Prospects of induced pluripotent stem cells in treating advancing Alzheimer's disease: A review.

The World Health Organization has identified Alzheimer's disease (AD), the leading cause of dementia globally, as a public health priority. However, the complex multifactorial pathology of AD means that its etiology remains incompletely understood. Despite being recognized a century ago, incomplete knowledge has hindered the development of effective treatments for AD. Recent scientific advancements, particularly in induced pluripotent stem cell (iPSC) technology, show great promise in elucidating the fundamental mechanisms of AD. iPSCs play a dual role in regenerating damaged cells for therapeutic purposes and creating disease models to understand AD pathology and aid in drug screening. Nevertheless, as an emerging field, iPSC technology requires further technological advancement to develop effective AD treatments in the future. Thus, this review summarizes recent advances in stem cell therapies, specifically iPSCs, aimed at understanding AD pathology and developing treatments.

Progresses in overcoming the limitations of in vitro erythropoiesis using human induced pluripotent stem cells.

Researchers have attempted to generate transfusable oxygen carriers to mitigate RBC supply shortages. In vitro generation of RBCs using stem cells such as hematopoietic stem and progenitor cells (HSPCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) has shown promise. Specifically, the limited supplies of HSPCs and ethical issues with ESCs make iPSCs the most promising candidate for in vitro RBC generation. However, researchers have encountered some major challenges when using iPSCs to produce transfusable RBC products, such as enucleation and RBC maturation. In addition, it has proven difficult to manufacture these products on a large scale. In this review, we provide a brief overview of erythropoiesis and examine endeavors to recapitulate erythropoiesis in vitro using various cell sources. Furthermore, we explore the current obstacles and potential solutions aimed at enabling the large-scale production of transfusable RBCs in vitro.

Replacing Animal Testing with Stem Cell-Organoids : Advantages and Limitations.

Various groups including animal protection organizations, medical organizations, research centers, and even federal agencies such as the U.S. Food and Drug Administration, are working to minimize animal use in scientific experiments. This movement primarily stems from animal welfare and ethical concerns. However, recent advances in technology and new studies in medicine have contributed to an increase in animal experiments throughout the years. With the rapid increase in animal testing, concerns arise including ethical issues, high cost, complex procedures, and potential inaccuracies.Alternative solutions have recently been investigated to address the problems of animal testing. Some of these technologies are related to stem cell technologies, such as organ-on-a-chip, organoids, and induced pluripotent stem cell models. The aim of the review is to focus on stem cell related methodologies, such as organoids, that can serve as an alternative to animal testing and discuss its advantages and limitations, alongside regulatory considerations.Although stem cell related methodologies has shortcomings, it has potential to replace animal testing. Achieving this requires further research on stem cells, with potential societal and technological benefits.

A global regulatory science agenda for vaccines.

The Decade of Vaccines Collaboration and development of the Global Vaccine Action Plan provides a catalyst and unique opportunity for regulators worldwide to develop and propose a global regulatory science agenda for vaccines. Regulatory oversight is critical to allow access to vaccines that are safe, effective, and of assured quality. Methods used by regulators need to constantly evolve so that scientific and technological advances are applied to address challenges such as new products and technologies, and also to provide an increased understanding of benefits and risks of existing products. Regulatory science builds on high-quality basic research, and encompasses at least two broad categories. First, there is laboratory-based regulatory science. Illustrative examples include development of correlates of immunity; or correlates of safety; or of improved product characterization and potency assays. Included in such science would be tools to standardize assays used for regulatory purposes. Second, there is science to develop regulatory processes. Illustrative examples include adaptive clinical trial designs; or tools to analyze the benefit-risk decision-making process of regulators; or novel pharmacovigilance methodologies. Included in such science would be initiatives to standardize regulatory processes (e.g., definitions of terms for adverse events [AEs] following immunization). The aim of a global regulatory science agenda is to transform current national efforts, mainly by well-resourced regulatory agencies, into a coordinated action plan to support global immunization goals. This article provides examples of how regulatory science has, in the past, contributed to improved access to vaccines, and identifies gaps that could be addressed through a global regulatory science agenda. The article also identifies challenges to implementing a regulatory science agenda and proposes strategies and actions to fill these gaps. A global regulatory science agenda will enable regulators, academics, and other stakeholders to converge around transformative actions for innovation in the regulatory process to support global immunization goals.

Transforming growth factor-ß1 bioassay involving matrix metalloproteinase-2 induction.

