Synthesis of new 2-aminothiazolyl/benzothiazolyl-based 3,4-dihydropyrimidinones and evaluation of their effects on adenocarcinoma gastric cell migration.

Gastric cancer is one of the malignant tumors of the gastrointestinal tract that, despite its decrease in recent years, is still the fourth most common cancer and the second leading cause of cancer-related death. Various strategies including chemotherapy are used to keep cancer cells from spreading and induce apoptotic death in them. Recent studies have shown that dihydropyrimidinones (DHPMs) are privileged structures in medicinal chemistry due to their pharmacological effects. A number of new 2-aminothiazolyl/benzothiazolyl derivatives of 3,4-DHPMs (3-8) were synthesized and structurally identified, and then their effects on the migration behavior of human AGS cells (gastric cancer cells) were investigated. Molecular docking and molecular dynamics (MD) simulations were applied to explore binding potential and realistic binding model of the assessed derivatives through identification of key amino acid residues within L5/α2/α3 allosteric site of kinesin 5 (Eg5) as a validated microtubule-dependent target for monastrol as a privileged DHPM derivative.

Poly (L-lactic acid) nanofibrous scaffolds support the proliferation and neural differentiation of mouse neural stem and progenitor cells.

BACKGROUND: The distribution and growth of cells on nanofibrous scaffolds seem to be an indispensable precondition in cell tissue engineering. The potential use of biomaterial scaffolds in neural stem cell therapy is increasingly attracting attention. AIM: In this study, we produced porous nanofibrous scaffolds fabricated from random poly-L-lactic acid (PLLA) to support neurogenic differentiation of neural stem and progenitor cells (NSPCs), isolated from the subventricular zone (SVZ) of the adult mouse brain. METHODS: The viability and proliferation of the NSPCs on the nanofibrous PLLA scaffold were also tested by nuclear staining with 4, 6-diamidino-2-phenylindole dihydrochloride (DAPI), 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and scanning electron microscopy (SEM). To investigate the differentiation potential of NSPCs on the scaffolds, the cells were treated with a neurogenic differentiation medium, and immunostaining was done to detect neuronal and glial cells after 14 and 21 days of cultivation. Furthermore, the morphology of differentiated cells on the scaffold was examined using SEM. RESULTS: The DAPI staining revealed the proliferation of NSPCs onto the surface of the nanofibrous PLLA scaffold. DAPI-positive cells were counted on days 2 and 5 after cultivation. The mean number of cells in each microscopic field was significantly (p < .05) increased (51 ± 19 on day 2 compared to 77 ± 25 cells on day 5). The results showed that the cell viability on PLLA scaffolds significantly increased compared to control groups. Moreover, cell viability was significantly increased 5 days after culturing (262.3 ± 50.2) as compared to 2 days culture in Vitro (174.2 ± 28.3, p < .05). Scanning electron micrographs also showed that the NSPCs adhered and differentiated on PLLA scaffolds. We found that the neural cell markers, microtubule-associated protein 2 (MAP2) and glial fibrillary acidic protein (GFAP), were expressed in NSPCs seeded on random PLLA scaffolds after 21 days of cultivation. CONCLUSION: These results suggest that the PLLA nano-scaffolds, due to their biocompatible property, are an appropriate structure for the proliferation, differentiation, and normal growth of NSPCs.

Serotonin depletion during the postnatal developmental period causes behavioral and cognitive alterations and decreases BDNF level in the brain of rats.

