Cell-related Diseases Research Articles

Curcumin attenuates the scurfy-induced immune disorder, a model of IPEX syndrome, with inhibiting Th1/Th2/Th17 responses in mice

BackgroundImmunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX) is a lethal autoimmune disease caused by mutations in the Foxp3 gene scurfin (scurfy). Immunosuppressive therapy for IPEX patients has been generally ineffective and has caused severe side effects, however curcumin has shown immune regulation properties for inflammatory diseases, such as rheumatoid arthritis, psoriasis, and inflammatory bowel diseases without side effects. ObjectiveThe aim of this study was to investigate whether curcumin would attenuate symptoms of IPEX in mouse model and would prolong its survival period. MethodsC57BL/6 mice were separated into scurfy or wild-type litter mate groups by genotyping, and each group subsequently was separated into 2 subgroups that were fed a 1% curcumin containing or normal diet from the last day of breast-feeding. After weaning, pups were fed either a 1% curcumin containing or normal diet until all scurfy mice die for survival data. To elucidate immune cell proportions in spleen and lymph nodes, cells were analyzed by flowcytometry. Cellular cytokine production was accessed to investigate the effects of curcumin in T cell differentiation in vitro. ResultsScurfy mice fed a 1% curcumin diet survived 4.0-fold longer compared to scurfy (92.5 days) mice fed a normal diet (23 days). A curcumin diet decreased all of the Th1/Th2/Th17 cell populations and attenuated diverse symptoms such as splenomegaly in scurfy mice. In vitro experiments showed that curcumin treatment directly decreased the Th1/Th2/Th17 cytokine production of IFN-γ, IL-4, and IL-17A in CD4+ T cells. ConclusionsCurcumin diet attenuated the scurfy-induced immune disorder, a model of IPEX syndrome, by inhibiting Th1/Th2/Th17 responses in mice. These results have implications for improving clinical therapy for patients with IPEX and other T cell related autoimmune diseases.

Transcriptional Regulation of T Cell Metabolism Reprograming.

T cell activation, differentiation, and function are tightly regulated by a complex network of transcription factors, epigenetic modifications, and signaling pathways of both TCR and cytokines. Over the past decade, it is increasingly clear that T cell immune responses are also regulated by their associated metabolic reprograming. Compared with relatively well-understood transcriptional regulation of T cell activation, differentiation, and function, less is known about the transcriptional regulation of T cell metabolic reprograming during T cell immune responses. In this review, we first describe how signaling pathways of TCR and cytokines regulate metabolic reprograming and then focus on transcription factors that control metabolic pathways and outcomes of T cell immune responses. A better understanding of T cell metabolic regulation will provide new strategies and targets for the treatment of T cell-related diseases.

Effect of aging on stem cells

Pluripotent stem cells have the remarkable self-renewal ability and are capable of differentiating into multiple diverse cells. There is increasing evidence that the aging process can have adverse effects on stem cells. As stem cells age, their renewal ability deteriorates and their ability to differentiate into the various cell types is altered. Accordingly, it is suggested aging-induced deterioration of stem cell functions may play a key role in the pathophysiology of the various aging-associated disorders. Understanding the role of the aging process in deterioration of stem cell function is crucial, not only in understanding the pathophysiology of aging-associated disorders, but also in future development of novel effective stem cell-based therapies to treat aging-associated diseases. This review article first focuses on the basis of the various aging disease-related stem cell dysfunction. It then addresses the several concepts on the potential mechanism that causes aging-related stem cell dysfunction. It also briefly discusses the current potential therapies under development for aging-associated stem cell defects.

Stringent comparative sequence analysis reveals SOX10 as a putative inhibitor of glial cell differentiation.

