Aggressive variant prostate cancer with multiple subcutaneous metastases: a case report.

A 71-year-old man with bone metastasis of hormone-sensitive prostate cancer was treated with androgen deprivation therapy and apalutamide. Radium-223 and radiation therapy were administered after it become castration resistant. Although prostate-specific antigen levels remained low, multiple subcutaneous metastases of neuroendocrine prostate cancer were observed. A review of the pre-treatment prostate needle biopsy revealed a small component with features suggestive of neuroendocrine differentiation. Phosphatase and tensine homolog loss and tumor protein p53 overexpression were observed, confirming the diagnosis of aggressive variant prostate cancer. Platinum-based chemotherapy was administered; however, the patient died 28 months after diagnosis. In this case, if the diagnosis of aggressive variant prostate cancer had been made at an earlier time by biopsy specimens, there might have been a possibility to improve the prognosis by the earlier introduction of the platinum-based regimen. Supplementary Information: The online version contains supplementary material available at 10.1007/s13691-024-00673-7.

Quantitative parameters of dual-layer spectral detector computed tomography for evaluating differentiation grade and lymphovascular and perineural invasion in colorectal adenocarcinoma.

PURPOSE: To explore the predictive value of dual-layer spectral detector CT (SDCT) quantitative parameters for determining differentiation grade, lymphovascular invasion (LVI) and perineural invasion (PNI) in colorectal adenocarcinoma (CRAC) patients. METHODS: A total of 106 eligible patients with CRAC were included in this study. Spectral parameters, including CT values at 40 and 100 keV, the effective atomic number (Zeff), the iodine concentration (IC), the slope of the spectral Hounsfield unit (HU) curve (λHU), and the normalized iodine concentration (NIC) in the arterial phase (AP) and venous phase (VP), were compared according to the differentiation grade and the status of LVI and PNI. The diagnostic accuracies of the quantitative parameters with statistical significance were determined via receiver operating characteristic (ROC) curves, and the area under the curve (AUC) was calculated. RESULTS: There were 57 males and 49 females aged 43-86 (69 ± 10) years. The measured values of the spectral quantitative parameters of the CRAC were consistent within the observer (ICC range: 0.800-0.926). The 40 keV-AP, IC-AP, NIC-AP, 40 keV-VP, and IC-VP were significantly different among the different differentiation grades in the CRAC (P = 0.040, AUC = 0.673; P = 0.035, AUC = 0.684; P = 0.031, AUC = 0.639; P = 0.044, AUC = 0.663 and P = 0.035, AUC = 0.666, respectively). A statistically significant difference was observed in 40 keV-VP, 100 keV-VP, Zeff-VP, IC-VP, and λHU-VP between LVI-positive and LVI-negative patients (P = 0.003, AUC = 0.688; P = 0.015, AUC = 0.644; P = 0.001, AUC = 0.688; P = 0.001, AUC = 0.703 and P = 0.003, AUC = 0.677, respectively). There were no statistically significant differences in the values of the spectral parameters of the PNI state of patients with CRAC (P > 0.05). CONCLUSION: The quantitative parameters of SDCT had good diagnostic efficacy in differentiating between different grades and statuses of LVI in patients with CRAC; however, SDCT did not have value for identifying the state of PNI.

The dynamic expression of YAP is essential for the development of male germ cells derived from human embryonic stem cells.

YAP plays a vital role in controlling growth and differentiation in various cell lineages. Although the expression of YAP in mice testicular and spermatogenic cells suggests its role in mammalian spermatogenesis, the role of YAP in the development of human male germ cells has not yet been determined. Using an in vitro model and a gene editing approach, we generated human spermatogonia stem cell-like cells (hSSLCs) from human embryonic stem cells (hESCs) and investigated the role of YAP in human spermatogenesis. The results showed that reducing YAP expression during the early stage of spermatogenic differentiation increased the number of PLZF+ hSSLCs and haploid spermatid-like cells. We also demonstrated that the up-regulation of YAP is essential for maintaining spermatogenic cell survival during the later stages of spermatogenic differentiation. The expression of YAP that deviates from this pattern results in a lower number of hSSLCs and an increased level of spermatogenic cell death. Taken together, our result demonstrates that the dynamic expression pattern of YAP is essential for human spermatogenesis. Modulating the level of YAP during human spermatogenesis could improve the production yield of male germ cells derived from hESCs, which could provide the optimization method for in vitro gametogenesis and gain insight into the application in the treatment of male infertility.