A survey of the literature indicates that the developmental disruptions in serotonin (5-HT) levels can influence the brain development and the function. To the best of our knowledge, so far, there are a few studies about the effects of developmental period 5-HT depletion on cognition and behavior of adult male and female rats. Therefore, in the present study, we examined the effects of postnatal days (PND 10-20) administration of para-chlorophenylalanine (PCPA, 100 mg/kg, s.c) a 5-HT synthesis inhibitor, on anxiety-related behaviors, pain sensitivity, short-term recognition memory, and hippocampal and prefrontal cortex (PFC) brain-derived neurotrophic factor (BDNF) mRNA expression in adult male and female rats. Novel object recognition memory (NORM) and behavioral parameters (anxiety-like behaviors and pain sensitivity) were evaluated in early adulthood and after that, the hippocampi and PFC of the rat's brain were removed for the determination of BDNF mRNA expression. Our results indicated that the postnatal period administration of PCPA impaired short-term NORM. The postnatal developmental period treatment with PCPA also increased anxiety-like behaviors in the open field and elevated plus maze (EPM) tests. Postnatal PCPA treatment increased pain sensitivity in the hot plate test in both male and female rats, especially in female animals. In addition, postnatal days serotonin depletion decreased BDNF level in the hippocampus and PFC of both male and female rats. These findings demonstrate that serotonin plays the main role in neurodevelopment, cognitive functions, and behavior. Therefore, serotonergic system dysregulation during the developmental periods may have more adverse influences on the brain development of rats.

Iron depletion with deferoxamine protects bone marrow-derived mesenchymal stem cells against oxidative stress-induced apoptosis.

Bone marrow mesenchymal stem cells (BM-MSCs) are multipotent cells with self-renewal properties, making them an ideal candidate for regenerative medicine. Recently, numerous studies show that about more than 99% of transplanted cells are destroyed because of the stressful microenvironment. Meanwhile, in the target organs, iron overload can produce oxidative stress introducing it as the most important stress factor. The present study was aimed at increasing BM-MSCs' viability against oxidative stress microenvironment using iron depletion by deferoxamine (DFO). Mesenchymal stem cells are isolated and characterized from rat bone marrow. Then, the sensitivity of BM-MSCs against H2O2-induced oxidative stress was evaluated through half of the inhibitory concentration (IC50) estimation by using MTT assay. The maximum non-inhibitory concentration of DFO on BM-MSCs was determined. The next step was the comparison between DFO pre-treated BM-MSCs and untreated cells against H2O2-induced apoptosis. BM-MSCs were identified with morphologic and flow cytometry analysis. IC50 of H2O2 was determined as 0.55 mM at 4 h. Also, the maximum non-inhibitory concentration of DFO was ascertained as 5 µM at 48 h. Our results demonstrated that pretreatment with DFO significantly potentiates BM-MSCs against H2O2-induced oxidative stress which was confirmed by MTT assay, AO/EB double staining, DAPI staining, and activated caspase 3 quantification as well as western blot test. Expression of cleaved caspase 3 and pAKT/AKT ratio obviously demonstrated DFO can resist the cells against cytotoxicity. These findings may help to develop better stem cell culture medium for MSC-based cell therapy. Moreover, regulation of cell stress can be used in practical subjects.

Protective Effect of Gallic Acid on Testicular Tissue, Sperm Parameters, and DNA Fragmentation against Toxicity Induced by Cyclophosphamide in Adult NMRI Mice.

PURPOSE: This study aimed to investigate the protective effect of Gallic acid (GA) on the Cyclophosphamide (CP) toxicity induced in the reproductive system. MATERIALS AND METHODS: After a pilot study for dose responses of Gallic acid ,Forty adult male NMRI mice were divided into 5 groups (n=8): control, sham (NaCl Serum: 0.2mL per day), CP (15 mg kg-1 per week; IP), GA (12.5 mg kg-1 per day ; IP) and GA (12.5 mg kg-1 per day ; IP) +CP(15 mg kg-1 per week; IP). After treatment, the left testis was detached and used for Histological examination and right testis used for Malondialdehyde (MDA) measures. Left caudal epididymis was placed in the Ham's F10 medium and released spermatozoa were used in order to analyze sperm parameters. Sperm DNA fragmentation was assessed by Sperm Chromatin Dispersion (SCD) method. RESULTS: In the CP group, there was a significant increase in the sperm DNA fragmentation (% 57.89 ± 23.91) compared with control group (% 24.52 ± 10.27). That was significantly improved by GA  (12.5 mg kg-1 per day ; IP)  in GA+CP group (% 28.4 ± 8.85) compared to CP group (p< .001).A significant increase was reported about MDA levels in CP group (6.26 ± 2.59) in compared with the control group (4.30 ± 2.05), But GA (3.24 ± 1.33) decreased it in GA+ CP group (p< .01).  The histopathological investigation revealed marked testicular atrophy in CP group, whereas GA diminished these deviations (P< .05). CONCLUSION: Gallic acid can modify the reproductive toxicity of cyclophosphamide in NMRI mice and increase the antioxidant capacity of testis tissue.

