EMBO Molecular Medicine Research Articles

Investigation of tau post‐translational modification based on T217 and T231 in human plasma as new biomarkers

AbstractBackgroundPost‐translational modification (PTM) of human tau protein is of high importance as an indicator for predicting the progress of Alzheimer’s disease (AD). Particularly, phosphorylation and O‐glycosylation on tau have been observed at relatively high levels in Alzheimer’s disease (AD) patients and healthy controls, respectively [1]. Recently, a study reported that an increase in the level of phosphorylation at T217 and T231 was observed in the initial stages of the preclinical Alzheimer’s continuum [2]. Reference: [1] C. Alquezar et al. Frontiers in Neurology, 11 (2021) 595532. [2] Marc Suárez‐Calvet et al. EMBO Molecular Medicine, 12 (2020) e12921.MethodTo investigate the PTM of tau protein in human blood plasma, an electrochemical sensor with 1 µm gap between working and counter electrodes was performed and obtained Taumeter indicating the ratio of phosphorylation and O‐glycosylation on the surface of tau protein, where antibodies for phosphorylated T217 and T231 were used [3]. To explore the clinical association, standardized uptake value ratio (SUVR) of amyloid‐positron emission tomography (PET), mini‐mental state examination (MMSE), and clinical dementia rating scale sum of boxes (CDR‐SB) were also investigated and compared to Taumeters. Reference: [3] Yoon et al. Alzheimer’s & Dementia, 18 (2022) e061465.ResultA total of 43 participants (normal control (NC, n = 15), mild cognitive impairment (MCI, n = 14), and AD (n = 14) were investigated. Taumeters for T217 (p = 0.00423, AUC = 0.82667) and T231 (p = 0.00034, AUC = 0.86222) were obtained and analyzed through one‐way analysis of variance (ANOVA) between NC and AD groups (Figure 2). In regression analysis, Taumeter for T217 (r = 0.23824, p = 0.12394) was more correlated with amyloid‐PET SUVR than Taumeter for T231 (r = 0.28072, p = 0.06824) (Figures 3a‐b). Taumeter for T217 (r = ‐0.51246, p = 0.00044) was also more correlated with MMSE score than Taumeter for T231 (r = ‐0.07186, p = 0.64701) (Figures 3c‐d). Taumeter for T217 (r = 0.57937, p<0.0001) was more correlated with the CDR‐SB score than Taumeter for T231 (r = 0.16254, p = 0.29768) (Figures 3e‐f).ConclusionIn this study, we investigated the correlation between Taumeters for T217 and T231, amyloid‐PET SUVR, MMSE score, and CDR‐SB score. As a result, Taumeter for T217 indicates more strong correlation with analytical results of amyloid‐PET SUVR, MMSE score, and CDR‐SB score than Taumter for T231.

Maternal dietary habit influences fetal life

Diet and nutrition have a tremendous influence on health and disease. Dietary constituents can affect health and have been known to supplement with essential nutrients, minerals, and calories for physiological homeostasis. However, diet can also affect gene expression through epigenetic reprogramming or by altering the level of micronutrients. While a nutrigenomics study has delineated this causal link, a recent study published in EMBO Molecular Medicine by Grant et al. went a step further to establish that maternal intake of dietary fibers can alter the fetal gut microbiome, influencing the diversity of the intestinal bacterial flora, thereby affecting the gut-brain axis. Although the relationship between diet and fertility in males and females has been reported, the effect on postnatal life is not well documented. In this study by Grant et al. at the (Luxembourg Institute of Health, Esch-sur-Alzette, Luxembourg), the authors reported that selected feeding of fiber-free diets to pregnant mice alters the gut microbiome composition of their neonate pups depriving them of protective and beneficial commensal, Akkermansia muciniphila, a mucin-foraging bacterium. Further, these animals exhibited heightened immune activity by enriching defense response pathways and IL-22 expression. Therefore, the protective role of A. muciniphila is associated with its protection against chronic inflammation through TLR4 signaling. The author’s study has far-reaching conclusions on improving human health outcomes by the rational choice of food, drugs, and lifestyle to prevent gut dysbiosis and colonization of the right microbiome.

