomodulatory activity is unknown. Therefore, we investigated the chemical properties of KRG-P and its intestinal immune responses in vitro and in vivo. (2) Methods: KRG-P monosaccharide composition and molecular weight were determined using high-performance liquid and size-exclusion chromatography systems. Immunoglobulin A (IgA) and α-defensin-1 transcript levels were measured using a SYBR Green qRT-PCR; defensin-1, Granulocyte-macrophage colony-stimulating factor (GM-CSF), and IgA protein levels were determined using Western blotting and ELISA kits. (3) Results: The molecular weight of KRG-P was estimated to be 106 kDa, and it contained neutral sugar (74.3%), uronic acid (24.6%), and proteins (1%). In vitro studies of intestinal immunomodulatory activity of KRG-P indicated that GM-CSF and IgA levels increased in Peyer’s patch cells to higher levels than those obtained with KRG and induced bone marrow cell proliferation. In in vivo study, oral KRG-P administration to mice upregulated the expression of α-defensin-1 and IgA in the small intestinal tissue and that of secreted IgA in the feces. (4) Conclusions: KRG-P contributed to the modulation of intestinal immunity and maintenance of intestinal homeostasis against intestinal infection.

Reduce proliferation of human bone marrow cells from acute myeloblastic leukemia with minimally differentiation by blocking lncRNA PVT1.

Acute myeloblastic leukemia with minimally differentiation (AML-M0) is a subtype of acute leukemia with poor prognosis. The recent studies have shown that long non-coding RNAs (lncRNAs) play an important role in different cellular processes, such as cell cycle control and proliferation. Plasmacytoma variant translocation 1 (PVT1) is one of those lncRNAs that is significantly upregulated in AML. LncRNAs could be downregulated or blocked by locked nucleic acids (LNA) which are oligonucleotide strands. In this study, lncRNA PVT1 was blocked by antisense LNA GapmeRs in human bone marrow cancerous blast cells. Cells were transfected with PVT1 antisense LNA GapmeRs at 24, 48, and 72h post-transfection. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was accomplished to evaluate the PVT1 and c-Myc expression. Cell viability was evaluated by MTT assay, and apoptosis and necrosis were assessed by Annexin V/propidium iodide staining assay. The results of this study indicated that the downregulation of PVT1 in blast cells could induce apoptosis, and necrosis and reduce cell viability. The expression of c-Myc was downregulated by blockage of PVT1 and it shows that the expression of these two genes are correlated. The findings declare that inhibition of PVT1 could be a new target in the treatment of AML-M0 and help to approach more to treatments with fewer side effects.

Induction of blood-circulating bile acids supports recovery from myelosuppressive chemotherapy

AbstractChemotherapeutic agents can reduce bone marrow (BM) activity, causing myelosuppression, a common life-threatening complication of cancer treatment. It is challenging to predict the patients in whom prolonged myelosuppression will occur, resulting in a delay or discontinuation of the treatment protocol. An early indicator of recovery from myelosuppression would thus be highly beneficial in clinical settings. In this study, bile acids (BAs) were highly increased in the systemic circulation as a natural response during recovery from myelosuppression, supporting regeneration of BM cells. BA levels in the blood of pediatric cancer patients and mice treated with chemotherapeutic agents were increased, in synchrony with early proliferation of BM cells and recovery from myelosuppression. In a mouse model of altered BA composition, Cyp8b1 knockout mice, a subset of mice recovered poorly after chemotherapy. The poor recovery correlated with low levels and changes in composition of BAs in the liver and systemic circulation. Conversely, BA supplementation in chemotherapy-treated wild-type mice resulted in significantly improved recovery. The results suggest that part of the mechanism by which BAs support recovery is the suppression of endoplasmic reticulum stress pathways in expanding and recovering hematopoietic cells. The findings propose a novel role of BAs as early markers of recovery and active components of the recovery process after chemotherapy.

Hepatosplenic T Cell Lymphoma: A Rare Disease

Hepatosplenic T cell lymphoma (HSTCL) is an uncommon neoplasm comprising 5% of peripheral T-cell lymphomas. We report an uncommon case of Peripheral T-cell lymphoma that is characterized by primary extranodal disease with malignant T cell proliferation in spleen, liver and bone marrow. 19 year old male patient presented with fever, weakness and pain abdomen for 2 months. On clinical examination he was pale and had massive hepatosplenomegaly. The diagnosis was quite challenging as thorough clinical, hematological and immunophenotypic correlation was required.