BackgroundThe transcription factor SOX10 is essential for all stages of Schwann cell development including myelination. SOX10 cooperates with other transcription factors to activate the expression of key myelin genes in Schwann cells and is therefore a context-dependent, pro-myelination transcription factor. As such, the identification of genes regulated by SOX10 will provide insight into Schwann cell biology and related diseases. While genome-wide studies have successfully revealed SOX10 target genes, these efforts mainly focused on myelinating stages of Schwann cell development. We propose that less-biased approaches will reveal novel functions of SOX10 outside of myelination.ResultsWe developed a stringent, computational-based screen for genome-wide identification of SOX10 response elements. Experimental validation of a pilot set of predicted binding sites in multiple systems revealed that SOX10 directly regulates a previously unreported alternative promoter at SOX6, which encodes a transcription factor that inhibits glial cell differentiation. We further explored the utility of our computational approach by combining it with DNase-seq analysis in cultured Schwann cells and previously published SOX10 ChIP-seq data from rat sciatic nerve. Remarkably, this analysis enriched for genomic segments that map to loci involved in the negative regulation of gliogenesis including SOX5, SOX6, NOTCH1, HMGA2, HES1, MYCN, ID4, and ID2. Functional studies in Schwann cells revealed that: (1) all eight loci are expressed prior to myelination and down-regulated subsequent to myelination; (2) seven of the eight loci harbor validated SOX10 binding sites; and (3) seven of the eight loci are down-regulated upon repressing SOX10 function.ConclusionsOur computational strategy revealed a putative novel function for SOX10 in Schwann cells, which suggests a model where SOX10 activates the expression of genes that inhibit myelination during non-myelinating stages of Schwann cell development. Importantly, the computational and functional datasets we present here will be valuable for the study of transcriptional regulation, SOX protein function, and glial cell biology.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3167-3) contains supplementary material, which is available to authorized users.

Abstract 4020: Inhibition of KIT in vivo modifies immune cell populations to improve the efficacy of checkpoint inhibitors in syngeneic mouse tumor models

Abstract The KIT receptor tyrosine kinase plays critical roles in GIST and a range of other tumor types, and when activated by somatic mutation serves as a potent oncogenic driver in these neoplasms. Whereas small molecule inhibitors of the tyrosine kinase domain of KIT have demonstrated considerable success in treatment of GIST patients with some KIT mutations, there remains a need to develop additional KIT-directed therapies for treatment of GIST patients that fail to respond to these agents, or that develop resistance during therapy. Furthermore, KIT is prominently expressed on mast cells, which promote an immune evasive environment within the tumor microenvironment by influencing the function of other immune cells, such as myeloid derived suppressor cells (MDSC’s). However, the potential impact of KIT inhibition on anti-tumor immunity has not been studied extensively to date. KTN0158 is a humanized anti-KIT IgG1 monoclonal antibody that specifically binds to the extracellular domain of KIT, and is being developed as a potential therapy for cancer and other mast cell-related diseases such as neurofibromatosis type 1 (NF1). KTN0158 inhibits KIT signaling and function in vitro and in vivo and has demonstrated anti-tumor activity in dogs with mast cell tumors expressing either wild-type or mutant KIT. In order to explore the potentially broad anti-tumor benefit of KIT inhibition by an antibody, a series of syngeneic tumor models were evaluated for sensitivity and immune cell profile changes in response to a surrogate antibody that recognizes mouse KIT (ACK2), dosed as either a single agent or in combination with T cell checkpoint inhibitors. Within this panel of tumor models, ACK2 strongly enhanced the anti-tumor activity provided by an anti-CTLA4 antibody in the colon26 model, while exhibiting no anti-tumor activity when dosed as a single agent. The colon26 cell line does not express detectable levels of KIT, and does not exhibit sensitivity to ACK2 or SCF treatment in proliferation assays performed in vitro, suggesting that this effect of ACK2 is not due to a direct effect on the tumor cells. Strikingly, ACK2 treatment was associated with pronounced effects on immune cell populations, including a profound decrease in both intra-tumoral and splenic monocytic MDSC counts. These observations suggest that KIT inhibition in vivo has the potential to modulate immune cell populations including MDSC's and mast cells, thereby targeting immune suppressive innate immune cells in the tumor and sensitizing the tumor to immune checkpoint inhibitors. Furthermore, the data provide a rationale to investigate KTN0158 in combination with immune checkpoint inhibitors across a range of human tumor types. Citation Format: Andrew J. Garton, Lori Lopresti-Morrow, Scott Seibel, Theresa LaVallee, Richard Gedrich. Inhibition of KIT in vivo modifies immune cell populations to improve the efficacy of checkpoint inhibitors in syngeneic mouse tumor models. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4020.

