Authors: May-Simera HL, Wan Q, Jha BS, Hartford J, Khristov V, Dejene R, Chang J, Patnaik S, Lu Q, Banerjee P, Silver J, Insinna-Kettenhofen C, Patel D, Lotfi M, Malicdan M, Hotaling N, Maminishkis A, Sridharan R, Brooks B, Miyagishima K, Gunay-Aygun M, Pal R, Westlake C, Miller S, Sharma R, Bharti K
Journal: Cell Rep. 2018 Jan 2;22(1):189-205. doi: 10.1016/j.celrep.2017.12.038.
Primary cilia are sensory organelles that protrude from the cell membrane. Defects in the primary cilium cause ciliopathy disorders, with retinal degeneration as a prominent phenotype. Here, we demonstrate that the retinal pigment epithelium (RPE), essential for photoreceptor development and function, requires a functional primary cilium for complete maturation and that RPE maturation defects in ciliopathies precede photoreceptor degeneration. Pharmacologically enhanced ciliogenesis in wild-type induced pluripotent stem cells (iPSC)-RPE leads to fully mature and functional cells. In contrast, ciliopathy patient-derived iPSC-RPE and iPSC-RPE with a knockdown of ciliary-trafficking protein remain immature, with defective apical processes, reduced functionality, and reduced adult-specific gene expression. Proteins of the primary cilium regulate RPE maturation by simultaneously suppressing canonical WNT and activating PKCδ pathways. A similar cilium-dependent maturation pathway exists in lung epithelium. Our results provide insights into ciliopathy-induced retinal degeneration, demonstrate a developmental role for primary cilia in epithelial maturation, and provide a method to mature iPSC epithelial cells for clinical applications.
Authors: Huang Y, Mao K, Chen X, Sun MA, Kawabe T, Li W, Usher N, Zhu J, Urban JF Jr, Paul WE, Germain RN
Journal: Science. 2018 Jan 5;359(6371):114-119. doi: 10.1126/science.aam5809.
Innate lymphoid cells (ILCs) are innate counterparts of adaptive T lymphocytes, contributing to host defense, tissue repair, metabolic homeostasis, and inflammatory diseases. ILCs have been considered to be tissue-resident cells, but whether ILCs move between tissue sites during infection has been unclear. We show here that interleukin-25- or helminth-induced inflammatory ILC2s are circulating cells that arise from resting ILC2s residing in intestinal lamina propria. They migrate to diverse tissues based on sphingosine 1-phosphate (S1P)-mediated chemotaxis that promotes lymphatic entry, blood circulation, and accumulation in peripheral sites, including the lung, where they contribute to anti-helminth defense and tissue repair. This ILC2 expansion and migration is a behavioral parallel to the antigen-driven proliferation and migration of adaptive lymphocytes to effector sites and indicates that ILCs complement adaptive immunity by providing both local and distant tissue protection during infection.
Authors: Zheng H, Pomyen Y, Hernandez MO, Li C, Livak F, Tang W, Dang H, Greten TF, Davis JL, Zhao Y, Mehta M, Levin Y, Shetty J, Tran B, Budhu A, Wang XW
Journal: Hepatology. 2018 Jan 9. doi: 10.1002/hep.29778. [Epub ahead of print]
Intratumor molecular heterogeneity of hepatocellular carcinoma (HCC) is partly attributed to the presence of hepatic cancer stem cells (CSCs). Different CSC populations defined by various cell surface markers may contain different oncogenic drivers, posing a challenge in defining molecular-targeted therapeutics. We combined transcriptomic and functional analyses of HCC cells at the single cell level to assess the degree of CSC heterogeneity. We provide evidence that hepatic CSCs at the single-cell level are phenotypically, functionally and transcriptionally heterogeneous. We found that different CSC subpopulations contain distinct molecular signatures. Interestingly, distinct genes within different CSC subpopulations are independently associated with HCC prognosis, suggesting that a diverse hepatic CSC transcriptome affects intratumor heterogeneity and tumor progression.
