PL-hMSC and CH-hMSC derived soluble factors inhibit proliferation but improve hGBM cell migration by activating TGF-β and inhibiting Wnt signaling

Glioblastoma multiforme (GBM) is one of the most common and aggressive brain tumors. GBM resists most chemotherapeutic agents, resulting in a high mortality rate in patients. Human mesenchymal stem cells (hMSCs), which are parts of the cancer stroma, have been shown to be involved in the development and progression of GBM. However, different sources of hMSCs might affect GBM cells differently. In the present study, we established hMSCs from placenta(PL-hMSC) and chorion (CH-hMSC) to study the effects of their released soluble factors on the proliferation, migration, invasion, gene expression, and survival of human GBM cells, U251. We found that the soluble factors derived from CH-hMSCs and PL-hMSCs suppressed the proliferation of U251 cells in a dose-dependent manner. In contrast, soluble factors derived from both hMSC sources increased U251 migration without affecting their invasive property.  The soluble factors derived from these hMSCs decreased the expression levels of CyclinD1, E2Fs and MYC genes that promote GBM cell proliferation but increased the expression level of TWIST gene, which promotes EMT and GBM cell migration. Thefunctional study suggests that both hMSCs might exert their effects, at least in part, by activating TGF-b and suppressing Wnt/b-catenin signaling in U251 cells. Our study provides a better understanding of the interaction between GBM cells and gestational tissue-derived hMSCs. This knowledge might be used to develop safer and more effective stem cell therapy that improves the survival and quality of life of patients with GBM by manipulating the interaction between hMSCs and GBM cells.

Fucoxanthin diminishes oxidative stress damage in human placenta-derived mesenchymal stem cells through the PI3K/Akt/Nrf-2 pathway

Placenta-derived mesenchymal stem cells (PL-MSCs) have therapeutic potential in various clinical contexts due to their regenerative and immunomodulatory properties. However, with increasing age or extensive in vitro culture, their viability and function are gradually lost, thus restricting their therapeutic application. The primary cause of this deterioration is oxidative injury from free radicals. Therefore, enhancing cell viability and restoring cellular repair mechanisms of PL-MSCs in an oxidative stress environment are crucial in this context. Fucoxanthin, a carotenoid derived from brown seaweed, demonstrates antioxidant activity by increasing the production of antioxidant enzymes and lowering the levels of reactive oxygen species (ROS). This study aimed to determine whether fucoxanthin protects PL-MSCs from hydrogen peroxide (H2O2)-induced oxidative stress. After characterization, PL-MSCs were co-treated with fucoxanthin and H2O2 for 24 h (co-treatment) or pre-treated with fucoxanthin for 24 h followed by H2O2 for 24 h (pre-treatment). The effects of fucoxanthin on cell viability and proliferation were examined using an MTT assay. The expression of antioxidant enzymes, PI3K/Akt/Nrf-2 and intracellular ROS production were investigated in fucoxanthin-treated PL-MSCs compared to the untreated group. The gene expression and involvement of specific pathways in the cytoprotective effect of fucoxanthin were investigated by high-throughput NanoString nCounter analysis. The results demonstrated that co-treatment and pre-treatment with fucoxanthin restored the viability and proliferative capacity of PL-MSCs. Fucoxanthin treatment increased the expression of antioxidant enzymes in PL-MSCs cultured under oxidative stress conditions and decreased intracellular ROS accumulation. Markedly, fucoxanthin treatment could restore PI3K/Akt/Nrf-2 expression in H2O2-treated PL-MSCs. High-throughput analysis revealed up-regulation of genes involved in cell survival pathways, including cell cycle and proliferation, DNA damage repair pathways, and down-regulation of genes in apoptosis and autophagy pathways. This study demonstrated that fucoxanthin protects and rescues PL-MSCs from oxidative stress damage through the PI3K/Akt/Nrf-2 pathway. Our data provide the supporting evidence for the use of fucoxanthin as an antioxidant cytoprotective agent to improve the viability and proliferation capacity of PL-MSCs both in vitro and in vivo required to increase the effectiveness of MSC expansion for therapeutic applications.

The Human Placental Amniotic Membrane Mesenchymal-Stromal-Cell-Derived Conditioned Medium Inhibits Growth and Promotes Apoptosis of Human Cholangiocarcinoma Cells In Vitro and In Vivo by Suppressing IL-6/JAK2/STAT3 Signaling

Mesenchymal stromal cells (MSCs) have recently been shown to play an important role in the growth and progression of many solid tumors, including cholangiocarcinoma (CCA). The human placental amniotic membrane (hPAM) is one of the most favorable sources of MSCs due to its availability and non-invasive harvesting procedure. However, the role of human placental amniotic membrane mesenchymal stromal cells (hPAMSCs) in the growth and progression of human CCA has not yet been determined. This study investigates the effects of conditioned medium derived from hPAMSCs (PA-CM) on the properties of three human CCA cell lines and explores possible mechanisms of action. Varying concentrations of PA-CM were used to treat CCA cells to determine their effects on the proliferation and apoptosis of CCA cells. The results showed that PA-CM inhibited the proliferation and colony-forming capacity of KKU100, KKU213A, and KKU213B cells. PA-CM also promoted the apoptosis of these CCA cells by causing the loss of mitochondrial membrane potential. Western Blotting confirmed that PA-CM induced CCA cell apoptosis by increasing the levels of the Bax/Bcl-2 ratio, cleaved caspase 3, and cleaved PARP, possibly by inhibiting the IL-6/JAK2/STAT3 signaling pathway. Moreover, our in vivo study also confirmed the suppressive effect of hPAMSCs on CCA cells by showing that PA-CM reduced tumor volume in nude mice transplanted with human CCA cells. Taken together, our results demonstrate that PA-CM has potent tumor-suppressive effects on human CCA cells and could potentially be used in combination with chemotherapy to develop a more effective treatment for CCA patients.

Intron Regions as Genetic Markers for Population Genetic Investigations of Opisthorchis viverrini sensu lato and Clonorchis sinensis

Opisthorchiasis and clonorchiasis are prevalent in Southeast and Far-East Asia, which are caused by the group 1 carcinogenic liver flukes Opisthorchis viverrini sensu lato and Clonorchis sinensis infection. There have been comprehensive investigations of systematics and genetic variation of these liver flukes. Previous studies have shown that O. viverrini is a species complex, called "O. viverrini sensu lato". More comprehensive investigations of molecular systematics and population genetics of each of the species that make up the species complex are required. Thus, other polymorphic genetic markers need to be developed. Therefore, this study aimed to characterize the intron regions of taurocyamine kinase gene (TK) to examine the genetic variation and population genetics of O. viverrini and C. sinensis collected from different geographical isolates and from a range of animal hosts. We screened seven intron regions embedded in TK. Of these, we selected an intron 5 of domain 1 (TkD1Int5) region to investigate the genetic variation and population genetics of theses liver flukes. The high nucleotide and haplotype diversity of TkD1Int5 was detected in O. viverrine. Heterozygosity with several insertion/deletion (indel) regions were detected in TkD1Int5 of the O. viverrine samples, whereas only an indel nucleotide was detected in one C. sinensis sample. Several O. viverrine samples contained three different haplotypes within a particular heterozygous sample. There were no genetic differences between C. sinensis isolated from various animal host. Heterozygous patterns specifically detected in humans was observed in C. sinensis. Thus, TkD1Int5 is a high polymorphic genetic marker, which could be an alternative marker for further population genetic investigations of these carcinogenic liver flukes and other related species from a wide geographical distribution and variety of animal hosts.

Distribution of Blastocystis subtypes isolated from various animal hosts in Thailand

Blastocystis is a parasitic protist of a variety of hosts, including humans. Mapping the distribution of Blastocystis and its genetic variants across different host species can help us understand the epidemiology of this organism and its role in health and disease. This study aimed to identify subtypes of Blastocystis detected in different animal hosts in Thailand. A total of 825 fecal samples belonging to 18 vertebrate orders, 36 families, 68 genera, and 80 species were collected. Of these, 111 specimens were Blastocystis-positive by culture. Seventy-nine samples were subjected to small subunit (SSU) ribosomal DNA amplification by PCR, and reliable subtype data were obtained for 61 specimens. At least 14 subtypes (ST), namely ST1 to ST10, ST14/ST24/ST25 complex, ST23, ST26, and ST29 were detected. In addition, Blastocystis was found in tortoises. ST1 (3.2%) and ST5 (11.5%) were found in pigs, ST2 (1.6%) and ST3 (3.2%) in non-human primates, ST4 (14.7%) in rodents and ruminants, ST6 (4.9%), ST7 (30%), ST9 (1.6%), and ST29 (1.6%) in birds, ST8 (6.6%) in Green peafowl and East Asian Porcupine, and ST10 (4.9%), ST14/ST24/ST25 (9.8%), ST23 (1.6%) and ST26 (1.6%) in ruminants. The sequence recovered from the elongated tortoises (Indotestudo elongata) (3.2%) was phylogenetically placed within the reptilian cluster of Blastocystis, for which no subtype system is available yet. Of note, we did not obtain Blastocystis sequences from any of the many canids and felids sampled in the study, and our data are in support of host specificity of Blastocystis, according to both colonization and subtype distribution.