Protective effect of gallic acid on apoptosis of sperm and in vitro fertilization in adult male mice treated with cyclophosphamide.

BACKGROUND: Alteration of free radicals (reactive oxygen species) causes mammals' sperm damage. Gallic acid (GA) is known as an antioxidant which is effective against oxidative stress. The purpose of this study was to evaluate the antioxidant effects of GA on the sperm apoptosis and in vitro fertilization (IVF) in adult male mice treated with cyclophosphamide (CP). MATERIALS AND METHODS: Following a pilot study to find the dose responses of GA, 40 adult male naval medical research institute (NMRI) mice (32 ± 3 g) were divided into five groups (n = 8): control, sham (normal saline, NS: 0.2 mL per day), CP (15 mg kg-1 per week; intraperitoneal, IP), GA (12.5 mg kg -1 per day; IP), and GA+CP. After the treatment, sperm parameters were analyzed. The apoptosis of sperm was measured by Annexin-PI staining method followed by flow cytometry detection. Fertility was assessed by IVF method among the groups. RESULTS: The difference in sperm parameter and fertility rate between the control (% 80.05 ± 6.53) and cyclophosphomide groups (% 51.82 ± 10.78) was significant (P < .001) but GA plus CP (% 78.16 ± 5.71) restored the fertilization rate (P < .001). Also, a remarkable increase was noted regarding apoptotic sperm in CP group vs the control group. The comparison in the five groups shows that GA cotreatment was significantly effective in reducing the apoptosis rate caused by cyclophosphamide (P < .05). CONCLUSION: It was ultimately attained that GA has a potent antioxidant effect which could inhibit the detrimental effect of CP on the apoptosis and fertility rate of sperm in the mouse.

Germ cell differentiation of bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BM-MSCs) were first cultured under induction of retinoic acid (RA), Sertoli cells conditioned medium and RA + con (conditioned medium) as treatment groups. The presence of Sertoli cells was confirmed by immunocytochemistry of follicle-stimulating hormone receptor in Sertoli cells and flow cytometry by anti-Gata4 antibody. Cell viability and morphology of nucleus and cytoplasm of BM-MSCs were evaluated by MTT test and DAPI staining respectively. The expression of Oct4, Plzf, Scp3, Caspases 8, 9 and 3 genes was evaluated by RT-PCR. For increasing the accuracy of experiment, the expression of Vasa and SCP3 genes was investigated quantitatively by real-time PCR after 0, 5, 10, 15 days of culture. The results showed that the number of apoptotic cells increased in RA group. The expression of apoptosis genes (Caspases 3, 8 and 9) was also observed in this group all days of culture. Measurement of Vasa and Scp3 genes by RT-PCR confirmed the positive effects of retinoic acid on increasing of genes expression. So, in this study, a group with maximum expression of differentiation genes and minimum expression of apoptotic genes was RA + conditioned medium group. DNA fragmentation was not observed in all groups.

The Telomerase Activity of Selenium-Induced Human Umbilical Cord Mesenchymal Stem Cells Is Associated with Different Levels of c-Myc and p53 Expression.

Selenium-as a trace element-is nutritionally essential for humans. It prevents cancerous growth by inhibiting the telomerase activity but the mechanism involved in regulation of telomerase activity in normal telomerase-positive cells remains to be elucidated. Here, we find out whether the effect of sodium selenite and selenomethionine on telomerase activity in human umbilical cord-derived mesenchymal stem cells (hUCMSCs) is associated with different levels of c-Myc and p53 expression. The use of different staining methods including ethidium bromide/acridine orange and DAPI in addition to telomeric repeat amplification protocol assay and real-time PCR indicated that different forms of selenium have opposite impacts on c-Myc and p53 expressions in both hUCMSCs and AGS, a gastric adenocarcinoma cell line, as a positive control. Our findings suggest that the signaling pathways involved in the regulation of telomerase activity in malignant and normal telomerase-positive cell types are somewhat different, at least on the c-Myc and P53 expression levels.

