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Publisher Copyright: © 2020, The Author(s). Severe blood disorders and cancer are the leading cause of death and disability from noncommunicable diseases in the global pediatric population and a major financial burden. The most frequent of these conditions, namely sickle cell disease and severe thalassemia, are highly curable by blood or bone marrow transplantation (BMT) which can restore a normal health-related quality of life and be cost-effective. This position paper summarizes critical issues in extending global access to BMT based on ground experience in the start-up of several BMT units in middle-income countries (MICs) across South-East Asia and the Middle East where close to 700 allogeneic BMTs have been performed over a 10-year period. Basic requirements in terms of support systems, equipment, and consumables are summarized keeping in mind WHO’s model essential lists and recommendations. BMT unit setup and maintenance costs are summarized as well as those per transplant. Low-risk BMT is feasible and safe in MICs with outcomes comparable to high-income countries but at a fraction of the cost. This report might be of assistance to health care institutions in MICs interested in developing hematopoietic stem cell transplantation services and strengthening context appropriate tertiary care and higher medical education.

Ineffective haemopoiesis in patients with myelodysplasia (MDS) may be a consequence of defective marrow stromal cells. We have measured the growth of normal haemopoietic progenitors from cord blood mononuclear cells (MNC) in secondary long-term cultures on irradiated stromal layers grown from the marrow of normal subjects and MDS patients. Stromal layers were established in 25 cm2 flasks by inoculating 20 x 1 O6 bone marrow MNC in 10 ml of modified McCoy's 5A medium (glucose reduced to 400 mg/l and supplemented with 450 mg galactose/l) buffered with 40 mM HEPES.The proportion of the flask surface covered by stromal cells was estimated after 5 weeks primary growth (confluence %) and layers irradiated (10 Gy). Secondary cultures were established by re-inoculating with 5 x lo6 MNC from cord blood. Confluence ranged from 60-100% in normal cultures (n = 25; median = 95%) and 40-100% in MDS cultures (n = 26; median = 90%; ns). After 5 weeks secondary culture the CFU-GM from cord blood had a median value of 58.0/culture when grown on normal stroma (n = 20) and 4.3 on MDS stroma (n = 19; p = 0.0002). Median erythroid colonies numbered 15/culture with normal stroma (n = 13) and 0 with MDS stroma (n = 19; p = 0.004). In cultures with 90% confluence, or more, the median CFU-GM were 98.9hormal culture (n = 13) and 6.1IMDS culture (n = 12; p = 0.002); and the median period of CFU-GM detectability was 10 weeks on normal stroma (n = 9) and 5 weeks on MDS stroma (n = 13; p = 0.0005). There was little evidence of correlation between confluence and secondary CFU-GM numbers in weeks 4 to 7; but the period of CFU-GM detectability was correlated to confluence on normal stroma (n = 16; r, = 0.6463; p = 0.006) but not on MDS stroma (n = 20; r, = 0.2964; ns). Mean culture pH values were identical at week 5 (normal = 7.13, n = 23; MDS = 7.13, n = 19; ns) suggesting there was no difference in the underlying metabolic activity. We conclude that stromal layers from MDS marrow are defective in their ability to support normal haemopoiesis; and the variation in this defectiveness is greater than the measured variation in confluence and is independent of it.

Objective The purpose of this study is to systematically review the literature and to evaluate the outcomes following bone marrow stimulation (BMS) for nonprimary osteochondral lesions of the talus (OLT). Design A literature search was performed to identify studies published using PubMed (MEDLINE), EMBASE, CDSR, DARE, and CENTRAL. The review was performed according to the PRISMA guidelines. Two authors separately and independently screened the search results and conducted the quality assessment using the Methodological Index for Non-Randomized Studies (MINORS). Studies were pooled on clinical, sports, work, and imaging outcomes, as well as revision rates and complications. The primary outcome was clinical success rate. Results Five studies with 70 patients were included in whom nonprimary OLTs were treated with secondary BMS. The pooled clinical success rate was 61% (95% confidence interval [CI], 50-72). The rate of return to any level of sport was 83% (95% CI, 70-91), while the return to pre-injury level of sport was 55% (95% CI, 34-74). The rate of return to work was 92% (95% CI, 78-97), and the complication rate was assessed to be 10% (95% CI, 4-22). Imaging outcomes were heterogeneous in outcome assessment, though a depressed subchondral bone plate was observed in 91% of the patients. The revision rate was 27% (95% CI, 18-40). Conclusions The overall success rate of arthroscopic BMS for nonprimary osteochondral lesions of the talus was 61%, including a revision rate of 27%. Return to sports, work, and complication outcomes yielded fair to good results.

Objective To compare clinical, sports, work, and radiological outcomes between primary and secondary osteochondral lesions of the talus (OLTs; Design Secondary OLTs were matched to primary OLTs in a 1:2 ratio to assess the primary outcome measure—the Numeric Rating Scale (NRS) during activities. Secondary outcomes included the pre- and 1-year postoperative NRS at rest, American Orthopaedic Foot and Ankle Society score, Foot and Ankle Outcome Score subscales, and the EQ-5D general health questionnaire. The rates and time to return to work and sports were collected. Radiological examinations were performed preoperatively and at final follow-up using computed tomography (CT). Results After matching, 22 and 12 patients with small (Conclusion No differences in outcomes were observed between arthroscopic bone marrow stimulation in primary and secondary OLTs at 1-year follow-up. Repeat BMS may therefore be a viable treatment option for failed OLTs in the short term.

