Silver nanoparticles induce the cardiomyogenic differentiation of bone marrow derived mesenchymal stem cells via telomere length extension

Investigation the apoptotic effect of silver nanoparticles (Ag-NPs) on MDA-MB 231 breast cancer epithelial cells via signaling pathways

Background

The discovery of novel cancer therapeutic strategies leads to the development of nanotechnology-based methods for cancer treatment. Silver nanoparticles (Ag-NPs) have garnered considerable interest owing to their size, shape, and capacity to modify chemical, optical, and photonic properties. This study aimed to investigate the impact of Ag-NPs on inducing of apoptosis in MDA-MB 231 cells by examining specific signaling pathways.

Materials and methods

The cytotoxicity of Ag-NPs was determined using an MTT assay in MDA-MB 231 cells. The apoptotic effects were assessed using the Annexin-V/PI assay. Real-time PCR and western blotting were conducted to analyze the expression of apoptosis-related genes and proteins, respectively. Levels of ERK1/2 and cyclin D1 were measured using ELISA. Cell cycle assay was determined by flow cytometry. Cell migration was evaluated by scratch assay.

Results

The results revealed that Ag-NPs triggered apoptosis and cell cycle arrest in MDA-MB 231 cells. The expression level of Bax (pro-apoptotic gene) was increased, while Bcl-2 (anti-apoptotic gene) expression was decreased. Increased apoptosis was correlated with increased levels of p53 and PTEN. Additionally, notable alterations were observed in protein expression related to the Janus kinase/Signal transducers (JAK/STAT) pathway, including p-AKT. Additionally, reduced expression of h-TERT was observed following exposure to Ag-NPs. ELISA results demonstrated a significant reduction in p-ERK/Total ERK and cyclin D1 levels in Ag-NPs-exposed MDA-MB 231 cells. Western blotting analysis also confirmed the reduction of p-ERK/Total ERK and cyclin D1. Decreased level of cyclin D is associated with suppression of cell cycle progression. The migratory ability of MDA-MB-231 cells was reduced upon treatment with Ag-NPs.

Conclusions

Our findings revealed that Ag-NPs influenced the proliferation, apoptosis, cell cycle, and migration in MDA-MB 231 cells, possibly by modulating protein expression of the AKT/ERK/Cyclin D1 axis.

Electromagnetic field (50 Hz) enhance metabolic potential and induce adaptive/reprogramming response mediated by the increase of N6-methyladenosine RNA methylation in adipose-derived mesenchymal stem cells in vitro

BACKGROUND

Electromagnetic fields (EMF) have an impact on numerous cellular processes. It can positively and negatively affect adipose-derived stem cells (ASCs) thus their fate through the influence of specific factors and protein secretion. EMF can be a great factor for preconditioning ASCs for regenerative medicine purposes, however, understanding the cell's biological response to its effects in vitro is essential.

METHODS

ASCs were exposed to the EMF (50 Hz; 1.5 mT) for 24 and 48 h, and then cell biological response was analyzed.

RESULTS

24 h exposure of ASCs to EMF, significantly increased N6-methyladenosine (m6A) RNA methylation, indicating epitranscriptomic changes as an important factor in ASCs preconditioning. Furthermore, the expression of stem cell markers such as Nanog, Oct-4, Sox-2, CD44, and CD105 increased after 24 h of EMF exposure. Besides, western blot analysis showed upregulation of p21 and DNMT2/TRDMT1 protein levels compared to control cells with no differences in the p53 profile. Moreover, after 24 h of exposure to EMF, cell membrane flexibility, the metabolic potential of cells as well as the distribution, morphology, and metabolism of mitochondria were altered.

CONCLUSION

ASCs undergo a process of mobilization and adaptation under the EMF influence through the increased m6A RNA modifications. These conditions may "force" ASCs to redefine their stem cell fate mediated by RNA-modifying enzymes and alter their reprogramming decision of as differentiation begins.

Ag2 O-TiO2 -NTs enhance osteogenic activity in vitro by modulating TNF-α/β-catenin signaling in bone marrow-derived mesenchymal stem cells

The toxic effects of nanoparticles-silver oxide (Ag2 O) limited its use. However, loading Ag2 O nanoparticles into titanium dioxide (TiO2 ) nanotubes (Ag2 O-TiO2 -NTs) has more efficient biological activity and safety. The aim of this study was to observe the effect of Ag2 O-TiO2 -NTs on osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and its mechanism. The enzyme activity of lactate dehydrogenase (LDH) and the expression of RUNX family transcription factor 2 (Runx2), OPN, OCN in BMSCs were detected by quantitative real time polymerase chain reaction. At 14 days of induction, the mineralization ability and alkaline phosphatase (ALP) activity of cells in each group were observed by Alizarin Red S staining and ALP staining. In addition, the protein levels of tumor necrosis factor-α (TNF-α) and β-catenin in BMSCs of each group were observed by western blot. After 14 days of the induction, the mineralization ability and ALP activity of BMSCs in the Ag2 O-TiO2 -NTs group were significantly enhanced compared with those in the Ag2 O and TiO2 groups. Western blot analysis showed that the BMSCs in the Ag2 O-TiO2 -NTs group exhibited much lower protein level of TNF-α and higher protein level of β-catenin than those in the Ag2 O and TiO2 groups.Ag2 O-TiO2 -NTs enhance the osteogenic activity of BMSCs by modulating TNF-α/β-catenin signaling.

Improving the development of human engineered cardiac tissue by gold nanorods embedded extracellular matrix for long-term viability

A myocardial infarction (MI), commonly called a heart attack, results in the death of cardiomyocytes (CMs) in the heart. Tissue engineering provides a promising strategy for the treatment of MI, but the maturation of human engineered cardiac tissue (hECT) still requires improvement. Conductive polymers and nanomaterials have been incorporated into the extracellular matrix to enhance the mechanical and electrical coupling between cardiac cells. Here we report a simple approach to incorporate gold nanorods (GNRs) into the fibrin hydrogel to form a GNR-fibrin matrix, which is used as the major component of the extracellular matrix for forming a 3D hECT construct suspended between two flexible posts. The hECTs made with GNR-fibrin hydrogel showed markers of maturation such as higher twitch force, synchronous beating activity, sarcomere maturation and alignment, t-tubule network development, and calcium handling improvement. Most importantly, the GNR-hECTs can survive over 9 months. We envision that the hECT with GNRs holds the potential to restore the functionality of the infarcted heart.

Emodin suppresses adipogenesis of bone marrow derived mesenchymal stem cells from aplastic anemia via increasing TRIB3 expression

BACKGROUND

Increasing evidence indicate that enhanced adipogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) could contribute to the adiposity alteration in marrow microenvironment of aplastic anemia (AA). Identifying small molecule drugs with role in inhibiting adipogenesis of BM-MSCs may represent a novel direction in AA therapy by improving BM-MSCs mediated marrow microenvironment.

METHODS

For the purpose, we isolated AA BM-MSCs through whole bone marrow cell culture, evaluated a series of small molecule drugs using the in vitro adipogenic differentiation model of BM-MSCs, and finally focused on emodin, a natural anthraquinone derivative. Subsequently, we systematically investigated the molecular mechanism of emodin in attenuating adipogenic process by means of microarray profiling, bioinformatics analysis and lentivirus-mediated functional studies and rescue assay.

