A mechanosensitive peri-arteriolar niche for osteogenesis and lymphopoiesis.

Stromal cells in adult bone marrow that express leptin receptor (LEPR) are a critical source of growth factors, including stem cell factor (SCF), for the maintenance of haematopoietic stem cells and early restricted progenitors1-6. LEPR+ cells are heterogeneous, including skeletal stem cells and osteogenic and adipogenic progenitors7-12, although few markers have been available to distinguish these subsets or to compare their functions. Here we show that expression of an osteogenic growth factor, osteolectin13,14, distinguishes peri-arteriolar LEPR+ cells poised to undergo osteogenesis from peri-sinusoidal LEPR+ cells poised to undergo adipogenesis (but retaining osteogenic potential). Peri-arteriolar LEPR+osteolectin+ cells are rapidly dividing, short-lived osteogenic progenitors that increase in number after fracture and are depleted during ageing. Deletion of Scf from adult osteolectin+ cells did not affect the maintenance of haematopoietic stem cells or most restricted progenitors but depleted common lymphoid progenitors, impairing lymphopoiesis, bacterial clearance, and survival after acute bacterial infection. Peri-arteriolar osteolectin+ cell maintenance required mechanical stimulation. Voluntary running increased, whereas hindlimb unloading decreased, the frequencies of peri-arteriolar osteolectin+ cells and common lymphoid progenitors. Deletion of the mechanosensitive ion channel PIEZO1 from osteolectin+ cells depleted osteolectin+ cells and common lymphoid progenitors. These results show that a peri-arteriolar niche for osteogenesis and lymphopoiesis in bone marrow is maintained by mechanical stimulation and depleted during ageing.

The effect of parathyroid hormone on osteogenesis is mediated partly by osteolectin.

We previously described a new osteogenic growth factor, osteolectin/Clec11a, which is required for the maintenance of skeletal bone mass during adulthood. Osteolectin binds to Integrin α11 (Itga11), promoting Wnt pathway activation and osteogenic differentiation by leptin receptor+ (LepR+) stromal cells in the bone marrow. Parathyroid hormone (PTH) and sclerostin inhibitor (SOSTi) are bone anabolic agents that are administered to patients with osteoporosis. Here we tested whether osteolectin mediates the effects of PTH or SOSTi on bone formation. We discovered that PTH promoted Osteolectin expression by bone marrow stromal cells within hours of administration and that PTH treatment increased serum osteolectin levels in mice and humans. Osteolectin deficiency in mice attenuated Wnt pathway activation by PTH in bone marrow stromal cells and reduced the osteogenic response to PTH in vitro and in vivo. In contrast, SOSTi did not affect serum osteolectin levels and osteolectin was not required for SOSTi-induced bone formation. Combined administration of osteolectin and PTH, but not osteolectin and SOSTi, additively increased bone volume. PTH thus promotes osteolectin expression and osteolectin mediates part of the effect of PTH on bone formation.

Noncanonical NF-κB pathway controls the production of type I interferons in antiviral innate immunity.

Production of type I interferons (IFN-I) is a crucial innate immune mechanism against viral infections. IFN-I induction is subject to negative regulation by both viral and cellular factors, but the underlying mechanism remains unclear. We report that the noncanonical NF-κB pathway was stimulated along with innate immune cell differentiation and viral infections and had a vital role in negatively regulating IFN-I induction. Genetic deficiencies in major components of the noncanonical NF-κB pathway caused IFN-I hyperinduction and rendered cells and mice substantially more resistant to viral infection. Noncanonical NF-κB suppressed signal-induced histone modifications at the Ifnb promoter, an action that involved attenuated recruitment of the transcription factor RelA and a histone demethylase, JMJD2A. These findings reveal an unexpected function of the noncanonical NF-κB pathway and highlight an important mechanism regulating antiviral innate immunity.

Targeted genetic screening in mice through haploid embryonic stem cells identifies critical genes in bone development.