CONCLUSION: Our work provides unique perspectives into the previously unappreciated diversity of CSC subpopulations, whose molecular heterogeneity further highlights their role in tumor heterogeneity, prognosis and hepatic CSC therapy.
Authors: White AM, Slater ME, Ng G, Hingson R, Breslow R
Journal: Alcohol Clin Exp Res. 2018 Feb;42(2):352-359. doi: 10.1111/acer.13559. Epub 2018 Jan 2.
BACKGROUND: Acute alcohol consumption and chronic alcohol consumption increase the burden placed on emergency departments (EDs) by contributing to injury and disease. Whether the prevalence of alcohol-related ED visits in the United States has changed in recent years is unknown. The purpose of this study was to examine trends in ED visits involving acute and chronic alcohol consumption in the United States by age and sex between 2006 and 2014.
METHODS: Data from the Nationwide Emergency Department Sample (NEDS), the largest all-payer ED database in the United States involving 945 hospitals in 33 states and Washington, DC, were analyzed to assess changes in prevalence and rates of ED visits involving acute and chronic alcohol consumption by age and sex over time among persons aged ≥12 between 2006 and 2014.
RESULTS: Between 2006 and 2014, the number of ED visits involving alcohol consumption increased 61.6%, from 3,080,214 to 4,976,136. The rate increased 47% from 1,223 to 1,802 per 100,000 population and the total cost of such visits increased 272% from $4.1 billion to $15.3 billion. The number of acute alcohol-related ED visits increased 51.5% from 1,801,006 to 2,728,313 and the rate increased 40% from 720.9 to 1,009.6 per 100,000 population. The number chronic alcohol-related visits increased 75.7% from 1,279,208 to 2,247,823 and the rate increased 57.9% from 502.2 to 792.9 per 100,000. The annual percentage change in rates of all alcohol-related ED visits was larger for females than for males (5.3% vs. 4.0%). Other drug involvement increased the likelihood of admission for inpatient treatment.
CONCLUSIONS: Alcohol consumption contributed to an increasing number of ED visits in the United States between 2006 and 2014, especially among females. Increased utilization of evidence-based interventions is needed.
Authors: Zhu G, Lynn GM, Jacobson O, Chen K, Liu Y, Zhang H, Ma Y, Zhang F, Tian R, Ni Q, Cheng S, Wang Z, Lu N, Yung BC, Wang Z, Lang L, Fu X, Jin A, Weiss ID, Vishwasrao H, Niu G, Shroff H, Klinman DM, Seder RA, Chen X.
Journal: Nat Commun. 2017 Dec 5;8(1):1954. doi: 10.1038/s41467-017-02191-y.
Subunit vaccines have been investigated in over 1000 clinical trials of cancer immunotherapy, but have shown limited efficacy. Nanovaccines may improve efficacy but have rarely been clinically translated. By conjugating molecular vaccines with Evans blue (EB) into albumin-binding vaccines (AlbiVax), here we develop clinically promising albumin/AlbiVax nanocomplexes that self-assemble in vivo from AlbiVax and endogenous albumin for efficient vaccine delivery and potent cancer immunotherapy. PET pharmacoimaging, super-resolution microscopies, and flow cytometry reveal almost 100-fold more efficient co-delivery of CpG and antigens (Ags) to lymph nodes (LNs) by albumin/AlbiVax than benchmark incomplete Freund's adjuvant (IFA). Albumin/AlbiVax elicits ~10 times more frequent peripheral antigen-specific CD8+cytotoxic T lymphocytes with immune memory than IFA-emulsifying vaccines. Albumin/AlbiVax specifically inhibits progression of established primary or metastatic EG7.OVA, B16F10, and MC38 tumors; combination with anti-PD-1 and/or Abraxane further potentiates immunotherapy and eradicates most MC38 tumors. Albumin/AlbiVax nanocomplexes are thus a robust platform for combination cancer immunotherapy.
