The Role of Notch and Wnt Signaling in MSC Communication in Normal and Leukemic Bone Marrow Niche

Navigating the Immunological Crossroads: Mesenchymal Stem/Stromal Cells as Architects of Inflammatory Harmony in Tissue-Engineered Constructs

In the dynamic landscape of tissue engineering, the integration of tissue-engineered constructs (TECs) faces a dual challenge-initiating beneficial inflammation for regeneration while avoiding the perils of prolonged immune activation. As TECs encounter the immediate reaction of the immune system upon implantation, the unique immunomodulatory properties of mesenchymal stem/stromal cells (MSCs) emerge as key navigators. Harnessing the paracrine effects of MSCs, researchers aim to craft a localized microenvironment that not only enhances TEC integration but also holds therapeutic promise for inflammatory-driven pathologies. This review unravels the latest advancements, applications, obstacles, and future prospects surrounding the strategic alliance between MSCs and TECs, shedding light on the immunological symphony that guides the course of regenerative medicine.

Plasticity and crosstalk of mesenchymal stem cells and macrophages in immunomodulation in sepsis

Sepsis is a multisystem disease characterized by dysregulation of the host immune response to infection. Immune response kinetics play a crucial role in the pathogenesis and progression of sepsis. Macrophages, which are known for their heterogeneity and plasticity, actively participate in the immune response during sepsis. These cells are influenced by the ever-changing immune microenvironment and exhibit two-sided immune regulation. Recently, the immunomodulatory function of mesenchymal stem cells (MSCs) in sepsis has garnered significant attention. The immune microenvironment can profoundly impact MSCs, prompting them to exhibit dual immunomodulatory functions akin to a double-edged sword. This discovery holds great importance for understanding sepsis progression and devising effective treatment strategies. Importantly, there is a close interrelationship between macrophages and MSCs, characterized by the fact that during sepsis, these two cell types interact and cooperate to regulate inflammatory processes. This review summarizes the plasticity of macrophages and MSCs within the immune microenvironment during sepsis, as well as the intricate crosstalk between them. This remains an important concern for the future use of these cells for immunomodulatory treatments in the clinic.

Nlrc3 signaling is indispensable for hematopoietic stem cell emergence via Notch signaling in vertebrates

Hematopoietic stem and progenitor cells generate all the lineages of blood cells throughout the lifespan of vertebrates. The emergence of hematopoietic stem and progenitor cells is finely tuned by a variety of signaling pathways. Previous studies have revealed the roles of pattern-recognition receptors such as Toll-like receptors and RIG-I-like receptors in hematopoiesis. In this study, we find that Nlrc3, a nucleotide-binding domain leucine-rich repeat containing family gene, is highly expressed in hematopoietic differentiation stages in vivo and vitro and is required in hematopoiesis in zebrafish. Mechanistically, nlrc3 activates the Notch pathway and the downstream gene of Notch hey1. Furthermore, NF-kB signaling acts upstream of nlrc3 to enhance its transcriptional activity. Finally, we find that Nlrc3 signaling is conserved in the regulation of murine embryonic hematopoiesis. Taken together, our findings uncover an indispensable role of Nlrc3 signaling in hematopoietic stem and progenitor cell emergence and provide insights into inflammation-related hematopoietic ontogeny and the in vitro expansion of hematopoietic stem and progenitor cells.

Signaling Pathways in Trans-differentiation of Mesenchymal Stem Cells: Recent Advances

Mesenchymal stem cells are a group of multipotent cells that can be induced to differentiate into other cell types. The cells fate is decided by various signaling pathways, growth factors, and transcription factors in differentiation. The proper coordination of these factors will result in cell specification. MSCs are capable of being differentiated into osteogenic, chondrogenic, and adipogenic lineages. Different conditions induces the MSCs into particular phenotypes. The MSC trans-differentiation ensues as a response to environmental factors or due to circumstances that prove to favor trans-differentiation. Depending on the stage at which they are expressed, and the genetic alterations they undergo prior to their expression, transcription factors can accelerate the process of trans-differentiation. Further research has been conducted on the challenging aspect of MSCs being developed into non-mesenchymal lineage. The cells that are differentiated in this way maintain their stability even after being induced in animals. The recent advancements in the trans-differentiation capacities of MSCs on induction with chemicals, growth inducers, improved differentiation mediums, growth factors from plant extracts, and electrical stimulation are discussed in this paper. Signaling pathways have a great effect on MSCs trans-differentiation and they need to be better understood for their applications in therapeutic techniques. So, this paper tends to review the major signaling pathways that play a vital role in the trans-differentiation of MSC.

