Effects of Oral Pirfenidone on Colon Anastomosis Healing and Adhesion Formation in Rats.

INTRODUCTION: Many experimental studies have examined multiple drugs or treatments to improve the healing of intestinal anastomoses. Synthetic prostacyclin analogs, immunosuppressants, erythropoietin, growth hormone, insulin-like growth factor type 1, synthetic metalloproteinases inhibitors, and hyperbaric oxygen therapy have produced promising results in low-risk models of anastomosis dehiscence. However, in high-risk models, only hyperbaric oxygen therapy has been shown to be useful. Pirfenidone (PFD), a commonly used antifibrosing drug, has not been shown to be effective for this purpose. Our objective was to evaluate the effects of PFD on anastomosis healing and adhesion genesis in a low-risk rat model of dehiscence of colonic anastomosis. METHODS: An experimental study was conducted on 40 healthy Wistar rats randomly assigned to the control group or PFD experimental group (20 rats in each group). Colon anastomosis was performed 3 cm above the peritoneal reflection using the same technique in all animals. Mechanical resistance was studied by measuring bursting pressure. Adhesions were evaluated macroscopic and histologically using common staining techniques. Animals received the first PFD dose 12 h after surgery at a dose of 500 mg/kg one a day (SID) for 5 consecutive days. On day 6, the animals were reoperated on to measure the bursting pressure in situ and to classify adhesions macroscopically, and the anastomosed colon was resected for histological analysis. RESULTS: There were no deaths, complications, or anastomosis dehiscence in either group. The mean bursting pressure was 120.8 ± 11 mm Hg and 135.5 ± 12.4 in the control and PFD groups, respectively (p < 0.001). The adhesions were less dense and had less inflammatory cell infiltration in the PFD group (p < 0.02 and 0.002, respectively). Collagen content was slightly higher in the PFD group (p = 0.04). CONCLUSIONS: Our results revealed favorable effects of PFD in this low-risk colon anastomosis model; for example, the bursting pressure was higher, and the macroscopic adhesions were soft and exhibited less inflammatory infiltration and higher collagen content in the PFD group than in the control group. The results showing that PFD treatment was associated with better healing of minor adhesions seem to be paradoxical because the therapeutic indications for this drug are directed at treating fibrosing diseases.

Motor Function Deficits in the Estrogen Receptor Beta Knockout Mouse: Role on Excitatory Neurotransmission and Myelination in the Motor Cortex.

BACKGROUND: Male estrogen receptor beta (ERß) knockout (BERKO) mice display anxiety and aggression linked to, among others, altered serotonergic signaling in the basolateral amygdala and dorsal raphe, impaired cortical radial glia migration, and reduced GABAergic signaling. The effects on primary motor cortex (M1 cortex) and locomotor activity as a consequence of ERß loss have not been investigated. OBJECTIVE: The aim of this study was to determine whether locomotor activity is altered as a consequence of the changes in the M1 cortex. METHODS: The locomotor activity of male wild-type (WT) and BERKO mice was evaluated using the open-field and rotarod tests. Molecular changes in the M1 cortex were analyzed by RNA sequencing, electron microscopy, electrophysiology, and immunohistological techniques. In addition, we established oligodendrocyte (OL) cultures from WT and BERKO mouse embryonic stem cells to evaluate OL function. RESULTS: Locomotor profiling revealed that BERKO mice were more active than WT mice but had impaired motor coordination. Analysis of the M1 cortex pointed out differences in synapse function and myelination. There was a reduction in GABAergic signaling resulting in imbalanced excitatory and inhibitory neurotransmission as well as a defective OL differentiation accompanied by myelin defects. The effects of ERß loss on OL differentiation were confirmed in vitro. CONCLUSION: ERß is an important regulator of GABAergic interneurons and OL differentiation, which impacts on adult M1 cortex function and may be linked to increased locomotor activity and decreased motor coordination in BERKO mice.

Role of estrogen receptor beta in neural differentiation of mouse embryonic stem cells.