This study addresses the potential to reverse age-associated morbidity by establishing methods to restore the aged hematopoietic system. Parabiotic animal models indicated that young secretome could restore aged tissues, leading us to establish a heterochronic transwell system with aged mobilized peripheral blood (MPB), co-cultured with young MPB or umbilical cord blood (UCB) cells. Functional studies and omics approaches indicate that the miRNA cargo of microvesicles (MVs) restores the aged hematopoietic system. The in vitro findings were validated in immune deficient (NSG) mice carrying an aged hematopoietic system, improving aged hallmarks such as increased lymphoid:myeloid ratio, decreased inflammation and cellular senescence. Elevated MYC and E2F pathways, and decreased p53 were key to hematopoietic restoration. These processes require four restorative miRs that target the genes for transcription/differentiation, namely PAX and phosphatase PPMIF. These miRs when introduced in aged cells were sufficient to restore the aged hematopoietic system in NSG mice. The aged MPBs were the drivers of their own restoration, as evidenced by the changes from distinct baseline miR profiles in MPBs and UCB to comparable expressions after exposure to aged MPBs. Restorative natural killer cells eliminated dormant breast cancer cells in vivo, indicating the broad relevance of this cellular paradigm - preventing and reversing age-associated disorders such as clearance of early malignancies and enhanced responses to vaccine and infection.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stromal cells that have a critical role in the maintenance of skeletal tissues such as bone, cartilage, and the fat in bone marrow. In addition to providing microenvironmental support for hematopoietic processes, BM-MSCs can differentiate into various mesodermal lineages including osteoblast/osteocyte, chondrocyte, and adipocyte that are crucial for bone metabolism. While BM-MSCs have high cell-to-cell heterogeneity in gene expression, the cell subtypes that contribute to this heterogeneity in vivo in humans have not been characterized. To investigate the transcriptional diversity of BM-MSCs, we applied single-cell RNA sequencing (scRNA-seq) on freshly isolated CD271+ BM-derived mononuclear cells (BM-MNCs) from two human subjects. We successfully identified LEPRhiCD45low BM-MSCs within the CD271+ BM-MNC population, and further codified the BM-MSCs into distinct subpopulations corresponding to the osteogenic, chondrogenic, and adipogenic differentiation trajectories, as well as terminal-stage quiescent cells. Biological functional annotations of the transcriptomes suggest that osteoblast precursors induce angiogenesis coupled with osteogenesis, and chondrocyte precursors have the potential to differentiate into myocytes. We also discovered transcripts for several clusters of differentiation (CD) markers that were either highly expressed (e.g., CD167b, CD91, CD130 and CD118) or absent (e.g., CD74, CD217, CD148 and CD68) in BM-MSCs, representing potential novel markers for human BM-MSC purification. This study is the first systematic in vivo dissection of human BM-MSCs cell subtypes at the single-cell resolution, revealing an insight into the extent of their cellular heterogeneity and roles in maintaining bone homeostasis.

As a new type of non-coding RNA, the role of circular RNA (circRNA) in various diseases and tumors has received considerable attention. Studies have shown that circRNAs play an important role in the progression of acute myeloid leukemia (AML) via different mechanisms. However, the specific underlying molecular mechanism of circRNAs in the proliferation of AML cells remians unclear. This study aimed to clarify the biological role and mechanism of circCRKL in AML. The results indicated low circCRKL expression in AML cell lines and samples. Moreover, the overexpression of circCRKL inhibited the proliferation and colony-forming ability of AML cells, while its silencing promoted them. In addition, bioinformatics tools and luciferase assays revealed that circCRKL could sponge miR-196a-5p and miR-196b-5p to promote the expression of p27. Furthermore, circCRKL inhibited AML cell proliferation via the miR-196a-5p/miR-196b-5p/p27 axis, suggesting a potential new target for AML therapy.

Bone remodeling is a dynamic process between bone formation mediated by osteoblasts and bone resorption mediated by osteoclasts. Disrupted bone remodeling is a key factor in postmenopausal osteoporosis, a metabolic disorder characterized by deteriorated bone microarchitecture and increased risk of fracture. Recent studies have shown that piwi-binding RNA (piRNA) is involved in the pathogenesis of certain diseases at the post-transcriptional level. Here, we analyzed piRNA-63049 (piR-63049), which may play an essential role in bone remodeling. The expression of piR-63049 significantly increased in both bone tissues and plasma of osteoporotic rats and postmenopausal osteoporotic patients. Overexpressing piR-63049 could inhibit the osteoblastogenesis of bone marrow stromal cells (BMSCs) while knocking down piR-63049 could promote the osteoblastogenesis of BMSCs through the Wnt2b/β-catenin signaling pathway. Moreover, knocking-down piR-63049 (piR-63049-antagonist) in vivo could attenuate the bone loss in ovariectomized rats by promoting bone formation. Taken together, the current study shows that piR-63049 inhibits bone formation through the Wnt2b/β-catenin signaling pathway. This novel piRNA may be a potential target to increase bone formation in bone loss disorders such as postmenopausal osteoporosis.

Finding new strategies for the treatment of heart failures using stem cells has attracted a lot of attention. Meanwhile, nanotechnology-based approaches to regenerative medicine hypothesize a possible combination of stem cells and nanotechnology in the treatment of diseases. This study aims to investigate the in vitro effect of silver nanoparticles (Ag-NPs) on the cardiomyogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs) through detection of cardiac markers. For this purpose, MSCs were isolated from bone marrow resident and differentiated to the cardiac cells using a dedicated medium with Ag-NPs. Also, the cardiomyogenic differentiation of BM-MSCs was confirmed using immunocytochemistry. Then, real-time PCR and western blotting assay were used for measuring absolute telomere length (TL) measurement, and gene and protein assessment of the cells, respectively. It was found that 2.5 µg/mL Ag-NPs caused elongation of the telomeres and altered VEGF, C-TnI, VWF, SMA, GATA-4, TERT, and cyclin D protein and gene expression in the cardiomyogenically differentiated BM-MSCs. Also, there was a significant increase in the protein and gene expression of Wnt3 and β-catenin as main components of pathways. We concluded that Ag-NPs could change the in vitro expression of cardiac markers of BM-MSCs via the Wnt3/β-catenin signaling pathway.