AML alters bone marrow stromal cell osteogenic commitment via Notch signaling

Introduction

Acute myeloid leukemia (AML) is a highly heterogeneous malignancy caused by various genetic alterations and characterized by the accumulation of immature myeloid blasts in the bone marrow (BM). This abnormal growth of AML cells disrupts normal hematopoiesis and alters the BM microenvironment components, establishing a niche supportive of leukemogenesis. Bone marrow stromal cells (BMSCs) play a pivotal role in giving rise to essential elements of the BM niche, including adipocytes and osteogenic cells. Animal models have shown that the BM microenvironment is significantly remodeled by AML cells, which skew BMSCs toward an ineffective osteogenic differentiation with an accumulation of osteoprogenitors. However, little is known about the mechanisms by which AML cells affect osteogenesis.

Methods

We studied the effect of AML cells on the osteogenic commitment of normal BMSCs, using a 2D co-culture system.

Results

We found that AML cell lines and primary blasts, but not normal hematopoietic CD34+ cells, induced in BMSCs an ineffective osteogenic commitment, with an increase of the early-osteogenic marker tissue non-specific alkaline phosphatase (TNAP) in the absence of the late-osteogenic gene up-regulation. Moreover, the direct interaction of AML cells and BMSCs was indispensable in influencing osteogenic differentiation. Mechanistic studies identified a role for AML-mediated Notch activation in BMSCs contributing to their ineffective osteogenic commitment. Inhibition of Notch using a γ-secretase inhibitor strongly influenced Notch signaling in BMSCs and abrogated the AML-induced TNAP up-regulation.

Discussion

Together, our data support the hypothesis that AML infiltration produces a leukemia-supportive pre-osteoblast-rich niche in the BM, which can be partially ascribed to AML-induced activation of Notch signaling in BMSCs.

A comprehensive analysis of cell-autonomous and non-cell-autonomous regulation of myeloid leukemic cells: The prospect of developing novel niche-targeting therapies

Leukemic cells (LCs) arise from the hematopoietic stem/and progenitor cells (HSCs/HSPCs) and utilize cues from the bone marrow microenvironment (BMM) for their regulation in the same way as their normal HSC counterparts. Mesenchymal stromal cells (MSCs), a vital component of the BMM promote leukemogenesis by creating a protective and immune-tolerant microenvironment that can support the survival of LCs, helping them escape chemotherapy, thereby resulting in the relapse of leukemia. Conversely, MSCs also induce apoptosis in the LCs and inhibit their proliferation by interfering with their self-renewal potential. This review discusses the work done so far on cell-autonomous (intrinsic) and MSCs-mediated non-cell-autonomous (extrinsic) regulation of myeloid leukemia with a special focus on the need to investigate the extrinsic regulation of myeloid leukemia to understand the contrasting role of MSCs in leukemogenesis. These mechanisms could be exploited to formulate novel therapeutic strategies that specifically target the leukemic microenvironment.

EGF, TGF-α and Amphiregulin Differently Regulate Endometrium-Derived Mesenchymal Stromal/Stem Cells

The prototypical receptor tyrosine kinase epidermal growth factor receptor (EGFR) is regulated by a set of its ligands, which determines the specificity of signaling and intracellular fate of the receptor. The EGFR signaling system is well characterized in immortalized cell lines such as HeLa derived from tumor tissues, but much less is known about EGFR function in untransformed multipotent stromal/stem cells (MSCs). We compared the effect of epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and amphiregulin (AREG) on physiological responses in endometrial MSCs (enMSC) and HeLa cells. In addition, using Western blotting and confocal microscopy, we studied the internalization and degradation of EGFR stimulated by the three ligands in these cell lines. We demonstrated that unlike HeLa, EGF and TGF-α, but not AREG, stimulated enMSC proliferation and prevented decidual differentiation in an EGFR-dependent manner. In HeLa cells, EGF targeted EGFR for degradation, while TGF-α stimulated its recycling. Surprisingly, in enMSC, both ligands caused EGFR degradation. In both cell lines, AREG-EGFR internalization was not registered. In HeLa cells, EGFR was degraded within 2 h, restoring its level in 24 h, while in enMSC, degradation took more than 4-8 h, and the low EGFR level persisted for several days. This indicates that EGFR homeostasis in MSCs may differ significantly from that in immortalized cell lines.