Osteogenic differentiation and proliferation potentials of human bone marrow and umbilical cord-derived mesenchymal stem cells on the 3D-printed hydroxyapatite scaffolds

Mesenchymal stem cells (MSCs) are a promising candidate for bone repair. However, the maintenance of MSCs injected into the bone injury site remains inefficient. A potential approach is to develop a bone-liked platform that incorporates MSCs into a biocompatible 3D scaffold to facilitate bone grafting into the desired location. Bone tissue engineering is a multistep process that requires optimizing several variables, including the source of cells, osteogenic stimulation factors, and scaffold properties. This study aims to evaluate the proliferation and osteogenic differentiation potentials of MSCs cultured on 2 types of 3D-printed hydroxyapatite, including a 3D-printed HA and biomimetic calcium phosphate-coated 3D-printed HA. MSCs from bone marrow (BM-MSCs) and umbilical cord (UC-MSCs) were cultured on the 3D-printed HA and coated 3D-printed HA. Scanning electron microscopy and immunofluorescence staining were used to examine the characteristics and the attachment of MSCs to the scaffolds. Additionally, the cell proliferation was monitored, and the ability of cells to differentiate into osteoblast was assessed using alkaline phosphatase (ALP) activity and osteogenic gene expression. The BM-MSCs and UC-MSCs attached to a plastic culture plate with a spindle-shaped morphology exhibited an immunophenotype consistent with the characteristics of MSCs. Both MSC types could attach and survive on the 3D-printed HA and coated 3D-printed HA scaffolds. The MSCs cultured on these scaffolds displayed sufficient osteoblastic differentiation capacity, as evidenced by increased ALP activity and the expression of osteogenic genes and proteins compared to the control. Interestingly, MSCs grown on coated 3D-printed HA exhibited a higher ALP activity and osteogenic gene expression than those cultured on the 3D-printed HA. The finding indicated that BM-MSCs and UC-MSCs cultured on the 3D-printed HA and coated 3D-printed HA scaffolds could proliferate and differentiate into osteoblasts. Thus, the HA scaffolds could provide a suitable and favorable environment for the 3D culture of MSCs in bone tissue engineering. Additionally, biomimetic coating with octacalcium phosphate may improve the biocompatibility of the bone regeneration scaffold.

Human Mesenchymal Stem Cells Derived from the Placenta and Chorion Suppress the Proliferation while Enhancing the Migration of Human Breast Cancer Cells

BACKGROUND

Breast cancer is the most frequently diagnosed malignancy among women, resulting from abnormal proliferation of mammary epithelial cells. The highly vascularized nature of breast tissue leads to a high incidence of breast cancer metastases, resulting in a poor survival rate. Previous studies suggest that human mesenchymal stem cells (hMSCs) play essential roles in the growth, metastasis, and drug responses of many cancers, including breast cancer. However, hMSCs from different sources may release different combinations of cytokines that affect breast cancer differently.

METHODS

In this study, we have isolated hMSCs from the placenta (PL-hMSCs) and the chorion (CH-hMSCs) and determined how these hMSCs affect the proliferation, migration, invasion, and gene expression of two human breast cancer cells, MCF-7 and MDA-MB-231, as well as the possible mechanisms underlying those effects.

RESULTS

The results showed that the soluble factors derived from PL-hMSCs and CH-hMSCs inhibited the proliferation of MCF-7 and MDA-MB-231 cells but increased the migration of MDA-MB-231 cells. The study of gene expression showed that PL-hMSCs and CH-hMSCs downregulated the expression levels of the protooncogene CyclinD1 while upregulating the expression levels of tumor suppressor genes, P16 and P21 in MCF-7 and MDA-MB-231 cells. Furthermore, hMSCs from both sources also increased the expression levels of MYC, SNAI1, and TWIST, which promote the epithelial-mesenchymal transition and migration of breast cancer cells in both cell lines. The functional study suggests that the suppressive effect of CH-hMSCs and PL-hMSCs on MCF-7 and MDA-MB231 cell proliferation was mediated, at least in part, through IFN-γ.

CONCLUSIONS

Our study suggests that CH-hMSCs and PL-hMSCs inhibited breast cancer cell proliferation by negatively regulating CYCLIND1 expression and upregulating the expression of the P16 and P21 genes. In contrast, hMSCs from both sources enhanced breast cancer cell migration, possibly by increasing the expression of MYC, SNAI1, and TWIST genes in those cells.

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

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

Genetic diversity and phylogenetic analyses of ixodid ticks infesting cattle in northeast Thailand: the discovery of Rhipicephalus microplus clade C and the rarely detected R. haemaphysaloides

In total, 160 ticks infesting cattle in the northeast region of Thailand were collected and used for molecular investigation. Three tick species-Rhipicephalus microplus Canestrini, Rhipicephalus haemaphysaloides Supino and Haemaphysalis bispinosa Neumann-were identified based on morphology and DNA sequences of mitochondrial cytochrome c oxidase subunit 1 (CO1) and 16S ribosomal RNA (16S rRNA). In total, 26 and seven unique haplotypes of the CO1 and 16S rRNA genes, respectively, were recovered. Phylogenetic analysis using the CO1 sequence revealed that the R. microplus from northeastern Thailand were grouped into the previously described clades A and C, whereas the 16S rRNA phylogenetic tree assigned all isolates of R. microplus from Northeast Thailand into the previously described clade B. Clade C of the CO1 phylogenetic tree is a new genetic assemblage recently discovered from India and Malaysia, which has now been detected in our study. The haplotype network also demonstrated that R. microplus is divided into two haplogroups corresponding to the assemblage of the CO1 phylogenetic tree. Our findings strongly support the previous genetic assemblage classification and evidence that R. microplus from Northeast Thailand is a species complex comprising at least two genetic assemblages, i.e., clades A and C. However, further investigation is needed and should involve more comprehensive genetic and morphological analyses and cover a larger part of their distributional range throughout Southeast Asia.

Andrographolide Reduces Lipid Droplet Accumulation in Adipocytes Derived from Human Bone Marrow Mesenchymal Stem Cells by Suppressing Regulators of Adipogenesis

Obesity has become a major public health concern; so, a strategy to prevent or reduce obesity is a priority. The inhibition of lipid droplet accumulation and adipogenesis process provides a target for the treatment of obesity. Herein, the effect of andrographolide (AP) on lipid accumulation in adipocytes derived from human bone marrow mesenchymal stem cells (hBM-MSCs) was examined. AP at concentrations of 1, 2.5, 5, and 10 μM reduced lipid droplet accumulation in the adipocytes by suppressing the adipogenic differentiation of hBM-MSCs. Concurrently, the expressions of adipogenic marker genes and the level of adipokines secreted by adipocytes were suppressed. Gene screening analysis showed a negative regulation of genes involved in the adipogenesis process. In conclusion, we demonstrated for the first time an antilipid accumulation in adipocytes from hBM-MSCs by AP. The compound may potentially be a novel therapeutic agent for the treatment of obesity as well as obesity-related diseases.

Andrographolide promotes proliferative and osteogenic potentials of human placenta-derived mesenchymal stem cells through the activation of Wnt/β-catenin signaling

Introduction

The in vitro expansion and differentiation of mesenchymal stem cells derived from bone marrow (BM-hMSCs) are considered as potential therapeutic tools for clinical applications in bone tissue engineering and regenerative medicine. However, invasive sampling and reduction in number and proliferative capacity with age are the major limitations of BM-hMSCs. Recently, human placenta-derived MSCs (PL-hMSCs) obtained by a non-invasive procedure have attracted much interest. Attempts to increase the potential of PL-hMSCs would be an important paradigm in regenerative medicine. Herein, we examined the proliferative and osteogenic effect of andrographolide (AP) on PL-hMSCs.