Rationale: Bone marrow-derived mesenchymal stem cells (BM-MSCs) recruited into breast tumors regulate the behavior of tumor cells via various mechanisms and affect clinical outcomes. Although signaling molecules, such as transforming growth factor β (TGF-β), are known to transmit signals between BM-MSCs and breast tumor cells for recruiting BM-MSCs, it is unclear which specific intrinsic molecules involved in cell motility mediate the migration of BM-MSCs into breast tumor. It is also unclear as to how specific intrinsic molecules contribute to the migration. Methods: Conditioned medium (CM) from breast tumor cells (MCF-7 and MDA-MB-231) that simulates breast tumor secreting TGF-β was used to examine the migration of BM-MSCs into breast tumors. A three-dimensional migration assay was performed to investigate the collective migration of BM-MSCs, maintaining cell-cell adhesion, toward breast tumor cells. Results: N-cadherin formed adherens junction-like structures on the intercellular borders of BM-MSCs, and TGF-β increased the expression of N-cadherin on these borders. Knockdown of Smad4 impaired the TGF-β-mediated increase in N-cadherin expression in BM-MSCs, but inhibitors of non-canonical TGF-β pathways, such as extracellular signal-regulated kinases, Akt, and p38, did not affect it. siRNA-mediated knockdown of N-cadherin and Smad4 impaired the migration of BM-MSCs in response to TGF-β. Conditioned medium from breast tumor cells also enhanced the expression of N-cadherin in BM-MSCs, but inactivation of TGF-β type 1 receptor (TGFBR1) with SB505124 and TGFBR1 knockdown abolished the increase in N-cadherin expression. BM-MSCs collectively migrated toward CM from MDA-MB-231 in vitro while maintaining cell-cell adhesion through N-cadherin. Knockdown of N-cadherin abolished the migration of BM-MSCs toward the CM from breast tumor cells. Conclusion: In the present study, we identified N-cadherin, an intrinsic transmembrane molecule in adherens junction-like structures, on BM-MSCs as a mediator for the migration of these cells toward breast tumor. The expression of N-cadherin increases on the intercellular borders of BM-MSCs through the TGF-β canonical signaling and they collectively migrate in response to breast tumor cells expressing TGF-β via N-cadherin-dependent cell-cell adhesion. We, herein, introduce a novel promising strategy for controlling and re-engineering the breast tumor microenvironment.

Aging tissues undergo a progressive decline in regenerative potential. This decline in regenerative responsiveness has been attributed to changes in tissue-specific stem cells and their niches. In bone, aged skeletal stem/progenitor cell dysfunction is characterized by decreased frequency and impaired osteogenic differentiation potential. This aging phenotype ultimately results in compromised regenerative responsiveness to injury. The age-associated increase of inflammatory mediators, known as inflamm-aging, has been identified as the main culprit driving skeletal stem cell dysfunction. Here, we utilized a mouse model of parabiosis to decouple aging from inflammation. Using the Nfkb1-/- mouse as a model of inflamm-aging, we demonstrate that a shared systemic circulation between a wild-type and Nfkb1-/- mouse results in an aging phenotype of the wild-type skeletal stem and progenitor cells, shown by CFU-fs and osteogenic and adipogenic differentiation assays. Our findings demonstrate that exposure to an inflammatory secretome results in a phenotype similar to the one observed in aging.

Objective: The present study aimed to determine the prognostic value of HOXA cluster antisense RNA2 (HOXA-AS2) in acute myeloid leukemia (AML), and to explore its potential molecular mechanisms. We also screening of potential drugs targeting HOXA-AS2 in AML. Methods: The level 3 raw genome-wide RNA sequencing dataset of AML was download from The Cancer Genome Atlas (TCGA) Data Portal, and the potential molecular mechanisms and drugs prediction of HOXA-AS2 in AML were explored using multiple bioinformatics analysis approaches. Results: TCGA AML cohort dataset indicated that HOXA-AS2 was significantly up-regulated in AML bone marrow tissues, and high HOXA-AS2 expression was related to poor overall survival (log-rank P=0.0284, hazard ratio 1.640, 95% confidence interval 1.046-2.573). Functional enrichment of differentially expressed genes (DEGs) suggested that the difference in prognosis between AML patients with high- and low-HOXA-AS2 expression may be due to differences in biological processes and pathways, including cell adhesion, angiogenesis, mitogen-activated protein kinase, cell differentiation, and other biological processes, and phosphatidylinositol 3 kinase-protein kinase B and Wnt signaling pathways. We also screened out three potential HOXA-AS2-targeted therapeutic drugs for AML, megestrol, carmustine, and cefoxitin, based on these DEGs. Functional enrichment analysis of HOXA-AS2-co-expressed genes revealed that HOXA-AS2 may act a part in AML by regulating nuclear factor-κB transcription factor activity, DNA methylation, angiogenesis, apoptosis, cell migration, Toll-like receptor 4, and Wnt signaling pathways. Conclusion: Our findings suggest that HOXA-AS2 is up-regulated in the bone marrow in patients with AML, and may serve as a novel prognostic biomarker for AML.

Patients with type 2 diabetes mellitus (T2DM) have a high risk of fracture and experience poor bone healing. In recent years, bone mesenchymal stem cells (BMSCs) and endothelial progenitor cells (EPCs) have become the most commonly used cells in cell therapy and tissue engineering. In this study, we found that high glucose levels had a negative effect on the differentiation of BMSCs and EPCs. Considering that EPCs-BMSCs sheets can provide endothelial cells and osteoblastic cells, we transplanted cell sheets into T2DM rats with bilateral skull defects. The outcomes of the in vivo study revealed that EPCs-BMSCs sheets promoted ossification, which was verified by micro-CT and immunohistochemistry (IHC) analyses. Furthermore, we detected the VEGF content in the culture supernatant using an enzyme-linked immunosorbent assay (ELISA). The results showed that the BMSCs co-cultured with EPCs presented a higher level of VEGF than other cells. To assess the differentiation and migration of BMSCs exposed to VEGF, ALP staining, scratch assay and qRT-PCR analysis were performed. In addition, we used immunofluorescence and western blotting analysis to further explore the related mechanisms. The results showed that cells cultured with VEGF had a stronger actin cytoskeleton and a greater amount of nuclear and total YAP than cells cultured without VEGF. Taken together, our results indicate that co-culture with EPCs could promote the osteogenesis of BMSCs partially via VEGF. Furthermore, YAP and F-actin play important roles in this process.

