Thiol reductive stress activates the hypoxia response pathway.

Owing to their capability to disrupt the oxidative protein folding environment in the endoplasmic reticulum (ER), thiol antioxidants, such as dithiothreitol (DTT), are used as ER-specific stressors. We recently showed that thiol antioxidants modulate the methionine-homocysteine cycle by upregulating an S-adenosylmethionine-dependent methyltransferase, rips-1, in Caenorhabditis elegans. However, the changes in cellular physiology induced by thiol stress that modulate the methionine-homocysteine cycle remain uncharacterized. Here, using forward genetic screens in C. elegans, we discover that thiol stress enhances rips-1 expression via the hypoxia response pathway. We demonstrate that thiol stress activates the hypoxia response pathway. The activation of the hypoxia response pathway by thiol stress is conserved in human cells. The hypoxia response pathway enhances thiol toxicity via rips-1 expression and confers protection against thiol toxicity via rips-1-independent mechanisms. Finally, we show that DTT might activate the hypoxia response pathway by producing hydrogen sulfide. Our studies reveal an intriguing interaction between thiol-mediated reductive stress and the hypoxia response pathway and challenge the current model that thiol antioxidant DTT disrupts only the ER milieu in the cell.

Dental pulp stem cell secretome ameliorates d-galactose induced accelerated aging in rat model.

Advancing age is associated with several diseases and disorders due to multiorgan atrophy. The increasing proportion of elderly humans demands the identification of means to counteract aging and age-associated disorders. There is an increased depletion of stem cells in the aged organs, resulting in their inability to repair the damage and hence organ degeneration. Stem cell therapy has been implicated in counteracting aging and shown promise. However, the use of stem cells encounters several side effects and complications such as handling and storage of the cells for transplantation purpose. Stem cells secretome has proven to be of significant importance in a variety of disorders. In this study, we have shown that secretome derived from dental pulp stem cells (DPSCs) can reverse the age-associated degeneration induced by chronic exposure to d-galactose in a rat model. The secretome was able to increase muscle grip strength and animal activity. Secretome also improved the kidney function and hepatic biochemistry similar to healthy controls as evaluated by renal function test and Fourier-transform infrared spectroscopy. We also showed that secretome reduced the levels of monoamine oxidase and acetylcholinesterase in the brain and liver, indicating aging reversal. Finally, proteomic profiling of DPSCs secretome revealed the presence of 13 proteins which have antiaging functions. Thus, our study provides first proof of concept that DPSCs secretome can render protection against d-galactose induced accelerated aging.

Knockdown of E-cadherin induces cancer stem-cell-like phenotype and drug resistance in cervical cancer cells.

Cervical cancer is one of the leading causes of mortality amongst women in developing countries, and resistance to therapy is the main reason for treatment failure. Recent advances suggest that cancer stem cells (CSCs) are critically involved in regulating the chemo-resistant behavior of cervical cancer cells. In our study, cells with the CSC phenotype were isolated, and we examined the expression levels of stem cell markers and genes associated with epithelial-mesenchymal transition (EMT) using different assays. However, the cells with the CSC phenotype could not be cultured for further cytotoxicity studies, so we established a model of CSC in cervical cancer cells. We performed siRNA-mediated knockdown of E-cadherin in these cells, and studied them for EMT-associated stem-cell-like properties. We also performed dose-dependent cell viability assays using clinically relevant drugs such as cisplatin, cyclopamine, and GANT58 to analyze the drug resistant behavior of these cancer cells. We found that knockdown of E-cadherin induces EMT in cervical cancer cells, imparting stem-cell like characteristics along with enhanced tumorsphere formation, cell migration, invasiveness, and drug resistance. This is the first study to establish a CSC model in cervical cancer cells by knockdown of E-cadherin, which can be used to develop anti-cancer therapies.

ALDH1 & CD133 in invasive cervical carcinoma & their association with the outcome of chemoradiation therapy.