RESULTS

We found that emodin presented significantly suppressive effect on the in vitro adipogenic differentiation of AA BM-MSCs. Further mechanistic investigation revealed that emodin could increase the expression of Tribbles homolog 3 (TRIB3) which exhibited remarkably decreased expression in AA BM-MSCs compared with the normal counterparts and was subsequently demonstrated as a negative regulator in adipogenesis of AA BM-MSCs. Besides, TRIB3 depletion alleviated the suppressive effect of emodin on the adipogenic differentiation of AA BM-MSCs.

CONCLUSION

Our findings propose that emodin mediated TRIB3 up-regulation alleviates the adipogenic capacity of AA BM-MSCs, and emodin could serve as a potential therapeutic regimen for AA therapy.

Metal-Based Nanoparticles for Cardiovascular Diseases

Globally, cardiovascular diseases (CVDs) are the leading cause of death and disability. While there are many therapeutic alternatives available for the management of CVDs, the majority of classic therapeutic strategies were found to be ineffective at stopping or significantly/additionally slowing the progression of these diseases, or they had unfavorable side effects. Numerous metal-based nanoparticles (NPs) have been created to overcome these limitations, demonstrating encouraging possibilities in the treatment of CVDs due to advancements in nanotechnology. Metallic nanomaterials, including gold, silver, and iron, come in various shapes, sizes, and geometries. Metallic NPs are generally smaller and have more specialized physical, chemical, and biological properties. Metal-based NPs may come in various forms, such as nanoshells, nanorods, and nanospheres, and they have been studied the most. Massive potential applications for these metal nanomaterial structures include supporting molecular imaging, serving as drug delivery systems, enhancing radiation-based anticancer therapy, supplying photothermal transforming effects for thermal therapy, and being compounds with bactericidal, fungicidal, and antiviral qualities that may be helpful for cardiovascular diseases. In this context, the present paper aims to review the applications of relevant metal and metal oxide nanoparticles in CVDs, creating an up-to-date framework that aids researchers in developing more efficient treatment strategies.

Investigation of L-carnitine effects on CD44+ cancer stem cells from MDA-MB-231 breast cancer cell line as anti-cancer therapy

Breast cancer stem cells (BCSCs) are a small subpopulation of breast cancer cells, capable of metastasis, recurrence, and drug resistance in breast cancer patients. Therefore, targeting BCSCs appears to be a promising strategy for the treatment and prevention of breast cancer metastasis. Mounting evidence supports the fact that carnitine, a potent antioxidant, modulates various mechanisms by enhancing cellular respiration, inducing apoptosis, and reducing proliferation and inflammatory responses in tumor cells. The objective of this study was to investigate the impact of L-carnitine (LC) on the rate of proliferation and induction of apoptosis in CD44⁺ CSCs. To achieve this, the CD44⁺ cells were enriched using the Magnetic-activated cell sorting (MACS) isolation method, followed by treatment with LC at various concentrations. Flow cytometry analysis was used to determine cell apoptosis and proliferation, and western blotting was performed to detect the expression levels of proteins. Treatment with LC resulted in a significant decrease in the levels of p-JAK2, p-STAT3, Leptin receptor, and components of the leptin pathway. Moreover, CD44⁺ CSCs-treated cells with LC exhibited a reduction in the proliferation rate, accompanied by an increase in the percentage of apoptotic cells. Hence, it was concluded that LC could potentially influence the proliferation and apoptosis of CD44⁺ CSC by modulating the expression levels of specific protein.

Effects of nanomaterial exposure on telomere dysfunction, hallmarks of mammalian and zebrafish cell senescence, and zebrafish mortality

Environmental and occupational exposure to hazardous substances accelerates biological aging. However, the toxic effects of nanomaterials on telomere and cellular senescence (major hallmarks of the biological aging) remained controversial. This study was to synthesize all published evidence to explore the effects of nanomaterial exposure on the telomere change, cellular senescence and mortality of model animals. Thirty-five studies were included by searching electronic databases (PubMed, Embase and Web of Science). The pooled analysis by Stata 15.0 software showed that compared with the control, nanomaterial exposure could significantly shorten the telomere length [measured as kbp: standardized mean difference (SMD) = -1.88; 95% confidence interval (CI) = -3.13 - - 0.64; % of control: SMD = -1.26; 95%CI = -2.11- - 0.42; < 3 kbp %: SMD = 5.76; 95%CI = 2.92 - 8.60), increase the telomerase activity (SMD = -1.00; 95%CI = -1.74 to -0.26), senescence-associated β-galactosidase levels in cells (SMD = 8.20; 95%CI = 6.05 - 10.34) and zebrafish embryos (SMD = 7.32; 95%CI = 4.70 - 9.94) as well as the mortality of zebrafish (SMD = 3.83; 95%CI = 2.94 - 4.72)]. The expression levels of telomerase TERT, shelterin components (TRF1, TRF2 and POT1) and senescence biomarkers (p21, p16) were respectively identified to be decreased or increased in subgroup analyses. In conclusion, this meta-analysis demonstrates that nanomaterial exposure is associated with telomere attrition, cell senescence and organismal death.

Hypoxia-treated umbilical mesenchymal stem cell alleviates spinal cord ischemia-reperfusion injury in SCI by circular RNA circOXNAD1/ miR-29a-3p/ FOXO3a axis

Spinal cord ischemia reperfusion (SCIR) injury leads to spinal cord function injury, neural dysfunction and sometimes paralysis or even paraplegia, which severely impair the physical and mental health of individuals. Mesenchymal stem cells (MSCs) are a group of stem cells that have been widely studied for treatment of various diseases. This work aimed to study the therapeutic potential of hypoxia-induced exosomal circular RNA OXNAD1 from human umbilical cord mesenchymal stem cells (HucMSCs) against SCIR. We established an in vivo rat spinal cord injury (SCI) model and conducted treatment with exosomes that isolated from hypoxia-HucMSCs. Hypoxia-HucMSCs-derived exosomal circOXNAD1 alleviated the spinal cord tissue injury in SCI, improved limb motor function, decreased production of inflammatory factors including the IL-1 β, IL-6, and TNF-α. The in vitro hypoxia and reoxygenation (H/R) model demonstrated that Hypoxia-HucMSCs-derived exosomal circOXNAD1 improved neuron proliferation and alleviated apoptosis. Mechanistically, circOXNAD1 directly interact with miR-29a-3p and miR-29a-3p targets the 3'UTR of FOXO3a in neurons. Inhibition of miR-29a-3p and overexpression of FOXO3a reversed the effects of circOXNAD1 depletion in PC12 cell phenotypes. In conclusion, Hypoxia elevated the level circOXNAD1 in exosomes that derived from HuMSCs. The exosomal circOXNAD1 alleviated SCI through sponging miR-29a-3p and consequently elevated the FOXO3a expression. Our findings provided novel evidence for MSC-derived exosomal circOXNAD1in the treatment of SCI.