Methods

Mesenchymal stem cells were isolated from full-term normal human placentas and were characterized before using. Cell cytotoxicity and proliferative effect of AP were examined by MTT and BrdU assay, respectively. The non-toxicity concentrations of AP were further assessed for osteogenic effect determined by alkaline phosphatase (ALP) expression and activity, alizarin red staining, and osteoblast-specific gene expressions. Screening of genes involved in osteogenic differentiation-related pathways modulated by AP was explored by a NanoString nCounter analysis.

Results

PL-hMSCs generated in this study met the MSC criteria set by the International Society of Cellular Therapy. The non-cytotoxic concentrations of AP on PL-hMSCs are up to 10 μM. The compound increased PL-hMSC proliferation concomitant with increases in Wnt/β-catenin level and activity. It also enhanced osteogenic differentiation in association with osteoblast-specific mRNA expression. Further, AP promoted bone formation and increased bone structural protein level, osteocalcin, in osteoblastic cells. Gene screening analysis showed the upregulation of genes related to Wnt/β-catenin, TGFβ/BMP, SMAD, and FGF signaling pathways.

Conclusion

We demonstrated, for the first time, the potential role of AP in promoting proliferation, osteogenic differentiation, and osteoblast bone formation of PL-hMSCs. This study suggests that AP may be an effective novel agent for the improvement of PL-hMSCs and stem cell-based therapy for bone regeneration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02312-x.

MicroRNA treatment modulates osteogenic differentiation potential of mesenchymal stem cells derived from human chorion and placenta

Mesenchymal stem cells (MSCs) are important in regenerative medicine because of their potential for multi-differentiation. Bone marrow, chorion and placenta have all been suggested as potential sources for clinical application. However, the osteogenic differentiation potential of MSCs derived from chorion or placenta is not very efficient. Bone morphogenetic protein-2 (BMP-2) plays an important role in bone development. Its effect on osteogenic augmentation has been addressed in several studies. Recent studies have also shown a relationship between miRNAs and osteogenesis. We hypothesized that miRNAs targeted to Runt-related transcription factor 2 (Runx-2), a major transcription factor of osteogenesis, are responsible for regulating the differentiation of MSCs into osteoblasts. This study examines the effect of BMP-2 on the osteogenic differentiation of MSCs isolated from chorion and placenta in comparison to bone marrow-derived MSCs and investigates the role of miRNAs in the osteogenic differentiation of MSCs from these sources. MSCs were isolated from human bone marrow, chorion and placenta. The osteogenic differentiation potential after BMP-2 treatment was examined using ALP staining, ALP activity assay, and osteogenic gene expression. Candidate miRNAs were selected and their expression levels during osteoblastic differentiation were examined using real-time RT-PCR. The role of these miRNAs in osteogenesis was investigated by transfection with specific miRNA inhibitors. The level of osteogenic differentiation was monitored after anti-miRNA treatment. MSCs isolated from chorion and placenta exhibited self-renewal capacity and multi-lineage differentiation potential similar to MSCs isolated from bone marrow. BMP-2 treated MSCs showed higher ALP levels and osteogenic gene expression compared to untreated MSCs. All investigated miRNAs (miR-31, miR-106a and miR148) were consistently downregulated during the process of osteogenic differentiation. After treatment with miRNA inhibitors, ALP activity and osteogenic gene expression increased over the time of osteogenic differentiation. BMP-2 has a positive effect on osteogenic differentiation of chorion- and placenta-derived MSCs. The inhibition of specific miRNAs enhanced the osteogenic differentiation capacity of various MSCs in culture and this strategy might be used to promote bone regeneration. However, further in vivo experiments are required to assess the validity of this approach.

Genetic differentiation of Southeast Asian Paragonimus Braun, 1899 (Digenea: Paragonimidae) and genetic variation in the Paragonimus heterotremus complex examined by nuclear DNA sequences

Southeast Asian lung flukes, the causative agents of human and animal paragonimiasis, comprise at least 14 species. Of these, seven species; Paragonimus bangkokensis, P. harinasutai, P. macrorchis, P. siamensis, P. westermani, P. heterotremus and P. pseudoheterotremus were studied. Two regions of domain 1 of taurocyamine kinase; TkD1 (exon) and TkD1Int2 (intron 2), were used as genetic markers for elucidating their genetic differentiation, genetic variation, and heterozygosity. The TkD1 region was conserved between these species but can potentially be used to differentiate all seven species. However, the TkD1Int2 region had a high level of polymorphism, which is suitable for investigation of genetic variation within or between closely related species, especially P. heterotremus and P. pseudoheterotremus as well as for a phylogenetic analyses of the genus Paragonimus. Heterozygosity was mostly observed in DNA samples extracted from adult P. heterotremus including samples taken from sputum of paragonimiasis patients, whereas DNA extracted from metacercariae was not, except in the samples from Myanmar. Our findings provide evidence of DNA recombination and incomplete lineage sorting of P. heterotremus and P. pseudoheterotremus in TkD1Int2, which suggesting gene flow between these two species.

Phylogeographic genetic variation of Indoplanorbis exustus (Deshayes, 1834) (Gastropoda: Planorbidae) in South and Southeast Asia

The freshwater snail Indoplanorbis exustus play an important role as the sole intermediate host of several medically- and economically-important trematodes, especially zoonotic schistosomes and echinostomes, which can infect and cause diseases in livestock and people. This study aims to explore the mitochondrial cytochrome c oxidase subunit 1 sequence variation of I. exustus collected from new geographical areas; 459 specimens of I. exustus were collected from 43 localities in South and Southeast Asia. The 42 haplotypes (Ie1 - Ie42) we detected were classified into haplogroups I - V. Phylogenetic analyses revealed five major clades, A - E, in concordance with all previous studies. Clade E contained two subclades, E1 (haplogroup I) and E2 (haplogroup II). The most widespread genetic group was subclade E1. Clade A, clade B (haplogroup V), and clade C (haplogroup IV) were found only in South Asia, whereas clade D (haplogroup III) was specifically found in Southeast Asia. In Thailand, I. exustus showed high genetic divergence with 21 haplotypes. Several isolates showed significant genetic differences from others with unique haplotype(s). Hence, we confidently conclude our findings support all previous studies that I. exustus is a species complex with at least four major lineages and five haplogroups. Our additional analyses of 35 samples from Sri Lanka showed these were indeed an independent genetic group as previously found, but they can now be classified as a unique group forming subclade E2 (haplogroup II) of I. exustus sensu lato.

Human serum enhances the proliferative capacity and immunomodulatory property of MSCs derived from human placenta and umbilical cord

Background

Mesenchymal stromal cells (MSCs) are considered potential candidates that hold great promise in the treatment of immune-related diseases. For therapeutic applications, it is necessary to isolate and expand MSCs with procedures complying with good manufacturing practice (GMP). Recent studies reported the use of human serum (HS) instead of fetal bovine serum (FBS) for the expansion of bone marrow-derived MSCs. Nevertheless, there are only limited data on HS as an alternative to FBS for the isolation and expansion of umbilical (UC-MSCs) and placenta-derived MSCs (PL-MSCs). In this study, we evaluate the effect of HS compared to FBS on the proliferative and immunosuppressive capacities of these MSCs.

Methods

PL-MSCs and UC-MSCs were isolated and cultured in HS- or FBS-supplemented media. The MSC characteristics, including morphology, immunophenotype, and differentiation ability, were verified. The proliferative and immunosuppressive capacities were also examined. In addition, the proliferative-enhancing factors in both sera were explored using proteomic analysis.

Results

PL-MSCs and UC-MSCs proliferated faster in HS-supplemented medium than in equivalent levels of FBS-supplemented medium. Adipogenic and osteogenic differentiations occurred at nearly identical levels in HS- and FBS-supplemented media. Interestingly, MSCs cultured in HS-supplemented medium had a similar immunosuppressive effect as MSCs cultured in FBS-supplemented medium. Proteomic analysis revealed that Con-A binding glycoproteins with a molecular weight > 100 kDa in FBS could significantly enhance MSC proliferation. In contrast, the proliferative enhancing factors in HS were found in the Con-A non-binding fraction and WGA binding fraction with a molecular weight > 100 kDa.

Conclusions

Taken together, our results suggest applications for the use of HS instead of FBS for the isolation and expansion of PL-MSCs and UC-MSCs for cell therapy in the future. Furthermore, this study identifies factors in HS that are responsible for its proliferative and immunosuppressive effects and might thus lead to the establishment of GMPs for the therapeutic use of MSCs.