Authors: Kines RC, Varsavsky I, Choudhary S, Bhattacharya D, Spring S, McLaughlin R, Kang SJ, Grossniklaus HE, Vavvas D, Monks S, MacDougall JR, de Los Pinos E, Schiller JT.
Journal: Mol Cancer Ther. 2017 Dec 14. doi: 10.1158/1535-7163.MCT-17-0953. [Epub ahead of print]
The work outlined herein describes AU-011, a novel recombinant papillomavirus-like particle (VLP) drug conjugate and its initial evaluation as a potential treatment for primary uveal melanoma. The VLP is conjugated with a phthalocyanine photosensitizer, IRDye 700DX, that exerts its cytotoxic effect through photoactivation with a near-infrared laser. We assessed the anticancer properties of AU-011 in vitro utilizing a panel of human cancer cell lines and in vivo using murine subcutaneous and rabbit orthotopic xenograft models of uveal melanoma. The specificity of VLP binding (tumor targeting), mediated through cell surface heparan sulfate proteoglycans (HSPG), was assessed using HSPG-deficient cells and by inclusion of heparin in in vitro studies. Our results provide evidence of potent and selective anticancer activity, both in vitro and in vivo AU-011 activity was blocked by inhibiting its association with HSPG using heparin and using cells lacking surface HSPG, indicating that the tumor tropism of the VLP was not affected by dye conjugation and cell association is critical for AU-011-mediated cytotoxicity. Using the uveal melanoma xenograft models, we observed tumor uptake following intravenous (murine) and intravitreal (rabbit) administration and, after photoactivation, potent dose-dependent tumor responses. Furthermore, in the rabbit orthotopic model, which closely models uveal melanoma as it presents in the clinic, tumor treatment spared the retina and adjacent ocular structures. Our results support further clinical development of this novel therapeutic modality that might transform visual outcomes and provide a targeted therapy for the early-stage treatment of patients with this rare and life-threatening disease.
Authors: Szczot M, Pogorzala LA, Solinski HJ, Young L, Yee P, Le Pichon CE, Chesler AT, Hoon MA.
Journal: Cell Rep. 2017 Dec 5;21(10):2760-2771. doi: 10.1016/j.celrep.2017.11.035.
Piezo2 is a mechanically activated ion channel required for touch discrimination, vibration detection, and proprioception. Here, we discovered that Piezo2 is extensively spliced, producing different Piezo2 isoforms with distinct properties. Sensory neurons from both mice and humans express a large repertoire of Piezo2 variants, whereas non-neuronal tissues express predominantly a single isoform. Notably, even within sensory ganglia, we demonstrate the splicing of Piezo2 to be cell type specific. Biophysical characterization revealed substantial differences in ion permeability, sensitivity to calcium modulation, and inactivation kinetics among Piezo2 splice variants. Together, our results describe, at the molecular level, a potential mechanism by which transduction is tuned, permitting the detection of a variety of mechanosensory stimuli.
Authors: Kim K, Pedersen LC, Kirby TW, DeRose EF, London RE
Journal: Nucleic Acids Res. 2017 Dec 1;45(21):12374-12387. doi: 10.1093/nar/gkx941.
Aprataxin and PNKP-like factor (APLF) is a DNA repair factor containing a forkhead-associated (FHA) domain that supports binding to the phosphorylated FHA domain binding motifs (FBMs) in XRCC1 and XRCC4. We have characterized the interaction of the APLF FHA domain with phosphorylated XRCC1 peptides using crystallographic, NMR, and fluorescence polarization studies. The FHA-FBM interactions exhibit significant pH dependence in the physiological range as a consequence of the atypically high pK values of the phosphoserine and phosphothreonine residues and the preference for a dianionic charge state of FHA-bound pThr. These high pK values are characteristic of the polyanionic peptides typically produced by CK2 phosphorylation. Binding affinity is greatly enhanced by residues flanking the crystallographically-defined recognition motif, apparently as a consequence of non-specific electrostatic interactions, supporting the role of XRCC1 in nuclear cotransport of APLF. The FHA domain-dependent interaction of XRCC1 with APLF joins repair scaffolds that support single-strand break repair and non-homologous end joining (NHEJ). It is suggested that for double-strand DNA breaks that have initially formed a complex with PARP1 and its binding partner XRCC1, this interaction acts as a backup attempt to intercept the more error-prone alternative NHEJ repair pathway by recruiting Ku and associated NHEJ factors.