Melanoma Differentiation-associated Gene 5-Positive Rapidly Progressive Interstitial Lung Disease Successfully Treated with Tofacitinib.

Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody-positive dermatomyositis is associated with rapidly progressive interstitial lung disease (RP-ILD). We encountered a man in his 40s who presented with a history of a fever and dry cough. Based on laboratory tests and computed tomography scans of his chest, he was diagnosed with anti-MDA5 antibody-positive dermatomyositis with RP-ILD refractory to antimicrobial agents. Although the patient was treated with glucocorticoids, calcineurin inhibitors, intravenous cyclophosphamide, and plasma exchange, ventilatory management was still required. The patient survived additional therapy with tofacitinib; however, he developed a catheter-related pulmonary embolism as a complication.

Human platelet lysate supports SH-SY5Y neuroblastoma cell proliferation and differentiation into a dopaminergic-like neuronal phenotype under xenogeneic-free culture conditions.

SH-SY5Y is a human neuroblastoma cell line that can be differentiated into several neuronal phenotypes, depending on culture conditions. For this reason, this cell line has been widely used as an in vitro model of neurodegenerative conditions, such as Parkinson's disease (PD). However, most studies published to date used fetal bovine serum (FBS) as culture medium supplement for SH-SY5Y cell differentiation. We report on the testing of human platelet lysate (hPL) as a culture medium supplement to support SH-SY5Y cell culture. Both standard hPL and a fibrinogen-depleted hPL (FD-hPL) formulation, which does not require the addition of anticoagulants to culture media, promoted an increase in SH-SY5Y cell proliferation in comparison to FBS, without compromising metabolic activity. SH-SY5Y cells cultured in hPL or FD-hPL also displayed a higher number of neurite extensions and stained positive for MAP2 and synaptophysin, in the absence of differentiation stimuli; reducing hPL or FD-hPL concentration to 1% v/v did not affect cell proliferation or metabolic activity. Furthermore, following treatment with retinoic acid (RA) and further stimulation with brain-derived neurotrophic factor (BDNF) and nerve growth factor beta (NGF-ß), the percentage of SH-SY5Y cells stained positive for dopaminergic neuronal differentiation markers (tyrosine hydroxylase [TH] and Dopamine Transporter [DAT]) was higher in hPL or FD-hPL than in FBS, and gene expression of dopaminergic markers TH, DAT, and DR2 was also detected. Overall, the data herein presented supports the use of hPL to differentiate SH-SY5Y cells into a neuronal phenotype with dopaminergic features, and the adoption of FD-hPL as a fully xenogeneic free alternative to FBS to support the use of SH-SY5Y cells as a neurodegeneration model.

Single cell spatial biology over developmental time can decipher pediatric brain pathologies.

Pediatric low grade brain tumors and neurodevelopmental disorders share proteins, signaling pathways, and networks. They also share germline mutations and an impaired prenatal differentiation origin. They may differ in the timing of the events and proliferation. We suggest that their pivotal distinct, albeit partially overlapping, outcomes relate to the cell states, which depend on their spatial location, and timing of gene expression during brain development. These attributes are crucial as the brain develops sequentially, and single-cell spatial organization influences cell state, thus function. Our underlying premise is that the root cause in neurodevelopmental disorders and pediatric tumors is impaired prenatal differentiation. Data related to pediatric brain tumors, neurodevelopmental disorders, brain cell (sub)types, locations, and timing of expression in the developing brain are scant. However, emerging single cell technologies, including transcriptomic, spatial biology, spatial high-resolution imaging performed over the brain developmental time, could be transformational in deciphering brain pathologies thereby pharmacology.

