Changes in gene expression in pressure ulcers debrided by different approaches - a pilot study

Pressure ulcers (PUs), also known as pressure injuries, are chronic wounds that represent potential lifelong complications. Pressure ulcers of a deep category (III and IV) are often indicated for surgical treatment - debridement and surgical reconstruction. Sharp surgical debridement is widely used in the debridement of PUs; however, the Versajet® hydrosurgery system is becoming an increasingly popular tool for tangential excision in surgery due to its numerous advantages. This work focused on the expression of selected genes, especially those associated with oxidative stress, in PUs debrided by two approaches - sharp surgical debridement and debridement using Versajet® hydrosurgery system. Expression of following genes was evaluated: NFE2L2, ACTA2, NFKB1, VEGFA, MKI67, HMOX1, HMOX2, HIF1A, and SOD2. ACTB and PSMB were used as housekeeping genes. So far, five patients have been enrolled in the study. Preliminary results suggest no significant difference in gene expression with different pressure ulcer treatment approaches except NFE2L2, despite the macroscopic differences. However, the results revealed correlations between the expression of some genes, namely HIF1A and SOD2, VEGFA and SOD2 and VEGFA and HIF1A. These results may indicate a connection between hypoxia, oxidative stress, pressure ulcer healing processes and angiogenesis.

Cryopreserved clinical-grade human embryonic stem cell-derived dopaminergic progenitors function in Parkinson's disease models

AIM

Parkinson's Disease (PD) is a common age-related neurodegenerative disorder with a rising prevalence. Human pluripotent stem cells have emerged as the most promising source of cells for midbrain dopaminergic (mDA) neuron replacement in PD. This study aimed to generate transplantable mDA progenitors for treatment of PD.

MATERIALS AND METHODS

Here, we optimized and fine-tuned a differentiation protocol using a combination of small molecules and growth factors to induce mDA progenitors to comply with good manufacturing practice (GMP) guidelines based on our clinical-grade human embryonic stem cell (hESC) line.

KEY FINDINGS

The resulting mDA progenitors demonstrated robust differentiation and functional properties in vitro. Moreover, cryopreserved mDA progenitors were transplanted into 6-hydroxydopamine-lesioned rats, leading to functional recovery.

SIGNIFICANCE

We demonstrate that our optimized protocol using a clinical hESC line is suitable for generating clinical-grade mDA progenitors and provides the ground work for future translational applications.

Chicken Interspecies Chimerism Unveils Human Pluripotency

Human pluripotent stem cells (hPSCs) are commonly kept in a primed state but also able to acquire a more immature naive state under specific conditions in vitro. Acquisition of naive state changes several properties of hPSCs and might affect their contribution to embryonic development in vivo. However, the lack of an appropriate animal test system has made it difficult to assess potential differences for chimera formation between naive and primed hPSCs. Here, we report that the developing chicken embryo is a permissive host for hPSCs, allowing analysis of the pluripotency potential of hPSCs. Transplantation of naive-like and primed hPSCs at matched developmental stages resulted in robust chimerism. Importantly, the ability of naive-like but not of primed hPSCs to form chimera was substantially reduced when injected at non-matched developmental stages. We propose that contribution to chick embryogenesis is an informative and versatile test to identify different pluripotent states of hPSCs.

Temporal activation of LRH-1 and RAR-γ in human pluripotent stem cells induces a functional naïve-like state

Naïve pluripotency can be established in human pluripotent stem cells (hPSCs) by manipulation of transcription factors, signaling pathways, or a combination thereof. However, differences exist in the molecular and functional properties of naïve hPSCs generated by different protocols, which include varying similarities with pre-implantation human embryos, differentiation potential, and maintenance of genomic integrity. We show here that short treatment with two chemical agonists (2a) of nuclear receptors, liver receptor homologue-1 (LRH-1) and retinoic acid receptor gamma (RAR-γ), along with 2i/LIF (2a2iL) induces naïve-like pluripotency in human cells during reprogramming of fibroblasts, conversion of pre-established hPSCs, and generation of new cell lines from blastocysts. 2a2iL-hPSCs match several defined criteria of naïve-like pluripotency and contribute to human-mouse interspecies chimeras. Activation of TGF-β signaling is instrumental for acquisition of naïve-like pluripotency by the 2a2iL induction procedure, and transient activation of TGF-β signaling substitutes for 2a to generate naïve-like hPSCs. We reason that 2a2iL-hPSCs are an easily attainable system to evaluate properties of naïve-like hPSCs and for various applications.