Blastocystis subtypes detected in long-tailed macaques in Thailand-Further evidence of cryptic host specificity

Blastocystis is an enteric parasitic protist with a widespread distribution in a variety of human and non-human hosts and supposedly a source of zoonotic transmission. This study aimed to determine the frequency and distribution of Blastocystis subtypes in free-ranging Macaca fascicularis (long-tailed macaques, LTMs) in Thailand. A total of 628 faecal samples were collected from free-ranging LTMs inhabiting fourteen tourist attraction sites in Thailand. Fresh faecal samples were individually cultured in Jones' medium, and Blastocystis-positive samples were subtyped using nuclear small subunit ribosomal DNA (SSU rDNA) sequencing. Two hundred and sixty-three (41.87%) samples were positive by culture, and 197 and 154 were successfully SSU rDNA-amplified and sequenced, respectively. Three subtypes (ST1, ST2, and ST3) comprising 19 alleles were observed. ST3 was the most common subtype detected (36.55%), followed by ST2 and ST1 (24.37% and 17.26%, respectively). Some subtype alleles not previously observed were identified. A couple of strains appeared similar to those found in humans as evidenced by SSU rDNA allelic profiles, while further evidence of cryptic host specificity emerged. This study provides the first data on Blastocystis subtypes in non-human primates in Thailand and confirms the trend observed in other Old-World countries with regard to the colonization rate and subtype distribution.

Seroprevalence of Toxoplasma gondii in free range chickens (Gallus domesticus) in Khon Kaen province, Thailand

Toxoplasmosis is caused by the infective stage of Toxoplasma gondii and is often acquired from contaminated food and water. Data on the prevalence of T. gondii in freerange chickens (Gallus domesticus) in Khon Kaen province, Northeast Thailand, are limited. A total of 257 serum samples were collected and antibodies to T. gondii were examined by the latex agglutination test; 26 (10.1%) free-range chickens were positive. By logistic regression, the seroprevalence rate was 3.8 fold higher in the rainy season compared to the dry season (OR=3.81, 95% CI=1.39-10.47, P=0.006). The mean rainfall in the seropositive group (3.48 ± 2.05 mm) was significantly higher (P=0.028) compared to the seronegative group (2.42 ± 2.35 mm). The point biserial correlation coefficients showed a positive association between seropositivity and mean rainfall (r=0.137, P=0.028) but no significant associations for temperature or humidity. In conclusion, the presence of T. gondii infection in free-range chickens in Khon Kaen province suggests environmental contamination. The wet season and mean rainfall are significant associations with seroprevalence. The prevention of faecal contamination from cats to the environment is a good strategy to reduce the risk of infection in soil feeding animal such as chicken.

Bone morphogenetic protein-2 enhances the osteogenic differentiation capacity of mesenchymal stromal cells derived from human bone marrow and umbilical cord

Mesenchymal stromal cells (MSCs) are multipotent cells that can give rise to different cell types of the mesodermal lineages. They are powerful sources for cell therapy in regenerative medicine as they can be isolated from various tissues, and can be expanded and induced to differentiate into multiple lineages. Recently, the umbilical cord has been suggested as an alternative source of MSCs. Although MSCs derived from the umbilical cord can be induced to differentiate into osteoblasts with a phenotypic similarity to that of bone marrow-derived MSCs, the differentiation ability is not consistent. In addition, MSCs from the umbilical cord require a longer period of time to differentiate into osteoblasts. Previous studies have demonstrated the benefits of bone morphogenetic protein-2 (BMP-2) in bone tissue regeneration. In addition, several studies have supported the use of BMP-2 in periodontal regeneration, sinus lift bone-grafting and non-unions in oral surgery. Although the use of BMP-2 for bone tissue regeneration has been extensively investigated, the BMP-2-induced osteogenic differentiation of MSCs derived from the umbilical cord has not yet been fully examined. Therefore, in this study, we aimed to examine the effects of BMP-2 on the osteogenic differentiation of MSCs derived from umbilical cord compared to that of MSCs derived from bone marrow. The degree of osteogenic differentiation following BMP-2 treatment was determined by assessing alkaline phosphatase (ALP) activity, and the expression profiles of osteogenic differentiation marker genes, osterix (Osx), Runt-related transcription factor 2 (Runx2) and osteocalcin (Ocn). The results revealed that BMP-2 enhanced the osteogenic differentiation capacity of MSCs derived from both bone marrow and umbilical cord as demonstrated by increased ALP activity and the upregulation of osteogenic differentiation marker genes. The enhancement of the osteogenic differentiation capacity of MSCs by BMP-2 suggests that these MSCs may be used as alternative sources for bone engineering or cell therapy in regenerative medicine.

Rapid identification of nine species of diphyllobothriidean tapeworms by pyrosequencing

The identification of diphyllobothriidean tapeworms (Cestoda: Diphyllobothriidea) that infect humans and intermediate/paratenic hosts is extremely difficult due to their morphological similarities, particularly in the case of Diphyllobothrium and Spirometra species. A pyrosequencing method for the molecular identification of pathogenic agents has recently been developed, but as of yet there have been no reports of pyrosequencing approaches that are able to discriminate among diphyllobothriidean species. This study, therefore, set out to establish a pyrosequencing method for differentiating among nine diphyllobothriidean species, Diphyllobothrium dendriticum, Diphyllobothrium ditremum, Diphyllobothrium latum, Diphyllobothrium nihonkaiense, Diphyllobothrium stemmacephalum, Diplogonoporus balaenopterae, Adenocephalus pacificus, Spirometra decipiens and Sparganum proliferum, based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene as a molecular marker. A region of 41 nucleotides in the cox1 gene served as a target, and variations in this region were used for identification using PCR plus pyrosequencing. This region contains nucleotide variations at 12 positions, which is enough for the identification of the selected nine species of diphyllobothriidean tapeworms. This method was found to be a reliable tool not only for species identification of diphyllobothriids, but also for epidemiological studies of cestodiasis caused by diphyllobothriidean tapeworms at public health units in endemic areas.

A singleplex real-time fluorescence resonance energy transfer PCR with melting curve analysis for the differential detection of Paragonimus heterotremus, Echinostoma malayanum and Fasciola gigantica eggs in faeces

BACKGROUND

Because the eggs of Paragonimus, Echinostoma and Fasciola are very similar in size and shape, it is difficult to distinguish and accurately identify species by the morphology of their eggs, which is a standard diagnostic method.

METHODS

In this study, a novel assay combining a real-time fluorescence resonance energy transfer PCR and melting curve analysis using one set of primers and fluorophore-labelled hybridization probes specific for the 28S rDNA region was developed for the molecular detection of Paragonimus heterotremus, Echinostoma malayanum and Fasciola gigantica eggs.

RESULTS

This assay could detect and distinguish P. heterotremus, E. malayanum and F. gigantica DNA with the distinct melting temperature (Tm) values of 57.99±0.08, 62.12±0.15 and 74.10±0.18, respectively. The assay can also be used to detect and distinguish DNA from P. bangkokensis, P. harinasutai, P. machorchis, E. revolutum, Hypodereum conoideum and F. hepatica, which have different Tm values. The sensitivity of this assay enabled the detection of one egg of P. heterotremus, E. malayanum or F. gigantica per 100 mg of faeces. In addition, the specificity testing showed no fluorescence signal for other parasites.

CONCLUSIONS

Due to the sensitivity and specificity of our assay in detecting P. heterotremus, E. malayanum and F. gigantica, our method could be used to accurately diagnose these three medically important parasitic groups and has potential implications for molecular epidemiological investigations of human and/or animal infections.

The Biological Characteristics of Placenta Derived Mesenchymal Stem Cells Cultured in Human Serum

OBJECTIVE

Evidence exists indicating that mesenchymal stem cells (MSCs) are promising candidate for therapeutic applications. One major obstacle for their clinical use is the biosafety of fetal bovine serum (FBS), which is a crucial part of all media currently used for culture of MSCs. Although some recent studies recommended substituting FBS with human serum (HS) for the expansion of MSCs for clinical use, the characteristics and functional capacity of the expanded cells has only been partially explored. In addition, limited experience indicates that HS may replace FBS in some but not all culture systems. Currently, relatively little is known about using HS instead of FBS for isolation and expansion of placenta derived MSCs. Therefore, this study aimed to compare the exploit of HS and FBS as a supplement in terms of their impact on biological characteristics of MSCs.