Background & objectives: Chemoradiation is the standard therapy for locally advanced invasive cervical cancer and response to treatment determines the outcome. Cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) play a role in response to treatment and hence the aim of this study was to evaluate if their levels in pre-treatment biopsies by immunohistochemistry (IHC) could predict response to treatment and outcome. Methods: The study comprised 60 patients with FIGO Stage IIB/III invasive cervical carcinoma treated by chemoradiation. They were divided into two groups based on their clinical outcome: group 1, 30 patients who had no evidence of disease at 48 month follow up and group 2, 30 patients who had disease relapse within 6-12 months of treatment completion. IHC was performed for CSC markers (ALDH1, CD133, Nanog and Oct-4), EMT markers (E-cadherin and vimentin) and squamocolumnar junction (KRT7) markers and H-scores determined. Intergroup comparison was performed. The expression of these markers was also evaluated in histological sections of cervical pre-cancer (CIN1 and CIN3) in comparison to normal cervix. Results: Cervical Intraepithelial Neoplasia grade 3 (CIN3) showed high expression of ALDH1 and KRT7 as compared to normal cervical epithelium. Aldehyde dehydrogenase 1 (ALDH1) and CD133 were overexpressed in 70 and 24 per cent cervical carcinoma cases whereas E-cadherin showed reduced expression in invasive carcinoma as compared to normal controls. ALDH1 overexpression was significantly associated with disease relapse in invasive cervical carcinoma treated by chemoradiation (P<0.01). Interpretation & Conclusions: Determination of ALDH1 levels in pre-treatment cervical biopsies of invasive cervical carcinoma may be useful for prediction of response to chemoradiation, with high levels predicting for a poor response.

Insulin growth factor-1 pathway in cervical carcinoma cancer stem cells.

Cancer stem cells (CSC) drive tumour progression and are implicated in relapse and resistance to conventional cancer therapies. Identification of differentially expressed genes by gene expression (GEP) profiling may help identify the differentially activated signalling pathways in cancer stem cells as opposed to bulk tumour cells which will provide new insights into cancer stem cell biology and aid in identification of novel therapeutic targets. Our study focused on the inhibition of CSC from cervical cancer cell lines by targeting insulin-like growth factor (IGF), which was identified by differential GEP. Targeted inhibition of IGF-1 by JB-1 trifluoroacetate (inhibitor of IGF) was carried out in SiHa, RSBS-14 and RSBS-43 cervical cancer derived cell lines. Effect of cisplatin was also evaluated. Inhibition of IGF-1 signalling was confirmed by demonstration of reduction in p-Akt levels. The cell biological effects of IGF-1 inhibition included an increase in G2M/S fraction, increased apoptosis and decreased invasive ability. JB-1 and cisplatin showed synergism. However, transcript levels of stemness and EMT markers showed variable levels following IGF inhibition. Overall, this proof-of-concept study has shown that IGF-1 is an attractive target for inhibition of CSC in invasive cervical cancer.

Sonic hedgehog pathway activation regulates cervical cancer stem cell characteristics during epithelial to mesenchymal transition.

Resistance to therapy and metastasis remains one of the leading causes of mortality due to cervical cancer despite advances in detection and treatment. The mechanism of epithelial to mesenchymal transition (EMT) provides conceptual explanation to the invasiveness and metastatic spread of cancer but it has not been fully understood in cervical cancer. This study aims to investigate the mechanism by which silencing of E-cadherin gene regulates EMT leading to proliferation, invasion, and chemoresistance of cervical cancer cells through the Hedgehog (Hh) signaling pathway. We developed an in vitro EMT model by the knockdown of E-cadherin expression in cervical cancer cell lines. To understand the role of developmental pathway like Hh in the progression of cervical cancer, we investigated the expression of Hh pathway mediators by array in E-cadherin low cervical cancer cells and observed upregulation of Hh pathway. This was further validated on low passage patient-derived cell lines and cervical carcinoma tissue sections from cervical cancer patients. Further, we evaluated the role of two inhibitors (cyclopamine and GANT58) of the Hh pathway on invasiveness and apoptosis in E-cadherin low cervical cancer cells. In conclusion, we observed that inhibition of Hh pathway with GANT58 along with current therapeutic procedures could be more effective in targeting drug-resistant EMT cells and bulk tumor cells in cervical cancer.

Epithelial to mesenchymal transition induces stem cell like phenotype in renal cell carcinoma cells.