In vitro simulation of the acute lymphoblastic leukemia niche: a critical view on the optimal approximation for drug testing

Acute lymphoblastic leukemia with the worst prognosis is related to minimal residual disease. Minimal residual disease not only depends on the individual peculiarities of leukemic clones but also reflects the protective role of the acute lymphoblastic leukemia microenvironment. In this review, we discuss in detail cell-to-cell interactions in the 2 leukemic niches, more explored bone marrow and less studied extramedullary adipose tissue. A special emphasis is given to multiple ways of interactions of acute lymphoblastic leukemia cells with the bone marrow or extramedullary adipose tissue microenvironment, indicating observed differences in B- and T-cell-derived acute lymphoblastic leukemia behavior. This analysis argued for the usage of coculture systems for drug testing. Starting with a review of available sources and characteristics of acute lymphoblastic leukemia cells, mesenchymal stromal cells, endothelial cells, and adipocytes, we have then made an update of the available 2-dimensional and 3-dimensional systems, which bring together cellular elements, components of the extracellular matrix, or its imitation. We discussed the most complex available 3-dimensional systems like "leukemia-on-a-chip," which include either a prefabricated microfluidics platform or, alternatively, the microarchitecture, designed by using the 3-dimensional bioprinting technologies. From our analysis, it follows that for preclinical antileukemic drug testing, in most cases, intermediately complex in vitro cell systems are optimal, such as a "2.5-dimensional" coculture of acute lymphoblastic leukemia cells with niche cells (mesenchymal stromal cells, endothelial cells) plus matrix components or scaffold-free mesenchymal stromal cell organoids, populated by acute lymphoblastic leukemia cells. Due to emerging evidence for the correlation of obesity and poor prognosis, a coculture of adipocytes with acute lymphoblastic leukemia cells as a drug testing system is gaining shape.

Simulation of Microgravity and Coculturing with Hematopoietic Cells Oppositely Modulate Wnt Signaling in Mesenchymal Stromal Cells

The osteogenic potential of mesenchymal stromal cells (MSCs) can determine bone homeostasis and the physical characteristics of bones. Microgravity reduces the ability of these cells to differentiate in osteogenic direction. It has been shown that the addition of hematopoietic stem and progenitor cells (HSPCs) to MSC culture in vitro can have the opposite effect. The aim of this study was to identify transcriptional changes in 84 genes associated with Wnt signaling in MSCs during microgravity simulation and interaction with HSPCs. The results indicate an increase in the non-canonical Wnt signaling activity during coculturing of MSCs and HSPCs, while simulated microgravity enhances the canonical component of this signaling pathway. These changes may underlie the modulation of osteogenic potential of MSCs in hematopoietic niche under microgravity.

Self-Renewal and Pluripotency in Osteosarcoma Stem Cells' Chemoresistance: Notch, Hedgehog, and Wnt/β-Catenin Interplay with Embryonic Markers

Osteosarcoma is a highly malignant bone tumor derived from mesenchymal cells that contains self-renewing cancer stem cells (CSCs), which are responsible for tumor progression and chemotherapy resistance. Understanding the signaling pathways that regulate CSC self-renewal and survival is crucial for developing effective therapies. The Notch, Hedgehog, and Wnt/β-Catenin developmental pathways, which are essential for self-renewal and differentiation of normal stem cells, have been identified as important regulators of osteosarcoma CSCs and also in the resistance to anticancer therapies. Targeting these pathways and their interactions with embryonic markers and the tumor microenvironment may be a promising therapeutic strategy to overcome chemoresistance and improve the prognosis for osteosarcoma patients. This review focuses on the role of Notch, Hedgehog, and Wnt/β-Catenin signaling in regulating CSC self-renewal, pluripotency, and chemoresistance, and their potential as targets for anti-cancer therapies. We also discuss the relevance of embryonic markers, including SOX-2, Oct-4, NANOG, and KLF4, in osteosarcoma CSCs and their association with the aforementioned signaling pathways in overcoming drug resistance.