The ability to propagate mature cells and tissue from pluripotent stem cells offers enormous promise for treating many diseases, including neurodegenerative diseases. Before such cells can be used successfully in neurodegenerative diseases without causing unwanted cell growth and migration, genes regulating growth and migration of neural stem cells need to be well characterized. Estrogen receptor beta (ERß) is essential for migration of neurons and glial cells in the developing mouse brain. To examine whether ERß influences differentiation of mouse embryonic stem cells (mESC) into neural lineages, we compared control and ERß knockout (BERKO) mESCs at defined stages of neural development and examined the effects of an ERß-selective ligand (LY3201) with a combination of global and targeted gene-expression profiling and the expression of key pluripotency markers. We found that ERß was induced in embryoid bodies (EBs) and neural precursor cells (NPCs) during development. Proliferation was higher in BERKO NPCs and was inhibited by LY3201. Neurogenesis was reduced in BERKO ES cells, and oligodendrogliogenesis was enhanced. BERKO EBs expressed higher levels of key ectodermal and neural progenitor markers and lower levels of markers for mesoderm and endoderm lineages. ERß-regulated factors are involved in cell adhesion, axon guidance, and signaling of Notch and GABA receptor pathways, as well as factors important for the differentiation of neuronal precursors into dopaminergic neurons (Engrailed 1) and for the oligodendrocyte fate acquisition (Olig2). Our data suggest that ERß is an important component for differentiation into midbrain neurons as well as for preventing precocious oligodendrogliogenesis.

Fluoxetine Affects Differentiation of Midbrain Dopaminergic Neurons In Vitro.

Recent meta-analyses found an association between prenatal exposure to the antidepressant fluoxetine (FLX) and an increased risk of autism in children. This developmental disorder has been related to dysfunctions in the brains' rewards circuitry, which, in turn, has been linked to dysfunctions in dopaminergic (DA) signaling. The present study investigated if FLX affects processes involved in dopaminergic neuronal differentiation. Mouse neuronal precursors were differentiated into midbrain dopaminergic precursor cells (mDPCs) and concomitantly exposed to clinically relevant doses of FLX. Subsequently, dopaminergic precursors were evaluated for expression of differentiation and stemness markers using quantitative polymerase chain reaction. FLX treatment led to increases in early regional specification markers orthodenticle homeobox 2 (Otx2) and homeobox engrailed-1 and -2 (En1 and En2). On the other hand, two transcription factors essential for midbrain dopaminergic (mDA) neurogenesis, LIM homeobox transcription factor 1 α (Lmx1a) and paired-like homeodomain transcription factor 3 (Pitx3) were downregulated by FLX treatment. The stemness marker nestin (Nes) was increased, whereas the neuronal differentiation marker ß3-tubulin (Tubb3) decreased. Additionally, we observed that FLX modulates the expression of several genes associated with autism spectrum disorder and downregulates the estrogen receptors (ERs) α and ß Further investigations using ERß knockout (BERKO) mDPCs showed that FLX had no or even opposite effects on several of the genes analyzed. These findings suggest that FLX affects differentiation of the dopaminergic system by increasing production of dopaminergic precursors, yet decreasing their maturation, partly via interference with the estrogen system.

Aminochrome induces dopaminergic neuronal dysfunction: a new animal model for Parkinson's disease.

L-Dopa continues to be the gold drug in Parkinson's disease (PD) treatment from 1967. The failure to translate successful results from preclinical to clinical studies can be explained by the use of preclinical models which do not reflect what happens in the disease since these induce a rapid and extensive degeneration; for example, MPTP induces a severe Parkinsonism in only 3 days in humans contrasting with the slow degeneration and progression of PD. This study presents a new anatomy and develops preclinical model based on aminochrome which induces a slow and progressive dysfunction of dopaminergic neurons. The unilateral injection of aminochrome into rat striatum resulted in (1) contralateral rotation when the animals are stimulated with apomorphine; (2) absence of significant loss of tyrosine hydroxylase-positive neuronal elements both in substantia nigra and striatum; (3) cell shrinkage; (4) significant reduction of dopamine release; (5) significant increase in GABA release; (6) significant decrease in the number of monoaminergic presynaptic vesicles; (7) significant increase of dopamine concentration inside of monoaminergic vesicles; (8) significant increase of damaged mitochondria; (9) significant decrease of ATP level in the striatum (10) significant decrease in basal and maximal mitochondrial respiration. These results suggest that aminochrome induces dysfunction of dopaminergic neurons where the contralateral behavior can be explained by aminochrome-induced ATP decrease required both for anterograde transport of synaptic vesicles and dopamine release. Aminochrome could be implemented as a new model neurotoxin to study Parkinson's disease.