BACKGROUND: Metastatic dissemination of solid tumors is often initiated by reactivation of an embryonic development program, epithelial-to-mesenchymal-transition (EMT). EMT has been associated with acquiring invasiveness and resistance to conventional therapies. However, the precise role of EMT during renal cell carcinoma is still debatable and is under investigation. In this context, our study is designed to evaluate the role of cyclosporine (CsA) and transforming growth factor-ß (TGFß) administration in inducing EMT-like state in renal carcinoma cells. We also studied the associated phenotypic changes which may lead to tumor metastasis. METHODS: The morphological changes in renal cell carcinoma cells (A498) treated with TGF-ß/CsA were observed by microscopy. Atomic force microscope was used to evaluate the changes in elasticity of cells treated with TGF-ß/CsA. The expression of mesenchymal and chemoresistance genes were checked by RT-PCR. Assays for migration, invasion, sphere formation ability and expression of cancer stem cell-like phenotypes were done to evaluate the metastatic potential of these cells. Lineage specific differentiations were also done to determine the acquisition of stem-cell like phenotype. RESULTS: Our results showed that treatment with TGF-ß/CsA led to loss of epithelial characteristics and gain of mesenchymal phenotype in vitro. Changes in shape and elastic properties of the cancer cells favoured metastatic progression, increased tumorisphere formation and invasiveness post treatment. We also observed higher expression of chemoresistance and stemness markers in EMT-induced cells. These cells also differentiated to various lineages like osteoblasts, adipocytes, neural and hepatic cells when induced with the respective differentiation media. CONCLUSION: We concluded that TGF-ß/CsA treatment led to acquisition of EMT-like cancer stem cells phenotype that enhanced local invasion and dissemination of renal carcinoma cells. This subpopulation of cells with EMT-like phenotype a can provide a better perception of the metastatic process. This can provide an in vitro system for testing pharmaceuticals for modulating EMT as a viable strategy within the therapeutic armamentarium for RCC patients. The results of our findings also suggest that CsA directly induced EMT like changes in epithelial cell which may be responsible for the potential risk of malignancy in transplant patients.

Significance of CD133 positive cells in four novel HPV-16 positive cervical cancer-derived cell lines and biopsies of invasive cervical cancer.

BACKGROUND: Cervical cancer is a major cause of cancer-related mortality in women in the developing world. Cancer Stem cells (CSC) have been implicated in treatment resistance and metastases development; hence understanding their significance is important. METHODS: Primary culture from tissue biopsies of invasive cervical cancer and serial passaging was performed for establishing cell lines. Variable Number Tandem Repeat (VNTR) assay was performed for comparison of cell lines with their parental tissue. Tumorsphere and Aldefluor assays enabled isolation of cancer stem cells (CSC); immunofluorescence and flow cytometry were performed for their surface phenotypic expression in cell lines and in 28 tissue samples. Quantitative real-time PCR for stemness and epithelial-mesenchymal transition (EMT) markers, MTT cytotoxicity assay, cell cycle analysis and cell kinetic studies were performed. RESULTS: Four low-passage novel cell lines designated RSBS-9, - 14 and - 23 from squamous cell carcinoma and RSBS-43 from adenocarcinoma of the uterine cervix were established. All were HPV16+. VNTR assay confirmed their uniqueness and derivation from respective parental tissue. CSC isolated from these cell lines showed CD133+ phenotype. In tissue samples of untreated invasive cervical cancer, CD133+ CSCs ranged from 1.3-23% of the total population which increased 2.8-fold in radiation-resistant cases. Comparison of CD133+ with CD133- bulk population cells revealed increased tumorsphere formation and upregulation of stemness and epithelial-mesenchymal transition (EMT) markers with no significant difference in cisplatin sensitivity. CONCLUSION: Low-passage cell lines developed would serve as models for studying tumor biology. Cancer Stem Cells in cervical cancer display CD133+ phenotype and are increased in relapsed cases and hence should be targeted for achieving remission.

Insights into cell-free therapeutic approach: Role of stem cell "soup-ernatant".