Highly Efficient Neural Differentiation of CD34-Positive Hair-Follicle-Associated Pluripotent Stem Cells Induced by Retinoic Acid and Serum-Free Medium.

Neural differentiation of hair-follicle-associated pluripotent (HAP) stem cells residing in the bulge area is a promising autologous source for stem cell therapy. In the present chapter, we describe the identification and enrichment of CD34(+) HAP stem cells by magnetic-activated cell sorting (MACS), and induce them to differentiate into neuronal and glial cells using defined neural-induction media. The different neural cell populations arising during in vitro differentiation from HAP stem cells are characterized by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry assay.

Protein Delivery of Thymidylate Kinase Mediated by Tumor-Specific Antibody-Precoated Microvesicles.

Molecular targeted therapy is an important, novel approach in the treatment of cancer because it interferes with certain molecules involved in carcinogenesis and tumor growth. Examples include monoclonal antibodies, microvesicles, and suicide genes. Several studies have focused on targeted therapies in prostate cancer, which is a serious cause of cancer death in men. We hypothesize that antibody-coated microvesicles can deliver thymidylate kinase, a suicide protein, to prostate cancer cells, potentiating them to death following azidothymidine (AZT) treatment.

The serpin PN1 is a feedback regulator of FGF signaling in germ layer and primary axis formation.

Germ layer formation and primary axis development rely on Fibroblast growth factors (FGFs). In Xenopus, the secreted serine protease HtrA1 induces mesoderm and posterior trunk/tail structures by facilitating the spread of FGF signals. Here, we show that the serpin Protease nexin-1 (PN1) is transcriptionally activated by FGF signals, suppresses mesoderm and promotes head development in mRNA-injected embryos. An antisense morpholino oligonucleotide against PN1 has the opposite effect and inhibits ectodermal fate. However, ectoderm and anterior head structures can be restored in PN1-depleted embryos when HtrA1 and FGF receptor activities are diminished, indicating that FGF signals negatively regulate their formation. We show that PN1 binds to and inhibits HtrA1, prevents degradation of the proteoglycan Syndecan 4 and restricts paracrine FGF/Erk signaling. Our data suggest that PN1 is a negative-feedback regulator of FGF signaling and has important roles in ectoderm and head development.

In vitro neural differentiation of CD34 (+) stem cell populations in hair follicles by three different neural induction protocols.

Differentiation of hair follicle stem cells (HFSCs) into neurons and glial cells represents a promising cell-based therapy for neurodegenerative diseases. The hair follicle bulge area is reported as a putative source of new stem cell population for many years. In vitro studies have implicated neural differentiation of HFSCs. Here, we report the identification and purification of CD34 (+) cells from hair follicle by magnetic activated cell sorting (MACS). We next determined the cytotoxic effects of all-trans retinoic acid (RA) by using cell viability assays. Moreover, the neural differentiation potential of CD34 (+) cells was evaluated in the presence of RA, serum-free condition, and neural differentiation medium (NDM) treatments by using immunocytochemistry and reverse transcription polymerase chain reaction (RT-PCR). Our results showed that the isolated CD34 (+) stem cells were 12% of the total cells in the bulge area, and the neural cells derived from the stem cells expressed nestin, microtubule-associated protein 2 (MAP2), and glial fibrillary acidic protein (GFAP). Interestingly, all the neural induction media supported neuronal differentiation most effectively, but treatment with serum-free medium significantly increased the number of GFAP-positive glial cells. Moreover, increasing RA concentration (≥10 µM) leads to increased cell death in the cells, but a lower concentration of RA (1 µM) treatment results in a decrease in CD34-expressing stem cells. These findings show an instructive neuronal effect of three neural induction media in HFSCs, indicating the important role of this induction media in the specification of the stem cells toward a neural phenotype.