MATERIAL AND METHOD

MSCs derived from placenta were cultured in Dulbecco’s Modified Eagle’s Medium supplemented with 10% fetal bovine serum or 10% human serum. The morphology, the expression of MSC markers, the differentiation ability and the proliferation characteristics were examined.

RESULTS

The results demonstrated that MSCs cultured in DMEM supplemented with 10% HS had similar characteristics to MSCs cultured in DMEM supplemented with 10% FBS. Interestingly, MSCs cultured in DMEM supplemented with 10% HS had greater expansion potential than that of MSCs cultured in DMEM supplemented with 10% FBS.

CONCLUSION

The results obtained from this study imply some application in the use of HS instead of FBS for expansion of placenta derived MSCs. The HS-expanded MSCs might be useful and safe for use as a therapeutic tool in regenerative medicine.

Pyrosequencing Using SL and 5S rRNA as Molecular Markers for Identifying Zoonotic Filarial Nematodes in Blood Samples and Mosquitoes

BACKGROUNDS

Lymphatic filariasis is principally caused by Wuchereria bancrofti, and Brugia malayi. The other two filarial nematode species, Brugia pahangi and Dirofilaria immitis, possibly cause human zoonotic diseases.

METHODS

We propose the development of a PCR assay linked with DNA pyrosequencing as a rapid tool to identify W. bancrofti, B. malayi, B. pahangi, and D. immitis in blood samples and mosquitoes. Primers targeting the fragment of the 5S ribosomal RNA and spliced leader sequences were newly designed and developed to identify these four filarial nematodes. Analytical sensitivity and specificity were evaluated.

RESULTS

Pyrosequencing determination of nucleotide variations within 36 nucleotides for B. malayi and B. pahangi, and 32 nucleotides for W. bancrofti and D. immitis is sufficient for differentiation of those filarial nematodes, and for detection of intraspecies genetic variation of B. malayi. This analysis could detect a single B. malayi, B. pahangi, W. bancrofti, and D. immitis microfilaria in blood samples.

CONCLUSIONS

Overall, the PCR-linked pyrosequencing-based method was faster than direct sequencing and less expensive than real-time PCR or direct sequencing. This is the possibility of choice that can be applied in a high-throughput platform for identification and surveillance of reservoirs and vectors infected with lymphatic filaria in endemic areas.

Mitochondrial DNA sequences of 37 collar-spined echinostomes (Digenea: Echinostomatidae) in Thailand and Lao PDR reveals presence of two species: Echinostoma revolutum and E. miyagawai

The "37 collar-spined" or "revolutum" group of echinostomes is recognized as a species complex. The identification of members of this complex by morphological taxonomic characters is difficult and confusing, and hence, molecular analyses are a useful alternative method for molecular systematic studies. The current study examined the genetic diversity of those 37 collar-spined echinostomes which are recognized morphologically as Echinostoma revolutum in Thailand and Lao PDR using the cytochrome c oxidase subunit 1 (CO1) and the NADH dehydrogenase subunit 1 (ND1) sequences. On the basis of molecular investigations, at least two species of 37 collar-spined echinostomes exist in Southeast Asia, namely E. revolutum and Echinostoma miyagawai. The specimens examined in this study, coming from ducks in Thailand and Lao PDR, were compared to isolates from America, Europe and Australia for which DNA sequences are available in public databases. Haplotype analysis detected 6 and 26 haplotypes when comparing the CO1 sequences of E. revolutum and E. miyagawai, respectively, from different geographical isolates from Thailand and Lao PDR. The phylogenetic trees, ND1 haplotype network and genetic differentiation (ɸST) analyses showed that E. revolutum were genetically different on a continental scale, i.e. Eurasian and American lineages.

The Effects of TNF-α on Osteogenic Differentiation of Umbilical Cord Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are multipotent stem cells which are able to differentiate into various lineages including osteoblasts, adipocytes and chondrocytes. They can be isolated from several tissues including bone marrow, adipose tissue, placenta and umbilical cord. Although MSCs could be diferentiated into osteoblasts under appropriate culture condition, their osteogenic differentiation capacity is still not very efficient. Previous studies reported that TNF-α could promote osteogenic differentiation of bone marrow derived MSCs by triggering NF-κB signaling pathway. However, the effect of TNF-α on the osteogenic differentiation ability ofumbilical cord derived MSCs has not been investigated. This study aimed to examine the effect of TNF-α on osteogenic differentiation of umbilical cord derived MSCs (UC-MSCs). The results demonstrated that TNF-α has osteopromotive effect for umbilical cord derived MSCs as evidenced by more matrix mineralization and alkaline phosphatase staining. Interestingly, UC-MSCs cultured in osteogenic differentiation medium supplemented with TNF-α had significantly increase expression of Osteocalcin, the marker of mature osteoblasts, when it was compared to UC-MSCs cultured in osteogenic differentiation medium without TNF-α (p < 0.05). On the contrary, the UC- MSCs cultured in osteogenic differentiation medium supplemented with TNF-α had significantly lower levels of Runx2 and Osterix (the markers of immature osteoblasts) than UC-MSCs cultured with osteogenic differentiation medium without TNF-α. The present study suggested that TNF-α promotes osteogenic differentiation of UC-MSCs. The data add a possibilityfor the use of UC-MSCs as an alternative source for cell replacement therapy in bone defect.

The expression of neurogenic markers after neuronal induction of chorion-derived mesenchymal stromal cells

OBJECTIVES

Chorion is a tissue of early embryologic period that is discarded after delivery. It might be the potential source of mesenchymal stromal cells (MSCs) that can be used for research and eventually for therapeutic studies. At present, the biological properties and the differentiation capacity of chorion-derived MSCs are still poorly characterised. The objective of this study is to characterise and explore the differentiating potential of chorion-derived MSCs towards the neuronal lineages.

METHODS

Chorionic membrane was digested with enzyme and cultured in Dulbecco's Modified Eagle's medium supplemented with 10% fetal bovine serum. The expression of MSC markers was examined using flow cytometry. The adipogenic, osteogenic and neurogenic differentiation were examined by culturing in appropriate induction media. The expression of neuronal markers was determined by immunofluorescence and quantitative real time-PCR.

RESULTS

Chorion-derived MSCs were easily expanded up to 20 passages. They were positive for MSC markers (CD73, CD90 and CD105), and negative for haematopoietic markers (CD34 and CD45). Chorion-derived MSCs could differentiate into several mesodermal-lineages including adipocytes and osteoblasts. Moreover, chorion-derived MSCs could differentiate into neuronal-like cells as characterised by cell morphology and the presence of neural markers including MAP-2, glial fibrillary acidic protein (GFAP) and beta-tubulin III.

DISCUSSION

Chorion-derived MSCs can be readily obtained and expanded in culture. These cells also have transdifferentiation capacity as evidenced by their neuronal differentiation potential. Therefore, chorion can be used as an alternative source of MSCs for stem cell therapy in nervous system disorders.

Genetic characterization and phylogenetic analysis of echinostomes

We conducted this study to identify species and determine the phylogenetic relationships using ribosomal DNA (rDNA) sequences [partial sequences of 28S rDNA and second internal transcribed spacer (IT52)] of echinostomes collected from free-grazing ducks in Phitsanulok Province, Thailand. Four adult echinostomes were morphologically identified as Echinostoma revolutum, 4 as Hypoderaeulm conoideurn and 2 unidentified. Sequences of other species/isolates of echinostomes retrieved from the GenBank database were employed to compare and construct the phylogenetic tree. Three major lineages were found, namely, genus Echinostoma, genus Echinoparyphiulm and genus Hypoderaeulm. One of the unidentified echinostome specimen was 99% identical to and clustered with genus Echinoparyphiurm, whereas the other was located in the "revolutum" roup, but was closely related to the geographical isolates from America rather than from Thailand. This study indicates that 28S rDNA and 1T52 regions are suitable molecular markers for genetic characterization and phylogenetic analysis of echinostomes.

Rapid molecular identification of human taeniid cestodes by pyrosequencing approach

Taenia saginata, T. solium, and T. asiatica are causative agents of taeniasis in humans. The difficulty of morphological identification of human taeniids can lead to misdiagnosis or confusion. To overcome this problem, several molecular methods have been developed, but use of these tends to be time-consuming. Here, a rapid and high-throughput pyrosequencing approach was developed for the identification of three human taeniids originating from various countries. Primers targeting the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of the three Taenia species were designed. Variations in a 26-nucleotide target region were used for identification. The reproducibility and accuracy of the pyrosequencing technology was confirmed by Sanger sequencing. This technique will be a valuable tool to distinguish between sympatric human taeniids that occur in Thailand, Asia and Pacific countries. This method could potentially be used for the molecular identification of the taeniid species that might be associated with suspicious cysts and lesions, or cyst residues in humans or livestock at the slaughterhouse.