Authors: Sung EJ, Ryuda M, Matsumoto H, Uryu O, Ochiai M, Cook ME, Yi NY, Wang H, Putney JW, Bird GS, Shears SB, Hayakawa Y
Journal: Proc Natl Acad Sci U S A. 2017 Dec 26;114(52):13786-13791. doi: 10.1073/pnas.1712453115. Epub 2017 Dec 11.
A systems-level understanding of cytokine-mediated, intertissue signaling is one of the keys to developing fundamental insight into the links between aging and inflammation. Here, we employed Drosophila, a routine model for analysis of cytokine signaling pathways in higher animals, to identify a receptor for the growth-blocking peptide (GBP) cytokine. Having previously established that the phospholipase C/Ca2+ signaling pathway mediates innate immune responses to GBP, we conducted a dsRNA library screen for genes that modulate Ca2+ mobilization in Drosophila S3 cells. A hitherto orphan G protein coupled receptor, Methuselah-like receptor-10 (Mthl10), was a significant hit. Secondary screening confirmed specific binding of fluorophore-tagged GBP to both S3 cells and recombinant Mthl10-ectodomain. We discovered that the metabolic, immunological, and stress-protecting roles of GBP all interconnect through Mthl10. This we established by Mthl10 knockdown in three fly model systems: in hemocyte-like Drosophila S2 cells, Mthl10 knockdown decreases GBP-mediated innate immune responses; in larvae, Mthl10 knockdown decreases expression of antimicrobial peptides in response to low temperature; in adult flies, Mthl10 knockdown increases mortality rate following infection with Micrococcus luteus and reduces GBP-mediated secretion of insulin-like peptides. We further report that organismal fitness pays a price for the utilization of Mthl10 to integrate all of these various homeostatic attributes of GBP: We found that elevated GBP expression reduces lifespan. Conversely, Mthl10 knockdown extended lifespan. We describe how our data offer opportunities for further molecular interrogation of yin and yang between homeostasis and longevity.
Authors: Al-Ramahi I, Panapakkam Giridharan SS, Chen YC, Patnaik S, Safren N, Hasegawa J, de Haro M, Wagner Gee AK, Titus SA, Jeong H, Clarke J, Krainc D, Zheng W, Irvine RF, Barmada S, Ferrer M, Southall N, Weisman LS, Botas J, Marugan JJ.
Journal: Elife. 2017 Dec 26;6. pii: e29123. doi: 10.7554/eLife.29123.
The discovery of the causative gene for Huntington's disease (HD) has promoted numerous efforts to uncover cellular pathways that lower levels of mutant huntingtin protein (mHtt) and potentially forestall the appearance of HD-related neurological defects. Using a cell-based model of pathogenic huntingtin expression, we identified a class of compounds that protect cells through selective inhibition of a lipid kinase, PIP4Kγ. Pharmacological inhibition or knock-down of PIP4Kγ modulates the equilibrium between phosphatidylinositide (PI) species within the cell and increases basal autophagy, reducing the total amount of mHtt protein in human patient fibroblasts and aggregates in neurons. In two Drosophila models of Huntington's disease, genetic knockdown of PIP4K ameliorated neuronal dysfunction and degeneration as assessed using motor performance and retinal degeneration assays respectively. Together, these results suggest that PIP4Kγ is a druggable target whose inhibition enhances productive autophagy and mHtt proteolysis, revealing a useful pharmacological point of intervention for the treatment of Huntington's disease, and potentially for other neurodegenerative disorders.