Structural, luminescence and geno/cytoxicity study of carbon dots derived fromOpuntia ficus-indica(L.) Mill

Carbon dots derived from nopal significantly increase the number of micronuclei in mouse erythrocytes and inhibit mouse bone marrow cell proliferation.

Synergistic and toxicity-attenuating effects of Periplaneta americana extract CII-3 combined with cisplatin on lewis lung cancer-bearing mice

Objective: The objective was to study the synergistic and attenuating effects of CII-3 combined with cisplatin. Materials and Methods: A Lewis tumor-bearing mouse model was established. After 15 days of continuous administration of CII-3 and cisplatin, the pathological changes in the tumor, liver, lung, and femur tissues were observed; the life prolongation rate, tumor inhibition rate, Q value, organ indices, spleen T- and B-lymphocyte proliferation activities, NK cell killing activity, the bone marrow cell proliferation rate and cell cycle phase, and the number of peripheral blood cells and bone marrow nucleated cells were measured. The expression of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in mouse serum and bone marrow tissue was measured. Results: The combination of CII-3 and cisplatin could enhance the ability of cisplatin to inhibit tumor cell proliferation and protects the liver damage and femoral injury and could significantly increase the life prolongation rate; tumor inhibition rate of cisplatin; the liver, spleen, lung, and thymus indices; the T- and B-lymphocyte proliferation activity; the NK cell killing activity; and the number of peripheral blood cells and bone marrow nucleated cells. The combination of drugs can stimulate the transformation of bone marrow cells from S phase to G2/M phase, significantly increase the proliferation rate of bone marrow cells and the contents of G-CSF and GM-CSF in mouse serum, and downregulate the mRNA and protein levels of them in bone marrow tissue. Conclusion: These results suggest that CII-3 combined with cisplatin can significantly enhance the antitumor effect and reduce the toxicity and side effects of cisplatin in Lewis tumor-bearing mice.

The Coumarin Derivative 5'-Hydroxy Auraptene Suppresses Osteoclast Differentiation via Inhibiting MAPK and c-Fos/NFATc1 Pathways.

The phytochemical substances, coumarin derivatives, have demonstrated antiresorptive bone effects by suppressing osteoclast differentiation in vitro and in vivo. Recently, we have identified 5′-hydroxy auraptene (5′-HA), a coumarin derivative isolated from Lotus lalambensis Schweinf, as a novel stimulator for osteoblast differentiation. In this study, we investigated the effect of 5′-HA on osteoclast differentiation of mouse bone marrow (BM) cells. The effect of 5′-HA on BM cell proliferation and osteoclast differentiation was determined by measuring cell viability and tartrate-resistant acid phosphatase (TRAP) enzyme activity, quantification of TRAP+ multinucleated cells (TRAP+MNCs), and quantitative real-time PCR (qPCR) of osteoclastic gene expression. Regulation of NF-κB, c-Fos/NFATc1, and MAPK signaling pathways by 5′-HA during osteoclastogenesis was measured by the NF-κB reporter assay and Western blot analysis. 5′-HA significantly suppresses the receptor activator of NF-κB ligand (RANKL) induced osteoclast differentiation of BM cells in a dose-dependent manner. Consistently, treatment of BM cells with 5′-HA significantly inhibited RANKL-induced activation of NF-κB and c-Fos/NFATc1 pathways in a dose-dependent manner. Furthermore, RANKL-induced phosphorylation of ERK1/2, p-38, and JNK was significantly inhibited by 5′-HA in BM cells. In conclusion, we identified 5′-HA as a novel coumarin derivative that suppresses RANKL-induced osteoclastogenesis via inhibiting c-Fos/NFATc1 and MAPK signaling pathways.

First Insights into the Effect of Low-Dose X-Ray Irradiation in Adipose-Derived Stem Cells.

(1) Background: Emerging interest of physicians to use adipose-derived stem cells (ADSCs) for regenerative therapies and the fact that low-dose irradiation (LD-IR ≤ 0.1 Gy) has been reported to enhance the proliferation of several human normal and bone-marrow stem cells, but not that of tumor cells, lead to the idea of improving stem cell therapies via low-dose radiation. Therefore, the aim of this study was to investigate unwanted side effects, as well as proliferation-stimulating mechanisms of LD-IR on ADSCs. (2) Methods: To avoid donor specific effects, ADSCs isolated from mamma reductions of 10 donors were pooled and used for the radiobiological analysis. The clonogenic survival assay was used to classify the long-term effects of low-dose radiation in ADSCs. Afterwards, cytotoxicity and genotoxicity, as well as the effect of irradiation on proliferation of ADSCs were investigated. (3) Results: LD (≤ 0.1 Gy) of ionizing radiation promoted the proliferation and survival of ADSCs. Within this dose range neither geno- nor cytotoxic effects were detectable. In contrast, greater doses within the dose range of >0.1–2.0 Gy induced residual double-strand breaks and reduced the long-term survival, as well as the proliferation rate of ADSCs. (4) Conclusions: Our data suggest that ADSCs are resistant to LD-IR. Furthermore, LD-IR could be a possible mediator to improve approaches of stem cells in the field of regenerative medicine.