Progress and emerging techniques for biomaterial-based derivation of mesenchymal stem cells (MSCs) from pluripotent stem cells (PSCs)

The use of mesenchymal stem cells (MSCs) for clinical purposes has skyrocketed in the past decade. Their multilineage differentiation potentials and immunomodulatory properties have facilitated the discovery of therapies for various illnesses. MSCs can be isolated from infant and adult tissue sources, which means they are easily available. However, this raises concerns because of the heterogeneity among the various MSC sources, which limits their effective use. Variabilities arise from donor- and tissue-specific differences, such as age, sex, and tissue source. Moreover, adult-sourced MSCs have limited proliferation potentials, which hinders their long-term therapeutic efficacy. These limitations of adult MSCs have prompted researchers to develop a new method for generating MSCs. Pluripotent stem cells (PSCs), such as embryonic stem cells and induced PSCs (iPSCs), can differentiate into various types of cells. Herein, a thorough review of the characteristics, functions, and clinical importance of MSCs is presented. The existing sources of MSCs, including adult- and infant-based sources, are compared. The most recent techniques for deriving MSCs from iPSCs, with a focus on biomaterial-assisted methods in both two- and three-dimensional culture systems, are listed and elaborated. Finally, several opportunities to develop improved methods for efficiently producing MSCs with the aim of advancing their various clinical applications are described.

Simulated microgravity affects stroma-dependent ex vivo myelopoiesis

Microgravity is known negatively affect physiology of living beings, including hematopoiesis. Dysregulation of hematopoietic cells and supporting stroma relationships in bone marrow niche may be in charge. We compared the efficacy of ex vivo expansion of hematopoietic stem and progenitor cells (HSPCs) in presence of native or osteocommitted MSCs under simulated microgravity (Smg) using Random Positioning Machine (RPM). In comparison with 1 g, a decrease of MSC-associated HSPCs and an increase of floating HSPCs was observed after 7 days of Smg exposure. Among floating HSPCs, primitive progenitors were presented by late CD34⁺/133^-. Total CFUs as well as erythroid (BFU-E) and granulocytic (CFU-G) numbers were lower. MSC-associated primitive HSPCs demonstrated increased proportion of late CD34⁺/133^- in expense of early CD34^-/133⁺. Osteo-MSCs preferentially supported late primitive CD34⁺ and more committed HSPCs as followed from increase of CFUs, and CD235a⁺ erythroid progenitors. Under Smg, an increased VEGF, eotaxin, and GRO-a levels, and a decrease in RANTES were found in the osteo-MSC-HSPC co-cultures. IL-6,-8, -13, G-CSF, GRO-a, MCP-3, MIP-1b, VEGF increased in co-culture with osteo-MSCs vs intact MSCs. Based on the findings, the misbalance between primitive/committed HSPCs and a decrease in hematopoiesis-supportive activity of osteocommitted cells are supposed to underline hematopoietic disorders during space flights.

The role of Notch signaling in endometrial mesenchymal stromal/stem-like cells maintenance

Human endometrium undergoes cycles of regeneration in women of reproductive age. The endometrial mesenchymal stromal/stem cells (eMSC) contribute to this process. Notch signaling is essential for homeostasis of somatic stem cells. However, its role in eMSC remains unclear. We show with gain- and loss-of-function experiments that activation of Notch signaling promotes eMSC maintenance, while inhibition induces opposite effect. The activation of Notch signaling better maintains eMSC in a quiescent state. However, these quiescent eMSC can re-enter the cell cycle depending on the Notch and Wnt activities in the microenvironment, suggesting a crosstalk between the two signaling pathways. We further show that the Notch signaling is involved in endometrial remodeling event in a mouse menstrual-like model. Suppression of Notch signaling reduces the proliferation of Notch1⁺ label-retaining stromal cells and delays endometrial repair. Our data demonstrate the importance of Notch signaling in regulating the endometrial stem/progenitor cells in vitro and in vivo.