Ventricular remodeling following myocardial infarction (MI) is a major cause of heart failure, a condition prevalent in older individuals. Following MI, immune cells are mobilized to the myocardium from peripheral lymphoid organs and play an active role in orchestrating repair. While the effect of aging on mouse bone marrow (BM) has been studied, less is known about how aging affects human BM cells and their ability to regulate repair processes. In this study, we investigate the effect aging has on human BM cell responses post‐MI using a humanized chimeric mouse model. BM samples were collected from middle aged (mean age 56.4 ± 0.97) and old (mean age 72.7 ± 0.59) patients undergoing cardiac surgery, CD34+/− cells were isolated, and NOD‐scid‐IL2rγnull (NSG) mice were reconstituted. Three months following reconstitution, the animals were examined at baseline or subjected to coronary artery ligation (MI). Younger patient cells exhibited greater repopulation capacity in the BM, blood, and spleen as well as greater lymphoid cell production. Following MI, CD34+ cell age impacted donor and host cellular responses. Mice reconstituted with younger CD34+ cells exhibited greater human CD45+ recruitment to the heart compared to mice reconstituted with old cells. Increased cellular responses were primarily driven by T‐cell recruitment, and these changes corresponded with greater human IFNy levels and reduced mouse IL‐1β in the heart. Age‐dependent changes in BM function led to significantly lower survival, increased infarct expansion, impaired host cell responses, and reduced function by 4w post‐MI. In contrast, younger CD34+ cells helped to limit remodeling and preserve function post‐MI., To study the effect aging has on human cell responses post‐MI, we utilized a xenograft mouse (NSG) model using BM from middle aged (Y‐CD34+) and old patients (O‐CD34+). Our results demonstrate that O‐CD34+ reconstituted mice exhibit impaired donor and host cell responses while Y‐CD34+ reconstituted mice exhibit a greater donor lymphocyte and host myeloid cell responses post‐MI. Differences in cellular responses are associated with improved cardiac function in Y‐CD34+ reconstituted mice post‐MI.

International audience; Over the last two decades, increased interest of scientists to study bone marrow adiposity (BMA) in relation to bone and adipose tissue physiology has expanded the number of publications using different sources of bone marrow adipose tissue (BMAT). However, each source of BMAT has its limitations in the number of downstream analyses for which it can be used. Based on this increased scientific demand, the International Bone Marrow Adiposity Society (BMAS) established a Biobanking Working Group to identify the challenges of biobanking for human BMA-related samples and to develop guidelines to advance establishment of biobanks for BMA research. BMA is a young, growing field with increased interest among many diverse scientific communities. These bring new perspectives and important biological questions on how to improve and build an international community with biobank databases that can be used and shared all over the world. However, to create internationally accessible biobanks, several practical and legislative issues must be addressed to create a general ethical protocol used in all institutes, to allow for exchange of biological material internationally. In this position paper, the BMAS Biobanking Working Group describes similarities and differences of patient information (PIF) and consent forms from different institutes and addresses a possibility to create uniform documents for BMA biobanking purposes. Further, based on discussion among Working Group members, we report an overview of the current isolation protocols for human bone marrow adipocytes (BMAds) and bone marrow stromal cells (BMSCs, formerly mesenchymal), highlighting the specific points crucial for effective isolation. Although we remain far from a unified BMAd isolation protocol and PIF, we have summarized all of these important aspects, which are needed to build a BMA biobank. In conclusion, we believe that harmonizing isolation protocols and PIF globally will help to build international collaborations and improve the quality and interpretation of BMA research outcomes.

For PET imaging of mantle cell lymphoma (MCL), [18F]FDG (2-deoxy-2-[18F]fluoro-D-glucose) is the currently recommended radiotracer, although uptake is variable and bone marrow evaluation is limited. In this prospective study, we evaluated the novel CXCR4 (G-protein-coupled C-X-C chemokine receptor type 4) tracer [68Ga]Pentixafor in MCL patients, and compared it to [18F]FDG. Methods: MCL patients underwent [68Ga]Pentixafor-PET/MRI, and, if required for routine purposes, also [18F]FDG-PET/MRI, before treatment. PET was evaluated separately for 23 anatomic regions (12 lymph node stations and 11 organs/tissues), using MRI as the main reference standard. Standardized uptake values (SUVmax and SUVmean) and tumor-to-background ratios (TBRblood and TBRliver) were calculated. General Estimation Equations (GEE) were used to compare [68Ga]Pentixafor-PET and [18F]FDG-PET sensitivities and positive predictive values (PPV). For bone marrow involvement, where biopsy served as the main reference standard, and splenic involvement, receiver operating characteristic curves were used to determine the optimal SUV and TBR cut-off values, and areas under the curve (AUC) were calculated. Results: Twenty-two MCL patients were included. [68Ga]Pentixafor-PET sensitivity (100%) was significantly higher than for [18F]FDG-PET (75.2%) (P

Some adipocytes are produced from bone marrow hematopoietic stem cells. In vitro studies previously indicated that these bone marrow-derived adipocytes (BMDAs) were generated from adipose tissue macrophage (ATM) that lose their hematopoietic markers and acquire mesenchymal markers prior to terminal adipogenic differentiation. Here we interrogated whether this hematopoietic-to-mesenchymal transition drives BMDA production In vitro. We generated transgenic mice in which the lysozyme gene promoter (LysM) indelibly labeled ATM with green fluorescent protein (GFP). We discovered that adipose stroma contained a population of LysM-positive myeloid cells that simultaneously expressed hematopoietic/myeloid markers (CD45 and CD11b), and mesenchymal markers (CD29, PDGFRa and Sca-1) typically found on conventional adipocyte progenitors. These cells were capable of adipogenic differentiation In vitro and In vitro, while other stromal populations deficient in PDGFRa and Sca-1 were non-adipogenic. BMDAs and conventional adipocytes expressed common fat cell markers but exhibited little or no expression of hematopoietic and mesenchymal progenitor cell markers. The data indicate that BMDAs are produced from ATM simultaneously expressing hematopoietic and mesenchymal markers rather than via a stepwise hematopoietic-to-mesenchymal transition. Because BMDA production is stimulated by high fat feeding, their production from hematopoietic progenitors may maintain adipocyte production when conventional adipocyte precursors are diminished.