Emerging role of glutathione peroxidase 4 in myeloid cell lineage development and acute myeloid leukemia.

Phospholipid Hydroperoxide Gluthatione Peroxidase also called Glutathione Peroxidase 4 is one of the 25 described human selenoproteins. It plays an essential role in eliminating toxic lipid hydroxy peroxides, thus inhibiting ferroptosis and favoring cell survival. GPX4 is differentially expressed according to myeloid differentiation stage, exhibiting lower expression in hematopoietic stem cells and polymorphonuclear leucocytes, while harboring higher level of expression in common myeloid progenitors and monocytes. In addition, GPX4 is highly expressed in most of acute myeloid leukemia (AML) subtypes compared to normal hematopoietic stem cells. High GPX4 expression is consistently correlated to poor prognosis in patients suffering AML. However, the role of GPX4 in the development of the myeloid lineage and in the initiation and progression of myeloid leukemia remains poorly explored. Given its essential role in the detoxification of lipid hydroperoxides, and its overexpression in most of myeloid malignancies, GPX4 inhibition has emerged as a promising therapeutic strategy to specifically trigger ferroptosis and eradicate myeloid leukemia cells. In this review, we describe the most recent advances concerning the role of GPX4 and, more generally ferroptosis in the myeloid lineage and in the emergence of AML. We also discuss the therapeutic interest and limitations of GPX4 inhibition alone or in combination with other drugs as innovative therapies to treat AML patients.

Single-cell landscape of alternative polyadenylation in human lymphoid hematopoiesis.

Alternative polyadenylation (APA) is an essential post-transcriptional process that produces mature mRNA isoforms by regulating the usage of polyadenylation sites (PASs). APA is involved in lymphocyte activation; however, its role throughout the entire differentiation trajectory remains elusive. Here, we analyzed single-cell 3'-end transcriptome data from healthy subjects to construct a dynamic-APA landscape from hematopoietic stem and progenitor cells (HSPCs) to terminally differentiated lymphocytes. This analysis covered 19973 cells of 12 clusters from five lineages (B cells, CD4+ T cells, CD8+ T cells, natural killer cells, and plasmacytoid dendritic cells). A total of 2364 genes exhibited differential 3'UTR PAS usage, and 3021 genes displayed differential intronic cleavage during lymphoid differentiation. We observed a global trend of 3'UTR shortening during lymphoid differentiation. Nevertheless, specific events of both 3'UTR shortening and lengthening were also identified within each cluster. The APA patterns delineated three differentiation stages: HSPCs, precursor cells, and mature cells. Moreover, we demonstrated that the conversion of naïve T cells to memory T cells was accompanied by dynamic APA in transcription factor-encoding genes (TCF7 and NFATC2IP), immune function-related genes (BCL2, CD5, CD28, GOLT1B, and TMEM59), and protein ubiquitination-related genes (UBE2G1, YPEL5, and SUMO3). These findings expand our understanding of the underlying molecular mechanisms of APA and facilitate studies on the regulatory role of APA in lymphoid hematopoiesis.

Curcumin-activated Wnt5a pathway mediates Ca2+ channel opening to affect myoblast differentiation and skeletal muscle regeneration.