Neutrophils keep the peace

Asthma Allergic airway inflammation is a complex disease, and multiple immune and nonimmune factors contribute to its development and progression. Using a house dust mite–induced mouse model of allergic inflammation, Patel et al. found that depletion of neutrophils worsens airway inflammation and enhances myelopoiesis—the proliferation of bone marrow cells—driven by granulocyte colony-stimulating factor (G-CSF). Experiments demonstrate a previously unsuspected link between this hormone and type 2 innate lymphoid cells (ILC2s). G-CSF acts directly on both human and mouse ILC2s to promote production of the cytokines interleukin-5 and -13. Sci. Immunol. 4 , eaax7006 (2019).

A case of acute monocytic leukemia complicated with multiple myeloma

A case of acute monocytic leukemia complicated with multiple myeloma

Abstract 4144: Water extract from Chlorella vulgaris cell membrane fraction enhances host antitumor immune responses and inhibit colon carcinoma growth in mice

Abstract Natural products obtained from various resources are often used as new compounds or seed compounds of effective drugs for disease including cancer. The water extract partially purified from the cell membrane fraction of Chlorella vulgaris (CMWE) was evaluated on its antitumor and immunomodulatory effects in cell culture and a colon carcinoma mouse model. The CMWE was filtered through 0.22 μm pore size membrane for all experiments. In two-dimensional cell cultures, the CMWE treatment inhibited cell growth of both murine and human colon carcinoma cells in a dose- and time-dependent manner. In contrast, the cell proliferation of mouse splenocytes (SPLs) and bone marrow cells (BMCs) were stimulated by the treatment with CMWE. The treatment with CMWE also increased specific subpopulations of the cells in BMCs: antigen presenting cells (CD19+ B cells, 33D1+ dendritic cells and CD68+ macrophage), CD4+ and CD8+ T cells, whereas LY-6G+neutrophils were decreased. In a three-dimensional spheroid culture, spheroid growth of CT26 cells co-cultured with Jurkat cells (human T lymphoblasts) was significantly attenuated by CMWE treatment via induction of apoptosis. In a two-dimensional cell culture of Jurkat cells, mRNA levels of TNFα, IFNγ and granzyme B were significantly increased by CMWE treatment. In a mouse CT26 colon carcinoma peritoneal dissemination model, intraperitoneal injection of CMWE (30 mg/kg/day, started from 3 days after CT26 inoculation for 9 days, every other day) significantly attenuated the growth of CT26 colon carcinoma nodules in syngeneic mice by CMWE treatment-associated apoptosis without any noticeable adverse effect. Analysis of subpopulation of intraperitoneally infiltrating immune cells collected from CT26 cell tumor-bearing mice, indicated that CMWE treatment increased CD4+ and CD8+ T lymphocytes, CD19+ B cell, and CD68+ macrophage populations. In contrast, LY6G+neutrophil population was decreased as compared to PBS-treated group. The present study suggests that CMWE inhibits colon carcinoma growth via direct cell growth inhibition and a stimulation of the host antitumor immune responses. Taken together, the current study suggests that water extract obtained from the cell membrane fraction of Chlorella vulgaris contain significant bioactive materials that inhibit colon carcinoma growth. This study was supported by 2016EUGLENA-RC1 (MT), 2017EUGLENA-RC2 (MT), Kansas State University Johnson Cancer Research Center 2018CRA (NR and MT), and NIH grant P20 RR017686 (MT). Citation Format: Susumu Ishiguro, Nicole Robben, Deepa Upreti, Paige Cote, Sarah Greenway, Riley Burghart, Ayaka Nakashima, Masaaki Tamura. Water extract from Chlorella vulgaris cell membrane fraction enhances host antitumor immune responses and inhibit colon carcinoma growth in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4144.