Estrogen receptor ß controls MMP-19 expression in mouse ovaries during ovulation.

Estrogen receptor beta (ERß/ESR2) has a central role in mouse ovaries, as ERß knockout (BERKO) mice are subfertile due to an increase in fibrosis around the maturing follicle and a decrease in blood supply. This has a consequence that these follicles rarely rupture to release the mature oocyte. Matrix metalloproteinases (MMPs) are modulators of the extracellular matrix, and the expression of one specific MMP, MMP-19, is normally increased in granulosa cells during their maturation until ovulation. In this study, we demonstrate that MMP-19 levels are downregulated in BERKO mouse ovaries. Using human MCF-7 cells that overexpress ERß, we could identify MMP-19 to be a transcriptional target of ligand-bound activated ERß acting on a specificity protein-1 binding site. These data provide a molecular explanation for the observed follicle rupture defect that contributes to the subfertility of female BERKO mice.

Uric acid stones in the urinary bladder of aryl hydrocarbon receptor (AhR) knockout mice.

The aryl hydrocarbon receptor (AhR) knockout mice raised in the laboratory of Fujii-Kuriyama have been under investigation for several years because of the presence in their urinary bladder of large, yellowish stones. The stones are composed of uric acid and become apparent in the bladders as tiny stones when mice are 10 wk of age. By the time the mice are 6 mo of age, there are usually two or three stones with diameters of 3-4 mm. The urate concentration in the serum was normal but in the urine the concentration was 40-50 mg/dL, which is 10 times higher than that in the WT littermates. There were no apparent histological pathologies in the kidney or joints and the levels of enzymes involved in elimination of purines were normal. The source of the uric acid was therefore judged to be from degradation of nucleic acids due to a high turnover of cells in the bladder itself. The bladder was fibrotic and the luminal side of the bladder epithelium was filled with eosinophilic granules. There was loss of E-cadherin between some epithelial cells, with an enlarged submucosal area filled with immune cells and sometimes invading epithelial cells. We hypothesize that in the absence of AhR there is loss of detoxifying enzymes, which leads to accumulation of unconjugated cytotoxins and carcinogens in the bladder. The presence of bladder toxins may have led to the increased apoptosis and inflammation as well as invasion of epithelial cells in the bladders of older mice.

Mice depleted of the coxsackievirus and adenovirus receptor display normal spermatogenesis and an intact blood-testis barrier.

The coxsackievirus and adenovirus receptor (CXADR (CAR)) is a cell adhesion molecule expressed mainly in epithelial cells. Numerous evidence indicate that CXADR has an important role in testis development and function of the blood-testis barrier (BTB) in vitro. The role of CXADR in testis physiology in vivo has, however, not been addressed. We therefore constructed a conditional CXADR knockout (cKO) mouse model in which CXADR can be depleted at any chosen timepoint by the administration of tamoxifen. We report for the first time that testicular depletion of CXADR in adult and pubertal mice does not alter BTB permeability or germ cell migration across the BTB during spermatogenesis. Adult cKO mice display normal junctional ultra-structure and localization of the junctional proteins claudin-3, occludin, junction-associated molecule-A (JAM-A), and ZO1. The BTB was intact with no leakage of biotin and lanthanum tracers into the tubular lumen. Adult CXADR cKO mice were fertile with normal sperm parameters and litter size. Breeding experiments and genotyping of the pups demonstrated that CXADR-negative sperm could fertilize WT eggs. In addition, knocking down CXADR from postnatal day 9 (P9) does not affect testicular development and BTB formation. These cKO mice were analyzed at P49 and P90 and display an intact barrier and uncompromised fertility. We conclude that CXADR possesses no direct role in testicular physiology in vivo.

Magnesium-ibogaine therapy in veterans with traumatic brain injuries.