Therapeutic potential of stem cells and acitretin on inflammatory signaling pathway-associated genes regulated by miRNAs 146a and 155 in AD-like rats

Alzheimer's disease (AD) is one of the most common causes of dementia. Several drugs are used to improve the symptoms, but do not stop AD progression. There are more promising treatments that may have a significant role in AD diagnosis and treatment such as miRNAs and stem cells. The present study aims to develop a new approach for AD treatment by mesenchymal stem cells (MSCs) and/or acitretin with special reference to inflammatory signaling pathway as NF-kB and its regulator miRNAs in AD-like rat model. Fourty-five male albino rats were allotted for the present study. The experimental periods were divided into induction, withdrawal, and therapeutic phases. Expression levels of miR-146a, miR-155, necrotic, growth and inflammatory genes were assessed using RT-qPCR. Histopathological examination of brain tissues was performed in different rat groups. The normal physiological, molecular, and histopathological levels were restored after treatment with MSCs and/or acitretin. The present study demonstrates that the miR-146a and miR-155 might be used as promising biomarkers for AD. MSCs and/or acitretin proved their therapeutic potential in restoring the expression levels of targeted miRNAs and their related genes concerning NF-kB signaling pathway.

Granulocyte differentiation of rat bone marrow resident C-kit+ hematopoietic stem cells induced by mesenchymal stem cells could be considered as new option in cell-based therapy

Mesenchymal stem cells (MSCs) are effective in hematopoietic engraftment and tissue repair in stem cell transplantation. In addition, these cells control the process of hematopoiesis by secreting growth factors and cytokines. The aim of the present study is to investigate the effect of rat bone marrow (BM)-derived MSCs on the granulocyte differentiation of rat BM-resident C-kit⁺ hematopoietic stem cells (HSCs). The mononuclear cells were collected from rat BM using density gradient centrifugation and MSCs and C-kit⁺ HSCs were isolated. Then, cells were divided into two groups and differentiated into granulocytes; C-kit⁺ HSCs alone (control group) and co-cultured C-kit⁺ HSCs with MSCs (experimental group). Subsequently, the granulocyte-differentiated cells were collected and subjected to real-time PCR and Western blotting for the assessment of their telomere length (TL) and protein expressions, respectively. Afterwards, culture medium was collected to measure cytokine levels. CD34, CD16, CD11b, and CD18 granulocyte markers expression levels were significantly increased in the experimental group compared to the control group. A significant change was also observed in the protein expression of Wnt and β-catenin. In addition, MSCs caused an increase in the TL of granulocyte-differentiated cells. MSCs could affect the granulocyte differentiation of C-kit⁺ HSCs via increasing TL and Wnt/β-catenin protein expression.

TMT-based quantitative proteomic analysis of spheroid cells of endometrial cancer possessing cancer stem cell properties

BACKGROUND

Cancer stem cells (CSCs) play an important role in endometrial cancer progression and it is potential to isolate CSCs from spheroid cells. Further understanding of spheroid cells at protein level would help find novel CSC markers.

METHODS

Spheroid cells from endometrial cancer cell lines, Ishikawa and HEC1A, exhibited increased colony forming, subsphere forming, chemo-drug resistance, migration, invasion ability and tumorigenicity, verifying their cancer stem-like cell properties. The up-regulated CD90, CD117, CD133 and W5C5 expression also indicated stemness of spheroid cells. TMT-based quantitative proteomic analysis was performed to explore the potential alterations between parent cells and cancer stem-like spheroid cells. HK2-siRNA was transfected to Ishikawa and HEC1A cells to explore the roles and molecular mechanism of HK2 in endometrial cancer.

RESULTS

We identified and quantified a total of 5735 proteins and 167 overlapped differentially expressed proteins of two cell types, 43 proteins were up-regulated and 124 were down-regulated in spheroid cells comparing with parent cells. KEGG pathway revealed a significant role of HIF-1 pathway in spheroid cells. qRT-PCR and western blot results of GPRC5A, PFKFB3 and HK2 of HIF-1 pathway confirmed their elevated expressions in spheroid cells which were consistent with proteomic results. HK2 promoted cancer stemness in endometrial cancer.

CONCLUSION

These findings indicate that spheroid cells from endometrial cancer cell lines possess cancer stem-like cell properties and enrich CSCs. HIF-1 pathway is activated in endometrial cancer stem-like spheroid cells.

Human menstrual blood-derived stem cells reverse sorafenib resistance in hepatocellular carcinoma cells through the hyperactivation of mitophagy

BACKGROUND

Sorafenib is a first-line drug targeting the RTK-MAPK signalling pathway used to treat advanced hepatocellular carcinoma (HCC). However, tumour cells readily develop sorafenib resistance, limiting long-term therapy with this drug. In our previous study, we found that human menstrual blood-derived stem cells (MenSCs) altered the expression of some sorafenib resistance-associated genes in HCC cells. Therefore, we wanted to further explore the feasibility of MenSC-based combination therapy in treating sorafenib-resistant HCC (HCC-SR) cells.

METHODS

The therapeutic efficiency of sorafenib was determined using CCK-8 (Cell Counting Kit-8), Annexin V/PI and clone formation assays in vitro and a xenograft mouse model in vivo. DNA methylation was determined using RT‒PCR and methylated DNA immunoprecipitation (MeDIP). Autophagy was detected by measuring LC3-II degradation and autophagosome maturation. Transmission electron microscopy identified autophagosomes and mitochondria. Physiological functions of mitochondria were assessed by measuring the ATP content, reactive oxygen species (ROS) generation, and mitochondrial membrane potential (MMP).

RESULTS

The tumour suppressor genes BCL2 interacting protein 3 (BNIP3) and BCL2 interacting protein 3 like (BNIP3L) were silenced by promoter methylation and that BNIP3 and BNIP3L levels correlated negatively with sorafenib resistance in HCC-SR cells. Strikingly, MenSCs reversed sorafenib resistance. MenSCs upregulated BNIP3 and BNIP3L expression in HCC-SR cells via tet methylcytosine dioxygenase 2 (TET2)-mediated active demethylation. In HCC-SR cells receiving sorafenib and MenSC combination therapy, pressure from sorafenib and elevated BNIP3 and BNIP3L levels disrupted balanced autophagy. Hyperactivation of mitophagy significantly caused severe mitochondrial dysfunction and eventually led to the autophagic death of HCC-SR cells.

CONCLUSIONS

Our research suggests that combining sorafenib and MenSCs may be a potentially new strategy to reverse sorafenib resistance in HCC-SR cells.

The effects of encapsulation on NK cell differentiation potency of C-kit+ hematopoietic stem cells via identifying cytokine profiles

Natural killer cells (NK cells) can kill cancerous cells without prior sensitization. This feature makes them appealing candidates for cellular therapy. Due to the degradation rate and controlled release of these matrices, hydrogels hold great promise in cell differentiation. The study aims to investigate the effect of encapsulated alginate-gelatin on the differentiation potential of C-kit⁺ cells toward NK cells which are mediated by cytokines detection. Under both encapsulated and unencapsulated conditions, C-kit⁺ cells can differentiate into NK cells. In the following, real-time PCR and western blotting were done to investigate the mRNA and protein expression, respectively. Determine cytokine profiles from the collected culture medium conducted a Cytokine antibody array. The differentiated cells were then co-cultured with Molt-4 cells to examine the expression levels of INF-γ, TNF-α, and IL-10 using real-time-PCR. There was a substantial change in protein expression of the Notch pathway. Also, the encapsulation increased the mRNA expression of INF-γ and TNF-α in Molt-4 cells. Based on these findings, the encapsulation effects on the differentiation of C-kit⁺ cells toward NK cells could be related to the secreted cytokines such as interleukin-10 and INF-γ and the Notch protein expression.