Analysis of the BRAFV600E mutation in 19 cases of Langerhans cell histiocytosis in Japan

Langerhans cell histiocytosis (LCH) is a rare disease characterized by clonal proliferation of CD1a- and CD207 (langerin)-positive dendritic cells. Mutated BRAF (p.V600E) is observed in histiocyte-related diseases and dendritic cell-related diseases, including LCH. BRAFV600E is observed in some LCH cases and is thought to be involved in maintaining MAPK activation. We retrospectively analyzed BRAFV600E in 19 patients diagnosed with LCH. In our study, direct sequencing for exon 15, a mutation hotspot, demonstrated that 4 out of the 19 patients (21%) harbored a GTG > GAG (valine > glutamic acid) base substitution, which encodes BRAFV600E. The clinical impact of BRAFV600E in such diseases is unclear. The frequency of BRAFV600E in our LCH patients from Japan was lower than that reported in the United States and in Germany. However, reports from Asia tend to show a lower rate of the BRAFV600E mutation. These results imply the possibility of different genetic backgrounds in the pathogenesis of LCH across various ethnicities. We also performed an immunohistochemical analysis to detect BRAFV600E using the mutation-specific monoclonal antibody. However, immunohistochemical analysis failed to detect any mutated protein in any of the 4 BRAFV600E-positive cases. This implies that at present, BRAFV600E should be assessed by direct sequencing. Copyright © 2016 John Wiley & Sons, Ltd.

Novel Therapeutic Targets for Diseases of Endocrine or Immune System Developed through the Analysis of Cross-talk between Ca(2+) and Disease-related Cell Signaling

Novel Therapeutic Targets for Diseases of Endocrine or Immune System Developed through the Analysis of Cross-talk between Ca(2+) and Disease-related Cell Signaling

SCYL1-BP1 Affects Cell Cycle Arrest in Human Hepatocellular Carcinoma Cells via Cyclin F and RRM2

The cell cycle is regulated via important biological mechanisms. Controlled expression of cell cycle regulatory proteins is crucial to maintain cell cycle progression. However, unbalanced protein expression leads to many diseases, such as cancer. Previous research suggests that SCYL1-BP1 function might be related to cell cycle progression and SCYL1-BP1 dysfunction to diseases through undefined mechanisms. In this research, an unbiased yeast two-hybrid screen was used to find protein(s) with potential biological relevance to SCYL1-BP1 function, and a novel interaction was recognized between SCYL1-BP1 and Cyclin F. This interaction was chosen as a paradigm to study SCYL1-BP1 function in cell cycle progression and its possible role in tumorigenesis. We found that SCYL1-BP1 binds to Cyclin F both in vivo and in vitro. SCYL1-BP1 overexpression promoted expression of the CCNF gene and simultaneously delayed Cyclin F protein degradation. SCYL1-BP1 knockdown reduced the expression of endogenous Cyclin F. It was also demonstrated in functional assays that SCYL1-BP1 overexpression induces G2/M arrest in cultured liver cells. Furthermore, SCYL1-BP1 sustained RRM2 protein expression by reducing its ubiquitination. Thus, we propose that SCYL1- BP1 affects the cell cycle through increasing steady state levels of Cyclin F and RRM2 proteins, thus constituting a dual regulatory circuit. This study provides a possible mechanism for SCYL1-BP1-mediated cell cycle regulation and related diseases.

Luminescence- and nanoparticle-mediated increase of light absorption by photoreceptor cells: Converting UV light to visible light.