Suppression of p38-MAPK endows endoderm propensity to human embryonic stem cells

The ability of human embryonic stem cells (hESCs) to proliferate unlimitedly and give rise to all tissues makes these cells a promising source for cell replacement therapies. To realize the full potential of hESCs in cell therapy, it is necessary to interrogate regulatory pathways that influence hESC maintenance and commitment. Here, we reveal that pharmacological attenuation of p38 mitogen-activated protein kinase (p38-MAPK) in hESCs concomitantly augments some characteristics associated with pluripotency and the expressions of early lineage markers. Moreover, this blockage capacitates hESCs to differentiate towards an endoderm lineage at the expense of other lineages upon spontaneous hESC differentiation. Notably, hESCs pre-treated with p38-MAPK inhibitor exhibit significantly improved pancreatic progenitor directed differentiation. Together, our findings suggest a new approach to the robust endoderm differentiation of hESCs and potentially enables the facile derivation of various endoderm-derived lineages such as pancreatic cells.

In Vitro Spermatogenesis by Three-dimensional Culture of Spermatogonial Stem Cells on Decellularized Testicular Matrix

Background

In the males, Spermatogonial Stem Cells (SSCs) contribute to the production of sex cells and fertility. In vitro SSCs culture can operate as an effective strategy for studies on spermatogenesis and male infertility treatment. Cell culture in a three-dimensional (3D) substrate, relative to a two-dimensional substrate (2D), creates better conditions for cell interaction and is closer to in vivo conditions. In the present study, in order to create a 3D matrix substrate, decellularized testicular matrix (DTM) was used to engender optimal conditions for SSCs culture and differentiation.

Materials and Methods

After, testicular cells enzymatic extraction from testes of brain-dead donors, the SSCs were proliferated in a specific culture medium for four weeks, and after confirming the identity of the colonies derived from the growth of these cells, they were cultured on a layer of DTM as well as in 2D condition with a differentiated culture medium. In the Sixth week since the initiation of the differentiation culture, the expression of pre meiotic (OCT4 & PLZF ), meiotic (SCP3 & BOULE) and post meiotic (CREM & Protamine-2) genes were measured in both groups.

Results

The results indicated that the expression of pre meiotic, meiotic and post meiotic genes was significantly higher in the cells cultured on DTM (P ≤ 0.001).

Conclusion

SSCs culture in DTM with the creation of ECM and similar conditions with in vivo can be regarded as a way of demonstrating spermatogenesis in vitro, which can be adopted as a treatment modality for male infertility.

Expression analysis of genes encoding TEX11, TEX12, TEX14 and TEX15 in testis tissues of men with non-obstructive azoospermia

Objective

Spermatogenesis is a complex process controlled by a plethora of genes. Changes in expression and function of these genes may thus lead to spermatogenic deficiency and male infertility. TEX11, TEX12, TEX14 and TEX15 are germ cell-specific genes expressed in the testis. TEX11, involved in the initiation and maintenance of chromosome synapses in meiotic chromosomes, has been shown to be essential for meiosis and fertility in males. TEX14, a component of intercellular bridges in germ cells, is required for spermatogenesis and fertility. TEX12 and TEX15 are essential for correct assembly of the synaptonemal complex and thus meiosis progression.

Methods

In order to examine whether changes in expression of these genes is associated with impaired spermatogenesis, expression levels of these genes were quantified by RT-qPCR on samples retrieved from infertile patients submitted to diagnostic testicular biopsy at Royan institute. Samples were divided into two groups of 18 patients with non-obstructive azoospermia considered as case; nine patients with obstructive azoospermia were included in the control group.

Results

A significant down-regulation of these genes was observed in the SCOS group when compared to the control group.

Conclusion

This result suggests that regular expression of TEX11, TEX12, TEX14 and TEX15 is essential for the early stages of spermatogenesis.

Temporal Gene Expression and DNA Methylation during Embryonic Stem Cell Derivation

Objective

Dual inhibition of mitogen-activated protein kinase (MAPK) kinase (also known as MEK) and transforming growth factor β (TGFβ) type I receptors by PD0325901 and SB431542, known as R2i has been introduced as a highly efficient approach to the generation of mouse embryonic stem cells (ESC). In the present study, we investigated the molecular mechanisms underlying ESC derivation in the R2i condition.