Current advances in medicine have revolutionized the field of regenerative medicine dramatically with newly evolved therapies for repair or replacement of degenerating or injured tissues. Stem cells (SCs) can be harvested from different sources for clinical therapeutics, which include fetal tissues, umbilical cord blood, embryos, and adult tissues. SCs can be isolated and differentiated into desired lineages for tissue regeneration and cell replacement therapy. However, several loopholes need to be addressed properly before this can be extended for large-scale therapeutic application. These include a careful approach for patient safety during SC treatments and tolerance of recipients. SC treatments are associated with a number of risk factors and require successful integration and survival of transplanted cells in the desired microenvironment with concurrent tissue regeneration. Recent studies have focused on developing alternatives that can replace the cell-based therapy using paracrine factors. The development of stem "cell free" therapies can be devoted mainly to the use of soluble factors (secretome), extracellular vesicles, and mitochondrial transfer. The present review emphasizes on the paradigms related to the use of SC-based therapeutics and the potential applications of a cell-free approach as an alternative to cell-based therapy in the area of regenerative medicine.

Autophagy inhibition suppresses the tumorigenic potential of cancer stem cell enriched side population in bladder cancer.

The mechanisms that underlie tumor formation and progression have not been elucidated in detail in cancer biology. Recently, the identification of a tumor cell subset defined as cancer stem cells (CSCs), which is enriched for tumor initiating capacity, has engendered new perspectives towards selective targeting of tumors. In this study, we isolated the side population (SP) cells which share characteristics of CSCs from bladder cancer cell lines, T24 and UM-UC-3 by fluorescence activated cell sorting. The cells were cultured in serum free medium and expression profile of stem cell like markers (SOX-2, NANOG, KLF-4 and OCT-4), drug resistant genes (ABCG2 and MDR1) and spheroid forming capability were examined in SP, non-side population (NSP) and bulk T24 and UM-UC-3 cells. We observed that SP cells possessed a higher mRNA expression of SOX-2, NANOG, KLF-4, OCT-4, ABCG2, and MDR1 as well as a higher spheroid forming ability as compared to other bulk cells or NSP cells. The SP cells had low ROS levels and high GSH/GSSG ratio which may contribute to radio-resistance. The SP cells also showed substantial resistance to gemcitabine, mitomycin and cisplatin compared with the NSP counterpart. A high autophagic flux was observed in the SP cells. Both pharmacological and siRNA mediated inhibition of autophagy potentiated the chemotherapeutic effects of gemcitabine, mitomycin and cisplatin in these cells. We concluded that the ABCG2 expressing SP cells show autophagy associated cell survival and may be a potent target for developing more effective treatment in bladder carcinoma to enhance patient survival.

Effect of uncontrolled freezing on biological characteristics of human dental pulp stem cells.

Human dental pulp stem cells (hDPSCs) hold great promise as a source of adult stem cells for utilization in regenerative medicine. Successful storage and post thaw recovery of DPSCs without loss of function is a key issue for future clinical application. Most of the cryopreservation methods use controlled rate freezing and vapor phase nitrogen to store stem cells. But these methods are both expensive and laborious. In this study, we isolated DPSCs from a patient undergoing impacted mandibular third molar extraction. We adopted eight different methods of cryopreservation at -80 °C for long term storage of the DPSC aliquots. Various parameters like proliferation, cell death, cell cycle, retention of stemness markers and differentiation potential were studied post cryopreservation period of 1 year. We observed successful recovery of stem cells in every method and a significant difference in proliferation potential and cell death between samples stored by different methods. However, post thaw, all cells retained their stemness markers. All DPSCs stored by different methods were able to differentiate into osteoblast like cells, adipocytes and neural cells. Based on these parameters we concluded that uncontrolled freezing at a temperature of -80 °C is as effective as controlled freezing using ethanol vessels and other cryopreservation methods. To the best of our knowledge, our study provides the first proof of concept that long term storage in uncontrolled freezing of cells at -80 °C in 10 % DMSO does not affect the revival capacity of hDPSCs. This implies that DPSCs may be used successfully for tissue engineering and cell based therapeutics even after long term, uncontrolled cryopreservation.

Inhibition of grade dependent autophagy in urothelial carcinoma increases cell death under nutritional limiting condition and potentiates the cytotoxicity of chemotherapeutic agent.