BACKGROUND: Skeletal muscle injury is one of the most common sports injuries; if not properly treated or not effective rehabilitation treatment after injury, it can be transformed into chronic cumulative injury. Curcumin, an herbal ingredient, has been found to promote skeletal muscle injury repair and regeneration. The Wnt5a pathway is related to the expression of myogenic regulatory factors, and Ca2+ promotes the differentiation and fusion process of myoblasts. This study explored the effect and mechanism of curcumin on myoblast differentiation during the repair and regeneration of injured skeletal muscle and its relationship with the Wnt5a pathway and Ca2+ channel. METHODS: Myogenic differentiation of C2C12 cells was induced with 2% horse serum, and a mouse (male, 10 weeks old) model of acute skeletal muscle injury was established using cardiotoxin (20 µL). In addition, we constructed a Wnt5a knockdown C2C12 cell model and a Wnt5a knockout mouse model. Besides, curcumin was added to the cell culture solution (80 mg/L) and fed to the mice (50 mg/kg). Fluorescence microscopy was used to determine the concentration of Ca2+. Western blot and RT-qPCR were used to detect the protein and mRNA levels of Wnt5a, CaN, NFAT2, MyoD, Myf5, Pax7, and Myogenin. The expression levels of MyoD, Myf5, Myogenin, MHC, Desmin, and NFAT2 were detected using immunofluorescence techniques. In addition, MyoD expression was observed using immunohistochemistry, and morphological changes in mouse muscle tissue were observed using HE staining. RESULTS: During myoblast differentiation and muscle regeneration, Wnt5a expression was upregulated (P < 0.001) and the Wnt5a signalling pathway was activated. Wnt5a overexpression promoted the expression of MyoD, Myf5, Myogenin, MHC, and Desmin (P < 0.05), and conversely, knockdown of Wnt5a inhibited their expression (P < 0.001). The Wnt5a pathway mediated the opening of Ca2+ channels, regulated the expression levels of CaN, NFAT2, MyoD, Myf5, Myogenin, MHC, and Desmin (P < 0.01) and promoted the differentiation of C2C12 myoblasts and the repair and regeneration of injured skeletal muscle. The expression of Wnt5a, CaN, NFAT2, MyoD, Myogenin, Myf5, and MHC in C2C12 myoblast was significantly increased after curcumin intervention (P < 0.05); however, their expression decreased significantly after knocking down Wnt5a on the basis of curcumin intervention (P < 0.05). Similarly, in Wnt5a knockout mice, the promotion of muscle regeneration by curcumin was significantly attenuated. CONCLUSIONS: Curcumin can activate the Wnt5a signalling pathway and mediate the opening of Ca2+ channels to accelerate the myogenic differentiation of C2C12 cells and the repair and regeneration of injured skeletal muscle.

Suppressor of Cytokine Signaling Proteins 3 and 5 Potentially Delineate Polarization of Th cells in Chronic Rhinosinusitis.

Background: Chronic rhinosinusitis (CRS) is an inflammatory condition classified into chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic rhinosinusitis without nasal polyps (CRSsNP). Th cells manage inflammatory cells in CRS. Suppressor of Cytokine Signaling (SOCS) proteins regulate Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in Th cells by polarizing toward Th1, Th2, and Th17 cells. This study evaluated the levels of SOCS1,3,5 in CRS patients to find associations with Th cells. Methods: In this cross-sectional study, 20 CRSwNP patients, 12 CRSsNP patients, and 12 controls participated. The infiltration of CD4+ T cells was determined using immunohistochemistry. The expression of specific transcription factors and SOCS proteins was assessed using real-time PCR. Cytokine levels were evaluated using ELISA. SOCS protein levels were investigated using western blot analysis. Results: The expression of SOCS3 increased in the CRSwNP group compared to CRSsNP and control groups (p <0.001). SOCS3 protein levels increased in the CRSwNP group compared to CRSsNP (p <0.05) and control (p <0.001) groups. Although there was a significant difference in SOCS5 expression between CRSsNP and control groups, SOCS5 protein levels were significantly different between CRSsNP and control (p <0.001) and CRSwNP (p <0.05) groups. Conclusions: Targeted therapies may be suggested for CRS by modulating SOCS3 and SOCS5 proteins that are responsible for polarization of Th cells toward Th2 or Th1 cells, respectively. JAK-STAT pathway targeting, which encompasses numerous cells, can be limited to SOCS proteins to more effectively orchestrate Th cell differentiation.

T. gondii excretory proteins promote the osteogenic differentiation of human bone mesenchymal stem cells via the BMP/Smad signaling pathway.