Notch signaling promotes the quiescent state of endometrial mesenchymal stromal/stem cells (eMSC), whose re-rentry into the cell cycle is in turn influenced by Notch and Wnt signaling from the microenvironment.

Mesenchymal stem cells and their microenvironment

Mesenchymal stem cells (MSCs), coming from a wide range of sources, have multi-directional differentiation ability. MSCs play vital roles in immunomodulation, hematopoiesis and tissue repair. The microenvironment of cells often refers to the intercellular matrix, other cells, cytokines and humoral components. It is also the place for cells’ interaction. The stability of the microenvironment is pivotal for maintaining cell proliferation, differentiation, metabolism and functional activities. Abnormal changes in microenvironment components can interfere cell functions. In some diseases, MSCs can interact with the microenvironment and accelerate disease progression. This review will discuss the characteristics of MSCs and their microenvironment, as well as the interaction between MSCs and microenvironment in disease.

Properties of Leukemic Stem Cells in Regulating Drug Resistance in Acute and Chronic Myeloid Leukemias

Notoriously known for their capacity to reconstitute hematological malignancies in vivo, leukemic stem cells (LSCs) represent key drivers of therapeutic resistance and disease relapse, posing as a major medical dilemma. Despite having low abundance in the bulk leukemic population, LSCs have developed unique molecular dependencies and intricate signaling networks to enable self-renewal, quiescence, and drug resistance. To illustrate the multi-dimensional landscape of LSC-mediated leukemogenesis, in this review, we present phenotypical characteristics of LSCs, address the LSC-associated leukemic stromal microenvironment, highlight molecular aberrations that occur in the transcriptome, epigenome, proteome, and metabolome of LSCs, and showcase promising novel therapeutic strategies that potentially target the molecular vulnerabilities of LSCs.

Heat Shock Alters the Proteomic Profile of Equine Mesenchymal Stem Cells

The aim of this research was to determine the impact of heat stress on cell differentiation in an equine mesenchymal stem cell model (EMSC) through the application of heat stress to primary EMSCs as they progressed through the cell specialization process. A proteomic analysis was performed using mass spectrometry to compare relative protein abundances among the proteomes of three cell types: progenitor EMSCs and differentiated osteoblasts and adipocytes, maintained at 37 °C and 42 °C during the process of cell differentiation. A cell-type and temperature-specific response to heat stress was observed, and many of the specific differentially expressed proteins were involved in cell-signaling pathways such as Notch and Wnt signaling, which are known to regulate cellular development. Furthermore, cytoskeletal proteins profilin, DSTN, SPECC1, and DAAM2 showed increased protein levels in osteoblasts differentiated at 42 °C as compared with 37 °C, and these cells, while they appeared to accumulate calcium, did not organize into a whorl agglomerate as is typically seen at physiological temperatures. This altered proteome composition observed suggests that heat stress could have long-term impacts on cellular development. We propose that this in vitro stem cell culture model of cell differentiation is useful for investigating molecular mechanisms that impact cell development in response to stressors.

Non-canonical Wnt signaling participates in Jagged1-induced osteo/odontogenic differentiation in human dental pulp stem cells

Osteoblast differentiation requires the interaction of various cell signaling pathways to modulate cell responses. Notch and Wnt signaling are among the crucial pathways that control numerous biological processes, including osteo/odontogenic differentiation. The aim of the present study was to examine the involvement of Wnt signaling in the Jagged1-induced osteo/odontogenic differentiation in human dental pulp stem cells (hDPSCs). The Wnt-related gene expression was analyzed from publicly available data of Jagged1-treated human dental pulp cells. The mRNA expression of Wnt ligands (WNT2B, WNT5A, WNT5B, and WNT16) and Wnt inhibitors (DKK1, DKK2, and SOST) were confirmed using real-time polymerase chain reaction. Among the Wnt ligands, WNT2B and WNT5A mRNA levels were upregulated after Jagged1 treatment. In contrast, the Wnt inhibitors DKK1, DKK2, and SOST mRNA levels were downregulated. Recombinant WNT5A, but not WNT2B, significantly promoted in vitro mineral deposition by hDPSCs. Wnt signaling inhibition using IWP-2, but not DKK1, inhibited Jagged1-induced alkaline phosphatase (ALP) activity, mineralization, and osteo/odontogenic marker gene expression in hDPSCs. In conclusion, Jagged1 promoted hDPSC osteo/odontogenic differentiation by modulating the non-canonical Wnt pathway.