We developed new optic devices – singly-doped luminescence glasses and nanoparticle-coated lenses that convert UV light to visible light – for improvement of visual system functions. Tb3+ or Eu3+ singly-doped borate glasses or CdS-quantum dot (CdS-QD) coated lenses efficiently convert UV light to 542 nm or 613 nm wavelength narrow-band green or red light, or wide-spectrum white light, and thereby provide extra visible light to the eye. In zebrafish (wild-type larvae and adult control animals, retinal degeneration mutants, and light-induced photoreceptor cell degeneration models), the use of Tb3+ or Eu3+ doped luminescence glass or CdS-QD coated glass lenses provide additional visible light to the rod and cone photoreceptor cells, and thereby improve the visual system functions. The data provide proof-of-concept for the future development of optic devices for improvement of visual system functions in patients who suffer from photoreceptor cell degeneration or related retinal diseases.

Genetics of autoimmune diseases: perspectives from genome-wide association studies.

Genome-wide association studies (GWASs) for autoimmune diseases (ADs) have identified many risk loci and have provided insights into the etiology of each disease. Some of these loci, such asPTPN22,IL23RandSTAT4, are shared among different ADs, and the combination of risk loci may determine an individual's susceptibility for a disease. The majority of GWAS loci are expression quantitative trait loci (eQTLs), where disease-causing variants regulate expression of neighboring (or sometimes distant) genes. Because the eQTL effects are often cell type-specific, the incorporation of epigenetic data from disease-related cell types and tissues is expected to refine the identification of causal variants. The cumulative eQTL effects in multiple genes may influence the activity or fate of immune cells, which in turn may affect the function of the immune system in individuals. In this paper, I review the etiology of ADs by focusing on important immune cells (Th1 cells, Th17 cells and regulatory T cells), important pathways (antigen-receptor signaling and type I interferon signaling) and relevant genes identified in GWASs.

Targeting of Ly9 (CD229) Disrupts Marginal Zone and B1 B Cell Homeostasis and Antibody Responses.

Marginal zone (MZ) and B1 B cells have the capacity to respond to foreign Ags more rapidly than conventional B cells, providing early immune responses to blood-borne pathogens. Ly9 (CD229, SLAMF3), a member of the signaling lymphocytic activation molecule family receptors, has been implicated in the development and function of innate T lymphocytes. In this article, we provide evidence that in Ly9-deficient mice splenic transitional 1, MZ, and B1a B cells are markedly expanded, whereas development of B lymphocytes in bone marrow is unaltered. Consistent with an increased number of these B cell subsets, we detected elevated levels of IgG3 natural Abs and a striking increase of T-independent type II Abs after immunization with 2,4,6-trinitrophenyl-Ficoll in the serum of Ly9-deficient mice. The notion that Ly9 could be a negative regulator of innate-like B cell responses was supported by the observation that administering an mAb directed against Ly9 to wild-type mice selectively eliminated splenic MZ B cells and significantly reduced the numbers of B1 and transitional 1 B cells. In addition, Ly9 mAb dramatically diminished in vivo humoral responses and caused a selective downregulation of the CD19/CD21/CD81 complex on B cells and concomitantly an impaired B cell survival and activation in an Fc-independent manner. We conclude that altered signaling caused by the absence of Ly9 or induced by anti-Ly9 may negatively regulate development and function of innate-like B cells by modulating B cell activation thresholds. The results suggest that Ly9 could serve as a novel target for the treatment of B cell-related diseases.