Urine-derived mesenchymal stem cells-derived exosomes enhances survival and proliferation of aging retinal ganglion cells

OBJECTIVES

This study was designed to investigate to test the effect of exosomes from urine-derived mesenchymal stem cells (USCs) on the survival and viability of aging retinal ganglion cells (RGCs), and explored the preliminary related mechanisms.

METHODS

Primary USCs were cultured and identified by immunofluorescence staining. Aging RGCs models were established by D-galactose treatment and identified by β-Galactosidase staining. After treatment with USCs conditioned medium (with USCs removal), flow cytometry was performed to examine the apoptosis and cell cycle of RGCs. Cell viability of RGCs was detected by Cell-counting Kit 8 (CCK8) assay. Moreover, gene sequencing and bioinformatics analysis were applied to analyze the genetic variation after medium treatment in RGCs along with the biological functions of differentially expressed genes (DEGs).

RESULTS

The number of apoptotic aging RGCs was significantly reduced in USCs medium-treated RGCs. Besides, USCs-derived exosomes exert significant promotion on the cell viability and proliferation of aging RGCs. Further, sequencing data analyzed and identified DEGs expressed in aging RGCs and aging RGCs treated with USCs conditioned medium. The sequencing outcomes demonstrated 117 upregulated genes and 186 downregulated genes in normal RGCs group vs aging RGCs group, 137 upregulated ones and 517 downregulated ones in aging RGCs group vs aging RGCs + USCs medium group. These DEGs involves in numerous positive molecular activities to promote the recovery of RGCs function.

CONCLUSIONS

Collectively, the therapeutic potentials of USCs-derived exosomes include suppression on cell apoptosis, enhancement on cell viability and proliferation of aging RGCs. The underlying mechanism involves multiple genetic variation and changes of transduction signaling pathways.

Activation of PPAR-γ prevents TERT-mediated pulmonary vascular remodeling in MCT-induced pulmonary hypertension

Background

It has been demonstrated that elevated telomerase reverse transcriptase (TERT) expression or activity is implicated in pulmonary hypertension (PH). In addition, activation of peroxisome-proliferator-activated receptor γ (PPAR-γ) has been found to prevent PH progression. However, the molecular mechanism responsible for the protective effect of PPAR-γ activation on TERT expression in the pathogenesis of PH remains unknown. This study was performed to address these issues.

Methods

Intraperitoneal injection of monocrotaline (MCT) was used to establish PH. BIBR1532 was applied to inhibit the activity of telomerase. The right ventricular systolic pressure (RVSP) and histological analysis were used to detect the development of PH. The protein levels of p-Akt, t-Akt, c-Myc and TERT were determined by western blotting. Pharmacological inhibition of TERT by BIBR1532 effectively suppressed RVSP, RVHI and the WT% in MCT-induced PH rats.

Results

Pharmacological inhibition of Akt/c-Myc pathway by LY294002 diminished TERT upregulation, RVSP, RVHI and WT% in MCT-PH rats. Activation of PPAR-γ by pioglitazone inhibited p-Akt and c-Myc expressions and further downregulated TERT, thus to reduced RVSP, RVHI and WT% in MCT-treated PH rats.

Conclusions

In conclusion, TERT upregulation contributes to PH development in MCT-treated rats. Activation of PPAR-γ prevents pulmonary arterial remodeling through Akt/c-Myc/TERT axis suppression.

Upregulation of RIPK1 implicates in HEK 293T cell death upon transient transfection of A53T-α-synuclein

BACKGROUND

Alpha-synuclein (α-SN) is the central protein in synucleinopathies including Parkinson's disease. Nevertheless, the molecular mechanisms through which α-SN leads to neuronal death remain unclear.

METHODS

To elucidate the relationship between α-SN and apoptosis, some indicators of the intrinsic and extrinsic apoptotic cell death were assessed in normal and a stable HEK293T cell line expressing firefly luciferase after transfection with the wild-type (WT) and A53T mutant α-SN.

RESULTS

Opposite to WT-α-SN, overexpression of A53T-α-SN resulted in enhanced expression of almost two fold for RIPK1 (93.0 %), FADD (45 %), Caspase-8, and Casp-9 activity (52.0 %) in measured time. Transfection of both WT-α-SN and A53T-α-SN showed an increase in the Casp-3/Procasp-3 ratio (WT: 60.5 %; A53T: 41.0 %), Casp-3 activity (WT: 65.0 %; A53T: 20.5 %), and a decrease in luciferase activity (WT: 50 %; A53T: 34.8 %). Overexpression of A53T-α-SN brought about with more cell death percentage compared to WT-α-SN within 36 h. No significant alteration in cytochrome c and reactive oxygen species release into cytosol were observed for both WT-α-SN and A53T-α-SN.

CONCLUSION

Altogether, these findings highlight the link between disease related mutants of α-SN (like A53T-α-SN) in triggering of RIPK1-dependent extrinsic apoptotic pathway in cell death during neurodegeneration.

Cell surface markers for mesenchymal stem cells related to the skeletal system: A scoping review

Multipotent mesenchymal stromal cells (MSCs) have been described as bone marrow stromal cells, which can form cartilage, bone or hematopoietic supportive stroma. In 2006, the International Society for Cell Therapy (ISCT) established a set of minimal characteristics to define MSCs. According to their criteria, these cells must express CD73, CD90 and CD105 surface markers; however, it is now known they do not represent true stemness epitopes. The objective of the present work was to determine the surface markers for human MSCs associated with skeletal tissue reported in the literature (1994-2021). To this end, we performed a scoping review for hMSCs in axial and appendicular skeleton. Our findings determined the most widely used markers were CD105 (82.9%), CD90 (75.0%) and CD73 (52.0%) for studies performed in vitro as proposed by the ISCT, followed by CD44 (42.1%), CD166 (30.9%), CD29 (27.6%), STRO-1 (17.7%), CD146 (15.1%) and CD271 (7.9%) in bone marrow and cartilage. On the other hand, only 4% of the articles evaluated in situ cell surface markers. Even though most studies use the ISCT criteria, most publications in adult tissues don't evaluate the characteristics that establish a stem cell (self-renewal and differentiation), which will be necessary to distinguish between a stem cell and progenitor populations. Collectively, MSCs require further understanding of their characteristics if they are intended for clinical use.

The Metabolic Changes between Monolayer (2D) and Three-Dimensional (3D) Culture Conditions in Human Mesenchymal Stem/Stromal Cells Derived from Adipose Tissue

INTRODUCTION

One of the key factors that may influence the therapeutic potential of mesenchymal stem/stromal cells (MSCs) is their metabolism. The switch between mitochondrial respiration and glycolysis can be affected by many factors, including the oxygen concentration and the spatial form of culture. This study compared the metabolic features of adipose-derived mesenchymal stem/stromal cells (ASCs) and dedifferentiated fat cells (DFATs) cultivated as monolayer or spheroid culture under 5% O₂ concentration (physiological normoxia) and their impact on MSCs therapeutic abilities.

RESULTS

We observed that the cells cultured as spheroids had a slightly lower viability and a reduced proliferation rate but a higher expression of the stemness-related transcriptional factors compared to the cells cultured in monolayer. The three-dimensional culture form increased mtDNA content, oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), especially in DFATs-3D population. The DFATs spheroids also demonstrated increased levels of Complex V proteins and higher rates of ATP production. Moreover, increased reactive oxygen species and lower intracellular lactic acid levels were also found in 3D culture.