Materials and Methods

In this experimental study, zona-free whole E3.5 blastocysts were seeded on mouse embryonic fibroblast (MEF) feeder cells in both R2i and serum conventional media. The isolated inner cell mass (ICM), ESCs and the ICM-outgrowths were collected on days 3, 5 and 7 post-blastocyst culture for quantitative real time- polymerase chain reaction (qRT-PCR) analysis as well as to assess the DNA methylation status at the time points during the transition from ICM to ESC.

Results

qRT-PCR revealed a significantly higher expression of the pluripotency-related genes (Oct4, Nanog, Sox2, Rex1, Dppa3, Tcf3, Utf1, Nodal, Dax1, Sall4 and β-Catenin) and lower expression of early differentiation genes (Gata6, Lefty2 and Cdx2) in R2i condition compared to the serum condition. Moreover, the upstream region of Oct4 and Nanog showed a progressive increase in methylation levels in the upstream regions of the genes following in R2i or serum conditions, followed by a decrease of DNA methylation in ESCs obtained under R2i. However, the methylation level of ICM outgrowths in the serum condition was much higher than R2i, at levels that could have a repressive effect and therefore explain the absence of expression of these two genes in the serum condition.

Conclusion

Our investigation revealed that generation of ESCs in the ground-state of pluripotency could be achieved by inhibiting the MEK and TGF-β signaling pathways in the first 5 days of ESC derivation.

Exosomes secreted by hypoxic cardiosphere-derived cells enhance tube formation and increase pro-angiogenic miRNA

Exosomes are required for the regenerative effects of human cardiosphere-derived cells (CDCs). Studies show that they mimic the cardioprotective benefits of CDCs in rodents and porcine myocardial infarction (MI) models. Hypoxic preconditioning of stem cells increases the cardioprotective effects of exosomes in MI models by enhancing angiogenesis. Several exosomal microRNAs (miRNAs) up-regulate in response to hypoxia and play a role in cardioprotective and pro-angiogenic effects. In this study, we have demonstrated that human CDCs secreted exosomes under hypoxic conditions (1% O₂ for 2 days) enhanced tube formation by human umbilical vein endothelial cells (HUVECs) at a concentration of 25 µg/mL. Pro-angiogenic exosomal miRNAs including miR-126, miR-130a, and miR-210 showed a substantial increase (>2-, >2-, and >4-fold, respectively) in the hypoxic exosomes compared to normoxic CDC-derived exosomes. Our study suggested a significant benefit of hypoxic CDC exosomes for the treatment of cardiac diseases by induction of angiogenesis via enrichment of pro-angiogenic exosomal miRNAs.

Bioprocess development for mass production of size-controlled human pluripotent stem cell aggregates in stirred suspension bioreactor

Current protocols for the scalable suspension culture of human pluripotent stem cells (hPSCs) are limited by multiple biological and technical challenges that need to be addressed before their use in clinical trials. To overcome these challenges, we have developed a novel bioprocess platform for large-scale expansion of human embryonic and induced pluripotent stem cell lines as three-dimensional size-controlled aggregates. This novel bioprocess utilizes the stepwise optimization of both static and dynamic suspension culture conditions. After screening eight xeno-free media in static suspension culture and optimizing single-cell passaging in dynamic conditions, the scale-up from a static to a dynamic suspension culture in the stirred bioreactor resulted in a two- to threefold improvement in expansion rates, as measured by cell counts and metabolic activity. We successfully produced size-specific aggregates through optimization of bioreactor hydrodynamic conditions by using combinations of different agitation rates and shear protectant concentrations. The expansion rates were further improved by controlling oxygen concentration at normoxic conditions, and reached a maximum eightfold increase for both types of hPSCs. Subsequently, we demonstrated a simple and rapid scale-up strategy that produced clinically relevant numbers of hPSCs (∼2×10(9) cells) over a 1-month period by the direct transfer of "suspension-adapted frozen cells" to a stirred suspension bioreactor. We omitted the required preadaptation passages in the static suspension culture. The cells underwent proliferation over multiple passages in the demonstrated xeno-free dynamic suspension culture while maintaining their self-renewal capabilities, as determined by marker expressions and in vitro spontaneous differentiation. In conclusion, suspension culture protocols of hPSCs could be used to mass produce homogenous and pluripotent undifferentiated cells by identification and optimization of key bioprocess parameters that are complemented by a simple and rapid scale-up platform.

