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Pulmonary hypoplasia and respiratory failure are primary causes of death in patients with osteogenesis imperfecta (OI) type II. OI is a genetic skeletal disorder caused by pathogenic variants in genes encoding collagen type I. It is still unknown if the collagen defect also affects lung development and structure, causing lung hypoplasia in OI type II. The aim of this study was to investigate the intrinsic characteristics of OI embryonic lung parenchyma and to determine whether altered collagen type I may compromise airway development and lung structure. Lung tissue from nine fetuses with OI type II and six control fetuses, matched by gestational age, was analyzed for TTF-1 and collagen type I expression by immunohistochemistry, to evaluate the state of lung development and amount of collagen. The differentiation of epithelium into type 2 pneumocytes during embryonic development was premature in OI type II fetuses compared to controls (p

IntroductionRecent evidence suggests that the bone marrow (BM) plays a key role in the diffusion of P. falciparum malaria by providing a “niche” for the maturation of the parasite gametocytes, responsible for human-to-mosquito transmission. Suitable humanized in vivo models to study the mechanisms of the interplay between the parasite and the human BM components are still missing.MethodsWe report a novel experimental system based on the infusion of immature P. falciparum gametocytes into immunocompromised mice carrying chimeric ectopic ossicles whose stromal and bone compartments derive from human osteoprogenitor cells.ResultsWe demonstrate that immature gametocytes home within minutes to the ossicles and reach the extravascular regions, where they are retained in contact with different human BM stromal cell types.DiscussionOur model represents a powerful tool to study BM function and the interplay essential for parasite transmission in P. falciparum malaria and can be extended to study other infections in which the human BM plays a role.

Despite the significant improvements in terms of gender equality in recent years, numerous gaps – especially, the one related to the labour market – still persist all over the world also due to the COVID-19 pandemic. The present research intends to discuss whether the controversial gender quota systems – introduced in many countries as a form of positive action to foster a more diverse work environment – could face the crisis in order to avoid the loss of decades’ worth of achievements on equality. We chose to compare Italy – which implemented the quote rosa system in 2011 with mixed results – and Japan – which is reviewing its plan to promote women’s development after failing to achieve its objective of having at least 30% of women in leadership positions by 2020 – because both countries were still far from reaching their goals about gender equality and, therefore, in a vulnerable position when the pandemic hit., Italian Labour Law e-Journal, Vol. 15 No. 2 (2022)

Mastocytosis can be associated with other clonal or non-clonal hematologic diseases as well as a variety of non-hematologic malignancies. A 75-year-old Caucasian male patient was referred to us with a 5-month history of neutrophilic leukocytosis and mild splenomegaly. He had developed a cutaneous melanoma sixteen years ago. According to the clinical and pathological features, a final diagnosis of systemic mastocytosis was established. The patient started treatment with interferon-α at a dose of 3 MIU/day, combined with low doses of prednisone. We observed a rapid disappearance of symptoms. Unfortunately, after 3 months a diagnosis of pancreatic adenocarcinoma was established. A review of the literature suggests that mastocytes could have a pivotal role in several malignancies. Different chemokines, mitogenic factors, chemical mediators of inflammation, and specific gene mutations could explain the association between mastocytosis and other hematologic and non-hematologic disorders.

An experimental model of osteoarthrosis (OA) induced by injection of vitamin A in knees of rabbits is presented. This model represents a modification and improvement of a preexisting one (Boni et al., 1977; Benazzo et al., 1982) based on a higher number of vitamin A injections. In our model, two vitamin A injections were sufficient to induce OA without exposure of the subchondral bone. The advantages of this model are: 1) the maintaining of articular cartilage could make the experimental joints suitable to test the reparative efficiency of candidate intra-articular pharmacological treatments, 2) animal stress and the risk of infections are strongly reduced in compliance with European legislation on laboratory animal welfare., Scandinavian Journal of Laboratory Animal Sciences, Vol 31, N0 1 (2004)