The transforming growth factor-ß1 (TGF-ß1) bioassay developed in this study monitors increased luciferase activity in MCF10A cells containing the matrix metalloproteinase-2 (MMP-2) promoter with a luciferase reporter and treated with increasing TGF-ß1 concentrations. The response was linear in the concentration range from 75 to 2,500 pg/mL. The abilities of 3 types of TGF-ß in inducing MMP-2 were different. The luciferase activity induced by TGF-ß1 was about 2 times more than that by TGF-ß2 and TGF-ß3. The MMP-2 promoter bioassay showed greater reproducibility (coefficient of variation [CV] 10%) than the previously developed anticell proliferation assay of TF-1 cell (CV 16%) and the MMP-2 zymogram assay (CV 40%).

Validation of a HeLa Mx2/Luc reporter cell line for the quantification of human type I interferons.

Although antiviral assays have been the most widely available biological assays for interferons (IFNs), they are less sensitive and provide considerable interassay variation. In this study, we demonstrate a new reporter cell line, which is based on HeLa cells transfected with a plasmid containing a human Mx2 promoter driving a luciferase (Luc) cDNA. To characterize the specific gene expression profiles induced by interferon alpha, we analyzed the microarray results of interferon response gene expression induced by IFN-alpha2a or IFN-alpha2b treatment with HeLa cells. We found that the Mx2 gene increased the most by treatment with both IFN-alpha2a and IFN-alpha2b. Based on this result, we designed a reporter cell line, HeLa-Mx2, suitable for determination of IFN-alpha. HeLa cells were stably transfected with the luciferase gene under the control of Mx2 promoter. The expression of luciferase can be easily measured for luminescence using a 96-well luminometer and has been correlated with the concentration of added IFN and cell density. In the validation results, our reporter cell line had specificity for type I IFN, but the significant effects of a number of other cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-2, IL-5, IL-6 and GM-CSF, or type II interferon (IFN-gamma) were not observed. Moreover, the robustness of our cell line is demonstrated by the lack of an effect of the HeLa-Mx2 cell culture's age on the performance of the reporter gene assay. The reporter gene assay demonstrated reproducible dose-response curves for IFN-alpha2a in the range of 1-10,000 IU/ml. The 95% confidential limit and total coefficient of variation estimates ranged between 96 and 116 and 10.51% in the reducible range mentioned above, respectively. In conclusion, we established a stable IFN-responsible HeLa-Mx2 cell line, which has advantages with regard to simplicity, selectivity, and reliability over conventional cytopathic effect reduction assays used to quantify IFN-alpha activity.

Effects of sugar additives on protein stability of recombinant human serum albumin during lyophilization and storage.

Few researches on the protein stabilization of recombinant human serum albumin (rHSA) have been done. In the present study, we assessed the impact of sugar lyoprotectants on the protein stability of lyophilized rHSA (65 KDa) in the solid state. For the assessment, rHSA was formulated with sucrose and trehalose, respectively, alone or in combination with mannitol, which were lyophilized and stored at 35 degrees C. Degradation and aggregation of the resulting lyophilized formulations was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Induction of amorphous state by the lyophilactants with rHSA was determined by differential scanning calorimetry (DSC). The protein secondary structure of the rHSA in the formulations was analyzed by Fourier transform infrared spectroscopy (FT-IR). Results from SDS-PAGE analysis displayed that mannitol formulation caused aggregation resulting in a few bands that were greater than 65 KDa, whereas sucrose and trehalose formulations revealed no such aggregation. However, the aggregation of the protein decreased when mannitol was combined with sucrose or trehalose. DSC measurement supported the electrophoresis data showing that sucrose and trehalose formed complete amorphous state, but mannitol induced a partial amorphous state. These data indicate during lyophilization the most effective protein protection against aggregation was provided by sucrose and trehalose. The protection lasted during 4 months storage at 35 degrees C. FT-IR analysis displayed that the sucrose formulation inhibited deamidation. In conclusion, our data suggest that sucrose and trehalose as additives seems to be sufficient to protect from lyophilization of rHSA protein and also maintain its stability in the solid state during storage.

TGF-beta-induced transcriptional activation of MMP-2 is mediated by activating transcription factor (ATF)2 in human breast epithelial cells.