Isolation, Maintenance and Expansion of Adult Hematopoietic Stem/Progenitor Cells and Leukemic Stem Cells

Simple Summary

Transplantation of adult hematopoietic stem cells is an important therapeutic tool to help patients suffering from diverse hematological disorders. All types of blood cells can develop from a single hematopoietic stem cell underlining their enormous potential. Intense efforts are ongoing to generate “engraftable” human hematopoietic stem cells to treat hematopoietic diseases and to understand the molecular machinery driving them. Leukemic stem cells represent a low frequency subpopulation of leukemia cells that possess stem cell properties. They can instigate, maintain, and serially propagate leukemia in vivo, while they retain the capacity to differentiate into committed progenitors. Leukemic stem cells are unaffected by many therapeutic strategies and represent the major cause of relapse. We here describe all methods to maintain and expand murine and human hematopoietic cells in culture and describe their specific advantages. These methods are also employed to understand the biology of leukemic stem cells and to identify novel therapeutic strategies.

Abstract

Hematopoietic stem cells (HSCs) are rare, self-renewing cells that perch on top of the hematopoietic tree. The HSCs ensure the constant supply of mature blood cells in a tightly regulated process producing peripheral blood cells. Intense efforts are ongoing to optimize HSC engraftment as therapeutic strategy to treat patients suffering from hematopoietic diseases. Preclinical research paves the way by developing methods to maintain, manipulate and expand HSCs ex vivo to understand their regulation and molecular make-up. The generation of a sufficient number of transplantable HSCs is the Holy Grail for clinical therapy. Leukemia stem cells (LSCs) are characterized by their acquired stem cell characteristics and are responsible for disease initiation, progression, and relapse. We summarize efforts, that have been undertaken to increase the number of long-term (LT)-HSCs and to prevent differentiation towards committed progenitors in ex vivo culture. We provide an overview and compare methods currently available to isolate, maintain and enrich HSC subsets, progenitors and LSCs and discuss their individual advantages and drawbacks.

The Intercellular Communication Between Mesenchymal Stromal Cells and Hematopoietic Stem Cells Critically Depends on NF-κB Signalling in the Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) regulate the fate of the hematopoietic stem cells (HSCs) through both cell-cell interactions and paracrine mechanisms involving multiple signalling pathways. We have previously shown that co-culturing of HSCs with CoCl₂-treated MSCs expands functional HSCs. While performing these experiments, we had observed that the growth of CoCl₂-treated MSCs was significantly stunted. Here, we show that CoCl₂-treated MSCs possess activated NF-κB signalling pathway, and its pharmacological inhibition significantly relieves their growth arrest. Most interestingly, we found that pharmacological inhibition of NF-κB pathway in both control and CoCl₂-treated MSCs completely blocks their intercellular communication with the co-cultured hematopoietic stem and progenitor cells (HSPCs), resulting in an extremely poor output of hematopoietic cells. Mechanistically, we show that this is due to the down-regulation of adhesion molecules and various HSC-supportive factors in the MSCs. This loss of physical interaction with HSPCs could be partially restored by treating the MSCs with calcium ionophore or calmodulin, suggesting that NF-κB regulates intracellular calcium flux in the MSCs. Importantly, the HSPCs co-cultured with NF-κB-inhibited-MSCs were in a quiescent state, which could be rescued by re-culturing them with untreated MSCs. Our data underscore a critical requirement of NF-κB signalling in the MSCs in intercellular communication between HSCs and MSCs for effective hematopoiesis to occur ex vivo. Our data raises a cautionary note against excessive use of anti-inflammatory drugs targeting NF-κB.