Abstract 4589: Deciphering collagen-responsive mechanism in pancreatic tumor progression and immunology at single-cell resolution

Abstract A hallmark feature of PDAC is its desmoplastic stroma. However, clinical trials of generic strategies targeting PDAC stromal components have mostly failed or, in some cases, even accelerated tumor progression. These findings prompt us to re-evaluate the functional heterogeneity and selective targeting of the tumor stroma. Tumor stroma involves the prominent accumulation of type I collagen (Col1), the most abundant protein in PDAC and the human body. However, the precise molecular and mechanistic contributions of Col1 to PDAC remain unknown, due to the lack of mouse models for precise knockout of Col1. I have established a variety of novel transgenic mouse models that allow specific genetic deletion of Col1 in various cell populations including fibroblasts or cancer cells of spontaneous PDAC (Chen et al., Cancer Cell, 2022; Chen et al., Cancer Cell, 2021; Chen et al., Nature Communications, 2021). In addition, my prior studies underscore the importance of deciphering the functional heterogeneity of tumor microenvironment with both tumor-restraining and tumor-promoting functions (McAndrew, Chen, Darpolor et al., Cancer Discovery, 2022; Chen et al., Nature Reviews Clinical Oncology, 2021; Chen et al., EMBO Molecular Medicine, 2018; Chen et al., PLoS Biology, 2018). Specifically, my recent studies identified that Col1 deletion in fibroblasts significantly aggravates tumor progression and immune suppression, with enriched myeloid-derived suppressor cells (MDSCs) and inhibited T/B cells (Chen et al., Cancer Cell, 2021). On the contrary, Col1 deletion in cancer cells inhibited PDAC progression and immunosuppression, leading to beneficial intra-tumoral microbiome and enhanced efficacy of immunotherapy (Chen et al., Cancer Cell, 2022). In contrast to the normal Col1 heterotrimer (α1/α2/α1) produced by fibroblasts, pancreatic cancer cells produce abnormal oncogenic Col1 homotrimer (α1/α1/α1). Col1 homotrimers produced by cancer cells exhibits potent tumor-promoting functions, in contrast to the tumor-restraining functions of Col1 heterotrimers produced by fibroblasts. These findings, as validated in both transgenic mouse models and pancreatic tumor patient datasets, identify the distinct impact of various Col1 subtypes on tumor progression, immune landscape, and microbiome profile. Furthermore, my results underscore the need for new therapeutic strategy preferably targeting Col1 homotrimer-specific oncogenic effects in cancer cells via cancer-specific receptors, without disturbing Col1 heterotrimer-induced tumor-restraining functions. My current studies aim to dissect the cancer cell-intrinsic response and immune response to Col1 homotrimer versus Col1 heterotrimer, which may unravel the fundamental collagen-responsive mechanism by which cancer cells survive in the desmoplastic microenvironment, revealing potential vulnerabilities of PDAC. Citation Format: Yang Chen. Deciphering collagen-responsive mechanism in pancreatic tumor progression and immunology at single-cell resolution. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4589.

Targeting conformational changes in C-reactive protein to inhibit pro-inflammatory actions.

C-reactive protein (CRP) is a marker of acute inflammation and modulator of host defense against infections. CRP exists in conformationally distinct forms that exhibit opposing biological functions and could amplify tissue damage. Therefore, therapies that efficiently target the deleterious actions of CRP are needed. In this issue of EMBO Molecular Medicine, Zeller etal report development of a novel low molecular weight phosphocholine-mimetic that binds to pCRP and inhibits conformation change-mediated expression of pro-inflammatory actions without impairing its defense function and demonstrate its beneficial actions in preventing rejection of allograft transplants and renal ischemia-reperfusion injury.

Repurposing immunosuppressants for antileukemia therapy.

Drug repurposing, the strategy to identify new therapeutic use for clinically approved drugs has attracted much attention in recent years. This strategy offers various advantages over traditional approaches to develop new drugs, including shorter development timelines, low cost, and reduced risk of failure. In this issue of EMBO Molecular Medicine, Liu etal show that inosine monophosphate dehydrogenase (IMPDH) inhibitors, the well-known immunosuppressants have a potent therapeutic effect on the aggressive blood cancer, acute myeloid leukemia with MLL rearrangements. Intriguingly, the antileukemia effect of IMPDH inhibitors is mediated, at least in part through the overactivation of TLR signaling and Vcam1 upregulation. The robust antileukemia effect of IMPDH inhibitors, both invitro and invivo, together with their mechanistic findings provides a rational basis for repurposing IMPDH inhibitors for antileukemia therapy.