Cilostazol Suppresses IL-23 Production in Human Dendritic Cells via an AMPK-Dependent Pathway

Background/Aims: Cilostazol has been previously demonstrated to inhibit IL-23 production in human synovial macrophages via a RhoA/ROCK-dependent pathway. However, whether cilostazol affects IL-23 production in human dendritic cells remains largely unknown. The present study was designed to investigate this question and elucidate the possible underlying mechanisms. Methods: Human monocyte-derived dendritic cells (mo-DCs) were pretreated with or without cilostazol and then incubated with zymosan. Enzyme-linked immunosorbent assay (ELISA) and real time PCR analyses were used to measure IL-23 protein expression and RNA levels, respectively, whereas Western blotting was used to measure the expression and phosphorylation level of AMPK. Results: Our results demonstrated that cilostazol suppressed zymosan-induced IL-23 protein production in a concentration dependent manner without affecting dendritic cell viability. In addition, it was found that cilostazol suppressed the expression of the p19 and p40 subunits of IL-23. Moreover, cilostazol mimicked the effect of the AMPK agonist A-769662, as demonstrated by the fact that IL-23 production was also inhibited by A-769662, and the effect of cilostazol on IL-23 production was blocked by the AMPK antagonist Compound C. More importantly, Western blotting demonstrated that cilostazol led to an increased phosphorylation of AMPK. Conclusion: Collectively, our data suggest that cilostazol inhibits the production of IL-23 in human mo-DCs, potentially via the activation of AMPK. This suggests that cilostazol could be an effective anti-inflammatory agent in IL-23- and dendritic cell-related diseases.

Discovery of 8-Amino-imidazo[1,5-a]pyrazines as Reversible BTK Inhibitors for the Treatment of Rheumatoid Arthritis.

Bruton's tyrosine kinase (BTK) is a Tec family kinase with a well-defined role in the B cell receptor (BCR) pathway. It has become an attractive kinase target for selective B cell inhibition and for the treatment of B cell related diseases. We report a series of compounds based on 8-amino-imidazo[1,5-a]pyrazine that are potent reversible BTK inhibitors with excellent kinase selectivity. Selectivity is achieved through specific interactions of the ligand with the kinase hinge and driven by aminopyridine hydrogen bondings with Ser538 and Asp539, and by hydrophobic interaction of trifluoropyridine in the back pocket. These interactions are evident in the X-ray crystal structure of the lead compounds 1 and 3 in the complex with the BTK enzyme. Our lead compounds show desirable PK profiles and efficacy in the preclinical rat collagen induced arthritis model.

Targeting Mast Cells and Basophils with Anti-FcεRIα Fab-Conjugated Celastrol-Loaded Micelles Suppresses Allergic Inflammation.

Mast cells and basophils are effector cells in the pathophysiology of allergic diseases. Targeted elimination of these cells may be a promising strategy for the treatment of allergic disorders. Our present study aims at targeted delivery of anti-FcεRIα Fab-conjugated celastrol-loaded micelles toward FcεRIα receptors expressed on mast cells and basophils to have enhanced anti-allergic effect. To achieve this aim, we prepared celastrol-loaded (PEO-block-PPO-block-PEO, Pluronic) polymeric nanomicelles using thin-film hydration method. The anti-FcεRIα Fab Fragment was then conjugated to carboxyl groups on drug-loaded micelles via EDC amidation reaction. The anti-FcεRIα Fab-conjugated celastrol-loaded micelles revealed uniform particle size (93.43 ± 12.93 nm) with high loading percentage (21.2 ± 1.5% w/w). The image of micelles showed oval and rod like. The anti-FcεRIα Fab-conjugated micelles demonstrated enhanced cellular uptake and cytotoxity toward target KU812 cells than non-conjugated micelles in vitro. Furthermore, diffusion of the drug into the cells allowed an efficient induction of cell apoptosis. In mouse model of allergic asthma, treatment with anti-FcεRIα Fab-conjugated micelles increased lung accumulation of micelles, and significantly reduced OVA-sIgE, histamine and Th2 cytokines (IL-4, IL-5, TNF-α) levels, eosinophils infiltration and mucus production. In addition, in mouse model of passive cutaneous anaphylaxis, anti-FcεRIα Fab-conjugated celastrol-loaded micelles treatment significantly decreased extravasated evan's in the ear. These results indicate that anti-FcεRIα Fab-conjugated celastrol-loaded micelles can target and selectively kill mast cells and basophils which express FcεRIα, and may be efficient reagents for the treatment of allergic disorders and mast cell related diseases.