BACKGROUND: Bone defects, resulting from substantial bone loss that exceeds the natural self-healing capacity, pose significant challenges to current therapeutic approaches due to various limitations. In the quest for alternative therapeutic strategies, bone tissue engineering has emerged as a promising avenue. Notably, excretory proteins from Toxoplasma gondii (TgEP), recognized for their immunogenicity and broad spectrum of biological activities secreted or excreted during the parasite's lifecycle, have been identified as potential facilitators of osteogenic differentiation in human bone marrow mesenchymal stem cells (hBMSCs). Building on our previous findings that TgEP can enhance osteogenic differentiation, this study investigated the molecular mechanisms underlying this effect and assessed its therapeutic potential in vivo. METHODS: We determined the optimum concentration of TgEP through cell cytotoxicity and cell proliferation assays. Subsequently, hBMSCs were treated with the appropriate concentration of TgEP. We assessed osteogenic protein markers, including alkaline phosphatase (ALP), Runx2, and Osx, as well as components of the BMP/Smad signaling pathway using quantitative real-time PCR (qRT-PCR), siRNA interference of hBMSCs, Western blot analysis, and other methods. Furthermore, we created a bone defect model in Sprague-Dawley (SD) male rats and filled the defect areas with the GelMa hydrogel, with or without TgEP. Microcomputed tomography (micro-CT) was employed to analyze the bone parameters of defect sites. H&E, Masson and immunohistochemical staining were used to assess the repair conditions of the defect area. RESULTS: Our results indicate that TgEP promotes the expression of key osteogenic markers, including ALP, Runx2, and Osx, as well as the activation of Smad1, BMP2, and phosphorylated Smad1/5-crucial elements of the BMP/Smad signaling pathway. Furthermore, in vivo experiments using a bone defect model in rats demonstrated that TgEP markedly promoted bone defect repair. CONCLUSION: Our results provide compelling evidence that TgEP facilitates hBMSC osteogenic differentiation through the BMP/Smad signaling pathway, highlighting its potential as a therapeutic approach for bone tissue engineering for bone defect healing.

[The mechanism of SSO regulating SiO(2)-induced lipid metabolism disorders in macrophages was explored based on lipid metabolomics].

Objective: To investigate the mechanism of Sulfo-N-succinimidyloleate (SSO) regulating lipid metabolism disorder induced by silicon dioxide (SiO(2)) . Methods: In March 2023, Rat alveolar macrophages NR8383 were cultured in vitro and randomly divided into control group (C), SSO exposure group (SSO), SiO(2) exposure group (SiO(2)) and SiO(2)+SSO exposure group (SiO(2)+SSO). NR8383 cells were exposure separately or jointly by SSO and SiO(2) for 36 h to construct cell models. Immunofluorescence and BODIPY 493/ 503 staining were used to detect cluster of differentiation (CD36) and intracellular lipid levels, the protein expression levels of CD36, liver X receptors (LXR), P-mammalian target of rapamycin (P-mTOR) and cholinephosphotransferase 1 (CHPT1) were detected by Western blot, respectively, and lipid metabolomics was used to screen for different lipid metabolites and enrichment pathways. Single-factor ANOVA was used for multi-group comparison, and LSD test was used for pair-to-group comparison. Results: SiO(2) caused the expression of CD36 and P-mTOR to increase (P=0.012, 0.020), the expression of LXR to decrease (P=0.005), and the intracellular lipid level to increase. After SSO treatment, CD36 expression decreased (P=0.023) and LXR expression increased (P=0.000) in SiO(2)+SSO exposure group compared with SiO(2) exposure group. Metabolomics identified 87 different metabolites in the C group and SiO(2) exposure group, 19 different metabolites in the SiO(2) exposure group and SiO(2)+SSO group, and 5 overlaps of different metabolites in the two comparison groups, they are PS (22∶1/14∶0), DG (O-16∶0/18∶0/0∶0), PGP (i-13∶0/i-20∶0), PC (18∶3/16∶0), and Sphinganine. In addition, the differential metabolites of the two comparison groups were mainly concentrated in the glycerophospholipid metabolism and sphingolipid metabolism pathways. The differential gene CHPT1 in glycerophospholipid metabolic pathway was verified, and the expression of CHPT1 decreased after SiO(2) exposure. Conclusion: SSO may improve SiO(2)-induced lipid metabolism disorders by regulating PS (22∶1/14∶0), DG (O-16∶0/18∶0/0∶0), PGP (i-13∶0/i-20∶0), PC (18∶3/16∶0), SPA, glycerophospholipid metabolism and sphingolipid metabolism pathways.