Thermoresponsive Stiffness Softening of Hierarchically Porous Nanohybrid Membranes Promotes Niches for Mesenchymal Stem Cell Differentiation.

Despite the attention given to the development of novel responsive implants for regenerative medicine applications, the lack of integration with the surrounding tissues and the mismatch with the dynamic mechanobiological nature of native soft tissues remain in the current products. Hierarchical porous membranes based on a poly (urea-urethane) (PUU) nanohybrid have been fabricated by thermally induced phase separation (TIPS) of the polymer solution at different temperatures. Thermoresponsive stiffness softening of the membranes through phase transition from the semicrystalline phase to rubber phase and reverse self-assembly of the quasi-random nanophase structure is characterized at body temperature near the melting point of the crystalline domains of soft segments. The effects of the porous structure and stiffness softening on proliferation and differentiation of human bone-marrow mesenchymal stem cells (hBM-MSCs) are investigated. The results of immunohistochemistry, histological, ELISA, and qPCR demonstrate that hBM-MSCs maintain their lineage commitment during stiffness relaxation; chondrogenic differentiation is favored on the soft and porous scaffold, while osteogenic differentiation is more prominent on the initial stiff one. Stiffness relaxation stimulates more osteogenic activity than chondrogenesis, the latter being more influenced by the synergetic coupling effect of softness and porosity.

Pacritinib: A novel therapeutic agent for treating myelofibrosis

Selective inhibitors are an important advancement in clinical medicine, providing a method to target proteins within signal transductionpathways. One such inhibitor, pacritinib, targets Janus Kinase 2 (JAK2) to treat patients with myelofibrosis (MF). In MF patients diagnosedwith a specific point mutation (JAK2V61F), the JAK/STAT pathway is over-activated, leading to an increase in cell proliferation rates.Pacritinib restores normal JAK/STAT activity by targeting aberrant activity of JAK2V61F mutant proteins and inhibiting cell proliferation inbone marrow tissue. In recent studies, pacritinib has shown better results at treating MF than the best available therapy. Though pacritinibis a potentially effective treatment option, it does not address all aspects of MF and should be supplemented with other treatments.

Silk fibroin/poly(L-lactic acid-co-ε-caprolactone) electrospun nanofibrous scaffolds exert a protective effect following myocardial infarction.

Electrospinning using biocompatible polymer scaffolds, seeded with or without stem cells, is considered a promising technique for producing fibrous scaffolds with therapeutic possibilities for ischemic heart disease. However, no optimal scaffolds for treating ischemic heart disease have been identified thus far. In the present study, it was evaluated whether electrospun silk fibroin (SF)-blended poly(L-lactic acid-co-ε-caprolactone) [P(LLA-CL)] scaffolds that were seeded with cluster of differentiation 117 (c-kit)+ bone marrow (BM) cells may serve a protective role in cardiac remodeling following myocardial infarction (MI). Mechanical characteristics and cytocompatibility were compared between SF/P(LLA-CL) and P(LLA-CL) electrospun nanofibrous scaffolds in vitro. It was observed that MI led to a significant increase of the c-kit+ BM cell subpopulation in mice. Magnetic activated cell sorting was performed to harvest the c-kit+ cell population from the BM of mice following MI. c-kit+ BM cells were seeded on SF/P(LLA-CL) and P(LLA-CL) electrospun nanofibrous scaffolds. Results indicated that SF/P(LLA-CL) electrospun nanofibrous scaffolds were superior to P(LLA-CL) electrospun nanofibrous scaffolds in improving c-kit+ BM cell proliferation. Additionally, compared with pure SF/P(LLA-CL) electrospun nanofibrous scaffolds, SF/P(LLA-CL) scaffolds seeded with c-kit+ BM cells resulted in lower levels of MI markers and reduced infarct size, leading to greater global heart function improvement in vivo. The findings of the present study indicated that SF/P(LLA-CL) electrospun nanofibrous scaffolds seeded with c-kit+ BM cells exert a protective effect against MI and may be a promising approach for cardiac regeneration after ischemic heart disease.

Production of transgenic cattle by somatic cell nuclear transfer (SCNT) with the human granulocyte colony-stimulation factor (hG-CSF).