Mutagenic screening is powerful for identifying key genes involved in developmental processes. However, such screens are successful only in lower organisms. Here, we develop a targeted genetic screening approach in mice through combining androgenetic haploid embryonic stem cells (AG-haESCs) and clustered regularly interspaced palindromic repeats/CRISPR-associated protein 9 (CRISPR-Cas9) technology. We produced a mutant semi-cloned (SC) mice pool by oocyte injection of AG-haESCs carrying constitutively expressed Cas9 and an single guide RNA (sgRNA) library targeting 72 preselected genes in one step and screened for bone-development-related genes through skeletal analysis at birth. This yielded 4 genes: Zic1 and Clec11a, which are required for bone development, and Rln1 and Irx5, which had not been previously considered. Whereas Rln1-/- mice exhibited small skeletal size only at birth, Irx5-/- mice showed skeletal abnormalities both in postnatal and adult phases due to decreased bone mass and increased bone marrow adipogenesis. Mechanistically, iroquois homeobox 5 (IRX5) promotes osteoblastogenesis and inhibits adipogenesis by suppressing peroxisome proliferator activated receptor γ (PPARγ) activation. Thus, AG-haESC-mediated functional mutagenic screening opens new avenues for genetic interrogation of developmental processes in mice.

NCCN Guidelines® Insights: Hematopoietic Growth Factors, Version 1.2022.

The NCCN Guidelines for Hematopoietic Growth Factors provide recommendations for the appropriate use of growth factors in the clinical management of febrile neutropenia (FN), chemotherapy-induced thrombocytopenia (CIT), and chemotherapy-induced anemia (CIA). Management and prevention of these sequelae are an integral part of supportive care for many patients undergoing cancer treatment. The purpose of these guidelines is to operationalize the evaluation, prevention, and treatment of FN, CIT, and CIA in adult patients with nonmyeloid malignancies and to enable the patient and clinician to assess management options for FN, CIT, and CIA in the context of an individual patient's condition. These NCCN Guidelines Insights provide a summary of the important recent updates to the NCCN Guidelines for Hematopoietic Growth Factors, with particular emphasis on the incorporation of a newly developed section on CIT.

Stem cell-secreted factor therapy regenerates the ovarian niche and rescues follicles.

BACKGROUND: Ovarian senescence is a normal age-associated phenomenon, but increasingly younger women are affected by diminished ovarian reserves or premature ovarian insufficiency. There is an urgent need for developing therapies to improve ovarian function in these patients. In this context, previous studies suggest that stem cell-secreted factors could have regenerative properties in the ovaries. OBJECTIVE: This study aimed to test the ability of various human plasma sources, enriched in stem cell-secreted factors, and the mechanisms behind their regenerative properties, to repair ovarian damage and to promote follicular development. STUDY DESIGN: In the first phase, the effects of human plasma enriched in bone marrow stem cell soluble factors by granulocyte colony-stimulating factor mobilization, umbilical cord blood plasma, and their activated forms on ovarian niche, follicle development, and breeding performance were assessed in mouse models of chemotherapy-induced ovarian damage (n=7 per group). In addition, the proteomic profile of each plasma was analyzed to find putative proteins and mechanism involved in their regenerative properties in ovarian tissue. In the second phase, the most effective plasma treatment was validated in human ovarian cortex xenografted in immunodeficient mice (n=4 per group). RESULTS: Infusion of human plasma enriched bone marrow stem cell soluble factors by granulocyte colony-stimulating factor mobilization or of umbilical cord blood plasma-induced varying degrees of microvessel formation and cell proliferation and reduced apoptosis in ovarian tissue to rescue follicular development and fertility in mouse models of ovarian damage. Plasma activation enhanced these effects. Activated granulocyte colony-stimulating factor plasma was the most potent inducing ovarian rescue in both mice and human ovaries, and proteomic analysis indicated that its effects may be mediated by soluble factors related to cell cycle and apoptosis, gene expression, signal transduction, cell communication, response to stress, and DNA repair of double-strand breaks, the most common form of age-induced damage in oocytes. CONCLUSION: Our findings suggested that stem cell-secreted factors present in both granulocyte colony-stimulating factor-mobilized and umbilical cord blood plasma could be an effective treatment for increasing the reproductive outcomes in women with impaired ovarian function owing to several causes. The activated granulocyte colony-stimulating factor plasma, which is already enriched in both stem cell-secreted factors and platelet-enclosed growth factors, seems to be the most promising treatment because of its most potent restorative effects on the ovary together with the autologous source.