The G9a histone methyltransferase represses osteoclastogenesis and bone resorption by regulating NFATc1 function.

Epigenetic modifications affect cell differentiation via transcriptional regulation. G9a/EHMT2 is an important epigenetic modifier that catalyzes the methylation of histone 3 lysine 9 (H3K9) and interacts with various nuclear proteins. In this study, we investigated the role of G9a in osteoclast differentiation. When we deleted G9a by infection of Cre-expressing adenovirus into bone marrow macrophages (BMMs) from G9afl/fl (Ehmt2fl/fl) and induced osteoclastic differentiation by the addition of macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL), the number of TRAP-positive multinucleated osteoclasts significantly increased compared with control. Furthermore, the mRNA expression of osteoclast markers, TRAP, and cathepsin K, and to a lesser extent, NFATc1, a critical transcription factor, increased in G9a KO cells. Infection of wild-type (WT) G9a-expressing adenovirus in G9a KO cells restored the number of TRAP-positive multinucleated cells. In G9a KO cells, increased nuclear accumulation of NFATc1 protein and decreased H3K9me2 accumulation were observed. Furthermore, ChIP experiments revealed that NFATc1 binding to its target, Ctsk promoter, was enhanced by G9a deletion. For in vivo experiments, we created G9a conditional knock-out (cKO) mice by crossing G9afl/fl mice with Rank Cre/+ (Tnfrsf11aCre/+) mice, in which G9a is deleted in osteoclast lineage cells. The trabecular bone volume was significantly reduced in female G9a cKO mice. The serum concentration of the C-terminal telopeptide of type I collagen (CTX), a bone-resorbing indicator, was higher in G9a cKO mice. In addition, osteoclasts differentiated from G9a cKO BMMs exhibited greater bone-resorbing activity. Our findings suggest that G9a plays a repressive role in osteoclastogenesis by modulating NFATc1 function.

Aberrant early hematopoietic progenitor formation marks the onset of hematopoietic defects in Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is an inherited bone marrow failure disorder that often presents at infancy. Progress has been made in revealing causal mutated genes (SBDS and others), ribosome defects, and hematopoietic aberrations in SDS. However, the mechanism underlying the hematopoietic failure remained unknown, and treatment options are limited. Herein, we investigated the onset of SDS embryonic hematopoietic impairments. We generated SDS and control human-derived induced pluripotent stem cells (iPSCs). SDS iPSCs recapitulated the SDS hematological phenotype. Detailed stepwise evaluation of definitive hematopoiesis revealed defects that started at the early emerging hematopoietic progenitor (EHP) stage after mesoderm and hemogenic endothelium were normally induced. Hematopoietic potential of EHPs was markedly reduced, and the introduction of SBDS in SDS iPSCs improved colony formation. Transcriptome analysis revealed reduced expression of ribosome and oxidative phosphorylation-related genes in undifferentiated and differentiated iPSCs. However, certain pathways (e.g., DNA replication) and genes (e.g., CHCHD2) were exclusively or more severely dysregulated in EHPs compared with earlier and later stages. To our knowledge, this study offers for the first time an insight into the embryonic onset of human hematopoietic defects in an inherited bone marrow failure syndrome and reveals cellular and molecular aberrations at critical stages of hematopoietic development toward EHPs.

Elastin-derived peptides (EDPs) as a potential pro-malignancy factor in human leukemia cell lines.