We have previously shown that transforming growth factor (TGF)-beta up-regulates matrix metalloproteinase (MMP)-2 leading to the induction of oncogenic signaling in preneoplastic MCF10A human breast epithelial cells. The present study investigated the mechanism of transcriptional regulation of MMP-2 by TGF-beta in MCF10A cells. By using 5' deletion constructs of MMP-2 promoter, we demonstrated that binding sites for p53, S1, AP-1 and Sp1, and to a lesser extent CREB, GCN-His and PEA3, were potential cis-acting elements for TGF-beta-induced transcriptional activation of MMP-2 in MCF10A cells. Since activating transcription factor (ATF)2 was shown to mediate the TGF-beta-induced cellular responses, we examined the involvement of ATF2 in TGF-beta-activated MMP-2 gene transcription. TGF-beta increased DNA binding activity of AP-1 in which ATF2 was involved as evidenced by electrophoretic mobility shift assay. TGF-beta induced phosphorylation of ATF2 through p38 MAPK signaling. A dominant-negative (DN) ATF2 significantly inhibited the TGF-beta-induced up-regulation of MMP-2, but not that of MMP-9, suggesting that ATF2 may be a transcription factor responsible for transcriptional activation of MMP-2 gene by TGF-beta. Invasive and migratory phenotypes induced by TGF-beta were significantly inhibited by DN ATF2, indicating a critical role of ATF2 in TGF-beta-induced oncogenic progression of MCF10A cells. Taken together, this study demonstrates that ATF2 mediates the TGF-beta-induced MMP-2 transcriptional activation, elucidating a molecular mechanism for the malignant progression of human breast epithelial cells exerted by TGF-beta.

Retroviral delivery of TIMP-2 inhibits H-ras-induced migration and invasion in MCF10A human breast epithelial cells.

The matrix metalloproteases (MMPs) play important roles in invasion, metastasis and angiogenesis in various cell types. Tissue inhibitor of metalloprotease (TIMP)-2, an endogenous inhibitor of MMP-2, has been shown to inhibit invasion and metastasis. We have previously shown that MMP-2 is responsible for the H-ras-induced invasive and migrative phenotypes in MCF10A human breast epithelial cells. Here, we investigated the effect of TIMP-2 overexpression on migration and invasion in H-ras MCF10A cells. Human TIMP-2 gene was effectively introduced into H-ras MCF10A cells by retrovirus-mediated gene delivery. TIMP-2 overexpression mediated by retrovirus significantly inhibited migration as well as invasion of H-ras MCF10A cells in a dose-dependent manner. We also show the antiangiogenic effect of TIMP-2 gene delivery. Taken together, our study shows that retrovirus-mediated delivery of TIMP-2 efficiently inhibits metastatic progression of ras-transformed human breast epithelial cells, suggesting a potential use of the TIMP-2 gene therapy for the treatment of breast cancer.

Sodium dodecyl sulfate-capillary gel electrophoresis of polyethylene glycolylated interferon alpha.

Sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) using a hydrophilic replaceable polymer network matrix was applied to characterize the polyethylene glycol(PEG)ylated interferon alpha (PEG-IFN). The SDS-CGE method resulted in a clearer resolution in both the PEG-IFN species and the native IFN species. The distribution profile of PEGylation determined by SDS-CGE was consistent with that obtained by SDS-polyacrylamide gel electrophoresis (PAGE) with Coomassie blue or barium iodide staining. The result was also compared using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry. SDS-CGE was also useful for monitoring the PEGylation reaction to optimize the reaction conditions, such as reaction molar ratio. This study shows the potential of SDS-CGE as a new method for characterizing the PEGylated proteins with advantages of speed, minimal sample consumption and high resolution.

Production of neutralizing human monoclonal antibody directed to tetanus toxin in CHO cell.

By the fusion of lymphocytes from hyperimmunized people with heteromyeloma cells, 600 human hybridoma cell lines were generated. Even though seven cell lines produced antibodies against tetanus toxoid, only two antibodies from hybrid CH8 and CH5 only neutralized the tetanus toxin and completely protected the mice that had been challenged with the toxin even at the level of 90 mean lethal dose. The cDNA of light (L) chain and heavy (H) chain variable region was isolated, and then inserted into expression vectors containing human IgG constant regions. After transfection of the recombinant human IgG gene into Chinese Hamster Ovary (CHO) cells, transformants secreting the complete human antibody were selected. The recombinant human antibodies produced from CHO cells possessed neutralizing activity against tetanus toxin just like the original human antibodies produced from human hybridoma cell lines. Western blot analysis showed that rCH8 and rCH5 antibodies recognized the H chain of tetanus toxin and did not bind to its L chain. The neutralizing test showed that HmAb rCH5 had 4.55IU and HmAb rCH8 had 1.09IU/100 micro g of IgG, respectively. Mixing of the two HmAbs resulted in synergistic effects. On a weight basis (IU/100 micro g IgG), the highest potency values were obtained when the two HmAbs were combined in equal quantity. The neutralizing activity of rCH8 and rCH5 mixture was 6.94IU/100 micro g IgG.