In vitro study of the long-term cortisol treatment effects on the growth rate and proliferation of the neural stem/precursor cells.

Adult neural stem/precursor cells (NSPCs) residing in the subventricular zone of the lateral ventricles and the subgranular zone of the dentate gyrus of the hippocampus are involved in the memory formations and psychological problems. It is believed that basal levels of glucocorticoids are essential for neuronal development, plasticity, and survival, while stress-mediated levels of glucocorticoids produce neuronal loss. Degeneration of NSPCs by the apoptotic and necrotic stimuli have great devastating outcomes on the brain and contributes to the pathophysiology of neurological as well as psychological disorders. Using MTT assay, acridine orange, and TUNEL assay, we have demonstrated that cortisol at high and excessive (more than 5 µM) levels had anti-proliferative effects on the NSPCs derived from subventricular and subgranular zones in a dose- and time-dependent manner through apoptosis as well as necrosis. These outcomes can highlight the role of stress-mediated decline of adult neurogenesis in the aging brain and interconnect stress-mediated cortisol secretion with brain aging diseases.

Biological parameters influencing the human umbilical cord-derived mesenchymal stem cells' response to retinoic acid.

Human umbilical cord-derived mesenchymal stem cells (HUCMSCs) are multipotent fetal stem cells that differentiate into various cell lineages. In recent years, they have gained attention for therapeutic applications but very little is known about their sensitivity to chemical agents such as widely used retinoic acid (RA). As a morphogen inducing differentiation of mesenchymal stem cells, RA has for a long time been known to be a potent teratogen promoting craniofacial and limb abnormality in vertebrate embryos. Here, using MTT assay and EB/AO staining as well as TUNEL assay we show that RA in a concentration-dependent manner induces apoptosis through upregulating Caspase expression and increasing Bax/Bcl2 ratio. Moreover, different biological parameters such as initial time seeding, cell density, passage number and duration of RA treatment play a major role in HUCMSCs cytotoxic response to this agent.

Neuronal induction and regional identity by co-culture of adherent human embryonic stem cells with chicken notochords and somites.

The role of somites and notochords in neuroectoderm differentiation from the embryonic ectoderm and its subsequent patterning into regional compartments along rostro-caudal and dorso-ventral axes, especially in humans, remains elusive. Here, we demonstrate the co-culture effect of somites and notochords isolated from chicken embryos on the neuronal differentiation and regional identity of an adherent culture of human embryonic stem cells (hESCs). Notochord increased the efficiency and speed of neuronal induction, whereas somites had a weak neuronal inducing effect on hESCs. However, a synergistic effect was not observed when notochords and somites were used together. Moreover, in somite and notochord co-culture groups, hESCs-derived neuronal cells expressed HOXB4, OTX2, IRX3 and PAX6, indicative of dorsal hindbrain and ventral anterior identities, respectively. Our results reveal the influence of embryonic notochord and somite co-culture in providing neuronal induction as well as rostro-caudal and dorso-ventral regional identity of hESCs-derived neuronal cells. This study provides a model through which in vivo neuronal induction events may be imitated.

Neural induction in mouse embryonic stem cells by co-culturing with chicken somites.

The role of paraxial mesoderm or the somites in decision of ectoderm to acquire the neuroepithelial fate and its subsequent diversification to functional neural subtypes especially in mammalians is obscure. Here we report, for the first time, the influence of the co-culture of alginate bead-encapsulated somites isolated from chick embryos on neural differentiation in mouse embryonic stem cells-derived embryoid bodies (EBs). Using a combination of morphology, immunofluorescence, flow cytometry, semiquantitative, and conventional RT-PCR techniques, we show that the somites induce rosette structures and weakly enhance neural differentiation and neural markers in a dose-dependent manner in comparison to the control group, but its effect is lower than retinoic acid treatment of EBs. By liquid chromatography-mass spectrometry, it was revealed that somitic cells synthesized and released retinoids into the medium. However, no effective influence of somitic co-culture on rostrocaudal or dorsoventral patterning is seen. Therefore, like amphibians, somites have a modest neural-inducing activity in amniotes.