PURPOSE: We evaluated the status of autophagy in different grades of urothelial carcinoma and explored autophagy modulators as a potential adjunctive therapeutic agent for urothelial carcinoma. MATERIALS AND METHODS: The study was performed in tumor tissue from patients with low and high grade urothelial carcinoma, in normal urothelial tissue and in the T24 cell line. Autophagic vesicles and the expression of various autophagic proteins were studied in tissue samples by transmission electron microscopy and Western blot, respectively. The effect of autophagy induction and inhibition was evaluated by measuring AMPK and mTOR expression, cell viability and mitochondrial membrane potential. The therapeutic implication of autophagy was studied using cisplatin alone or combined with an autophagy inhibitor. RESULTS: High grade urothelial carcinoma showed a higher number of autophagic vesicles and significantly higher expression of autophagic proteins. Upon starvation cells cultured from high and low grade urothelial carcinoma demonstrated significant autophagy induction associated with AMPK activation and mTOR inhibition. AMPK inhibition decreased the autophagic response and increased cell death. Autophagy inhibition by wortmannin, 3-methyladenine and chloroquine increased mitochondrial hypopolarization as well as caspase-9 and 3 dependent cell death. Combined treatment with cisplatin and an autophagy inhibitor resulted in greater cell death than cisplatin treatment alone. CONCLUSIONS: Autophagy is related to urothelial carcinoma grade and regulated via the AMPK pathway for tumor cell survival. Autophagy inhibition leads to cancer cell death through an intrinsic apoptotic pathway. The potential application of autophagy inhibitors as an adjunct to chemotherapy for urothelial carcinoma must be explored.

Mining parasites for their potential as novel therapeutic agents against cancer.

Despite recent advances in the management and therapeutic of cancer, the treatment of the disease is limited by its high cost and severe side effects. In this scenario, there is an unmet need to identify novel treatment alternatives for this dreaded disease. Recently there is growing evidence that parasites may cause anticancer effects because of a negative correlation between parasitic infections and tumour growth despite some parasites that are known to exhibit pro-carcinogenic effects. It has been observed that parasites exert an anticancer effect either by activating the host's immune response or by secreting certain molecules that exhibit anticancer potential. The activation of the immune response by these parasitic organisms results in the inhibition of some of the hallmarks of cancer such as tumour proliferation, angiogenesis, and metastasis. This review summarizes the current advances as well as the mechanisms underlying the possible implications of this diverse group of organisms as anticancer agents.

Engineering a 3-dimensional tissue construct with adipose-derived stem cells for healing bone defect: An ex vivo study with femur head.

The compatibility of bone graft substitutes (BGS) with mesenchymal stem cells (MSCs) is an important parameter to consider for their use in repairing bone defects as it eventually affects the clinical outcome. In the present study, a few commercially available BGS - ß-tricalcium phosphate (ß-TCP), calcium sulfate, gelatin sponge, and different forms of hydroxyapatite (HAP) were screened for their interactions with MSCs from adipose tissue (ADSCs). It was demonstrated that HAP block favorably supported ADSC viability, morphology, migration, and differentiation compared to other scaffolds. The results strongly suggest the importance of preclinical evaluation of bone scaffolds for their cellular compatibility. Furthermore, the bone regenerative potential of HAP block with ADSCs was evaluated in an ex vivo bone defect model developed using patient derived trabecular bone explants. The explants were cultured for 45 days in vitro and bone formation was assessed by expression of osteogenic genes, ALP secretion, and high resolution computed tomography. Our findings confirmed active bone repair process in ex vivo settings. Addition of ADSCs significantly accelerated the repair process and improved bone microarchitecture. This ex vivo bone defect model can emerge as a viable alternative to animal experimentation and also as a potent tool to evaluate patient specific bone therapeutics under controlled conditions.

Clinical, histopathological, and immunohistochemical spectrum of hepatolithiasis: a tertiary care center-based study from north India.