Molecular structure, expression, and functional role of Clec11a in skeletal biology and cancers.

C-type lectin domain family 11 member A (Clec11a), also known as stem cell growth factor (SCGF), C-type lectin superfamily member 3 (CLECSF3), or osteolectin was initially identified as a growth factor for hematopoietic progenitor cells. The human Clec11a gene encodes a polypeptide of 323 amino acids with characteristics of a secreted glycoprotein encompassing two integrin-binding motifs, RGD (Arg-Gly-Asp) and LDT (Leu-Asp-Thr), a putative leucine zipper domain, and a functional C-type lectin domain. It regulates hematopoietic differentiation and homeostasis and exhibits a protective effect against severe malarial anemia and lipotoxicity. Furthermore, Clec11a promotes the differentiation of mesenchymal progenitors into mature osteoblasts in vitro and plays an important role in the maintenance of adult skeleton age-related bone loss and fracture repair. Receptor ligand binding results in activation of downstream signaling cascades including glycogen synthase kinase 3 (GSK3), ß-catenin, and Wnt, resulting in the expression of osteoblast-related gene transcripts including Alp, Runx2, Lef1, and Axin2. In addition, Clec11a is also associated with the development of several cancers, including leukemia, multiple myeloma, and gastrointestinal tract tumors. To date, however, the mechanisms governing transcription regulation of the Clec11a gene are not known and remain to be uncovered. Understanding the function and mechanism of action of Clec11a will pave the way for the development of Clec11a as a novel therapeutic target for conditions such as cancer, anemia, and skeletal diseases.

NCCN Guidelines Insights: Hematopoietic Growth Factors, Version 1.2020.

Management of febrile neutropenia (FN) is an integral part of supportive care for patients undergoing cancer treatment. The NCCN Guidelines for Hematopoietic Growth Factors provide suggestions for appropriate evaluation, risk determination, prophylaxis, and management of FN. These NCCN Guidelines are intended to guide clinicians in the appropriate use of growth factors for select patients undergoing treatment of nonmyeloid malignancies. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines regarding the incorporation of newly FDA-approved granulocyte-colony stimulating factor biosimilars for the prevention and treatment of FN.

Protective effects of Clec11a in islets against lipotoxicity via modulation of proliferation and lipid metabolism in mice.

The lipotoxicity is considered as one of the risk for diabetes. Here we report C-type lectin domain family 11, member A (Clec11a) as a new regulator in islet playing a protective role in lipotoxicity induced dysfunction. Islet transcriptome sequencing was performed using the high-fat diet induced obesity (DIO) mice model. We found a significant decrease of Clec11a expression in islets of DIO mice compared to normal control mice, which was further confirmed by real-time PCR. Immunostaining demonstrated the localization of the Clec11a protein in mouse islets. Administration of recombinant human Clec11a (rClec11a) protein promoted the proliferation of islet cells and rescued the inhibition of fatty acid on cell proliferation, which involved the activation of Erk signaling pathway. We also found that the rClec11a altered the expression of genes involved in lipid metabolism.

Medicinal Uses of Hematopoietic Growth Factors in Neonatal Medicine.

This review focuses on certain hematopoietic growth factors that are used as medications in clinical neonatology. It is important to note at the chapter onset that although all of the pharmacological agents mentioned in this review have been approved by the US Food and Drug administration for use in humans, none have been granted a specific FDA indication for neonates. Thus, in a sense, all of the agents mentioned in this chapter could be considered experimental, when used in neonates. However, a great many of the pharmacological agents utilized routinely in neonatology practice do not have a specific FDA indication for this population of patients. Consequently, many of the agents reviewed in this chapter are considered by some practitioners to be nonexperimental and are used when they judge such use to be "best practice" for the disorders under treatment.The medicinal uses of the agents in this chapter vary considerably, between geographic locations, and sometimes even within an institutions. "Consistent approaches" aimed at using these agents in uniform ways in the practice of neonatology are encouraged. Indeed some healthcare systems, and some individual NICUs, have developed written guidelines for using these agents within the practice group. Some such guidelines are provided in this review. It should be noted that these guidelines, or "consistent approaches," must be viewed as dynamic and changing, requiring adjustment and refinement as additional evidence accrues.