Ketones regulate endothelial homeostasis

In a recent paper in EMBO Molecular Medicine, Weis etal. reveal that cardiac endothelial cells can oxidize ketone bodies, which enhances cell proliferation, migration, and vessel sprouting. Furthermore, increasing ketone body levels with a ketogenic diet can increase endothelial cell proliferation and prevent blood vessel rarefication in hypertrophied mouse hearts. This suggests that increasing endothelial cell ketone oxidation has potential in treating heart failure.

Oxidized low-density lipoproteins as a novel risk factor and therapeutic target for ACM.

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease involving arrhythmia in young adults accompanied by structural changes at later stages. In this issue of EMBO Molecular Medicine, Sommariva etal (2021) identified a positive correlation between circulating levels of oxidized low-density lipoproteins (oxLDL) and ACM disease penetrance, which contributes to fibro-fatty cardiac remodeling viathe oxLDL/CD36/PPARγ axis. These data identify oxidized low-density lipoproteins as a risk factor for ACM and uncover a novel therapeutic intervention option to block disease pathogenesis.

Chloroquine or Hydroxychloroquine for COVID-19: Is Cardiotoxicity a Concern?

Chloroquine or Hydroxychloroquine for COVID-19: Is Cardiotoxicity a Concern?

Lipid-Laden Macrophages cross the Border to Cancer

Abstract Within atherosclerotic plaques, macrophages can take up cholesterol and thereby become lipid-laden cells. For long it has been thought that these foamy macrophages are the main contributors to chronic inflammatory responses in plaques. However, several publications lately highlighted that foamy plaque macrophages are less inflammatory than their non-foamy counterparts. Interestingly, a very recent EMBO Molecular Medicine paper by Wu et al. demonstrate that accumulation of lipids in tumor-associated macrophages (TAMs) elicits an immunosuppressive phenotype.

Abstract 839: Treatment and signaling contexts for the application of the imipridone ONC201 to prostate cancer cells

Abstract Prostate cancer is the most common non-cutaneous cancer in men and a significant cause of cancer mortality. In the majority of the cases localised disease is treated with surgery or radiotherapy and whilst androgen deprivation therapy can extend survival in the subset of cases that progress, metastatic disease is incurable. We have previously reported that oncogenic drivers of prostate cancer (e.g. PTEN loss or mutation), as well as therapy, lead to changes in the activation of prostate cancer cell stress signalling pathways and in particular the unfolded protein response (UPR)1. Here we assess whether the activation of the UPR in response to radiation mirrors the immunogenic/inflammatory response, which is known to characterize the initially acute apoptotic phase before resolving to a chronic level. Further we have evaluated the impact of combining radiation with ONC201, a novel anti-cancer small molecule in clinical trials that is known to activate the pro-apoptotic stress response signalling2. We find that ONC201 has a delayed cytotoxic effect as a single agent in prostate cancer cells, with significant dose-dependent reductions in cell viability occurring 72 hours post-treatment. However activation of multiple arms of the UPR occurs earlier and is detectable at 24 hours for ATF4, ATF6 and IRE1-XBP1 at the protein/mRNA levels in the absence of impacts on cell viability. This delayed impact on viability offers a time window within which to evaluate short-term administration of ONC201 as a ‘primer' to enhance the cytotoxic response to radiation. We show that ‘priming' does indeed enhance radiotherapy response as assessed by cell viability and clonogenic assays. Since PTEN-loss is a high-incidence event in the development and progression of prostate cancer and has been linked to prognosis, we have also evaluated the impact of altering PTEN expression in our models as well as the effect of knocking down core regulators of the UPR. Cumulatively this work represents a further progression to positioning ONC201 in an appropriate molecular context to have durable effects when combined with other therapies to treat prostate cancer. 1.Sheng, X. et al., EMBO Molecular Medicine 7, 788-801 (2015). 2.Allen, J. et al. Discovery and clinical introduction of first-in-class imipridone ONC201. Oncotarget (2016). doi:10.18632/oncotarget.11814 Citation Format: Francesca Amoroso, Adam Pickard, Kimberly Glass, Rohinton Tarapore, J. E. Allen, Ian G. Mills. Treatment and signaling contexts for the application of the imipridone ONC201 to prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 839.