Phoenix dactilyfera L. Pits Extract Restored Bone Homeostasis in Glucocorticoid-Induced Osteoporotic Animal Model through the Antioxidant Effect and Wnt5a Non-Canonical Signaling

Oxidative stress associated with long-term glucocorticoids administration is a route through which secondary osteoporosis can be developed. The therapeutic potential of Phoenix dactilyfera L. pits is offered by their balanced, valuable and diverse phytochemical composition providing protective potential against oxidative reactions, making it a good candidate to treat glucocorticoid-induced osteoporosis (GIO). This study evaluates the possible anti-osteoporotic effect of date pit extract (DPE) against dexamethasone (DEXA)-induced osteoporosis. Male rats were allocated into three control groups, which received saline, low and high doses of DPE (150 and 300 mg/kg/day), respectively. Osteoporosis-induced groups that received DEXA (1 mg/kg/day) were divided into DEXA only, DPE (2 doses) + DEXA, and ipriflavone + DEXA. Femoral bone minerals density and bone mineral content, bone oxidative stress markers, Wnt signaling, osteoblast and osteoclast differentiation markers, and femur histopathology were evaluated. DPE defeated the oxidative stress, resulting in ameliorative changes in Wnt signaling. DPE significantly reduced the adipogenicity and abolished the osteoclastogenic markers (RANKL/OPG ratio, ACP, TRAP) while enhancing the osteogenic differentiation markers (Runx2, Osx, COL1A1, OCN). In Conclusion DPE restored the balanced proliferation and differentiation of osteoclasts and osteoblasts precursors. DPE can be considered a promising remedy for GIO, especially at a low dose that had more potency.

High Circulating Sonic Hedgehog Protein Is Associated With Poor Outcome in EGFR-Mutated Advanced NSCLC Treated With Tyrosine Kinase Inhibitors

Introduction

Growing preclinical evidence has suggested that the Sonic hedgehog (Shh) pathway is involved in resistance to tyrosine kinase inhibitor (TKI) therapy for EGFR-mutated (EGFRm) non-small cell lung cancer (NSCLC). However, little is known concerning the prognostic value of this pathway in this context.

Materials and Methods

We investigated the relationship between plasma levels of Shh and EGFRm NSCLC patients’ outcome with EGFR TKIs. We included 74 consecutive patients from two institutions with EGFRm advanced NSCLC treated by EGFR TKI as first-line therapy. Plasma samples were collected longitudinally for each patient and were analyzed for the expression of Shh using an ELISA assay. The activation of the Shh–Gli1 pathway was assessed through immunohistochemistry (IHC) of Gli1 and RT-qPCR analysis of the transcripts of Gli1 target genes in 14 available tumor biopsies collected at diagnosis (baseline).

Results

Among the 74 patients, only 61 had baseline (diagnosis) plasma samples, while only 49 patients had plasma samples at the first evaluation. Shh protein was detectable in all samples at diagnosis (n = 61, mean = 1,041.2 ± 252.5 pg/ml). Among the 14 available tumor biopsies, nuclear expression of Gli1 was observed in 57.1% (8/14) of patients’ biopsies. Shh was significantly (p < 0.05) enriched in youth (age < 68), male, nonsmokers, patients with a PS > 1, and patients presenting more than 2 metastatic sites and L858R mutation. Higher levels of Shh correlated with poor objective response to TKI, shorter progression-free survival (PFS), and T790M-independent mechanism of resistance. In addition, the rise of plasma Shh levels along the treatment was associated with the emergence of drug resistance in patients presenting an initial good therapy response.

Conclusion

These data support that higher levels of plasma Shh at diagnosis and increased levels of Shh along the course of the disease are related to the emergence of TKI resistance and poor outcome for EGFR-TKI therapy, suggesting that Shh levels could stand both as a prognostic and as a resistance biomarker for the management of EGFR-mutated NSCLC patients treated with EGFR-TKI.

Mesenchymal stromal cells: Putative microenvironmental modulators become cell therapy

An exceptional safety profile has been shown in a large number of cell therapy clinical trials that use mesenchymal stromal cells (MSCs). However, reliable potency assays are still lacking to predict MSC immunosuppressive efficacy in the clinical setting. Nevertheless, MSCs are approved in Japan and Europe for the treatment of graft-versus-host and Crohn's fistular diseases, but not in the United States for any clinical indication. We discuss potential mechanisms of action for the therapeutic effects of MSC transplantation, experimental models that dissect tissue modulating function of MSCs, and approaches for identifying MSC effects in vivo by integrating biomarkers of disease and MSC activity.