Development of a PCR assay and pyrosequencing for identification of important human fish-borne trematodes and its potential use for detection in fecal specimens

BACKGROUND

Small liver and minute intestinal flukes are highly prevalent in Southeast Asia. Definitive diagnosis of parasite infection is usually achieved parasitologically by finding the fluke eggs in feces. However, their eggs are difficult to differentiate morphologically in fecal samples, even for experienced technicians. The present study developed a PCR assay coupled with DNA pyrosequencing for identification of the fish-borne trematodes (FBT), Opisthorchis viverrini, Clonorchis sinensis, Haplorchis taichui, H. pumilio and Stellantchasmus falcatus, and to evaluate potential detection in fecal specimens, and identification and differentiation of cercarial and metacercarial stages.

METHODS

Primers targeting the partial 28S large subunit ribosomal RNA gene were designed and about 46-47 nucleotides were selected as the target region for species identification by a PCR assay coupled with a pyrosequencing technique.

RESULTS

The nucleotide variations at 24 positions, which is sufficient for the identification of the five species of FBT were selected. The method could identify O. viverrini and C. sinensis eggs in feces, cercarial and metacercarial stages of O. viverrini, and metacercarial stage of H. pumilio and H. taichui. The detection limit was as little as a single O. viverrini or C. sinensis egg artificially inoculated in 100 mg of non-infected fecal sample (equivalent to 10 eggs per gram), indicating highly sensitivity. The method was found to be superior to the traditional microscopy method and was more rapid than Sanger DNA sequencing.

CONCLUSIONS

DNA pyrosequencing-based identification is a valuable tool for differentiating O. viverrini and other Opisthorchis-like eggs, and can be applied to epidemiological studies and for molecular taxonomic investigation of FBT in endemic areas.

Evidence to support natural hybridization between Anopheles sinensis and Anopheles kleini (Diptera: Culicidae): possibly a significant mechanism for gene introgression in sympatric populations

Background

Malaria caused by Plasmodium vivax is still a public health problem in the Republic of Korea (ROK), particularly regarding the recent re-emergence of this malarial species near the demilitarized zone in northwestern Paju City, Gyeonggi-do Province. Currently, at least 4 species (An. kleini, An. pullus, An. belenrae and An. lesteri) of the Hyrcanus Group are reported as possible natural vectors of vivax malaria in the ROK, and An. sinensis, which is the most dominant species, has long been incriminated as an important natural vector of this P. vivax. However, An. sinensis was ranked recently as a low potential vector. According to the discovery of natural hybrids between An. sinensis (a low potential vector for P. vivax) and An. kleini (a high potential vector for P. vivax) in Paju City, intensive investigation of this phenomenon is warranted under laboratory conditions.

Methods

Mosquitoes were collected during 2010-2012 from Paju City, ROK. Hybridization experiments used iso-female line colonies of these anophelines together with DNA analysis of ribosomal DNA [second internal transcribed spacer (ITS2)] and mitochondrial DNA [cytochrome c oxidase subunit I (COI)] of the parental colonies, F₁-hybrids and repeated backcross progenies were performed intensively by using a PCR-based assay and pyrosequencing technology.

Results

The results from hybridization experiments and molecular investigations revealed that the mitochondrial COI gene was introgressed from An. sinensis into An. kleini. The An. sinensis progenies obtained from consecutive repeated backcrosses in both directions, i.e., F₂-₁₁ progeny [(An. sinensis x An. kleini) x An. sinensis] and F₃-₅ progeny [(An. kleini x An. sinensis) x An. kleini] provided good supportive evidence.

Conclusions

This study revealed introgression of the mitochondrial COI gene between An. sinensis and An. kleini through consecutive repeated backcrosses under laboratory conditions. This new body of knowledge will be emphasized in reliable promising strategies in order to replace the population of An. kleini as a high potential vector for P. vivax, with that of a low potential vector, An. sinensis, through the mechanism of gene introgression in nature.

Immunosuppressive properties of mesenchymal stromal cells derived from amnion, placenta, Wharton's jelly and umbilical cord

BACKGROUND

The role of bone marrow-derived mesenchymal stromal cells (BM-MSC) in preventing the incidence and ameliorating the severity of graft-versus-host disease (GvHD) has recently been reported. However, as the collection of BM-MSC is an invasive procedure, more accessible sources of MSC are desirable.

AIM

This study aimed to explore the alternative sources of MSC from amnion, placenta, Wharton's jelly and umbilical cord, which are usually discarded.

METHODS

MSC from those tissues were isolated using mechanical dissociation and enzymatic digestion. Their capacity for proliferation and differentiation, and ability to suppress alloreactive T-lymphocytes were studied and compared with those of BM-MSC.

RESULTS

MSC derived from amnion, placenta, Wharton's jelly and umbilical cord were similar to BM-MSC regarding the cell morphology, the immunophenotype as well as the differentiation ability. These MSC also elicited a similar degree of immunosuppression, as evidenced by the inhibition of alloreactive T-lymphocytes in the mixed lymphocyte reaction, compared with that of BM-MSC. MSC from umbilical cord and Wharton's jelly had a higher proliferative capacity, whereas those from amnion and placenta had a lower proliferative capacity compared with BM-MSC.

CONCLUSION

The results obtained from this study suggest that MSC from amnion, placenta, Wharton's jelly and umbilical cord can therefore be potentially used for substituting BM-MSC in several therapeutic applications, including the treatment of GvHD.

Zoonotic echinostome infections in free-grazing ducks in Thailand

Free-grazing ducks play a major role in the rural economy of Eastern Asia in the form of egg and meat production. In Thailand, the geographical location, tropical climate conditions and wetland areas of the country are suitable for their husbandry. These environmental factors also favor growth, multiplication, development, survival, and spread of duck parasites. In this study, a total of 90 free-grazing ducks from northern, central, and northeastern regions of Thailand were examined for intestinal helminth parasites, with special emphasis on zoonotic echinostomes. Of these, 51 (56.7%) were infected by one or more species of zoonotic echinostomes, Echinostoma revolutum, Echinoparyphium recurvatum, and Hypoderaeum conoideum. Echinostomes found were identified using morphological criteria when possible. ITS2 sequences were used to identify juvenile and incomplete worms. The prevalence of infection was relatively high in each region, namely, north, central, and northeast region was 63.2%, 54.5%, and 55.3%, respectively. The intensity of infection ranged up to 49 worms/infected duck. Free-grazing ducks clearly play an important role in the life cycle maintenance, spread, and transmission of these medically important echinostomes in Thailand.

Rapid detection and identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in mosquito vectors and blood samples by high resolution melting real-time PCR

A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.5±0.2℃, 79.0±0.3℃, 76.8±0.1℃, and 79.9±0.1℃, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors.

Pluripotent gene expression in mesenchymal stem cells from human umbilical cord Wharton's jelly and their differentiation potential to neural-like cells

OBJECTIVE

To explore the expression of pluripotent genes in Whartons jelly derived MSCs (WJ-MSCs) and their neuronal differentiation potential.

MATERIAL AND METHOD

Gelatinous connective tissues from umbilical cord Wharton's jelly were digested with trypsin and then cultured in Dulbecco's Modified Eagle's Medium. The expressions of typical MSC markers as well as pluripotent markers were examined by flow cytometry and reverse transcription PCR, respectively. MSCs at passage 3 and 5 were used for in vitro adipogenic, osteogenic and neuronal differentiation by incubation with specific induction media.

RESULTS

WJ-MSCs could be easily expanded for more than 20 passages while maintaining their undifferentiated state and their marker expression profiles, being positive for typical MSC markers CD90, CD73, and CD105, and being negative for hematopoietic markers CD34 and CD45. Interestingly, the expression of several pluripotent marker genes including Oct4, Rex1, Sox2, and Nanog was detected in early passages of both cultured WJ-MSCs and BM-MSCs. WJ-MSCs were able to differentiate not only to mesodermal cells, such as adipocyte and osteoblast but also the neural-like cells as characterized by neuronal morphology and the expression of neuronal markers including MAP-2, GFAP, beta-tubulin III and Tau.