CONCLUSION

Our results may suggest that metabolic reconfiguration accompanies the transition from 2D to 3D culture and the processes of both mitochondrial respiration and glycolysis become more active. Intensified metabolism might be associated with the increased demand for energy, which is needed to maintain the expression of pluripotency genes and stemness state.

MiR-7-5p attenuates vascular smooth muscle cell migration and intimal hyperplasia after vascular injury by NF-kB signaling

Background

Atherosclerosis (AS) is the primary cause of coronary artery disease, which is featured by aberrant proliferation, differentiation, and migration of vascular smooth muscle cells (VSMCs). MicroRNAs play crucial roles in AS, but the function of miR-7-5p in AS remains unclear. Here, we aimed to explore the effect of miR-7-5p on AS and VSMCs in vitro and in vivo.

Methods

The in vivo rat AS model and apoE-/- mouse model were established. The carotid artery injury was checked by immunohistochemistry staining. The RNA levels of miR-7-5p and p65 were measured by qPCR assay. Protein levels were checked by western blotting. Cell apoptosis was evaluated by flow cytometry. Cell migration was checked by Transwell assay and wound healing assay. The potential interaction between miR-7-5p with p65 was checked by luciferase reporter gene assay.

Results

MiR-7-5p was downregulated and NF-κB p65 was upregulated in injured carotid arteries in rat model. The carotid artery injury in the AS rats and the treatment of miR-7-5p attenuated the phenotype in the model. Immunohistochemistry staining and Western blot analysis revealed that PCNA levels were increased in injured carotid arteries of the model rats and miR-7-5p could reverse the levels. The cell viability of VSMCs was induced by PDGF-BB but miR-7-5p blocked the phenotype. PDGF-BB decreased apoptosis of VSMCs, while miR-7-5p was able to restore the cell apoptosis in the model. PDGF-BB-induced migration of VSMCs was attenuated by miR-7-5p. miR-7-5p mimic remarkably repressed the luciferase activity of p65 in VSMCs. The levels of p65 were inhibited by miR-7-5p in the cells. The PDGF-BB-promoted cell viability and migration of VSMCs was repressed by miR-7-5p and p65 overexpression reversed the phenotype.

Conclusion

We concluded that miR-7-5p attenuates vascular smooth muscle cell migration and intimal hyperplasia after vascular injury by NF-kB signaling.

Wnt4 prevents apoptosis and inflammation of dental pulp cells induced by LPS by inhibiting the IKK/NF‑κB pathway

Wnt4 has been shown to promote the recovery of odontogenic differentiation of dental pulp stem cells under inflammatory conditions, but its role in inflammation and apoptosis of pulpitis remains to be elucidated. Lipopolysaccharide (LPS) (10 µg/ml) was applied to treat the human dental pulp cells (HDPCs) for 24 h. Western blotting measured the expressions of inflammatory cytokines and apoptosis-related proteins. Cell apoptosis was measured by flow cytometry. The level of Wnt4 was evaluated by reverse transcription-quantitative PCR and western blotting. The results indicated that LPS could promote inflammatory response and apoptosis in HDPCs and downregulated Wnt4 expression was found in LPS-HDPCs. Overexpression of Wnt4 ameliorated cell inflammatory response and apoptosis, presented by reduced expressions of IL-8, IL-6, TNF-α, IL-1β, Bax, cleaved-caspase 3 and enhanced Bcl-2 expression as well as decreased apoptosis rate. Moreover, overexpression of Wnt4 reduced the phosphorylation levels of IKK2, IκBα and p65 proteins upregulated by LPS. Finally, overexpression of IKK2 reversed the effects of Wnt4 on inflammation and apoptosis of LPS-HDPCs and NF-κB inhibitor reversed the effect of IKK2 overexpression in LPS-HDPCs. Wnt4 inhibited LPS-triggered inflammation and apoptosis in HDPCs via regulating the IKK/NF-κB signaling pathway, which provided a new viewpoint for understanding the pathological mechanism of pulpitis.

An autophagy-inducing stapled peptide promotes c-MET degradation and overrides adaptive resistance to sorafenib in c-MET+ hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) accounts for approximately 90% of primary liver cancer cases and ranks as the second leading cause of cancer related death. Multiple receptor tyrosine kinases such as EGFR, FGFR and c-MET have been shown to drive tumorigenesis and progression of HCC. However, tyrosine kinase inhibitors (TKIs) that target these kinases, including the FDA-approved sorafenib, only offer limited clinical success. Resistance to sorafenib and other TKIs also readily emerge in HCC patients, further limiting the usage of these drugs. Novel therapeutic strategies are needed to address the urgent unmet medical need for HCC patients.

Results

Autophagy is an evolutionally conserved lysosome-dependent degradation process that is also functionally implicated in HCC. We previously developed an autophagy-inducing stapled peptide (Tat-SP4) that induced autophagy and endolysosomal degradation of EGFR in lung cancer and breast cancer cells. Here we present data to show that Tat-SP4 also induced significant autophagic response in multiple HCC cell lines and promoted the endolysosomal degradation of c-MET to attenuate its downstream signaling activities although it didn't affect the intrinsically fast turnover of EGFR. Tat-SP4 also overrode adaptive resistance to sorafenib in c-MET⁺ HCC cells but employed the distinct mechanism of inducing non-apoptotic cell death.

Conclusion

With its distinct mechanism of promoting autophagy and endolysosomal degradation of c-MET, Tat-SP4 may serve as a novel therapeutic agent that complement and synergize with sorafenib to enhance its clinical efficacy in HCC patients.

miR-642a-5p increases glucocorticoid sensitivity by suppressing the TLR4 signalling pathway in THP-1 cells

The incidence rate of ulcerative colitis (UC) is increasing annually, and glucocorticoid (GC) resistance (GCR) is a common cause of UC-induced remission failure. Our previous studies have shown that the expression of miR-642a-5p is downregulated in UC with GCR, suggesting that miR-642a-5p may be related to the GC response. Therefore, we investigated the mechanism by which miR-642a-5p regulates the GC response in THP-1 cells.

We found that after treatment with miR-642a-5p mimics and DEX, the expression levels of glucocorticoid receptor (GR) in the nucleus and NF-κB p65 and p50 in the cytoplasm were increased (P < 0.05). miR-642a-5p mimics transfected into THP-1 cells could synergize with dexamethasone (DEX) to reduce lipopolysaccharide (LPS)-induced inflammatory factor levels such as TNF-α, IL-1β, IL-6 and IL-12 (P < 0.05). Bioinformatics analysis and luciferase reporter assays confirmed that TLR4 is a target gene of miR-642a-5p. miR-642a-5p mimic pretreatment enhanced the inhibitory effect of DEX on TLR4 induced by LPS and inhibited the expression of TLR4 on the cell surface (P < 0.05). Additionally, miR-642a-5p further prevented the nuclear import of NF-κB P65 and inhibited the phosphorylation of ERK, p38 and JNK.

These results suggest that miR-642a-5p can inhibit the inflammation by suppressing the TLR4 signalling pathway in THP-1 cells. It also highlights the TLR4 signalling pathway as a potential therapeutic target in anti-inflammation.