Activating mutations of the GNAS gene, which causes fibrous dysplasia of bone (FD), lead to remarkable changes in the properties of skeletal progenitors, and it is these changes that mediate the pathological effect of this gene on bone. Mutated skeletal stem cells lose the ability to differentiate into adipocytes, and to maintain in situ, and transfer heterotopically, the hematopoietic microenvironment, leading to abnormal bone marrow histology in FD. They overexpress molecular effectors of osteoclastogenesis, thus promoting inappropriate bone resorption leading to fragility of FD bone. They express the phosphate-regulating hormone FGF-23 at normal levels, whose excess in the serum of FD patients correlates with the massof osteogenic cells withinFDlesions, leading to osteomalacia and deformity of theFDbone, and revealing that bone is an endocrine organ regulating renal handling of phosphate. Mechanisms of allelic selection and stem cell selection occur in mutated skeletal stem cells and contribute to the inherent diversity and evolution over time in FD. The definition of the etiological role of GNAS mutations marks the watershed between many decades of descriptive observation and the definition of cellular and molecular mechanisms that would explain and hopefully allow for a cure for the disease. Placing stem cells at center stage has permitted substantial advances in one decade, and promises more for the one to come.

Mesenchymal stromal cells (MSCs) represent an essential component of the bone marrow (BM) niche and display disease-specific alterations in several myeloid malignancies. The aim of this work was to study possible MSC abnormalities in Philadelphia-negative myeloproliferative neoplasms (MPNs) in relationship to the degree of BM fibrosis. MSCs were isolated from BM of 6 healthy donors (HD) and of 23 MPN patients, classified in 3 groups according to the diagnosis and the grade of BM fibrosis: polycythemia vera and essential thrombocythemia (PV/ET), low fibrosis myelofibrosis (LF-MF), and high fibrosis MF (HF-MF). MSC cultures were established from 21 of 23 MPN patients. MPN-derived MSCs did not exhibit any functional impairment in their adipogenic/osteogenic/chondrogenic differentiation potential and displayed a phenotype similar to HD-derived MSCs but with a decreased expression of CD146. All MPN-MSC lines were negative for the patient-specific hematopoietic clone mutations (JAK2, MPL, CALR). MSCs derived from HF-MF patients displayed a reduced clonogenic potential and a lower growth kinetic compared to MSCs from HD, LF-MF, and PV/ET patients. mRNA levels of hematopoiesis regulatory molecules were unaffected in MSCs from HF-MF compared to HD. Finally, in vitro ActivinA secretion by MSCs was increased in HF-MF compared to LF-MF patients, in association with a lower hemoglobin value. Increased ActivinA immunolabeling on stromal cells and erythroid precursors was also observed in HF-MF BM biopsies. In conclusion, higher grade of BM fibrosis is associated with functional impairment of MSCs and the increased secretion of ActivinA may represent a suitable target for anemia treatment in MF patients.

Mucopolysaccharidosis type I (MPS-I), a lysosomal storage disorder caused by a deficiency of alpha-L-iduronidase enzyme, results in the progressive accumulation of glycosaminoglycans and consequent multiorgan dysfunction. Despite the effectiveness of hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT) in correcting clinical manifestations related to visceral organs, complete improvement of musculoskeletal and neurocognitive defects remains an unmet challenge and provides an impact on patients' quality of life. We tested the therapeutic efficacy of combining HSCT and ERT in the neonatal period. Using a mouse model of MPS-I, we demonstrated that the combination therapy improved clinical manifestations in organs usually refractory to current treatment. Moreover, combination with HSCT prevented the production of anti-IDUA antibodies that negatively impact ERT efficacy. The added benefits of combining both treatments also resulted in a reduction of skeletal anomalies and a trend towards decreased neuroinflammation and metabolic abnormalities. As currently there are limited therapeutic options for MPS-I patients, our findings suggest that the combination of HSCT and ERT during the neonatal period may provide a further step forward in the treatment of this rare disease.

Umbilical cord blood (UCB) is a promising source of stem cells to use in early haematopoietic stem cell transplantation (HSCT) approaches for several genetic diseases that can be diagnosed at birth. Mucopolysaccharidosis type I (MPS-I) is a progressive multi-system disorder caused by deficiency of lysosomal enzyme α-L-iduronidase, and patients treated with allogeneic HSCT at the onset have improved outcome, suggesting to administer such therapy as early as possible. Given that the best characterized MPS-I murine model is an immunocompetent mouse, we here developed a transplantation system based on murine UCB. With the final aim of testing the therapeutic efficacy of UCB in MPS-I mice transplanted at birth, we first defined the features of murine UCB cells and demonstrated that they are capable of multi-lineage haematopoietic repopulation of myeloablated adult mice similarly to bone marrow cells. We then assessed the effectiveness of murine UCB cells transplantation in busulfan-conditioned newborn MPS-I mice. Twenty weeks after treatment, iduronidase activity was increased in visceral organs of MPS-I animals, glycosaminoglycans storage was reduced, and skeletal phenotype was ameliorated. This study explores a potential therapy for MPS-I at a very early stage in life and represents a novel model to test UCB-based transplantation approaches for various diseases.