Appropriate reference gene selection for real-time PCR data normalization during rat mesenchymal stem cell differentiation

Reverse transcription quantitative PCR (RT—qPCR) is one of the best methods for the study of mesenchymal stem cell (MSC) differentiation by gene expression analysis. This technique needs appropriate reference or housekeeping genes (HKGs) to normalize the expression of the genes of interest. In the present study the expression stability of six widely used HKGs including Actb, Btub, Hprt, B2m, Gusb and Tfrc was investigated during rat MSC differentiation into osteocytes, adipocytes and chondrocytes lineages using geNorm and NormFinder software. RT—qPCR data analyzed by geNorm revealed the different sets of suitable reference genes for each cell type. NormFinder also showed similar results. Analysis of the combined data of MSCs with each differentiated cell type revealed the considerable shift in expression of some reference genes during differentiation; for example Gusb and B2m were among the least stable genes in MSCs but the most stable in chondrocytes. Normalization of specific genes for each lineage by different reference genes showed considerable difference in their expression fold change. In conclusion, for the appropriate analysis of gene expression during rat MSC differentiation and also for monitoring differentiation procedures, it is better to consider precisely the reference gene stability and select suitable reference genes for each purpose.

Effect of anti-epileptic drugs on serum immunoglobulin levels in children

Epilepsy is one of the most frequent neurological disorders. Despite the advances and improvements in treatment of seizure disorders, immunologic alterations related to anticonvulsant drugs have been described. The aim of this paper is to assess the effect of some antiepileptic drugs on serum immunoglobulin levels in epileptic patients. Seventy-one patients with epilepsy were included in the study. Participants were divided into three groups based on their treatment with carbamazepine (n=33), sodium valproate (n=22) or phenobarbital (n=16) as monotherapy. Three samples were taken from each patient and serum immunoglobulin levels were measured before treatment, 3 months and 6 months after therapy. Overall, eleven patients out of 71 (15.5%) had a decrease in at least one serum immunoglobulin level (more than 2SD below age-matched control). In the patients receiving carbamazepine, 8 patients (24.2%) showed significant decline in at least one immunoglobulin (3 cases in IgA and 5 cases in IgG). In the group of treated with sodium valproate, 2 patients showed significant decrease in serum IgA level. Results of the last group indicated a significant reduction in serum IgG concentration only in one patient. No patient at all showed significant decrease in serum IgM level. This study suggests that anti-epileptic drugs could reduce serum immunoglobulins, especially IgA and IgG; among them carbamazepine effect is of more concern.

Selective immunoglobulin A deficiency in Iranian blood donors: prevalence, laboratory and clinical findings

Selective deficiency of immunoglobulin A (IgA) is the most frequent primary hypogammaglobulinemia. As some IgA-deficient patients have IgA antibodies in their plasma which may cause anaphylactic reactions, blood centers usually maintain a list of IgA-deficient blood donors to prepare compatible blood components. In this study we determined the incidence of selective IgA deficiency (SIgAD) in normal adult Iranian population. 13022 normal Iranian blood donors were included in this study. The assay which we used was adapted to the manual pipetting system and ELISA reader was used for screening. Other classes of immunoglobulins (G, M), as well as secretory IgA and IgG subclasses were tested in IgA deficient cases by ELISA. SPSS was used for statistical analysis.Among 13022 studied cases, 11608 blood donors were males (89.14%) and 1414 were females (10.86%). Their mean (+/-SD) age and weight were 38.5+/-11 years and 82+/-12 Kg respectively. Twenty of the screened samples were found by means of ELISA to be IgA-deficient (less than 5mg/dl), (frequency; 1:651). The data could indicate a compensation for IgA deficiency by serum IgM in one of our IgA deficient cases (Patient 5). We observed a correlation between IgG3 and serum IgA in deficient cases (r=0.498, P=0.025). Our results indicate that in present study the prevalence of S IgA D is in agreement with data from other Caucasians populations (from 1:300 to 1:700). In conclusion, Selective IgA Deficiency could be almost asymptomatic in most cases in general population. Our study suggests that; due to high frequency of IgA deficiency in Iran, it seems necessary to measure IgA levels for every blood donor and blood recipient to find IgA deficient cases.