Traumatic brain injury (TBI) is a leading cause of disability. Sequelae can include functional impairments and psychiatric syndromes such as post-traumatic stress disorder (PTSD), depression and anxiety. Special Operations Forces (SOF) veterans (SOVs) may be at an elevated risk for these complications, leading some to seek underexplored treatment alternatives such as the oneirogen ibogaine, a plant-derived compound known to interact with multiple neurotransmitter systems that has been studied primarily as a treatment for substance use disorders. Ibogaine has been associated with instances of fatal cardiac arrhythmia, but coadministration of magnesium may mitigate this concern. In the present study, we report a prospective observational study of the Magnesium-Ibogaine: the Stanford Traumatic Injury to the CNS protocol (MISTIC), provided together with complementary treatment modalities, in 30 male SOVs with predominantly mild TBI. We assessed changes in the World Health Organization Disability Assessment Schedule from baseline to immediately (primary outcome) and 1 month (secondary outcome) after treatment. Additional secondary outcomes included changes in PTSD (Clinician-Administered PTSD Scale for DSM-5), depression (Montgomery-Åsberg Depression Rating Scale) and anxiety (Hamilton Anxiety Rating Scale). MISTIC resulted in significant improvements in functioning both immediately (Pcorrected < 0.001, Cohen's d = 0.74) and 1 month (Pcorrected < 0.001, d = 2.20) after treatment and in PTSD (Pcorrected < 0.001, d = 2.54), depression (Pcorrected < 0.001, d = 2.80) and anxiety (Pcorrected < 0.001, d = 2.13) at 1 month after treatment. There were no unexpected or serious adverse events. Controlled clinical trials to assess safety and efficacy are needed to validate these initial open-label findings. ClinicalTrials.gov registration: NCT04313712 .

Case report: Ibogaine reduced severe neuropathic pain associated with a case of brachial plexus nerve root avulsion.

Brachial plexus nerve root avulsion results from complete separation of the nerve root from the spinal cord and is one of the most challenging types of neuropathic pain, coinciding with motor, sensory and autonomic deficits. The severe pain and typical impossibility of root reattachment often leads to requests for amputation. Ibogaine is an indole alkaloid producing psychoactive effects through reported actions upon multiple neurotransmitter systems, including NMDA, κ- and µ-opioid receptors and σ2 receptor sites, along with stimulation of neurotrophic factors GDNF and BDNF. In this case report we describe a 53-year-old male with two decades of severe intractable pain due to brachial plexus nerve root avulsion from vehicular trauma who was successfully treated with both high dose inpatient and low dose outpatient administrations of ibogaine. Though promising for future study, the adverse effects of high dose ibogaine administrations may limit tolerability of this saturation protocol to the most refractory cases.

Optimized single-cell RNA sequencing protocol to study early genome activation in mammalian preimplantation development.

Here, we present a modification of single-cell tagged reverse transcription protocol to study gene expression on a single-cell level or with limited RNA input. We describe different enzymes for reverse transcription and cDNA amplification, modified lysis buffer, and additional clean-up steps before cDNA amplification. We also detail an optimized single-cell RNA sequencing method for handpicked single cells, or tens to hundreds of cells, as input material to study mammalian preimplantation development. For complete details on the use and execution of this protocol, please refer to Ezer et al.1.

Neuroprotection against Aminochrome Neurotoxicity: Glutathione Transferase M2-2 and DT-Diaphorase.

Glutathione is an important antioxidant that plays a crucial role in the cellular protection against oxidative stress and detoxification of electrophilic mutagens, and carcinogens. Glutathione transferases are enzymes catalyzing glutathione-dependent reactions that lead to inactivation and conjugation of toxic compounds, processes followed by subsequent excretion of the detoxified products. Degeneration and loss of neuromelanin-containing dopaminergic neurons in the nigrostriatal neurons generally involves oxidative stress, neuroinflammation, alpha-synuclein aggregation to neurotoxic oligomers, mitochondrial dysfunction, protein degradation dysfunction, and endoplasmic reticulum stress. However, it is still unclear what triggers these neurodegenerative processes. It has been reported that aminochrome may elicit all of these mechanisms and, interestingly, aminochrome is formed inside neuromelanin-containing dopaminergic neurons during neuromelanin synthesis. Aminochrome is a neurotoxic ortho-quinone formed in neuromelanin synthesis. However, it seems paradoxical that the neurotoxin aminochrome is generated during neuromelanin synthesis, even though healthy seniors have these neurons intact when they die. The explanation of this paradox is the existence of protective tools against aminochrome neurotoxicity composed of the enzymes DT-diaphorase, expressed in these neurons, and glutathione transferase M2-2, expressed in astrocytes. Recently, it has been reported that dopaminergic neurons can be protected by glutathione transferase M2-2 from astrocytes, which secrete exosomes containing the protective enzyme.

Astrocytes protect dopaminergic neurons against aminochrome neurotoxicity.