Background aims: Cord blood (CB) and amniotic fluid (AF) could represent new and attractive mesenchymal stromal cell (MSC) sources, but their potential therapeutic applications are still limited by lack of standardized protocols for isolation and differentiation. In particular, chondrogenic differentiation has never been deeply investigated. Methods: MSCs were obtained from CB and AF samples collected during cesarean sections at term and compared for their biological and differentiation properties, with particular interest in cartilage differentiation, in which quantitative real-time polymerase chain reaction and immunohistochemical analyses were performed to evaluate the expression of type 2 collagen, type 10 collagen, SRY-box9 and aggrecan. Results: We were able to isolate MSCs from 12 of 30 (40%) and 5 of 20 (25%) CB and AF units, respectively. Fluorescence in situ hybridization analysis indicated the fetal origin of isolated MSC strains. Both populations expressed mesenchymal but not endothelial and hematopoietic markers, even though we observed a lower expression of human leukocyte antigen (HLA) I in CB-MSCs. No differences in proliferation rate and cell cycle analysis could be detected. After osteogenic induction, both populations showed matrix mineralization and typical marker expression. Under chondrogenic conditions, pellets derived from CB-MSCs, in contrast with AF-MSCs pellets, were significantly larger, showed cartilage-like morphology and resulted positive for chondrocyte-associated markers, such as type 2 collagen, type 10 collagen, SRY-box9 and aggrecan. Conclusions: Our results show that CB-MSCs and AF-MSCs collected at term differ from each other in their biological and differentiation properties. In particular, only CB-MSCs showed a clear chondrogenic potential and thus could represent an ideal candidate for cartilage-tissue engineering.

Human umbilical cord blood (CB) has attracted much attention as a reservoir for functional hematopoietic stem and progenitor cells, and, recently, as a source of blood-borne fibroblasts (CB-BFs). Previously, we demonstrated that bone marrow stromal cell (BMSC) and CB-BF pellet cultures make cartilage in vitro. Furthermore, upon in vivo transplantation, BMSC pellets remodelled into miniature bone/marrow organoids. Using this in vivo model, we asked whether CB-BF populations that express characteristics of the hematopoietic stem cell (HSC) niche contain precursors that reform the niche. CB ossicles were regularly observed upon transplantation. Compared with BM ossicles, CB ossicles showed a predominance of red marrow over yellow marrow, as demonstrated by histomorphological analyses and the number of hematopoietic cells isolated within ossicles. Marrow cavities from CB and BM ossicles included donor-derived CD146-expressing osteoprogenitors and host-derived mature hematopoietic cells, clonogenic lineage-committed progenitors and HSCs. Furthermore, human CD34+ cells transplanted into ossicle-bearing mice engrafted and maintained human HSCs in the niche. Our data indicate that CB-BFs are able to recapitulate the conditions by which the bone marrow microenvironment is formed and establish complete HSC niches, which are functionally supportive of hematopoietic tissue.