•

miR-642a-5p can inhibit the TLR4 signalling pathway induced by LPS and increase the glucocorticoid sensitivity in THP-1 cells.

A multi-omics study to characterize the transdifferentiation of human dermal fibroblasts to osteoblast-like cells

Background: Various skeletal disorders display defects in osteoblast development and function. An in vitro model can help to understand underlying disease mechanisms. Currently, access to appropriate starting material for in vitro osteoblastic studies is limited. Native osteoblasts and their progenitors, the bone marrow mesenchymal stem cells, (MSCs) are problematic to isolate from affected patients and challenging to expand in vitro. Human dermal fibroblasts in vitro are a promising substitute source of cells. Method: We developed an in vitro culturing technique to transdifferentiate fibroblasts into osteoblast-like cells. We obtained human fibroblasts from forearm skin biopsy and differentiated them into osteoblast-like cells with ß-glycerophosphate, ascorbic acid, and dexamethasone treatment. Osteoblastic phenotype was confirmed by staining for alkaline phosphatase (ALP), calcium and phosphate deposits (Alizarin Red, Von Kossa) and by a multi-omics approach (transcriptomic, proteomic, and phosphoproteomic analyses). Result: After 14 days of treatment, both fibroblasts and MSCs (reference cells) stained positive for ALP together with a significant increase in bone specific ALP (p = 0.04 and 0.004, respectively) compared to untreated cells. At a later time point, both cell types deposited minerals, indicating mineralization. In addition, fibroblasts and MSCs showed elevated expression of several osteogenic genes (e.g. ALPL, RUNX2, BMPs and SMADs), and decreased expression of SOX9. Ingenuity Pathways Analysis of RNA sequencing data from fibroblasts and MSCs showed that the osteoarthritis pathway was activated in both cell types (p_adj. = 0.003 and 0.004, respectively). Discussion: These data indicate that our in vitro treatment induces osteoblast-like differentiation in fibroblasts and MSCs, producing an in vitro osteoblastic cell system. This culturing system provides an alternative tool for bone biology research and skeletal tissue engineering.

Mesenchymal stem cells cause induction of granulocyte differentiation of rat bone marrow C-kit+ hematopoietic stem cells through JAK3/STAT3, ERK, and PI3K signaling pathways

OBJECTIVES

Hematopoietic stem cells (HSCs) are the cells that give rise to different types of blood cells during the hematopoiesis process. Mesenchymal stromal cells (MSCs) as key elements in the bone marrow (BM) niche interact with hematopoietic progenitor cells (HPCs) by secreting cytokines, which control HPCs maintenance and fate. Here we report that BM-MSCs are capable of inducing granulocytic differentiation of the C-Kit+ HSCs via activating JAK3/STAT3, ERK, and PI3K signaling pathways.

MATERIALS AND METHODS

For this purpose, BM-MSCs and C-kit⁺ HSCs were isolated. Next, cells were divided into two groups and differentiated into granulocytes: C-kit⁺ HSCs alone (control group) and co-cultured C-kit⁺ HSCs with MSCs (experimental group). Afterward, the gene and protein expression were assessed by real-time PCR and western blotting, respectively.

RESULTS

It was found that BM-MSCs resulted in increased JAK3/STAT3, ERK, and PI3K protein expression in granulocyte differentiated C-kit⁺ HSCs.

CONCLUSION

It should be concluded that MSCs could affect the granulocyte differentiation of C-kit⁺ HSCs via increasing JAK3/STAT3, ERK, and PI3K signaling pathways.

Combining structure-based pharmacophore modeling and machine learning for the identification of novel BTK inhibitors

Bruton's tyrosine kinase (BTK) is a critical enzyme which is involved in multiple signaling pathways that regulate cellular survival, activation, and proliferation, making it a major cancer therapeutic target. We applied the novel integrated structure-based pharmacophore modeling, machine learning, and other in silico studies to screen the Korean chemical database (KCB) to identify the potential BTK inhibitors (BTKi). Further evaluation of these inhibitors on three different human cancer cell lines showed significant cell growth inhibitory activity. Among the 13 compounds shortlisted, four demonstrated consistent cell inhibition activity among breast, gastric, and lung cancer cells (IC50 below 3 μM). The selected compounds also showed significant kinase inhibition activity (IC50 below 5 μM). The current study suggests the potential of these inhibitors for targeting BTK malignant tumors.

Construction of tandem diabody (IL-6/CD20)-secreting human umbilical cord mesenchymal stem cells and its experimental treatment on diffuse large B cell lymphoma

BACKGROUND

More than 40% patients with diffuse large B cell lymphoma (DLBCL) experienced relapse or refractory (R/R) lymphoma after the standard first R-CHOP therapy. IL-6 was reportedly associated with chemotherapy resistance of rituximab. Further, mesenchymal stem cells (MSCs) are known as the potential cell vehicle for their tropism toward tumor. A MSCs-based tandem diabody for treating DLBCL is currently lacking.

METHODS

We constructed a tandem diabody (Tandab(IL-6/CD20)) with modified umbilical cord MSCs (UCMSCs) and designed a cell-based Tandab releasing system. Western blot, qPCR and immunofluorescence were used to confirm the construction and expression of lentivirus-infected UCMSCs. The vitality, apoptosis and homing abilities of UCMSCs were examined via CCK-8 assay, apoptosis, wound healing and migration analysis. Cell binding assay was used to demonstrate the targeting property of Tandab binding to CD20-positive DLBCL cells. Furthermore, we evaluated the viability of SU-DHL-2 and SU-DHL-4 by using CCK-8 and EDU assay after the treatment of UCMSCs-Tandab(IL-6/CD20).

RESULTS

Tandab protein peaked at 6273 ± 487 pg/ml in the medium on day 7 after cell culture. The proliferation and homing ability of UCMSCs did not attenuate after genetically modification. Immunofluorescence images indicated the Tandab protein bound to the lymphoma cells. UCMSCs-Tandab(IL-6/CD20) inhibited the growth of SU-DHL-2 or SU-DHL-4 cells in vitro.

CONCLUSIONS

UCMSCs-Tandab(IL-6/CD20), which bound with both tumor-associated surface antigens and pro-tumor cytokines in tumor microenvironment, might serve as a potential treatment for DLBCL, evidenced by inhibiting the growth of SU-DHL-2 or SU-DHL-4 cells.

Riboflavin (Vitamin B2) Deficiency Induces Apoptosis Mediated by Endoplasmic Reticulum Stress and the CHOP Pathway in HepG2 Cells

Riboflavin is an essential micronutrient and a precursor of flavin mononucleotide and flavin adenine dinucleotide for maintaining cell homeostasis. Riboflavin deficiency (RD) induces cell apoptosis. Endoplasmic reticulum (ER) stress is considered to induce apoptosis, and C/EBP homologous protein (CHOP) is a key pathway involved in this process. However, whether RD-induced apoptosis is mediated by ER stress and the CHOP pathway remains unclear and needs further investigation. Therefore, the current study presents the effect of RD on ER stress and apoptosis in the human hepatoma cell line (HepG2). Firstly, cells were cultured in a RD medium (4.55 nM riboflavin) and a control (CON) medium (1005 nM riboflavin). We conducted an observation of cell microstructure characterization and determining apoptosis. Subsequently, 4-phenyl butyric acid (4-PBA), an ER stress inhibitor, was used in HepG2 cells to investigate the role of ER stress in RD-induced apoptosis. Finally, CHOP siRNA was transfected into HepG2 cells to validate whether RD triggered ER stress-mediated apoptosis by the CHOP pathway. The results show that RD inhibited cell proliferation and caused ER stress, as well as increased the expression of ER stress markers (CHOP, 78 kDa glucose-regulated protein, activating transcription factor 6) (p < 0.05). Furthermore, RD increased the cell apoptosis rate, enhanced the expression of proapoptotic markers (B-cell lymphoma 2-associated X, Caspase 3), and decreased the expression of the antiapoptotic marker (B-cell lymphoma 2) (p < 0.05). The 4-PBA treatment and CHOP knockdown markedly alleviated RD-induced cell apoptosis. These results demonstrate that RD induces cell apoptosis by triggering ER stress and the CHOP pathway.