The hG-CSF (human Granulocyte Colony-Stimulating Factor) is a growth and stimulation factor capable of inducing the proliferation of bone marrow cells, several types of leukocytes, among other hematopoietic tissue cells. hG-CSF is used in used to treat anomalies that reder a small number of circulating white blood cells, which may compromise the immune defenses of the affected person. For these reasons, the production of hG-CSF in a bioreactor system using the mammary gland of genetic modified animals is a possibility of adding value to the bovine genetic material and reducing the costs of hG-CSF production in pharmaceutical industry. In this study, we aimed the production of transgenic hG-CSF bovine through the lipofection of bovine primary fibroblasts with an hG-CSF expression cassette and cloning these fibroblasts by the somatic cell nuclear transfer (SCNT) technique. The bovine fibroblasts transfected with the hG-CSF cassette presented a stable insertion of this construct into their genome and were efficiently synchronized to G0/G1 cell cycle stage. The transgenic fibroblasts were cloned by SCNT and produced 103 transferred embryos and 2 pregnancies, one of which reached 7 months of gestation.

Cellular Composition and Expression of Cell Proliferation and Apoptosis Markers in Bone Marrow Cells after Heterotransplantation.

The effects of heterotransplantation on bone marrow structures were studied in experimental male mice. Suspension of the bone marrow from feline femur (1 ml bone marrow diluted in isotonic saline, 1:2) was injected into the caudal vein. Heterotransplantation led to an increase in the level of serotonin involved in cell differentiation. In 2 days, the counts of all cells except erythroid cells decreased. Immunohistochemical analysis of Ki-67 marker within 40 min after transplantation showed a significant increase of cell proliferative activity in comparison with that in intact mice. At later terms, the expression of Ki-67 in bone marrow cells decreased, while the expression of apoptosis regulator P-53 increased, which was associated with the presence of numerous dead cells.

The Effect of Dissociated Soft Tissue on Osteogenesis: A Preliminary In Vitro Study.

The purpose of this in vitro study was to examine the effect of dissociated soft tissue on bone marrow cell proliferation and differentiation under osteogenic conditions. Rat bone marrow cells were cultured to assess the stimulation of cell proliferation and differentiation. Harvested palatal mucosa was dissociated using a device (Rigenera; Human Brain Wave) and the dissociated soft tissue was cultured with rat bone marrow cells. Cell proliferation, differentiation, and mineralized nodule formation were assessed after 2 or 5 days of culturing. Bone marrow cell proliferation was assessed by quantifying the absorbance of a water-soluble tetrazolium salt using a cell proliferation assay kit. Bone marrow cell differentiation was assessed by alkaline phosphatase staining and real-time polymerase chain reaction. Mineralized nodule formation was assessed by Alizarin red staining. At day 2, cell proliferation, osteoblast specific gene expression, and mineralized nodule formation were significantly higher in the experimental group than in the control group. Alkaline phosphatase staining was also higher in the experimental group on day 2. Mineralized nodule formation area and osteoblast specific gene expression were also statistically higher in the experimental group on day 5. This study demonstrates that dissociated soft tissue elevates bone marrow cell proliferation and differentiation under osteogenic conditions.

Replicative senescence of hematopoietic cells in patients with idiopathic cytopenia of undetermined significance

We hypothesized that a subset of idiopathic cytopenia of undetermined significance (ICUS) is associated with an increased autonomous proliferation with exhaustion of hematopoiesis. The aim of this study was to investigate the cell turnover rate and replicative history of the bone marrow cells of ICUS patients. To this end, we examined telomere length (TL), proliferation, and apoptosis of the bone marrow cells of ICUS patients and healthy controls (HCs) using telomere quantitative fluorescence in situ hybridization and immunohistochemical staining for Ki-67 and cleaved caspase-3. We also performed targeted sequencing of 88 myeloid-associated genes. A total of 37 patients with ICUS were enrolled in this study, with a median age of 66 years (range: 31–83). TLs were significantly shorter in patients with ICUS than in the HCs (8.8, interquartile range [IQR] 6.8–12.1 vs 18.4, IQR 14.4–22.0, p < 0.0001). Proliferation (Ki-67-positive) and apoptosis (cleaved caspase-3-positive) were significantly increased in patients with ICUS compared to HCs (median = 20.0% vs 5.0%, p = 0.0003; 45.0% vs 22.5%, p = 0.0005, respectively). The shortening of TL and the increased proliferation and apoptotic activity was also prominent in patients with ICUS without mutation and dysplasia than in HCs (p < 0.0001, p < 0.0001, and p = 0.0093, respectively). TL was not associated with mutational profile and clinical characteristics as well in patients with ICUS. To our knowledge, this is the first study to show that ICUS is associated with premature replicative senescence with increased proliferation and apoptosis of bone marrow cells. Further study is needed to address the cause of replicative exhaustion in ICUS patients.