Content and aims: Ginsenoside RG1 (RG1) is thought to enhance proliferation and differentiation of stem cell, however, its role on paracrine efficacy of stem cell remains unclear. Here we examined if and how RG1 enhances the paracrine effects of bone marrow-derived mesenchymal stem cells (BM-MSCs) on radiation induced intestinal injury (RIII). Method Irradiated rats randomly received intraperitoneal injection of conditioned medium (CM) derived from non-activated BM-MSCs (MSC-CM) or BM-MSCs pre-activated by RG-1 (RG1-MSC-CM). Intestinal samples were collected, followed by the evaluation of histological and functional change, apoptosis, proliferation, inflammation, angiogenesis and stem cell regeneration. The effects of heme oxygenase-1 (HO-1) were investigated using HO-1 inhibitor or siRNA. Result RG1 enhanced the paracrine efficacy of BM-MSCs partially through upregulation of HO-1. RG1-MSC-CM rather than MSC-CM significantly improved the survival and intestinal damage of irradiated rats via improvement of intestinal proliferation/apoptosis, inflammation, angiogenesis and stem cell regeneration in a HO-1 dependent mechanism. The mechanism for the superior paracrine efficacy of RG1-MSC-CM is related to a higher release of two pivotal cytokines VEGF and IL-6. Conclusion Our study revealed that RG1 enhances paracrine effects of BM-MSCs on RIII, providing a novel method for maximizing the paracrine potential of MSCs.

Bone marrow (BM) is a primary metastatic site in prostate cancer (PC) and bone invasion is considered incurable. T cell-mediated immune surveillance is essential in controlling both tumorigenesis and initiation of metastases. Beside tropism, dissemination of PC cells to the BM may be facilitated by defects in BM immune homeostasis predisposing this niche to colonization. To evaluate the BM immune microenvironment in locally advanced, non-metastatic PC, we performed flow cytometry analysis of myeloid and lymphoid subsets in BM aspirates and peripheral blood collected during prostatectomy. Healthy BM aspirates served to establish a reference range for comparison. We found alterations in BM immune composition of PC patients, including an increased CD4/CD8 ratio, enrichment of CD4+ T cells, increased CD56+CD3+ NKT and CD56+CD3- NK yields compared to healthy controls. The lymphoid phenotype remained comparable regarding T cell activation and chemokine receptor-based polarization patterns. Additionally, we found increased B7H3 expression in the myeloid monocyte/macrophage subset and decreased DC infiltration in BM of PC patients. These findings suggest that alterations in the immune milieu may limit immune surveillance that compromise the ability of the BM microenvironment to prevent tumor dissemination, and predispose development of bone metastases in a subset of patients with localized PC.

Atg7, a critical component of autophagy machinery, is essential for counteracting hematopoietic aging. However, the non-autophagic role of Atg7 on hematopoietic cells remains fundamentally unclear. In this study, we found that loss of Atg7, but not Atg5, another autophagy-essential gene, in the hematopoietic system reduces CD11b myeloid cellularity including CD11b+Ly6G+ and CD11b+Ly6G- populations in mouse bone marrow. Surprisingly, Atg7 deletion causes abnormally accumulated histone H3.1 to be overwhelmingly trapped in the cytoplasm in the CD11b+Ly6G-, but not the CD11b+Ly6G+ compartment. RNA profiling revealed extensively chaotic expression of the genes required in nucleosome assembly. Functional assays further indicated upregulated aging markers in the CD11b+Ly6G- population. Therefore, our study suggests that Atg7 is essential for maintaining proper nucleosome assembly and limiting aging in the bone marrow CD11b+Ly6G- population.

PURPOSE The in vivo probing of restricted diffusion effects in large lipid droplets on a clinical MR scanner remains a major challenge due to the need for high b-values and long diffusion times. This work proposes a methodology to probe mean lipid droplet sizes using diffusion-weighted MRS (DW-MRS) at 3T. METHODS An analytical expression for restricted diffusion was used. Simulations were performed to evaluate the noise performance and the influence of particle size distribution. To validate the method, oil-in-water emulsions were prepared and examined using DW-MRS, laser deflection and light microscopy. The tibia bone marrow was scanned in volunteers to test the method repeatability and characterize microstructural differences at different locations. RESULTS The simulations showed accurate and precise droplet size estimation when a sufficient SNR is reached with minor dependence on the size distribution. In phantoms, a good correlation between the measured droplet sizes by DW-MRS and by laser deflection (R2 = 0.98; P = 0.01) and microscopy (R2 = 0.99; P \textless 0.01) measurements was obtained. A mean coefficient of variation of 11.5 % was found for the lipid droplet diameter in vivo. The average diameter was smaller at a proximal (50.1 $\pm$ 7.3 µm) compared with a distal tibia location (61.1 $\pm$ 6.8 µm) (P \textless 0.01). CONCLUSION The presented methods were able to probe restricted diffusion effects in lipid droplets using DW-MRS and to estimate lipid droplet size. The methodology was validated using phantoms and the in vivo feasibility in bone marrow was shown based on a good repeatability and findings in agreement with literature.