Comparison of the effects of co-transplantation of bone marrow hematopoietic stem cells and thymic multipotent stromal cells on the immune system of mice depending on methods

Physical interaction of multipotent stromal cells (MSCs) and hematopoietic stem cells (HSCs) is a modern approach to effective and focused changes in the properties of HSCs. Resulting of those contact interaction is significant activation of cells with following immune system restoration. The purpose of the study is to investigate the effect of co-transplantation of bone marrow hematopoietic stem cells (HSCs) and thymic multipotent stromal cells (MSCs) separately and as a union of cells on regeneration of the murine immune system, damaged by cyclophosphamide. MSCs were obtained from thymuses of C57BL mice using explant technique. Bone marrow cells (BMCs) were obtained by flushing out the femur with a nutrient medium. BMCs were cocultivated for 2 hours on the monolayer of thymus-derived MSCs. The immune deficiency of mice was modelled by the treatment with cyclophosphamide (CP). After that, the cells were co-transplanted in two methods (separately into different the retroorbital sinus and as a union after co-cultivation) and the parameters of the immune system were evaluated. It was shown, that separate co-transplantation of BMCs and thymus-derived MSCs is associated with the restoration of the number of bone marrow cells, thymus, spleen and lymph nodes with an increase in the proliferation index of lymph node cells by 1.4 times compared to control. It normalized the previous reduced concentration of hemoglobin and hematocrit in the blood. Co-transplantation had a suppressive effect on the blast transformation reaction, induced by phytohemagglutinin, by 4.3 times, but showed a stimulating effect on DTHR response by 1.6 times compared to control. Co-transplantation of the union of BMCs and MSCs is associated with the restoration of the number of bone marrow cells, spleen and lymph nodes. The level of spontaneous apoptosis of lymph node cells significantly increased by 3.3 times compared to control. It had not effect on hematological parameters, but is activated to impact the immune system. Thus, as a result of cells union administration showed normalization of the bactericidal activity of peritoneal macrophages, unlike the separate co-transplantation. This cells graft had a suppressive effect on the number of antibody-producing cells in the spleen by 4.2 times compared to control. Previous co-cultivation and contact interaction of cells change the properties of cell graft. The effect of co-transplantation of BMCs and thymic MSCs is not a simple additive effect of cells. It is acquiring the features typical to certain cell types, and the expression of new characteristics. We assume this phenomenon as a result development of complex cells cooperative processes in vivo and in vitro

ALCAP2 inhibits lung adenocarcinoma cell proliferation, migration and invasion via the ubiquitination of β-catenin by upregulating the E3 ligase NEDD4L

Lung cancer is recognized as the leading cause of cancer-related death worldwide, with non-small cell lung cancer (NSCLC) being the predominant subtype, accounting for approximately 85% of lung cancer cases. Although great efforts have been made to treat lung cancer, no proven method has been found thus far. Considering β, β-dimethyl-acryl-alkannin (ALCAP2), a natural small-molecule compound isolated from the root of Lithospermum erythrorhizon. We found that lung adenocarcinoma (LUAD) cell proliferation and metastasis can be significantly inhibited after treatment with ALCAP2 in vitro, as it can induce cell apoptosis and arrest the cell cycle. ALCAP2 also significantly suppressed the volume of tumours in mice without inducing obvious toxicity in vivo. Mechanistically, we revealed that ALCAP2-treated cells can suppress the nuclear translocation of β-catenin by upregulating the E3 ligase NEDD4L, facilitating the binding of ubiquitin to β-catenin and eventually affecting the wnt-triggered transcription of genes such as survivin, cyclin D1, and MMP9. As a result, our findings suggest that targeting the oncogene β-catenin with ALCAP2 can inhibit the proliferation and metastasis of LUAD cells, and therefore, ALCAP2 may be a new drug candidate for use in LUAD therapeutics.