CONCLUSION

The present study demonstrates that WJ-MSCs can be readily obtained and expanded in culture while maintaining their typical MSC characteristics. WJ-MSCs and BM-MSCs also expressed several genes associated with pluripotency and exhibited their plasticity by differentiation toward neuronal-cell lineage. Umbilical cord Wharton's jelly might have potential to become an alternative source of MSC for treating nervous system disorders.

Application of a real-time fluorescence resonance energy transfer polymerase chain reaction assay with melting curve analysis for the detection of Paragonimus heterotremus eggs in the feces of experimentally infected cats

Paragonimus heterotremus is a medically important lung fluke that causes human and animal paragonimiasis in Southeast Asia, including Thailand. In the current study, a real-time fluorescence resonance energy transfer polymerase chain reaction (real-time FRET PCR) with melting curve analysis was developed and evaluated to detect P. heterotremus eggs in the feces of experimentally infected cats. The detection limit of this method for the P. heterotremus DNA sequence was 3 × 102 copies of the positive control plasmid and 10−3 ng of P. heterotremus genomic DNA. The assay system could detect 10 eggs of P. heterotremus per gram of cat feces. No fluorescence signal was observed when DNA purified from 16 other organisms or genomic DNA from cats and human beings were tested. Real-time FRET PCR yielded positive results for all fecal samples from 17 P. heterotremus–infected cats and showed a negative relationship ( r = −0.852, P < 0.001) between the number of parasite eggs in feces and the number of PCR cycles. The assay could detect genomic DNA from P. heterotremus, P. westermani, P. macrorchis, P. siamensis, P. harinasutai, and P. bangkokensis and can differentiate P. heterotremus from the other 5 species. The 6 Paragonimus species examined were divided into 4 groups by melting peak analysis. This assay can be useful for the detection of, and epidemiological studies on, P. heterotremus infection in endemic areas.

Early detection of Trichinella spiralis in muscle of infected mice by real-time fluorescence resonance energy transfer PCR

Real-time fluorescence resonance energy transfer (FRET) PCR and melting curve analysis using newly developed fluorophore-labeled hybridization probes were applied for the detection of Trichinella spiralis DNA in muscle of mice following oral inoculation with 300 T. spiralis larvae. The developed assay could detect and differentiate T. spiralis, Trichinella papuae, and Trichinella pseudospiralis DNAs by the different melting temperatures (Tm). The assay had a detection limit of 5 × 10(2) positive control plasmid copies, which was equivalent to 1 ng of T. spiralis DNA spiked into 250 mg of muscle sample. No fluorescence signal was detected when the technique was applied to the DNA of 27 parasites other than Trichinella spp. The assay could detect T. spiralis DNA in muscle at 7, 14, and 21 days postinoculation. The range, mean ± standard deviation, and median of the Tm values of all positive muscle tissue samples were 60.4-60.8, 60.6 ± 0.2, and 60.5, respectively. This assay provides an effective tool for the specific, sensitive, and high-throughput detection of T. spiralis DNA in muscle during the early stage of infection. In addition, the technique can be useful for epidemiologic surveillance in naturally infected wildlife.

Molecular identification of Paragonimus species by DNA pyrosequencing technology

DNA pyrosequencing for PCR amplicons is an attractive strategy for the identification of microorganisms because of its short time performance for large number of samples. In this study, the primers targeting the fragment of ITS2 region of nuclear ribosomal RNA gene were newly developed for pyrosequencing-based identification of 6 Paragonimus species, Paragonimus bangkokensis, Paragonimus harinasutai, Paragonimus heterotremus, Paragonimus macrorchis, Paragonimus siamensis and Paragonimus westermani. Pyrosequencing determination of 39 nucleotides of partial ITS2 region could discriminate 6 Paragonimus species, and could also detect intra-species genetic variation of P. macrorchis. This DNA pyrosequencing-based identification can be a valuable tool to improve species-level identification of Paragonimus in the endemic areas.

Genetic differentiation among populations of Brachytrupes portentosus (Lichtenstein 1796) (Orthoptera: Gryllidae) in Thailand and the Lao PDR: the Mekong River as a biogeographic barrier

The Mekong River is known to act as a boundary between a number of terrestrial and freshwater species, including various parasites and their intermediate hosts as well as endangered mammal species. Little information is available, however, on the genetic differentiation between terrestrial invertebrates to the east and the west of this wide river. The genetic diversity among eight natural populations of Brachytrupes portentosus (Lichtenstein, 1796) (Orthoptera: Gryllidae) collected from Thailand and the Lao People's Democratic Republic (PDR) were analyzed by multilocus enzyme electrophoresis. The allelic profiles of 20 enzymes encoding 23 loci were analyzed. An average of 41% fixed differences was detected between the populations from Thailand and Lao PDR, which are separated by the Mekong River. The percent fixed differences ranged between 4% and 26% within the populations from Thailand and between 4% and 22% within the populations from Lao PDR. A phenogram shows that the eight populations fell into two major clusters based on the Thai and Lao sampling sites. The genetic distance between the samples within Thailand and within Lao PDR was related to the distances between sampling areas. The genetic variability between populations of this cricket indicates that genetic relationships are influenced by a natural barrier as well as by the geographical distance between these allopatric populations.

Differential detection of Trichinella papuae, T. spiralis and T. pseudospiralis by real-time fluorescence resonance energy transfer PCR and melting curve analysis

Trichinellosis caused by nematodes of Trichinella spp. is a zoonotic foodborne disease. Three Trichinella species of the parasite including Trichinella spiralis, Trichinella papuae and Trichinella pseudospiralis, have been etiologic agents of human trichinellosis in Thailand. Definite diagnosis of this helminthiasis is based on a finding of the Trichinella larva (e) in a muscle biopsy. The parasite species or genotype can be determined using molecular methods, e.g., polymerase chain reaction (PCR). This study has utilized real-time fluorescence resonance energy transfer PCR (real-time FRET PCR) and a melting curve analysis for the differential diagnosis of trichinellosis. Three common Trichinella species in Thailand were studied using one set of primers and fluorophore-labeled hybridization probes specific for the small subunit of the mitochondrial ribosomal RNA gene. Using fewer than 35 cycles as the cut-off for positivity and using different melting temperatures (T(m)), this assay detected T. spiralis, T. papuae and T. pseudospiralis in muscle tissue and found the mean T(m) ± SD values to be 51.79 ± 0.06, 66.09 ± 0.46 and 51.46 ± 0.09, respectively. The analytical sensitivity of the technique enabled the detection of a single Trichinella larva of each species, and the detection limit for the target DNA sequence was 16 copies of positive control plasmid. A test of the technique's analytical specificity showed no fluorescence signal for a panel of 19 non-Trichinella parasites or for human and mouse genomic DNA. Due to the sensitivity and specificity of the detection of these Trichinella species, as well as the fast and high-throughput nature of these tools, this method has application potential in differentiating non-encapsulated larvae of T. papuae from T. spiralis and T. pseudospiralis in tissues of infected humans and animals.

Molecular identification of Trichinella papuae from a Thai patient with imported trichinellosis

Previously, we reported the presence of imported trichinellosis in a Thai worker returning from Malaysia, who presented with progressive generalized muscle hypertrophy and weakness after eating wild boar meat. This work analyzed a partial small subunit of a mitochondrial ribosomal RNA gene of Trichinella larvae isolated from the patient. The results showed complete identity with a mitochondrial RNA gene of Trichinella papuae (GenBank accession no. EF517130). This is the first report of imported trichinellosis in Thailand caused by T. papuae. It is possible that T. papuae is widely distributed in the wildlife of Southeast Asia.

Spatial and temporal genetic variation of Echinostoma revolutum (Trematoda: Echinostomatidae) from Thailand and the Lao PDR

A total of 314 individual Echinostoma revolutum were collected at different locations and times from domestic ducks from Khon Kaen Province, Thailand and Vientiane Province, the Lao People's Democratic Republic (PDR). Genetic variation of these parasites was analyzed using multilocus enzyme electrophoresis at three polymorphic loci namely, glucose-6-phosphate dehydrogenase (G6pd), malic enzyme (Me) and peptidase valine-leucine (PepA). High levels of genetic variability were found within and between populations. Significant heterozygote deficiencies compared with the predictions under Hardy-Weinberg equilibrium were detected in populations from Thailand and the Lao PDR for all loci except G6pd-1. Significant genetic differentiation was observed between spatially separated populations from Thailand and the Lao PDR. This as also true for some samples collected at different times in Thailand. The variability found may be consistent with a Wahlund effect, genetic drift and/or other factors such as the population structure of snail hosts. Our data provide further insight into the process of genetic divergence within and among geographically and temporally isolated populations of E. revolutum, and potentially other medically important echinostomes in Southeast Asia.