Astrocytes protect neurons by modulating neuronal function and survival. Astrocytes support neurons in several ways. They provide energy through the astrocyte-neuron lactate shuttle, protect neurons from excitotoxicity, and internalize neuronal lipid droplets to degrade fatty acids for neuronal metabolic and synaptic support, as well as by their high capacity for glutamate uptake and the conversion of glutamate to glutamine. A recent reported astrocyte system for protection of dopamine neurons against the neurotoxic products of dopamine, such as aminochrome and other o-quinones, were generated under neuromelanin synthesis by oxidizing dopamine catechol structure. Astrocytes secrete glutathione transferase M2-2 through exosomes that transport this enzyme into dopaminergic neurons to protect these neurons against aminochrome neurotoxicity. The role of this new astrocyte protective mechanism in Parkinson´s disease is discussed.

Estrogen receptors do not influence angiogenesis after myocardial infarction.

BACKGROUND: There is controversy on whether estrogen receptors are present and functioning in the myocardium. Aims. To explore if after myocardial infarction (MI) estrogen receptors α (ERα) and ß (ERß) are upregulated in myocardial tissue and to explore if the presence/ absence of ERα or ERß influences angiogenesis after MI. METHODS: MI was induced by ligation of the left anterior descending artery in knockout (KO) mice, ERαKO and ERßKO, respectively, and non-KO littermate-controls, C57Bl/6 mice. The hearts were harvested after 12 days. A part of the periinfarct tissue was collected for ERα and ERß mRNA expression determination by real-time polymerase chain reaction. Using immunohistochemistry, ERα and ERß protein expression and capillary and arteriolar densities were blindly determined in the periinfarct area. RESULTS: In myocardium disrupted mRNA was upregulated in both ERαKO and ERßKO, (p < 0.005) and did not change after MI. There was no change in mRNA expression of ERα or ERß in wild type mice after MI. Expression of ERß in ERαKO and of ERα in ERßKO did not change. Following MI ERα or ERß could not be demonstrated by immunohistochemistry in either wild type or ERαKO or ERßKO. The capillary and arteriolar densities after MI did not differ between the groups in the periinfarct area. CONCLUSIONS: Although disrupted ER mRNA is upregulated in myocardium of ER knockout mice, no change in these or native receptors occurs following MI. At least in this model ER therefore seems not to have a role in myocardial arteriogenesis and angiogenesis after MI.

Estrogen receptor beta and neural development.

The female sex hormone estradiol (E2, 17ß-estradiol) has important functions in the developing brain. In addition to regulating sexual differentiation of the brain, E2 participates in the development of brain areas involved in functions unrelated to reproduction, such as cognition. E2 signals mainly thorough two estrogen receptors; estrogen receptor alpha (ERα) and beta (ERß). While ERα has distinct functions for sexual imprinting of the developing brain, ERß is considered to participate in the development of brain areas related to cognitive function. In this chapter we will focus on ERß's role during neural development. We will discuss the contributions of sex chromosomal and sex hormonal effects in this process and place it in relation to recent data on ERß obtained from stem cell models. Finally, we will discuss the lessons learned from mouse and stem cell models in understanding ERß's role in neural development and how new stem cell models, by addressing the human relevance, may help to advance our progress in this field.

Hematopoietic stem cell- and induced pluripotent stem cell-derived CAR-NK cells as reliable cell-based therapy solutions.

Hematopoietic stem cell- (HSC) and induced pluripotent stem (iPS) cell-derived natural killer (NK) cells containing engineered functions, such as chimeric antigen receptors (CAR), offer great promise for the treatment of seemingly incurable oncological malignancies. Today, some of the main challenges of CAR cell-based therapeutics are the long manufacturing time and safety of the cell sources used. Additional challenges include avoiding graft vs host disease (GVHD) and cytokine release syndrome (CRS). Here, we show compelling evidence for the use of NK cell therapeutics as a reliable off-the-shelf option, as they address key issues. Furthermore, we highlight how iPS cells and directed differentiation toward HSC and NK cells address industrial scalability and safety.

Generation of nonviral integration-free human iPS cell line KISCOi001-A from normal human fibroblasts, under defined xeno-free and feeder-free conditions.