Hepatolithiasis (HL), an uncommon disease among Indians, occurs due to a complex interplay of various structural and functional factors. We retrospectively evaluated the clinical and histopathological spectrum of HL (N = 19) with immunohistochemical evaluation for biliary apomucins and canalicular transporter proteins, both crucial for lithogenesis. Nineteen surgically resected cases were included. Histopathology was systematically evaluated. Immunohistochemistry for apomucins (MUC1, MUC2, MUC4, MUC5AC, and MUC6) and canalicular transporter proteins (BSEP and MDR3) was applied to all cases. The median age was 51 years with female preponderance (F:M = 1.4:1). The stone was cholesterol-rich in 71.4% and pigmented in 28.6% (n = 14). Histopathology showed variable large bile-duct thickening due to fibrosis and inflammation with peribiliary gland hyperplasia. Structural causes (Caroli disease, choledochal cyst, and post-surgical complication) were noted in 15.8% of cases (secondary HL). Expression of gel-forming apomucin MUC1, MUC2, and MUC5AC was seen in either bile duct epithelia or peribiliary glands in 84.2%, 10.5%, and 84.2% cases respectively. Loss of canalicular expression of MDR3 was noted in 42.1% of cases while BSEP was retained in all. Primary HL in the north Indian population can be associated with the loss of MDR3 expression (with retained BSEP) and/ or a shift in the phenotype of biliary apomucins to gel-forming apomucins. The former factor alters the bile acid/ phospholipid ratio while the latter parameter promulgates crystallization. In conjunction, these factors are responsible for the dominantly cholesterol-rich stones in the index population.

Immunomodulation by mesenchymal stem cells during osteogenic differentiation: Clinical implications during bone regeneration.

Critical bone defects resulting in delayed and non-union are a major concern in the field of orthopedics. Over the past decade, mesenchymal stem cells (MSCs) have become a promising frontier for bone repair and regeneration owing to their high expansion rate and osteogenic differentiation potential ex vivo. MSCs have also long been associated with their ability to modulate immune response in the recipients. These can even skew the immune response towards pro-inflammatory or anti-inflammatory type by sensing their local microenvironment. MSCs adopt anti-inflammatory phenotype at bone injury site and secrete various immunomodulatory factors such as IDO, NO, TGFß1 and PGE-2 which have redundant role in osteoblast differentiation and bone formation. As such, several studies have also sought to decipher the immunomodulatory effects of osteogenically differentiated MSCs. The present review discusses the immunomodulatory status of MSCs during their osteogenic differentiation and summarizes few mechanisms that cause immunosuppression by osteogenically differentiated MSCs and its implication during bone healing.

Mitochondria transfer as a potential therapeutic mechanism in Alzheimer's disease-like pathology.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by cognition decline and memory deterioration. The molecular pathogenic mechanism of AD is highly complex and still not completely clarified. While stem cell-based therapy for AD has been considered an optimal choice with specific properties however, immune rejection and risk of malignant transformation limit their therapeutic application. Growing evidence suggest that mitochondrial dysfunction has a critical role in the progression of AD. Since there have not been any effective treatment for AD, the drugs targeted to mitochondria may hold a great promise Therefore, the major objective of this study is to evaluate the therapeutic applicability of transplanting MSCderived mitochondria as a neuroprotective biomolecule in Alzheimer's disease pathology. The hallmarks of AD i.e aggregation of Aß protein and Tau protein were generated to mimic the AD like pathology in vitro. Further, morphology analysis, cell viability assay, and immunofluorescence assay have been done for validation. Mitochondria were isolated from dental pulp stem cell (DPSC) and their effect on internalization by neural cells was demonstrated by cell proliferation analysis and uptake studies while their therapeutic potential was characterized by morphology analysis, ROS study, and immunofluorescence analysis. We observed that internalization of DPSC-derived mitochondria led to significant neuroprotective in the cellular AD. Based on our results, it may be concluded that mesenchymal stem cellderived mitochondria can emerge as a potentially safe and effective modality in Alzheimer's disease.

Primary Culture of Dental Pulp Stem Cells.