Allozyme analysis of the temporal populations of Echinostoma revolutum collected from domestic ducks in Khon Kaen Province, Thailand

Four temporal populations of Echinostoma revolutum (ER1, ER2, ER3, ER4) were collected from domestic ducks in Khon Kaen Province, Thailand during February-October 2008. The ER1, ER2, ER3 and ER4 were collected in February, April, June and October, respectively. The 12 enzymes encoding 15 loci were examined. Two loci were found in each of 3 enzymes, namely glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and peptidase valine-leucine (PEPA). Of these, three loci, namely, G6pd-1, Me-1 and PepA-2, were polymorphic. Genotypes were assigned for the specific allelic profiles detected at these three polymorphic loci. Twenty-eight genotypes were observed in the 4 temporal populations of E. revolutum. Three genotypes, Er22, Er23 and Er25, were found in all populations. The Er6 genotype occurred had the highest frequency of all the populations. These 28 genotypes were clustered into 3 groups with genetic differences of 2-12% among the loci. A cluster of genotypes (Er1, Er3, Er9 and Er12) showed the greatest genetic difference among the genotypes (12% difference). These results show intraspecific variation exists in E. revolutum populations in domestic ducks from Khon Kaen Province, Thailand.

Isolation, characterization and neural differentiation potential of amnion derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) derived from amnion are considered to be adult stem cells that can be easily obtained in large quantities by a less invasive method in comparison to bone marrow-derived MSCs (BM-MSCs). However; the biological properties and the differentiation capacity of amnion-derived MSCs (AM-MSCs) are still poorly characterized. The objectives of this study were to isolate, characterize and explore the potential of AM-MSCs in differentiating toward neural lineage in comparison to those of BM-MSCs. To isolate AM-MSCs, amnion was digested with trypsin-EDTA and cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal bovine serum. The expression profiles of several MSC markers were examined by flow cytometry. AM-MSCs from passage 3-5 were used for adipogenic, osteogenic and neural differentiation assays by culturing in appropriate induction media. The expression of several neural marker genes, including MAP-2, GFAP and beta-tubulin III in AM-MSCs was determined by quantitative real time-PCR. The expression of neural-specific markers, MAP-2 and beta-tubulin III, was subsequently confirmed by immunocytochemistry using confocal laser microscope. The results demonstrated that AM-MSCs could be easily expanded to 18-20 passages while maintaining the undifferentiated state and exhibiting MSC markers (CD73, CD90, and CD105) but do not express the hematopoietic markers (CD34 and CD45). Similar to BM-MSCs, AM-MSCs were able to differentiate to several mesodermal-lineages including adipocytes and osteoblasts. Moreover; these cells could be induced to differentiate to neuron-like cells as characterized by cell morphology and the expression of several neural markers including MAP-2, GFAP and beta-tubulin III. The present study demonstrated that AM-MSCs can be easily obtained and expanded in culture. These cells also have transdifferentiation capacity as evidenced by their neural differentiation potential. According to the results, amnion can be used as an alternative source of MSCs for stem cell therapy in neurodegenerative diseases.

Comparison of endothelial progenitor cell function in type 2 diabetes with good and poor glycemic control

BACKGROUND

Endothelial progenitor cells (EPCs) play an important role in vascular repair and a decrease in the number of EPCs is observed in type 2 diabetes. However, there is no report on the change of EPCs after glycemic control. This study therefore aimed to investigate the EPC number and function in patients with good and poor glycemic control.

METHODS

The number of EPCs was studied using flow cytometry by co-expression of CD34 and VEGFR2. The EPCs were cultured and characterized by the expression of UEA-I, CD34, VEGFR2, vWF and Dil-Ac-LDL engulfment, as well as the ability to form capillary-like structures. An in vitro study on the effect of hyperglycemia on the proliferation and viability of the cultured EPCs was also performed.

RESULTS

The number of EPCs in type 2 diabetes was significantly decreased compared with healthy controls and there was an inverse correlation between the EPC numbers and plasma glucose, as well as HbA1C. The number and function of EPCs in patients with good glycemic control were recovered compared with those with poor glycemic control. When glucose was supplemented in the culture in vitro, there was a negative effect on the proliferation and viability of EPCs, in a dose-dependent manner, whereas the enhancement of apoptosis was observed.

CONCLUSION

There was EPC dysfunction in type 2 diabetes which might be improved by strict glycemic control. However, the circulating EPC number and proliferative function in patients with good glycemic control did not reach the level in healthy controls.

Evaluation of immunoglobulin G4 subclass antibody in a peptide-based enzyme-linked immunosorbent assay for the serodiagnosis of human fascioliasis

To improve the diagnosis of human fascioliasis caused byFasciola gigantica, we developed a peptide-based enzyme-linked immunosorbent assay (peptide-based ELISA) based on the detection of specific IgG4 subclass antibody. Two identified B-cell epitopes ofF. giganticacathepsin L1 were synthesized as single synthetic peptides, acetyl-DKIDWRESGYVTELKDQGNC-carboxamide (peptide L) and acetyl-DKIDWRESGYVTEVKDQGNC-carboxamide (peptide V), and their diagnostic potential was evaluated. The sera of 25 patients infected withF. gigantica, 212 patients with other parasitic infections, 32 cholangiocarcinoma patients and 57 healthy controls were analysed. The sensitivity, specificity, accuracy, and positive and negative predictive values of this assay were the same with both peptides at 100%, 99·7%, 99·7%, 96·2% and 100%, respectively. These highly sensitive and specific peptide-based ELISAs for the detection of specific IgG4 antibody could be useful for laboratory diagnosis of human fascioliasis in future large-scale surveys throughout Southeast Asia where this disease is prevalent.

Evaluation of immunoglobulin G subclass antibodies against recombinant Fasciola gigantica cathepsin L1 in an enzyme-linked immunosorbent assay for serodiagnosis of human fasciolosis

A cystatin capture enzyme-linked immunosorbent assay (ELISA) using recombinant Fasciola gigantica cathepsin L1 antigen was developed to detect specific immunoglobulin G (IgG) subclass antibodies (IgG1, IgG2, IgG3, and IgG4) and was evaluated for its diagnostic potential for human fasciolosis. In an analysis of the sera of 13 patients infected with F. gigantica, 209 patients with other parasitic infections, 32 cholangiocarcinoma patients, and 42 healthy controls, the IgG4-ELISA gave the highest diagnostic values. The sensitivity, specificity, accuracy, and positive and negative predictive values of this method based on the detection of IgG4 antibody were 100%, 99.3%, 99.3%, 86.7%, and 100%, respectively. The results revealed that restricting the ELISA to the detection of specific IgG4 antibody enhanced the specificity and accuracy for the serodiagnosis of human fasciolosis.

Potent epitopes derived from Fasciola gigantica cathepsin L1 in peptide-based immunoassay for the serodiagnosis of human fascioliasis

A peptide-based enzyme-linked immunosorbent assay (ELISA) was developed and evaluated for its diagnostic ability to detect human IgG antibodies against Fasciola gigantica cathepsin L1. Two previously identified B-cell epitopes of cathepsin L1 were synthesized as single synthetic peptides (acetyl-DKIDWRESGYVTEVKDQGNC-carboxamide and acetyl-DKIDWRESGYVTELKDQGNC-carboxamide) and their diagnostic potential was evaluated. The peptide-based ELISA was compared with an indirect ELISA with crude excretory-secretory products or with partially purified specific 27-kDa (FG27) antigen from adult F. gigantica. In an analysis of the sera of 13 patients infected with F. gigantica, 212 patients with other parasitic infections, 32 patients with cholangiocarcinoma, and 57 healthy controls, the sensitivity, specificity, accuracy, and positive and negative predictive values of this peptide-based ELISA with both peptides had the same performance and were shown to be 100%, 97.3%, 97.5%, 61.9%, and 100%, respectively. When 4 different ELISAs were compared, the results revealed that the specificity, sensitivity, accuracy, and negative predictive values of all antigens were similar except for the positive predictive value that was highest in the ELISA with the FG27 antigen. These results demonstrated that peptide antigens can be used in the serodiagnosis of human fascioliasis with the additional advantage that they are relatively cheap and easy to produce. This rapid, highly sensitive and specific peptide-ELISA has the potential to be used in future large-scale prevalence surveys throughout Southeast Asia.