KISCOi001-A is a healthy feeder-free and fully characterized human induced pluripotent stem (iPS) cell line cultured under xeno-free and defined conditions. The cell line is generated from normal human foreskin fibroblasts with non-integrating episomal plasmid vectors encoding OCT4, SOX2, KLF4, NANOG, LIN28, nontransforming L-MYC and dominant negative p53. The generated iPS cells are transgene-free and their pluripotency is confirmed by the expression of stem cell markers and capacity to differentiate into the cells of ectoderm, endoderm and mesoderm while their identity and karyotype stability is confirmed with Genomic assays.

Cellular Trafficking of Glutathione Transferase M2-2 Between U373MG and SHSY-S7 Cells is Mediated by Exosomes.

The enzyme glutathione transferase M2-2, expressed in human astrocytes, increases its expression in the presence of aminochrome and catalyzes the conjugation of aminochrome, preventing its toxic effects. Secretion of the enzyme glutathione transferase M2-2 from U373MG cells, used as a cellular model for astrocytes, has been reported, and the enzyme is taken up by neuroblastoma SYSH-S7 cells and provide protection against aminochrome. The present study provides evidence that glutathione transferase M2-2 is released in exosomes from U373MG cells, thereby providing a means for intercellular transport of the enzyme. With particular relevance to Parkinson disease and other degenerative conditions, we propose a new mechanism by which astrocytes may protect dopaminergic neurons against the endogenous neurotoxin aminochrome.

The hair follicle as an estrogen target and source.

For many decades, androgens have dominated endocrine research in hair growth control. Androgen metabolism and the androgen receptor currently are the key targets for systemic, pharmacological hair growth control in clinical medicine. However, it has long been known that estrogens also profoundly alter hair follicle growth and cycling by binding to locally expressed high-affinity estrogen receptors (ERs). Besides altering the transcription of genes with estrogen-responsive elements, 17beta-estradiol (E2) also modifies androgen metabolism within distinct subunits of the pilosebaceous unit (i.e., hair follicle and sebaceous gland). The latter displays prominent aromatase activity, the key enzyme for androgen conversion to E2, and is both an estrogen source and target. Here, we chart the recent renaissance of estrogen research in hair research; explain why the hair follicle offers an ideal, clinically relevant test system for studying the role of sex steroids, their receptors, and interactions in neuroectodermal-mesodermal interaction systems in general; and illustrate how it can be exploited to identify novel functions and signaling cross talks of ER-mediated signaling. Emphasizing the long-underestimated complexity and species-, gender-, and site-dependence of E2-induced biological effects on the hair follicle, we explore targets for pharmacological intervention in clinically relevant hair cycle manipulation, ranging from androgenetic alopecia and hirsutism via telogen effluvium to chemotherapy-induced alopecia. While defining major open questions, unsolved clinical challenges, and particularly promising research avenues in this area, we argue that the time has come to pay estrogen-mediated signaling the full attention it deserves in future endocrinological therapy of common hair growth disorders.

An effective serum- and xeno-free chemically defined freezing procedure for human embryonic and induced pluripotent stem cells.

BACKGROUND: Both human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) bear a great potential in regenerative medicine. In addition to optimized clinical grade culture conditions, efficient clinical grade cryopreservation methods for these cells are needed. Obtaining good survival after thawing has been problematic. METHODS: We used a novel, chemically defined effective xeno-free cryopreservation system for cryostorage and banking of hESCs and iPSCs. The earlier established slow freezing protocols have, even after recent improvements, resulted in low viability and thawed cells had a high tendency to differentiate. The medium is a completely serum and animal substance free product containing dimethylsulfoxide, anhydrous dextrose and a polymer as cryoprotectants. The cells were directly frozen at -70 degrees C, without a programmed freezer. RESULTS: The number of frozen colonies versus the number of surviving colonies differed significantly for both HS293 (chi(2) = 9.616 with one degree of freedom and two-tailed P = 0.0019) and HS306 (chi(2) = 8.801 with one degree of freedom and two-tailed P = 0.0030). After thawing, the cells had a high viability (90-96%) without any impact on proliferation and differentiation, compared with the standard freezing procedure where viability was much lower (49%). The frozen-thawed hESCs and iPSCs had normal karyotype and maintained properties of pluripotent cells with corresponding morphological characteristics, and expressed pluripotency markers after 10 passages in culture. They formed teratomas containing tissue components of the three germ layers. CONCLUSION: The defined freezing-thawing system described here offers an excellent simple option for banking of hESCs and iPSCs.