Co-targeting driver pathways in prostate cancer: two birds with one stone.

Co‐targeting strategies strive to improve cancer outcomes by combining therapies under contextualized genetic and environmental conditions that selectively target exploitable alterations in tumor cells. Adaptive survival pathways triggered by inhibition of driver genes in the androgen receptor (AR) or PI3K/AKT pathways are of great interest, since they are among the most frequently altered in castrate‐resistant prostate cancer (CRPC). Unfortunately, negative feedback loops exist between the AR and PI3K/AKT pathways such that targeting AR leads to activation of PI3K/AKT signaling, while PI3K/AKT pathway inhibition leads to increased AR transcriptional activity. Hence, targeting both pathways provides an opportunity for conditional lethality and a high therapeutic index. In this issue of EMBO Molecular Medicine , Yan et al (2018) present an elegant study showing that histone deacetylase 3 (HDAC3) acts as a common upstream activator of both AR and AKT signaling pathways, and use HDAC3 inhibitors as a monotherapy to co‐target two major pathways driving CRPC growth.

Abstract IA23: Using PARP inhibitors to target ATM-deficient cancers

Abstract The Ataxia-Telangiectasia Mutated (ATM) serine/threonine protein kinase plays an important role in orchestrating the cellular response to DNA double strand breaks (DSBs). Germline loss of ATM function results in Ataxia-Telangiectasia (A-T), a devastating childhood syndrome characterized by progressive loss of neuromuscular control, immune deficiency and cancer predisposition. ATM is also deleted in a large proportion of human mantle cell lymphoma (MCL) and other lymphomas and recent studies have revealed that ATM is altered in many sporadic cancers including lung, colorectal, breast and prostate cancer. We previously showed that MCL and gastric cancer cell lines with deletion or mutation of ATM are sensitive to the poly-ADP-ribose polymerase (PARP) inhibitor, olaparib and that loss of TP53 enhances olaparib sensitivity (Williamson et al Molecular Cancer Therapeutics, 2010, 9:347-57; Williamson et al, EMBO Molecular Medicine, 2012, 4, 515-527; Kubota et al, Cell Cycle 2014, 13: 2129-37). Here we show that lung and colorectal cancers with mutation or loss of ATM are similarly sensitive to olaparib. The potential for use of PARP and ATM inhibitors in the treatment of ATM deficient malignancies will be explored. Citation Format: Susan P. Lees-Miller. Using PARP inhibitors to target ATM-deficient cancers [abstract]. In: Proceedings of the AACR Special Conference on DNA Repair: Tumor Development and Therapeutic Response; 2016 Nov 2-5; Montreal, QC, Canada. Philadelphia (PA): AACR; Mol Cancer Res 2017;15(4_Suppl):Abstract nr IA23.

Gut flora connects obesity with pathological angiogenesis in the eye.

Neovascular age‐related macular degeneration (nvAMD) can cause severe vision loss among the elderly. Genetic risk factors for AMD include several variants related to the immune system and lipid metabolism. Obesity is a well‐known predisposing factor for nvAMD but how this metabolic disorder modulates angiogenesis in the posterior eye segment was largely unknown. In this issue of EMBO Molecular Medicine, Andriessen et al () show that high‐fat diet‐induced obesity causes dysbiosis in the gut that drives retinal inflammation and pathological angiogenesis in a mouse model of laser‐induced choroidal neovascularization (CNV).

Brain endothelial cell-targeted gene therapy of neurovascular disorders.

Neurovascular disorders are difficult to treat due to the blood–brain barrier (BBB), which prevents delivery of most drugs from the blood into the brain. Gene therapy can potentially overcome this barrier, but classical vectors are neither efficient nor specific enough to provide long‐lasting treatment or avoid off‐target effects. In this issue of EMBO Molecular Medicine , Korbelin et al (2016) describe an engineered adeno‐associated virus (AAV) with exceptional tropism for the brain that restores a normal phenotype in a mouse model of incontinentia pigmenti (IP), a severe human genetic disorder of brain vasculature.