Ethnicity-specific epigenetic variation in naïve CD4+ T cells and the susceptibility to autoimmunity.

BackgroundGenetic and epigenetic variability contributes to the susceptibility and pathogenesis of autoimmune diseases. T cells play an important role in several autoimmune conditions, including lupus, which is more common and more severe in people of African descent. To investigate inherent epigenetic differences in T cells between ethnicities, we characterized genome-wide DNA methylation patterns in naïve CD4+ T cells in healthy African-Americans and European-Americans, and then confirmed our findings in lupus patients.ResultsImpressive ethnicity-specific clustering of DNA methylation profiling in naïve CD4+ T cells was revealed. Hypomethylated loci in healthy African-Americans were significantly enriched in pro-apoptotic and pro-inflammatory genes. We also found hypomethylated genes in African-Americans to be disproportionately related to autoimmune diseases including lupus. We then confirmed that these genes, such as IL32, CD226, CDKN1A, and PTPRN2 were similarly hypomethylated in lupus patients of African-American compared to European-American descent. Using patch DNA methylation and luciferase reporter constructs, we showed that methylation of the IL32 promoter region reduces gene expression in vitro. Importantly, bisulfite DNA sequencing demonstrated that cis-acting genetic variants within and directly disrupting CpG sites account for some ethnicity-specific variability in DNA methylation.ConclusionEthnicity-specific inherited epigenetic susceptibility loci in CD4+ T cells provide clues to explain differences in the susceptibility to autoimmunity and possibly other T cell-related diseases between populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s13072-015-0037-1) contains supplementary material, which is available to authorized users.

Targeting KIT on innate immune cells enhances the antitumor activity of checkpoint inhibitors in vivo

Mast cell infiltrates are associated with tumors, though their role in the tumor microenvironment remains unclear. Mast cells express high levels of KIT throughout differentiation and as mature cells. Mast cells in tumors have been shown to release proinflammatory cytokines and promote angiogenesis, increasing tumor growth and metastasis. KIT signaling and mast cells also appear to modulate myleloid-derived suppressor cell (MDSC) development, recruitment and activity in tumors. Furthermore, treatment of tumor-bearing mice or cancer patients with small molecule KIT inhibitors or an anti-mouse KIT antibody decreased tumoral MDSCs and other immunosuppressive cells including regulatory T cells. KTN0158 is a humanized anti-KIT IgG1 monoclonal antibody that specifically binds KIT and is being developed as a potential therapy for cancer and mast cell-related diseases such as neurofibromatosis type 1 (NF1). It binds canine, feline, non-human primate and human KIT with high affinity, but does not bind mouse or rat KIT. KTN0158 inhibits KIT signaling and function in vitro and in vivo and has shown antitumor activity in dogs with mast cell tumors expressing either wild-type or mutant KIT. Immune checkpoint inhibitors targeting the CTLA-4 and PD-1 pathways have demonstrated single agent efficacy in cancer patients, and the combinations have shown superior efficacy in some preclinical and clinical settings. To test the effects of KIT inhibition on immune tolerance in syngeneic mouse tumor models, the anti-mouse KIT monoclonal antibody ACK2 was used as a surrogate for KTN0158 and tested alone and in combination with CTLA-4 and PD-1 inhibitors. In the Colon26 model, single agent treatment with the anti-KIT antibody had little antitumor activity. However, the combination of anti-KIT and anti-CTLA-4 had substantial antitumor effects, comparable to those observed for anti-CTLA-4 plus anti-PD1. These antitumor effects were dose-dependent. Pharmacodynamic assessments will also be presented. Collectively, these data suggest that the combination of immunotherapies targeting KIT on innate immune cells and checkpoint pathway inhibitors may have clinical benefit.

Reconstructing the in vivo dynamics of hematopoietic stem cells from telomere length distributions.