Purpose To evaluate the relationship between bone mineral density (BMD) and magnetic susceptibility, and between proton density fat fraction and susceptibility, in inflamed trabecular bone. Methods Two different phantoms modeling the fat fraction (FF) and BMD values of healthy bone marrow and disease states were scanned using a multiecho gradient echo acquisition at 3T. After correction for fat‐water chemical shift, susceptibility mapping was performed, and susceptibility measurements were compared with BMD and FF values using linear regression. Patients with spondyloarthritis were scanned using the same protocol, and susceptibility values were calculated in areas of inflamed bone (edema) and fat metaplasia, both before and after accounting for the contribution of fat to the total susceptibility. Results Susceptibility values in the phantoms were accurately described by a 2D linear function, with a negative correlation between BMD and susceptibility and a positive correlation between FF and susceptibility (adjusted R2 = 0.77; P = 3·10−5). In patients, significant differences in susceptibility were observed between fat metaplasia and normal marrow, but these differences were eliminated by removing the fat contribution to the total susceptibility. Conclusions BMD and proton density fat fraction both influence the total susceptibility of bone marrow and failure to account for the fat contribution could lead to errors in BMD quantification. We propose a method for removing the fat contribution from the total susceptibility, based on the observed linear relationship between susceptibility and FF. In inflamed bone, the overall increase in susceptibility in areas of fat metaplasia is at least partly due to increased fat content.

Rationale: Capillaries are composed of endothelial cells and the surrounding mural cells, pericytes. Microvascular repair after injury involves not only the proliferation of endothelial cells but also pericyte-based vessel stabilization. Exogenous bone marrow derived-putative endothelial progenitor cells (b-pEPCs) have the potential for vascular repair; however, their effect on vascular structure stabilization and pericyte-related pathobiological outcomes in the injured kidney has not been fully examined. Methods: We applied ischemia-reperfusion (IR) to induce renal vascular injury and renal fibrosis in mice. Platelet-derived growth factor receptor β (PDGFR-β)-DTR-positive mice were generated to deplete pericytes, and exogenous b-pEPCs and the PDGFR-β ligand, PDGF chain B (PDGF-BB), were employed to explore the relationship among b-pEPCs, pericytes, vascular repair, and early renal fibrosis. Results: Administration of b-pEPCs reduced IR-induced pericyte-endothelial detachment, pericyte proliferation, and myofibroblast transition via a paracrine mode, which preserved not only vascular stabilization but also ameliorated IR-initiated renal fibrosis. PDGF-BB upregulated the expression of PDGFR-β, exacerbated vascular abnormality, and pericyte-myofibroblast transition, which were ameliorated by b-pEPCs administration. The exogenous b-pEPCs and their culture medium (CM) induced vascular injury protection, and renal fibrosis was blocked by selective deletion of pericytes. Conclusion: Exogenous b-pEPCs directly protect against IR-induced vascular injury and prevent renal fibrosis by inhibiting the activation of PDGFR-β-positive pericytes.

Purpose: To explore whether radiomic features of fluorine-18-fluorodeoxyglucose ($^{18}F-FDG$) positron emission tomography-computed tomography (PET/CT) has association with bone marrow infiltration (BMI) in comparison to other conventional PET metrics. Material and methods: Forty-four patients (with pathologically proven lymphoma disease) underwent staging $^{18}F-FDG PET/CT$ scan. Primary tumour was semi-automatically or manually segmented with a threshold standardised uptake value (SUV) of 3. A total of 73 features were extracted from eight different textures. Spearman correlation was used to test the correlation of features with conventional quantitative metrics such as SUV, metabolic tumour volume, and total lesion glycolysis. Specificity and sensitivity (including 95% confidence intervals [CI]) for each of the studied parameters were derived using receiver operative characteristic (ROC) curves. Univariate and multivariate analyses were used to identify independent predictors associated with BMI. Results: Correlation between conventional PET metrics and features ranged between 0.50 and 0.97 for positive correlation (33 significant association features) and ranged from -0.52 to -0.97 for inverse correlation (three significant association features) for both strong and moderate correlations. Analysis of ROC curves showed that high-intensity long-run emphasis 4 bin, high-intensity large zone emphasis 64 bin, long-run emphasis (LRE) 64 bin, large-zone emphasis 64 bin, max spectrum 8 bin, busyness 64 bin, and code similarity 32 and 64 bin were significant discriminators of BMI among other features (area under curve > 0.682, p < 0.05). Univariate analyses of texture features showed that code similarity and long-run emphasis (both 64 bin) were significant predictors of bone marrow involvement. Multivariate analyses revealed that LRE (64 bin, p = 0.031) with an odds ratio of 1.022 and 95% CI of (1.002-1.043) were independent variables for bone marrow involvement. Conclusions: $^{18}F-FDG PET/CT$ radiomic features are synergistic to visual assessment of BMI in patients diagnosed with lymphoma using $^{18}F-FDG PET/CT$. Further assessment of long-run emphasis is highly warranted.

Despite continuous improvements of AML therapy, the prognosis of AML patients remains unsatisfactory. Recently, lncRNAs have been reported to participate in the development of AML. Our data demonstrated that MMP15 and LINC00963 were upregulated and miR-608 was decreased in AML cells (THP-1, HL-60, HEL and MOLM-13) compared to HS-5 cells. RT-qPCR results showed that LINC00963 levels were higher in the serum and bone marrow of AML cases than in controls. Moreover, overexpression of LINC00963 promoted AML cell growth and EMT progression in both THP-1 and HL-60 cells. Furthermore, miR-608 levels were downregulated in the serum and bone marrow of AML cases compared with controls, and Pearson's correlation analysis indicated that LINC00963 was negatively correlated with miR-608 in the serum and bone marrow of AML samples. In addition, we demonstrated that LINC00963 sponged miR-608 expression and that MMP-15 was a target of miR-608 in AML cells. Finally, rescue experiments indicated that ectopic expression of LINC00963 accelerated cell growth and EMT development by modulating MMP-15. These data demonstrated that LINC00963 acted as an oncogene and may be a potential target for AML treatment.