Neonatal bone marrow transplantation (nBMT) could offer a novel therapeutic opportunity for genetic disorders by providing sustainable levels of the missing protein at birth, thus preventing tissue damage. We tested this concept in Mucopolysaccharidosis type I (MPS IH, Hurler syndrome), a lysosomal storage disorder caused by deficiency of α-L-iduronidase (IDUA). MPS IH is characterized by a broad spectrum of clinical manifestations including severe progressive skeletal abnormalities. Although BMT increases the life span of MPS IH patients, musculoskeletal manifestations are only minimally responsive if the timing of BMT delays, suggesting already irreversible bone damage. In this study, we tested the hypothesis that transplanting normal bone marrow into newborn MPS I mice, soon after birth, can prevent skeletal dysplasia. 1- to 2-day-old mutant mice were conditioned using a single administration of 20 mg/kg busulfan and then injected via the superficial temporal vein with 2 x 106 bone marrow cells from wild type (WT) donors. Age-matched WT and untreated MPS I mice were used as controls. Transplantation of normal bone marrow cells into preconditioned MPS I and WT neonates led to a similar engraftment level at 37 weeks after nBMT (peripheral blood, median MPS I nBMT 81.30%, range from 0.80% to 95.80% vs. median WT nBMT 67.45%, range from 16.00% to 95.86%, p = 0.714). Spleen, PB and thymus cells of nBMT MPS I mice were repopulated with committed lymphoid and myeloid populations similar to the transplanted WT mice. The >50% replacement of the hematopoiesis resulted in a measurable increase in IDUA activity in visceral organs, especially in the spleen, showing a correlation between engraftment levels and enzyme activity with clearance of GAGs from blood and tissues. At the time of euthanasia (37-week-old), reconstitution of normal hematopoiesis in MPS I mice was associated with a consistent amelioration of bone pathology, as revealed by radiographic skeletal examination. Radiographic analysis has shown that the width of the humerus, radius/ulna, femur and tibia of untreated MPS I mice was significantly larger at comparison with WT littermates. For MPS I nBMT mice, long bone widths, including the humerus (p = 0.0014, vs. untreated MPS I mice), the radius/ulna (p = 0.0003, vs. untreated MPS I mice), the femur (p = 0.0003, vs. untreated MPS I mice), and the tibia (p = 0.0003, vs. untreated MPS I mice) significantly decreased, compared to untreated MPS I mice. Furthermore, several three-dimensional architectural parameters in femurs such as trabecular number and separation, cortical thickness and bone mineral volume were analyzed by micro-CT, resulting in a significant difference between untreated and nBMT MPS I mice. All examined nBMT MPS I mice displayed bone parameter values comparable to WT mice, confirming that nBMT mice had significant improvements in skeletal phenotype approaching complete normalization of each parameter tested. Histologically, in MPS I cortical bone, osteocytes were increased and contained vacuoles, likely reflecting GAGs storage. Histological amelioration of these features was consistently observed in femurs of all nBMT mice with a definite reduction in both hyperosteocytosis and lysosomal vacuolization, confirming that the perinatal treatment of the disease can positively impact the skeletal phenotype in MPS I. We also evaluated KS levels in the blood as a biomarker of MPS with skeletal dysplasia. Normalization of blood KS level strongly supports the notion that nBMT corrects the pathological and clinical bone lesions in nBMT MPS I mice. Our findings demonstrate that nBMT prevents some of the relevant abnormalities of the skeletal pathology in the MPS I mouse model. Moreover, improvements in bone parameters correlated with high levels of bone marrow-derived cell engraftment in multiple hematopoietic compartments, suggesting that the early and complete restoration of normal hematopoiesis can have significant impact on the bone development of newborn MPS I mice. Future clinical trials are needed to confirm our findings. Disclosures No relevant conflicts of interest to declare.

Mucopolysaccharidosis type I (MPS IH; Hurler syndrome) is a rare genetic disorder that is caused by mutations in the α-L-iduronidase (IDUA) gene, resulting in the deficiency of IDUA enzyme activity and intra-cellular accumulation of glycosaminoglycans. A characteristic skeletal phenotype is one of the many clinical manifestations in Hurler disease. Since the mechanism(s) underlying these skeletal defects are not completely understood, and bone and cartilage are mesenchymal lineages, we focused on the characterization of mesenchymal cells isolated from the bone marrow (BM) of 5 Hurler patients. IDUA-mutated BM stromal cells (BMSC) derived from MPS IH patients exhibited decreased IDUA activity, consistent with the disease genotype. The expansion rate, phenotype, telomerase activity, and differentiation capacity toward adipocytes, osteoblasts, chondrocytes, and smooth muscle cells in vitro of the MPS I BMSC lines were similar to those of BMSC from age-matched normal control donors. MPS I BMSC also had a similar in vivo osteogenic capacity as normal BMSC. However, MPS I BMSC displayed an increased capacity to support osteoclastogenesis, which may correlate with the up-regulation of the RANKL/RANK/OPG molecular pathway in MPS I BMSC compared with normal BMSC.