RRM2 regulates osteogenesis of mouse embryo fibroblasts via the Wnt/β‑catenin signaling pathway

Osteoporosis is a widespread bone metabolic disease characterized by reduced bone mass and bone microstructure deterioration. Ribonucleotide reductase M2 (RRM2) is a key enzyme in DNA synthesis and repair. The present study investigated the effect of RRM2 on osteogenesis of mouse embryo fibroblasts (MEFs) and its molecular mechanism. Bioinformatics analysis revealed that RRM2 expression was increased during osteogenesis of MEFs triggered by bone morphogenetic protein 9. Subsequently, MEFs were used as a mesenchymal stem cell model and osteogenic inducing medium was used to induce osteogenic differentiation. RRM2 protein expression was measured by western blotting during osteogenic differentiation induction of MEFs. RRM2 levels in MEFs were upregulated and downregulated by RRM2-overexpressing recombinant adenovirus and small interfering RNA-RRM2, respectively. Bone formation markers (RUNX family transcription factor 2, osterix, distal-less homeobox 5, collagen type I α1 chain, osteopontin and osteocalcin) were detected by reverse transcription-quantitative (RT-q) PCR and alkaline phosphatase (ALP) and Alizarin Red S staining were examined. The protein expression levels of β-catenin and the ratio of phosphorylated (p-)GSK-3β to GSK-3β were detected by western blotting and the RNA expression of downstream related target genes (β-catenin, axis inhibition protein 2 (AXIN2), transcription factor 7 like 2, lymphoid enhancer binding factor 1, c-MYC and Cyclin D1) in the Wnt/β-catenin signaling pathway was measured by RT-qPCR. RRM2 protein expression increased as the osteogenic differentiation induction period was extended. RRM2 overexpression increased osteogenic marker RNA expression, ALP activity, bone mineralization, the protein expression levels of β-catenin, the ratio of p-GSK-3β to GSK-3β and the RNA expression of downstream related target genes in the Wnt/β-catenin signaling pathway, whereas RRM2 knockdown had the opposite effect. The findings of the present study revealed that RRM2 overexpression enhanced osteogenic differentiation, while RRM2 knockdown reduced osteogenic differentiation. RRM2 may regulate osteogenic differentiation of MEFs via the canonical Wnt/β-catenin signaling pathway, providing a possible therapeutic target for osteoporosis.

Human chorion-derived mesenchymal stem cells suppress JAK2/STAT3 signaling and induce apoptosis of cholangiocarcinoma cell lines

Cholangiocarcinoma (CCA) is an aggressive malignancy arising from the damaged epithelial cells of the biliary tract. Previous studies have reported that the multi-potent mesenchymal stem cells (MSCs) activate a series of tumor signaling pathways by releasing several cytokines to influence tumor cell development. However, the roles and mechanisms of human chorion-derived MSCs (CH-MSCs) in cholangiocarcinoma progression have not been fully addressed. This present study aims to examine the effects of conditioned media derived from CH-MSCs (CH-CM) on CCA cell lines and investigate the respective underlying mechanism of action. For this purpose, MSCs were isolated from chorion tissue, and three cholangiocarcinoma cell lines, namely KKU100, KKU213A, and KKU213B, were used. MTT assay, annexin V/PI analysis, and JC-1 staining were used to assess the effects of CH-CM on proliferation and apoptosis of CCA cells, respectively. Moreover, the effect of CH-CM on caspase-dependent apoptotic pathways was also evaluated. The western blotting assay was also used for measuring the expression of JAK2/STAT3 signaling pathway-associated proteins. The results showed that CH-CM suppressed proliferation and promoted apoptosis of CCA cell lines. CH-CM treatment-induced loss of mitochondrial membrane potential (∆Ψm) in CCA cell lines. The factors presented in the CH-CM also inhibited JAK2/STAT3 signaling, reduced the expression of BCL-2, and increased BAX expression in CCA cells. In conclusion, our study suggests that the CH-CM has a potent anti-cancer effect on cholangiocarcinoma cells and thus provides opportunities for use in alternative cell therapy or in combination with a conventional chemotherapeutic drug to increase the efficiency of CCA treatment.

MicroRNA‑141 inhibits the differentiation of bone marrow‑derived mesenchymal stem cells in steroid‑induced osteonecrosis via E2F3

Osteonecrosis of the femoral head (ONFH) affects the life of patients. MicroRNA-141 (miR-141) has been found associated with proliferation of bone marrow-derived mesenchymal stem cells (BMSCs). E2F transcription factor 3 (E2F3) has been identified as the target of miR-141 to regulate cell proliferation. The aim of the present study was to investigate whether miR-141 and E2F3 were involved in the osteogenic differentiation of BMSCs during ONFH. BMSCs from 4-week-old Sprague-Dawley rats were transduced with miR-141 mimic or inhibitor lentiviruses. Alkaline phosphatase staining was performed to confirm osteogenic differentiation. Reverse transcription-quantitative PCR, luciferase reporter assays and western blot analysis were also used to examine the interaction between E2F3 and miR-141 in BMSCs from the control and ONFH rats. The lentiviral transductions were carried out successfully. The mRNA expression levels of miR-141 in ONFH were upregulated, while those of E2F3 were downregulated compared with the control rat. The luciferase reporter assays indicated that miR-141 could target E2F3. miR-141 knockdown upregulated the mRNA expression levels of E2F3. In addition, osteogenic differentiation of BMSCs was inhibited following miR-141 overexpression, but increased following miR-141 knockdown, as evidenced by the results of the alkaline phosphatase staining and western blot analysis. In conclusion, miR-141 inhibits the osteogenic differentiation of BMSCs in ONFH by targeting E2F3. These two molecules may represent novel candidates to examine in order to investigate the mechanism underlying ONFH.

Epiregulin increases stemness-associated genes expression and promotes chemoresistance of non-small cell lung cancer via ERK signaling

Background

Chemoresistance often causes the failure of treatment and death of patients with advanced non-small-cell lung cancer. However, there is still no resistance genes signature and available enriched signaling derived from a comprehensive RNA-Seq data analysis of lung cancer patients that could act as a therapeutic target to re-sensitize the acquired resistant cancer cells to chemo-drugs. Hence, in this study, we aimed to identify the resistance signature for clinical lung cancer patients and explore the regulatory mechanism.

Method

Analysis of RNA-Seq data from clinical lung cancer patients was conducted in R studio to identify the resistance signature. The resistance signature was validated by survival time of lung cancer patients and qPCR in chemo-resistant cells. Cytokine application, small-interfering RNA and pharmacological inhibition approaches were applied to characterize the function and molecular mechanism of EREG and downstream signaling in chemoresistance regulation via stemness.