Medication overuse in oncology: current trends and future implications for patients and society.

The high cost of cancer care worldwide is largely attributable to rising drugs prices. Despite their high costs and potential toxic effects, anticancer treatments could be subject to overuse, which is defined as the provision of medical services that are more likely to harm than to benefit a patient. We found 30 studies documenting medication overuse in cancer, which included 16 examples of supportive medication overuse and 17 examples of antineoplastic medication overuse in oncology. Few specific agents have been assessed, and no studies investigated overuse of the most toxic or expensive medications currently used in cancer treatment. Although financial, psychological, or physical harms of medication overuse in cancer could be substantial, there is little published evidence addressing these harms, so their magnitude is unclear. Further research is needed to better quantify medication overuse, understand its implications, and help protect patients and the health-care system from overuse.

Cerebrospinal Fluid Cytokine Expression Profile in Multiple Sclerosis and Chronic Inflammatory Demyelinating Polyneuropathy.

BACKGROUND: Cerebrospinal fluid (CSF) analysis in patients with particular neurologic disorders is a powerful tool to evaluate specific central nervous system inflammatory markers for diagnostic needs, because CSF represents the specific immune micro-environment to the central nervous system. METHODS: CSF samples from 49 patients with multiple sclerosis (MS), chronic inflammatory demyelinating polyneuropathy (CIDP), and non-inflammatory neurologic disorders (NIND) as controls were submitted to protein expression profiles of 47 inflammatory biomarkers by multiplex Luminex bead assay to investigate possible differences in the inflammatory process for MS and CIDP. RESULTS: Our results showed differences in CSF cytokine levels in MS and CIDP; in particular, IL12 (p40) was significantly highly expressed in MS in comparison with CIDP and NIND, while SDF-1α and SCGF-ß were significantly highly expressed in CIDP cohort when compared to MS and NIND. IL-9, IL-13, and IL-17 had higher expression levels in NIND if compared with the other groups. CONCLUSIONS: Our study showed that, despite some common pathogenic mechanisms, central and peripheral nervous system demyelinating diseases, such as MS and CIDP, differ in some specific inflammatory soluble proteins in CSF, underlining differences in the immune response involved in those autoimmune diseases.

Hematopoietic growth factors in lung cancer.

PURPOSE OF REVIEW: Most patients affected by lung cancer are treated with chemotherapy, and hence are at risk of myelosuppression. Hematopoietic growth factors have a relevant role in this setting, as they can improve quality of life, reduce the rate of chemotherapy-induced complications and allow the administration of full-dose chemotherapy. RECENT FINDINGS: Most data of hematologic growth factors in lung cancer come from dated publications or large trials involving different malignancies, thus limiting specific information for lung neoplasms. Nonetheless, most studies consistently identified myeloid growth factors as effective on specific end-points such as the duration and severity of neutropenia, or complications such as hospitalizations and febrile neutropenia; on the other hand, erythropoiesis-stimulating agents (ESAs) consistently improved anemia-specific end-points including hemoglobin values, transfusions rate and fatigue, although some specific safety issues characterized this drug class. The most recent international guidelines address these characteristics and include the main indications for hematologic growth factors in solid neoplasms, including lung cancer. SUMMARY: Myeloid growth factors and ESAs have a relevant role in selected patients undergoing chemotherapy for nonsmall cell lung cancer and small cell lung cancer. Notably, a comprehensive risk-benefit assessment is required in the specific case of ESAs.

Core-binding factor acute myeloid leukemia in first relapse: a retrospective study from the French AML Intergroup.