The extracellular matrix (ECM) is currently considered to be an important factor influencing the migration and progression of cancer cells. Therefore, the aim of our study was to investigate the mechanism of action of elastin-derived peptides in cancerous cells derived from the immunological system, i.e., HL-60, K562, and MEG-A2 cell lines. Moreover, an attempt to clarify the involvement of c-SRC kinase in EDP mechanism of action was also undertaken. Our data show that the VGVAPG and VVGPGA peptides are not toxic in the studied cell lines. Moreover, due to the involvement of KI67 and PCNA proteins in the cell cycle and proliferation, we can assume that neither peptide stimulates cell proliferation. Our data suggest that both peptides could initiate the differentiation process in all the studied cell lines. However, due to the different origins (HL-60 and K562-leukemic cell line vs. MEG-A2-megakaryoblastic origin) of the cell lines, the mechanism may differ. The increase in the ELANE mRNA expression noted in our experiments may also suggest enhancement of the migration of the tested cells. However, more research is needed to fully explain the mechanism of action of the VGVAPG and VVGPGA peptides in the HL-60, K562, and MEG-A2 cell lines. HIGHLIGHTS: • VGVAPG and VVGPGA peptides do not affect the metabolic activity of HL-60, K562, and MEG-A2 cells. • mTOR and PPARγ proteins are involved in the mechanism of action of VGVAPG and VVGPGA peptides. • Both peptides may initiate differentiation in HL-60, K562, and MEG-A2 cell lines.

Rankl genetic deficiency and functional blockade undermine skeletal stem and progenitor cell differentiation.

BACKGROUND: Skeletal Stem Cells (SSCs) are required for skeletal development, homeostasis, and repair. The perspective of their wide application in regenerative medicine approaches has supported research in this field, even though so far results in the clinic have not reached expectations, possibly due also to partial knowledge of intrinsic, potentially actionable SSC regulatory factors. Among them, the pleiotropic cytokine RANKL, with essential roles also in bone biology, is a candidate deserving deep investigation. METHODS: To dissect the role of the RANKL cytokine in SSC biology, we performed ex vivo characterization of SSCs and downstream progenitors (SSPCs) in mice lacking Rankl (Rankl-/-) by means of cytofluorimetric sorting and analysis of SSC populations from different skeletal compartments, gene expression analysis, and in vitro osteogenic differentiation. In addition, we assessed the effect of the pharmacological treatment with the anti-RANKL blocking antibody Denosumab (approved for therapy in patients with pathological bone loss) on the osteogenic potential of bone marrow-derived stromal cells from human healthy subjects (hBMSCs). RESULTS: We found that, regardless of the ossification type of bone, osteochondral SSCs had a higher frequency and impaired differentiation along the osteochondrogenic lineage in Rankl-/- mice as compared to wild-type. Rankl-/- mice also had increased frequency of committed osteochondrogenic and adipogenic progenitor cells deriving from perivascular SSCs. These changes were not due to the peculiar bone phenotype of increased density caused by lack of osteoclast resorption (defined osteopetrosis); indeed, they were not found in another osteopetrotic mouse model, i.e., the oc/oc mouse, and were therefore not due to osteopetrosis per se. In addition, Rankl-/- SSCs and primary osteoblasts showed reduced mineralization capacity. Of note, hBMSCs treated in vitro with Denosumab had reduced osteogenic capacity compared to control cultures. CONCLUSIONS: We provide for the first time the characterization of SSPCs from mouse models of severe recessive osteopetrosis. We demonstrate that Rankl genetic deficiency in murine SSCs and functional blockade in hBMSCs reduce their osteogenic potential. Therefore, we propose that RANKL is an important regulatory factor of SSC features with translational relevance.

Investigation on the molecular mechanism of SPA interference with osteogenic differentiation of bone marrow mesenchymal stem cells.