Results

The RTK and vitamin D signaling were enriched among resistance genes, where 6 genes were validated as resistance signature and associated with poor survival in patients. EREG/ERK signaling was activated by chemo-drugs in NSCLC cells. EREG protein promoted the NSCLC resistance to chemo-drugs by increasing stemness genes expression. Additionally, inhibition of EREG/ErbB had downregulated ERK signaling, resulting in decreased expression of stemness-associated genes and subsequently re-sensitized the resistant NSCLC cells and spheres to chemo-drugs.

Conclusions

These findings revealed 6 resistance genes signature and proved that EREG/ErbB regulated the stemness to maintain chemoresistance of NSCLC via ERK signaling. Therefore, targeting EREG/ErbB might significantly and effectively resolve the chemoresistance issue.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02859-3.

Notch1 activation of Jagged1 contributes to differentiation of mesenchymal stem cells into endothelial cells under cigarette smoke extract exposure

Background

Mesenchymal stem cells (MSCs) have shown therapeutic potential for engraftment to, differentiation into, endothelial cells (ECs). However, low-efficiency yields hinder their use as ECs for therapeutic vascularization.

Methods

The Notch1 signaling pathway is key to optimal pulmonary development. Recent evidence has shown that this pathway participated in angiogenesis. Herein, we found that in MSCs, Jagged1 was a target for Notch 1, resulting in a positive feedback loop that propagated a wave of ECs differentiation.

Results

In vitro, Jagged1 was found to be activated by Notch1 in MSCs, resulting in the RBP-Jκ-dependent expression of Jagged1 mRNA, a response that was blocked by Notch1 inhibition. Notch1 promoted the formation of cord-like structures on Matrigel. However, cigarette smoke extract inhibited this process, compared to that in control groups. Moreover, Notch1-overexpressing cells upregulated the expressing of HIF-1α gene. The HIF-1α was an angiogenic factor that clustered with Notch1, underscoring the critical role of Notch1 pathway in vessel assembly. Interestingly, this was abrogated by incubation with Notch1 shRNA.

Conclusions

Notch signaling pathway promotes differentiation of MSCs in to ECs. It also regulates angiogenesis and transcription of specific markers on ECs. These results provide a mechanism that regulates differentiation of MSCs into ECs phenotypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01913-3.

Vitamin D3 Stimulates Proliferation Capacity, Expression of Pluripotency Markers, and Osteogenesis of Human Bone Marrow Mesenchymal Stromal/Stem Cells, Partly through SIRT1 Signaling

The biology of vitamin D3 is well defined, as are the effects of its active metabolites on various cells, including mesenchymal stromal/stem cells (MSCs). However, the biological potential of its precursor, cholecalciferol (VD3), has not been sufficiently investigated, although its significance in regenerative medicine—mainly in combination with various biomaterial matrices—has been recognized. Given that VD3 preconditioning might also contribute to the improvement of cellular regenerative potential, the aim of this study was to investigate its effects on bone marrow (BM) MSC functions and the signaling pathways involved. For that purpose, the influence of VD3 on BM-MSCs obtained from young human donors was determined via MTT test, flow cytometric analysis, immunocytochemistry, and qRT-PCR. Our results revealed that VD3, following a 5-day treatment, stimulated proliferation, expression of pluripotency markers (NANOG, SOX2, and Oct4), and osteogenic differentiation potential in BM-MSCs, while it reduced their senescence. Moreover, increased sirtuin 1 (SIRT1) expression was detected upon treatment with VD3, which mediated VD3-promoted osteogenesis and, partially, the stemness features through NANOG and SOX2 upregulation. In contrast, the effects of VD3 on proliferation, Oct4 expression, and senescence were SIRT1-independent. Altogether, these data indicate that VD3 has strong potential to modulate BM-MSCs’ features, partially through SIRT1 signaling, although the precise mechanisms merit further investigation.

Mesenchymal stem cells promote caspase-3 expression of SH-SY5Y neuroblastoma cells via reducing telomerase activity and telomere length

Objective(s):

The use of mesenchymal stem cells in malignancies has attracted much attention due to their ability to deliver anticancer agents to tumors, including cytokines, chemokines, etc. This study aimed to investigate the effect of MSCs on the neuroblastoma SH-SY5Y cells through proliferation/apoptosis, senescence assessment, telomere length, and telomerase activity in vitro. BAX and BCL2 were also examined as potential signaling pathways in this process.

Materials and Methods:

For this reason, two cell populations (MSCs and SH-SY5Y cells) were co-cultured on trans-well plates for 7 days. In a subsequent step, SH-SY5Y cells were harvested from both control and experimental groups and subjected to flow cytometry, ELISA, real-time PCR, PCR-ELISA TRAP assay, and Western blotting assay for Ki67/Caspase3 investigation, β-Galactosidase assessment, telomere length, and telomerase activity assay. Also, expression of genes and proteins through real-time PCR and Western blotting demonstrated the involvement of the aforementioned signaling pathways in this process.

Results:

It was found that MSCs contributed significantly to decrease and increase of Ki-67 and Caspase-3, respectively. Also, MSCs dramatically reduced the length of telomere and telomerase activity and increased the β-Galactosidase activity in a significant manner. In addition, significant increase and decrease were also seen in BAX and BCL2 gene and protein expressions, respectively.

Conclusion:

These findings revealed that close interaction between MSCs and neuroblastoma cells causes inhibition of the SH-SY5Y cell proliferation and promotes cell senescence via BAX and caspase-3 cascade pathways.

L-carnitine in a certain concentration increases expression of cell surface marker CD34 and apoptosis in the rat bone marrow CD34+ hematopoietic stem cells

BACKGROUND

Stem cell based therapy has been encouraged as an attractive method in regenerative medicine. Poor survival and maintenance of the cells transferred into the damaged tissue are broadly accepted as serious barriers to enhancing the efficacy of regenerative medicine. For this reason, some antioxidants such as L-carnitine (LC) are used as a favorite strategy to improve cell survival and retention properties.

AIMS

This study aims to evaluate the effect of LC on the expression of CD34 marker and its effect on apoptosis and SUZ12 gene expression.

METHODS

Rat bone marrow mono-nuclear cells (rBMNCs) were isolated. Then, CD34+ hematopoietic stem cells (HSCs) were enriched using the magnetic activated cell sorting (MACS) method. The cells were treated with 0.2 and 0.4 mM LC. Gene and protein expression levels of the CD34 were then measured by real-time PCR and flow cytometry, respectively. The percentage of apoptosis and SUZ12 gene expression were measured using the Annexin V/PI method and real-time PCR, respectively.

RESULTS

The results showed that in the experimental group, of the CD34+ HSCs treated with 0.2 mM LC, gene and protein expressions of CD34 increased by 1.7 fold and 0.49%, respectively. At the concentration of 0.4 mM, the early cell apoptosis increased by 25.9% (P<0.05). Also, in the concentration of 0.2 and 0.4 mM LC, the SUZ12 gene expression increased by 1.10 and 1.75 folds compared to the control group (P<0.05 and P<0.01), respectively.

CONCLUSION

The results of this study could be used to improve chronic myeloid leukemia (CML) as a multidirectional therapeutic strategy.