We investigate the in vivo patterns of stem cell divisions in the human hematopoietic system throughout life. In particular, we analyze the shape of telomere length distributions underlying stem cell behavior within individuals. Our mathematical model shows that these distributions contain a fingerprint of the progressive telomere loss and the fraction of symmetric cell proliferations. Our predictions are tested against measured telomere length distributions in humans across all ages, collected from lymphocyte and granulocyte sorted telomere length data of 356 healthy individuals, including 47 cord blood and 28 bone marrow samples. We find an increasing stem cell pool during childhood and adolescence and an approximately maintained stem cell population in adults. Furthermore, our method is able to detect individual differences from a single tissue sample, i.e. a single snapshot. Prospectively, this allows us to compare cell proliferation between individuals and identify abnormal stem cell dynamics, which affects the risk of stem cell related diseases.

Applications of Atomic Force Microscopy in Exploring Drug Actions in Lymphoma-Targeted Therapy at the Nanoscale

Rituximab, a monoclonal antibody against the CD20 molecule expressed on B cells, has revolutionized the treatment of B cell lymphomas. The use of rituximab significantly improves the long-term survival rates of lymphoma patients. However, there are still many patients who develop resistance to rituximab. Hence, the urgent need is enhancing the potency of anti-CD20 antibodies beyond that achieved with rituximab to provide effective therapies for more patients. Traditional studies about the killing mechanisms of rituximab are commonly based on optical microscopy, which cannot reveal the detailed situations due to the limit of 200-nm resolution. Quantitatively investigating the actions of rituximab at the nanoscale is still scarce. The advent of atomic force microscopy (AFM) provides a powerful and versatile platform for in situ investigating the nanoscale behaviors of individual live cells. The applications of AFM in life sciences in the past decade have yielded a lot of novel insights into cell biology and related diseases. In this article, the typical applications (e.g., ultra-microstructures, mechanical properties, and molecular recognition) of AFM in investigating the three killing mechanisms of rituximab at the nanoscale are summarized; the challenges facing AFM single-cell assay and its future directions are also discussed.

‘Cell junctions of oral mucosa’- in a nutshell

Junctional complexes are specialized contacts between neighboring cells and between cells and the extracellular matrix. They play an important role in embryogenesis, growth and development, as well as being the cause of pathologies. These contacts lead to a number of different interactions that have a profound effect on cellular biology. Cell junctions are best visualized using conventional or freeze-fracture electron microscopy, which reveals the interacting plasma membranes are highly specialized in these regions. Cell adhesion molecules (CAMs) are proteins responsible for homophillic and heterophillic adhesions. They consist of various groups, including cadherins, selectins and intergrins and they facilitate cell adhesion, cell signaling, and motility. Dysregulation of these molecules can lead to various pathologies, for example mucocutaneous diseases and invasion of cancer. This review focuses on the pathophysiology of cell junctions and related diseases.

Using iPS Cells toward the Understanding of Parkinson's Disease.

Cellular reprogramming of somatic cells to human pluripotent stem cells (iPSC) represents an efficient tool for in vitro modeling of human brain diseases and provides an innovative opportunity in the identification of new therapeutic drugs. Patient-specific iPSC can be differentiated into disease-relevant cell types, including neurons, carrying the genetic background of the donor and enabling de novo generation of human models of genetically complex disorders. Parkinson’s disease (PD) is the second most common age-related progressive neurodegenerative disease, which is mainly characterized by nigrostriatal dopaminergic (DA) neuron degeneration and synaptic dysfunction. Recently, the generation of disease-specific iPSC from patients suffering from PD has unveiled a recapitulation of disease-related cell phenotypes, such as abnormal α-synuclein accumulation and alterations in autophagy machinery. The use of patient-specific iPSC has a remarkable potential to uncover novel insights of the disease pathogenesis, which in turn will open new avenues for clinical intervention. This review explores the current Parkinson’s disease iPSC-based models highlighting their role in the discovery of new drugs, as well as discussing the most challenging limitations iPSC-models face today.