Rationale: Articular cartilage injury is quite common. However, post-injury cartilage repair is challenging and often requires medical intervention, which can be aided by 3D printed tissue engineering scaffolds. Specifically, the high accuracy of Melt Electro-Writing (MEW) technology facilitates the printing of scaffolds that imitate the structure and composition of natural cartilage to promote repair. Methods: MEW and Inkjet printing technology was employed to manufacture a composite scaffold that was then implanted into a cartilage injury site through microfracture surgery. While printing polycaprolactone (PCL) or PCL/hydroxyapatite (HA) scaffolds, cytokine-containing microspheres were sprayed alternately to form multiple layers containing transforming growth factor-β1 and bone morphogenetic protein-7 (surface layer), insulin-like growth factor-1 (middle layer), and HA (deep layer). Results: The composite biological scaffold was conducive to adhesion, proliferation, and differentiation of mesenchymal stem cells recruited from the bone marrow and blood. Meanwhile, the environmental differences between the scaffold's layers contributed to the regional heterogeneity of chondrocytes and secreted proteins to promote functional cartilage regeneration. The biological effect of the composite scaffold was validated both in vitro and in vivo. Conclusion: A cartilage repair scaffold was established with high precision as well as promising mechanical and biological properties. This scaffold can promote the repair of cartilage injury by using, and inducing the differentiation and expression of, autologous bone marrow mesenchymal stem cells.

The immune system plays a vital role in cancer therapy, especially with the advent of immunotherapy. Radiation therapy induces iatrogenic immunosuppression referred to as radiation-induced lymphopenia (RIL). RIL correlates with significant decreases in the overall survival of cancer patients. Although the etiology and severity of lymphopenia are known, the mechanism(s) of RIL are largely unknown. We found that irradiation not only had direct effects on circulating lymphocytes but also had indirect effects on the spleen, thymus, and bone marrow. We found that irradiated cells traffic to the bone marrow and bring about the reduction of hematopoietic stem cells (HSC) and progenitor cells. Using mass cytometry analysis (CyTOF) of the bone marrow, we found reduced expression of CD11a, which is required for T cell proliferation and maturation. RNA Sequencing and gene set enrichment analysis of the bone marrow cells following irradiation showed down-regulation of genes involved in hematopoiesis. Identification of CD11a and hematopoietic genes involved in iatrogenic immune suppression can help identify mechanisms of RIL.

This study planned to investigate the relationship of dynamic thiol/disulfide homeostasis with the prognosis of myelodysplastic syndrome (MDS).80 patients who had been diagnosed with MDS between 2012 and 2017 and who were older than 18 were included in the study together with 80 healthy control subjects. The MDS diagnosis was confirmed using bone marrow aspiration-biopsy immunostaining. Dynamic thiol/disulfide homeostasis and ischemia-modified albumin (IMA) levels were examined.The average IMA (0.71±0.08 vs. 0.67±0.09; p=0.002), median disulfide (18.0 vs. 11.6; p0.001), median disulfide/native thiol (6 vs. 3; p0.001), and median disulfide/total thiol (5.4 vs. 2.9; p0.001) were found higher in the MDS patients compared to control group, and the median hemoglobin, median white blood cell count, median neutrophil count, median lymphocyte count, average native thiol (290.7±48.5 vs. 371.5±103.8; p0.001), average total thiol (328.2±48.9 vs. 393±105.5; p0.001), and average native thiol/total thiol (%) (88.3±4.3 vs. 94.2±2.1; p0.001) were found to below. Risk factors such as collagen tissue disease (HR:9.17; p=0.005), MDS-EB-1 (HR:10.14; p=0.032), MDS-EB-2 (HR:18.2; p=0.043), and disulfide/native thiol (HR:1.17; p=0.023) were found as the independent predictors anticipating progression to acute myeloid leukemia. In the Cox regression model, risk factors such as age (HR:1.05; p=0.002), MDS-EB-1 (HR:12.58; p0.001), MDS-EB-2 (HR:5.75; p=0.033), disulfide/native thiol (HR:1.14; p=0.040), and hemoglobin (HR:0.64; p=0.007) were found as predictors anticipating for mortality.We can argue that dynamic thiol/disulfide homeostasis could have significant effects on both the etiopathogenesis and the survival of patients with MDS, and it could be included in new prognostic scoring systems.Plan ove studije je bio da istraži vezu dinamične tiol/disulfidne homeostaze i prognoze mijelodisplastičnog sindroma (MDS).U istraživanje je uključeno 80 pacijenata kojima je dijagnostifikovan MDS između 2012. i 2017, starijih od 18 godina, i 80 zdravih kontrolnih ispitanika. MDS dijagnoza je potvrđena imunološkim bojenjem koštane srži dobijene aspiracionom biopsijom. Ispitani su dinamična tiol/disulfidna homeostaza i nivoi albumina modifikovanog ishemijom (IMA).Otkriveno je da su vrednosti prosečnog IMA (0,71 ± 0,08 nasuprot 0,67 ± 0,09; p = 0,002), vrednost medijane disulfida (18,0 naspram 11,6; p0,001) i disulfid/nativniog tiola (6 naspram 3; p0,001) i medijane disulfid/ukupnog tiola (5,4 naspram 2,9; p0,001) veće kod bolesnika sa MDS-om u poređenju sa kontrolnom grupom. Takođe, otkrivene su i niske vrednosti medijane hemoglobina, belih krvnih zrnaca, neutrofila, limfocita, prosečnog nativnog tiola (290,7 ± 48,5 naspram 371,5 ± 103,8; p0,001), prosečnog ukupnog tiola (328,2 ± 48,9 u odnosu na 393 ± 105,5; p0,001) i prosečnog nativnog tiola/ukupni tiol (%) (88,3 ± 4,3 prema 94,2 ± 2,1; p0,001). Faktori rizika poput bolesti kolagenskih tkiva (HR: 9,17; p = 0,005), MDS-EB-1 (HR: 10,14; p = 0,032), MDS-EB-2 (HR: 18,2; p = 0,043), i disulfid/nativni tiol (HR: 1,17; p = 0,023) su otkriveni kao nezavisni prediktori koji predviđaju napredovanje do akutne mijeloidne leukemije. Po Koksovom modelu regresije, faktori rizika kao što su starost (HR: 1,05; p = 0,002), MDS-EB-1 (HR: 12,58; p0,001), MDS-EB-2 (HR: 5,75; p = 0,033), disulfid/nativni tiol (HR: 1,14; p = 0,040) i hemoglobin (HR: 0,64; p = 0,007) smatraju se prediktorima smrtnosti.Možemo tvrditi da bi dinamička tiol-disulfidna homeostaza mogla da ima značajne efekte i na etiopatogenezu i na preživljavanje pacijenata sa MDS-om i da bi mogla biti uključena u nove prognostičke skoring sisteme.