Although core-binding factor-acute myeloid leukemia (CBF-AML) (t[8;21] or inv[16]/t[16;16]) represents a favorable cytogenetic AML subgroup, 30% to 40% of these patients relapse after standard intensive chemotherapy. The encouraging results of gemtuzumab ozogamicin (GO) in newly diagnosed AML, and particularly in CBF-AML, incited us to retrospectively investigate the impact of GO-based salvage in these patients. We retrospectively analyzed the outcome of 145 patients with CBF-AML (59 t[8;21], 86 inv[16]/t[16;16]) in first relapse. As salvage, 48 patients received GO-based chemotherapy and 97 patients received conventional chemotherapy. Median age was 43 years (range, 16-76). Median first complete remission duration was 12.1 months (range, 2.1-93.6). Overall, second complete remission (CR2) rate was 88%. With a median follow-up from relapse of 3.5 years, the estimated 5-year disease-free survival (DFS) was 50% and 5-year overall survival (OS) was 51%. Older age and shorter first complete remission duration was associated with a shorter OS. Patients treated with GO had similar CR2 rate but significantly higher 5-year DFS (68% vs 42%; P = .05) and OS (65% vs 44%; P = .02). In multivariate analysis, GO salvage was still associated with a significant benefit in DFS and OS. In the 78 patients who received allogeneic hematopoietic stem cell transplantation in CR2, GO before transplant significantly improved posttransplant DFS and OS without excess of treatment-related mortality.

Female tract cytokines and developmental programming in embryos.

In the physiological situation, cytokines are pivotal mediators of communication between the maternal tract and the embryo. Compelling evidence shows that cytokines emanating from the oviduct and uterus confer a sophisticated mechanism for 'fine-tuning' of embryo development, influencing a range of cellular events from cell survival and metabolism, through division and differentiation, and potentially exerting long-term impact through epigenetic remodelling. The balance between survival agents, including GM-CSF, CSF1, LIF, HB-EGF and IGFII, against apoptosis-inducing factors such as TNFα, TRAIL and IFNg, influence the course of preimplantation development, causing embryos to develop normally, adapt to varying maternal environments, or in some cases to arrest and undergo demise. Maternal cytokine-mediated pathways help mediate the biological effects of embryo programming, embryo plasticity and adaptation, and maternal tract quality control. Thus maternal cytokines exert influence not only on fertility and pregnancy progression but on the developmental trajectory and health of offspring. Defining a clear understanding of the biology of cytokine networks influencing the embryo is essential to support optimal outcomes in natural and assisted conception.

Comparative study of neural differentiation of bone marrow mesenchymal stem cells by different induction methods.

Neurogenic differentiation of bone marrow (BM) mesenchymal stem cells (MSCs) offers a new hope for patients with many neurological disorders. Several chemical inducers are employed to induce BMMSCs differentiation into nerve cells. In the present study, we compared different inducers [2-mercaptoethanol (BME), tretinoin (ATRA), dimethyl sulfoxide/butylated hydroxyanisole (DMSO/BHA), and indomethacin/3-isobutyl-1-methylxanthine (indomethacin/IBMX)] on the neurogenic differentiation of BMMSCs and aimed to identify a more efficient and safer method. The MSCs were first identified by their ability to adhere to plastic and by the expression of positive (CD44, CD90, and CD105) and negative (CD34) markers assessed by flow cytometry. The efficiency of the neurogenic differentiation was determined by assessing the mRNA and protein expression of nestin, microtubule-associated protein-2 (MAP2), neuron specific enolase (NSE), and glial fibrillary acidic protein (GFAP) by reverse transcription-polymerase chain reaction and western-blot, respectively. The effect of these inducers on cell viability was also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. This comprehensive study shows that indomethacin/IBMX is better than BME, DMSO/BHA, and ATRA both in terms of efficiency and safety, while BME suppressed the growth and proliferation of MSCs.

Twenty-five years of peripheral blood stem cell transplantation.

Peripheral blood stem cell transplantation (PBSCT) is the most common transplantation procedure performed in medicine. Its clinical introduction in 1986 replaced BM as a stem-cell source to approximately 100% in the autologous and to approximately 75% in the allogeneic transplantation setting. This historical overview provides a brief insight into the discovery of circulating hematopoietic stem cells in the early 1960s, the development of apheresis technology, the discovery of hematopoietic growth factors and small molecule CXCR4 antagonist for stem- cell mobilization, and in vivo experimental transplantation studies that eventually led to clinical PBSCT. Also mentioned are the controversies surrounding the engraftment potential of circulating stem cells before acceptance as a clinical modality. Clinical trials comparing the outcome of PBSCT with BM transplantation, registry data analyses, and the role of the National Marrow Donor Program (NMDP) in promoting unrelated blood stem-cell donation are addressed.