Binding of Staphylococcus aureus protein A (SPA) to osteoblasts induces apoptosis and inhibits bone formation. Bone marrow-derived mesenchymal stem cells (BMSCs) have the ability to differentiate into bone, fat and cartilage. Therefore, it was important to analyze the molecular mechanism of SPA on osteogenic differentiation. We introduced transcript sequence data to screen out differentially expressed genes (DEGs) related to SPA-interfered BMSC. Protein-protein interaction (PPI) network of DEGs was established to screen biomarkers associated with SPA-interfered BMSC. Receiver operating characteristic (ROC) curve was plotted to evaluate the ability of biomarkers to discriminate between two groups of samples. Finally, we performed GSEA and regulatory analysis based on biomarkers. We identified 321 DEGs. Subsequently, 6 biomarkers (Cenpf, Kntc1, Nek2, Asf1b, Troap and Kif14) were identified by hubba algorithm in PPI. ROC analysis showed that six biomarkers could clearly discriminate between normal differentiated and SPA-interfered BMSC. Moreover, we found that these biomarkers were mainly enriched in the pyrimidine metabolism pathway. We also constructed '71 circRNAs-14 miRNAs-5 mRNAs' and '10 lncRNAs-5 miRNAs-2 mRNAs' networks. Kntc1 and Asf1b genes were associated with rno-miR-3571. Nek2 and Asf1b genes were associated with rno-miR-497-5p. Finally, we found significantly lower expression of six biomarkers in the SPA-interfered group compared to the normal group by RT-qPCR. Overall, we obtained 6 biomarkers (Cenpf, Kntc1, Nek2, Asf1b, Troap, and Kif14) related to SPA-interfered BMSC, which provided a theoretical basis to explore the key factors of SPA affecting osteogenic differentiation.

Predictors for the Differentiation between Glioblastoma, Primary Central Nervous System Lymphoma, and Metastasis in Patients with a Solitary Enhancing Intracranial Mass.

Introduction Differentiation between glioblastoma (GBM), primary central nervous system lymphoma (PCNSL), and metastasis is important in decision-making before surgery. However, these malignant brain tumors have overlapping features. This study aimed to identify predictors differentiating between GBM, PCNSL, and metastasis. Materials and Methods Patients with a solitary intracranial enhancing tumor and a histopathological diagnosis of GBM, PCNSL, or metastasis were investigated. All patients with intracranial lymphoma had PCNSL without extracranial involvement. Demographic, clinical, and radiographic data were analyzed to determine their associations with the tumor types. Results The predictors associated with GBM were functional impairment ( p = 0.001), large tumor size ( p < 0.001), irregular tumor margin ( p < 0.001), heterogeneous contrast enhancement ( p < 0.001), central necrosis ( p < 0.001), intratumoral hemorrhage ( p = 0.018), abnormal flow void ( p < 0.001), and hypodensity component on noncontrast cranial computed tomography (CT) scan ( p < 0.001). The predictors associated with PCNSL comprised functional impairment ( p = 0.005), deep-seated tumor location ( p = 0.006), homogeneous contrast enhancement ( p < 0.001), absence of cystic appearance ( p = 0.008), presence of hypointensity component on precontrast cranial T1-weighted magnetic resonance imaging (MRI; p = 0.027), and presence of isodensity component on noncontrast cranial CT ( p < 0.008). Finally, the predictors for metastasis were an infratentorial ( p < 0.001) or extra-axial tumor location ( p = 0.035), smooth tumor margin ( p < 0.001), and presence of isointensity component on cranial fluid-attenuated inversion recovery MRI ( p = 0.047). Conclusion These predictors may be used to differentiate between GBM, PCNSL, and metastasis, and they are useful in clinical management.

Diagnostic Maze: Malignant Phyllodes Tumor Mimicking Metaplastic Breast Carcinoma.

Phyllodes tumors (PTs) are uncommon breast tumors. They represent a spectrum of benign to malignant neoplasms. These erratic tumors have traits ranging from fibroadenomas on one end of the spectrum to sarcomas on the other end. The presentation of PT is variable, thus posing a diagnostic difficulty. Malignant PTs are often associated with recurrence, poor prognosis, and adverse disease outcomes. The recent genetic studies produced by genome sequencing offer information about the molecular pathophysiology of PT, aid in enhancing diagnostic precision, and suggest possible therapeutic targets in cases of malignant PT. Planning a treatment modality and prognostication requires meticulous histopathological sampling, as it relies on a correct histopathological diagnosis. There are no definitive guidelines for surgical management and targeted therapy for malignant PTs due to the rarity of these cases and very little available literature on these topics. Here in this article, we address a malignant PT in a 74-year-old female that presented as a breast mass mimicking metaplastic breast carcinoma histologically. This article also illuminates how immunohistochemistry plays a vital role in the diagnosis of this tumor.