Telomeres length and telomerase activity are currently considered aging molecular stigmata. Water is a major requirement for our body and water should be alkaline. Recent reports have shown that aging is related to a reduced water intake. We wanted to investigate the effect of the daily intake of alkaline water on the molecular hallmark of aging and the anti-oxidant response. We watered a mouse model of aging with or without alkaline supplementation. After 10 months, we obtained the blood, the bone marrow and the ovaries from both groups. In the blood, we measured the levels of ROS, SOD-1, GSH, and the telomerase activity and analysed the bone marrow and the ovaries for the telomeres length. We found reduced ROS levels and increased SOD-1, GSH, telomerase activity and telomeres length in alkaline supplemented mice. We show here that watering by using alkaline water supplementation highly improves aging at the molecular level.

Fine-tuning of osteoclast differentiation (OD) and bone remodeling is crucial for bone homeostasis. Dissecting the mechanisms regulating osteoclastogenesis is fundamental to understanding the pathogenesis of various bone disorders including osteoporosis and arthritis. Nuclear factor erythroid 2-related factor 1 (NFE2L1, also known as NRF1), which belongs to the CNC-bZIP family of transcription factors, orchestrates a variety of physiological processes and stress responses. While Nfe2l1 gene may be transcribed into multiple alternatively spliced isoforms, the biological function of the different isoforms of NFE2L1 in bone metabolism, osteoclastogenesis in particular, has not been reported. Here we demonstrate that knockout of all isoforms of Nfe2l1 transcripts specifically in the myeloid lineage in mice [Nfe2l1(M)-KO] results in increased activity of osteoclasts, decreased bone mass and worsening of osteoporosis induced by ovariectomy and aging. In comparison, LysM-Cre-mediated Nfe2l1 deletion has no significant effect on the osteoblast and osteocytes. Mechanistic investigations using bone marrow cells and RAW 264.7 cells revealed that deficiency of Nfe2l1 leads to accelerated and elevated OD, which is attributed, at least in part, to enhanced accumulation of ROS in the early stage of OD and expression of nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 1α (Nfatc1/α). In addition, NFE2L1 regulates the transcription of multiple antioxidant genes and Nfatc1/α and OD in an isoform-specific manner. While long isoforms of NFE2L1 function as accelerators of induction of Nfatc1/α and antioxidant genes and OD, the short isoform NFE2L1-453 serves as a brake that keeps the long isoforms’ accelerator effects in check. These findings provide a novel insight into the regulatory roles of NFE2L1 in osteoclastogenesis and highlight that NFE2L1 is essential in regulating bone remodeling and thus may be a valuable therapeutic target for bone disorders., Graphical abstract Image 1, Highlights • Nfe2l1(M)-KO mice exhibit reduced bone mass and elevated osteoclast activity. • Lack of Nfe2l1 in myeloid lineage cells results in elevated osteoclastogenesis. • Lack of Nfe2l1 leads to ROS accumulation accelerating osteoclastogenesis. • Long isoforms of NFE2L1 positively regulate Nfatc1/α and osteoclastogenesis. • S-NFE2L1-453 functions as a brake on Nfatc1/α transcription and osteoclastogenesis.

Objective To test the hypothesis that superficial cartilage composition (T2) is associated with subsequent incidence or worsening of cartilage damage, and deep T2 with that of bone marrow lesions (BMLs) in knees without radiographic osteoarthritis (ROA). Design A total of 201 knees from the Osteoarthritis Initiative without ROA were included: 78 from the healthy reference cohort, 60 without ROA but with risk factors, and 63 without ROA but with contralateral ROA. Year 1 (Y1) superficial and deep cartilage T2 were derived in the medial and lateral (weightbearing) femur (MF/LF) and tibia (MT/LT), using sagittal multiecho spin echo magnetic resonance images. Cartilage and BMLs were assessed in the medial (MFTJ) and lateral femorotibial joint (LFTJ) at Y1 and 3 years later. Binary logistic regression statistics were applied. Results Incidence or worsening of cartilage damage was more frequent (MFTJ 15%, LFTJ 13%) than incidence or worsening of BMLs (6.0%, 4.5%). In knees with incident or worsening cartilage lesions in the MF and LT, deep layer T2 in the same plate was elevated (MF, 43.6 ± 4.0 vs. 41.3 ± 3.8 ms, P = 0.047; LT, 33.8 ± 2.3 vs. 32.0 ± 2.2 ms, P = 0.008) compared to those without. In knees with incident or worsening of BMLs in the LFTC and LT, superficial layer T2 was elevated (LFTJ, 49.6 ± 4.8 vs. 46.7 ± 3.1 ms; LT, 47.4 ± 4.9 vs. 44.0 ± 3.3 ms, both Ps = 0.04). Conclusions Contrary to our hypothesis, increased deep layer cartilage T2 was associated with subsequent worsening of cartilage damage, whereas superficial layer T2 was related to subsequent BML worsening. Yet, this relationship was observed in some, but not in all cartilage plates.