A critical role for SHP2 in STAT5 activation and growth factor-mediated proliferation, survival, and differentiation of human CD34+ cells.

SHP2, a cytoplasmic protein-tyrosine phosphatase encoded by the PTPN11 gene, plays a critical role in developmental hematopoiesis in the mouse, and gain-of-function mutations of SHP2 are associated with hematopoietic malignancies. However, the role of SHP2 in adult hematopoiesis has not been addressed in previous studies. In addition, the role of SHP2 in human hematopoiesis has not been described. These questions are of considerable importance given the interest in development of SHP2 inhibitors for cancer treatment. We used shRNA-mediated inhibition of SHP2 expression to investigate the function of SHP2 in growth factor (GF) signaling in normal human CD34(+) cells. SHP2 knockdown resulted in markedly reduced proliferation and survival of cells cultured with GF, and reduced colony-forming cell growth. Cells expressing gain-of-function SHP2 mutations demonstrated increased dependency on SHP2 expression for survival compared with cells expressing wild-type SHP2. SHP2 knockdown was associated with significantly reduced myeloid and erythroid differentiation with retention of CD34(+) progenitors with enhanced proliferative capacity. Inhibition of SHP2 expression initially enhanced and later inhibited STAT5 phosphorylation and reduced expression of the antiapoptotic genes MCL1 and BCLXL. These results indicate an important role for SHP2 in STAT5 activation and GF-mediated proliferation, survival, and differentiation of human progenitor cells.

Prognostic value of circulating levels of stem cell growth factor beta (SCGF beta) in patients with Chagas' disease and idiopathic dilated cardiomyopathy.

Chagas' disease (CD) often leads to dilated cardiomyopathy (DCM), and during its chronic stage hematopoietic stem or progenitor cells are involved in its pathological process. However, it is not clear whether stem cell growth factor (SCGF) beta can be regulated in patients with CD and idiopathic DCM. In present study, we aim to investigate the plasma SCGF beta concentration and its correlation with echocardiographic parameters and clinical outcome. In this prospective cohort study, SCGF beta levels were quantified in patients with CD (n=94), DCM (n=48), and control healthy subjects (n=25). In comparison with healthy subjects, no statistical difference can be detected in NYHA classes I-II patients. However, SCGF beta was significantly increased in advanced heart failure patients (NYHA III-IV), compared to CD patients without heart failure. There was no group difference between CD and DCM. However, despite this significant increase in advanced heart failure patients, SCGF beta had no significant correlation with echocardiographic parameters, and it cannot be used as a prognostic marker for mortality and heart transplantation. To our best knowledge, this is the first report of SCGF beta in heart failure patients. Although it is significantly increased in advanced heart failure patients caused by CD or DCM, its prognostic value for end points is minor.

Interrelationship and expression profiling of cyclooxygenase and angiogenic factors in Indian patients with multiple myeloma.

Multiple myeloma (MM) is classically illustrated by a desynchronized cytokine system with rise in inflammatory cytokines. There are recent reports which emphasized the potential role of angiogenesis in the development of MM. Role of cyclooxygenase 2 (COX-2) is well documented in the pathogenesis of solid tumors, but little is known about its occurrence and function in hematologic neoplasms. Involvement of neoangiogenesis is reported in the progression of MM, and angiopoietins probably contribute to this progression by enhancing neovascularization. Circulatory and mRNA levels of angiogenic factors and cyclooxygenase were determined in 125 subjects (75 MM patients and 50 healthy controls) by using enzyme-linked immunosorbent assay and quantitative PCR. We observed significant increase for angiogenic factors (Ang-1, Ang-2, hepatocyte growth factor, and vascular endothelial growth factor) and cyclooxygenase at circulatory level, as well as at mRNA level, as compared to healthy controls except insignificant increase for Ang-1 at circulatory level. We have also observed the significant positive correlation of all angiogenic factors with cyclooxygenase. The strong association found between angiogenic factors and COX-2 in this study may lead to the development of combination therapeutic strategy to treat MM. Therefore, targeting COX-2 by using its effective inhibitors demonstrating antiangiogenic and antitumor effects could be used as a new therapeutic approach for treatment of MM.