Journal Digest

Journal Digest

Successful correction of hemophilia by CRISPR/Cas9 genome editing invivo: delivery vector and immune responses arethe key to success.

Hemophilia B is a serious hemostasis disorder due to mutations of the factor IX gene in the X chromosome. Gene therapy has gained momentum in recent years as a therapeutic option for hemophilia B. In hemophilia, reconstitution with a mere 1–2% of the clotting factor improves the quality of life, while 5–20% suffices to ameliorate the bleeding disorder. A paper by Guan et al (2016) in this issue of EMBO Molecular Medicine reports on the direct CRISPRs/Cas9‐mediated correction in the liver of a hemophilia‐causing point mutation in FIX.

Amyloid-β in mitochondrial disease: mutation in a human metallopeptidase links amyloidotic neurodegeneration with mitochondrial processing.

There is increasing evidence that common molecular pathways in neurons are closely linked with mitochondrial function and that mitochondrial dysfunction is connected to various forms of neurodegenerative diseases. For instance, mitochondria are involved in amyloid‐β (Aβ) deposition in Alzheimer9s disease, although the exact molecular pathways remain largely unknown. Brunetti et al (2015) in this issue of EMBO Molecular Medicine provide a novel link between Aβ accumulation and mitochondria. A pathogenic mutation in a Norwegian family in the mitochondrial metallopeptidase PITRM1 is found to underlie a novel mitochondrial neurodegenerative phenotype associated with Aβ accumulation.

Vascular-targeted recombinant adeno-associated viral vectors for the treatment of rare diseases

ABSTRACTThere is a lack of treatment options for many rare genetic disorders. Gene therapy represents a promising and innovative approach to fill this gap. One of such rare disorders is incontinentia pigmenti caused by X-linked deletions or mutations in the Nemo gene. The disease affects the skin, teeth, and eyes and, most importantly, it leads to a severe vascular pathology of the central nervous system. The genetic treatment of vascular disorders such as incontinentia pigmenti critically depends on safe and efficient gene delivery. Thus, focus has been set on the development of suitable vector systems. In a recent issue of EMBO Molecular Medicine, we describe the development of a recombinant adeno-associated viral (AAV) vector with a unique tropism for the brain vascular endothelium (termed AAV-BR1) and, as a proof of principle that may be transferred to other vascular disorders, report on its therapeutic application in a mouse model of incontinentia pigmenti. Here, we discuss the implications of our fi...

Synaptic lipids in cortical function andpsychiatric disorders.

Psychiatric disorders, which include a variety of distinct infirmities, affect millions of people worldwide. Without intervention, the impact of these conditions is devastating, compromising the daily life of patients and their relatives. Although insights into the underlying cortical circuitry of psychiatric diseases have emerged over the years, our understanding of their pathophysiology, elucidation of pathophysiologic mechanisms and relevant advancements in clinical therapeutic strategies have been hampered by the complexity of these neural networks and the lack of reliable biomarkers in human subjects and animal models. In this issue of EMBO Molecular Medicine , Vogt and colleagues add significant new insights to the understanding of the etiology of psychiatric conditions by revealing novel contribution of synaptic lipids to altered circuit function and behavior in mice (Vogt et al , [2015][1]). [1]: #ref-14

Mutant Cullin causes cardiovascular compromise.

Mendelian hypertension is rare; however, Mendelian syndromes have taught us an amazing amount about mechanisms of distal sodium and chloride reabsorption, as well as how systemic hypertension might come about. In this issue of EMBO Molecular Medicine, Schumacher et al (2015) present a mouse model of the Cullin-3 (CUL3Δ403–459) mutation, which causes a form of pseudohypoaldosteronism type-2 (PHA-2). CUL3 is involved in ubiquitination. Surprising is the severity of the hypertension, which may be explained in part on the basis of CUL3 actions in vascular cells. The findings underscore the role of “cleanup” in the maintenance of normal physiology.