The human dental pulp represents a promising multipotent stem cell reservoir with pre-eminent regenerative competence that can be harvested from an extracted tooth. The neural crest-derived ecto-mesenchymal origin of dental pulp stem cells (DPSCs) bestows a high degree of plasticity that owes to its multifaceted benefits in tissue repair and regeneration. There are various practical ways of harvesting, maintaining, and proliferating adult stem cells being investigated for their use in regenerative medicine. In this work, we demonstrate the establishment of a primary mesenchymal stem cell culture from dental tissue by the explant culture method. The isolated cells were spindle-shaped and adhered to the plastic surface of the culture plate. The phenotypic characterization of these stem cells showed positive expression of the international society of cell therapy (ISCT)-recommended cell surface markers for MSC, such as CD90, CD73, and CD105. Further, negligible expression of hematopoietic (CD45) and endothelial markers (CD34), and less than 2% expression of HLA-DR markers, confirmed the homogeneity and purity of the DPSC cultures. We further illustrated their multipotency based on differentiation to adipogenic, osteogenic, and chondrogenic lineages. We also induced these cells to differentiate into hepatic-like and neuronal-like cells by adding corresponding stimulation media. This optimized protocol will aid in the cultivation of a highly expandable population of mesenchymal stem cells to be utilized in the laboratory or for preclinical studies. Similar protocols can be incorporated into clinical setups for practicing DPSC-based treatments.

Three-dimensional spheroid culture of dental pulp-derived stromal cells enhance their biological and regenerative properties for potential therapeutic applications.

Mesenchymal stem/stromal cell (MSC) spheroids generated in a three-dimensional (3D) culture system serve as a surrogate model that maintain stem cell characteristics since these mimic the in vivo behavior of cells and tissue more closely. Our study involved a detailed characterization of the spheroids generated in ultra-low attachment flasks. The spheroids were evaluated and compared for their morphology, structural integrity, viability, proliferation, biocomponents, stem cell phenotype and differentiation abilities with monolayer culture derived cells (2D culture). The in-vivo therapeutic efficacy of DPSCs derived from 2D and 3D culture was also assessed by transplanting them in an animal model of the critical-sized calvarial defect. DPSCs formed compact and well-organized multicellular spheroids when cultured in ultra-low attachment condition with superior stemness, differentiation, and regenerative abilities than monolayer cells. They maintained lower proliferative state and showed marked difference in the cellular biocomponents such as lipid, amide and nucleic acid between DPSCs from 2D and 3D cultures. The scaffold-free 3D culture efficiently preserves DPSCs intrinsic properties and functionality by maintaining them in the state close to the native tissues. The scaffold free 3D culture methods allow easy collection of a large number of multicellular spheroids of DPSCs and therefore, this can be adopted as a feasible and efficient method of generating robust spheroids for various in-vitro and in-vivo therapeutic applications.

Rat BM-MSCs secretome alone and in combination with stiripentol and ISRIB, ameliorated microglial activation and apoptosis in experimental stroke.

BACKGROUND: Stroke, a devastating neurological emergency, is the leading cause of worldwide mortality and functional disability. Combining novel neuroprotective drugs offers a way to improve the stroke intervention outcomes. In the present era, the combination therapy has been proposed as a plausible strategy to target multiple mechanisms and enhance the treatment efficacy to rescue stroke induced behavioral abnormalities and neuropathological damage. In the current study, we have investigated the neuroprotective effect of stiripentol (STP) and trans integrated stress response inhibitor (ISRIB) alone and in combination with rat bone marrow derived mesenchymal stem cells (BM-MSCs) secretome in an experimental model of stroke. MATERIALS & METHODS: Stroke was induced in male Wistar rats (n = 92) by temporary middle cerebral artery occlusion (MCAO). Three investigational agents were selected including STP (350 mg/kg; i.p.), trans ISRIB (2.5 mg/kg; i.p.) and rat BM-MSCs secretome (100 µg/kg; i.v). Treatment was administered at 3 hrs post MCAO, in four doses with a 12 hrs inter-dose interval. Post MCAO, neurological deficits, brain infarct, brain edema, BBB permeability, motor functional and memory deficits were assessed. Molecular parameters: oxidative stress, pro inflammatory cytokines, synaptic protein markers, apoptotic protein markers and histopathological damage were assessed. RESULTS: STP and trans ISRIB, alone and in combination with rat BM-MSCs secretome, significantly improved neurological, motor function and memory deficits along with significant reduction in pyknotic neurons in the brain of post MCAO rats. These results were correlating with significant reduction in pro-inflammatory cytokines, microglial activation and apoptotic markers in the brain of drug treated post MCAO rats. CONCLUSION: STP and trans ISRIB, alone and in combination with rat BM-MSCs secretome, might be considered as potential neuroprotective agents in the acute ischemic stroke (AIS) management.