Genetic variants predisposing to increased risk of kidney stone disease

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Abstract

BACKGROUND. Kidney stone disease (KSD) affects ~10% of adults, is heritable, and associated with mineral metabolic abnormalities. METHODS. Genetic variants and pathways increasing KSD risk via calcium and phosphate homeostasis were ascertained using genome-wide association analyses, region-specific Mendelian randomization (MR), and genetic colocalization. Utility of pathway modulation was estimated via drug-target MR, and effects of variants on calcium-sensing receptor (CaSR)-signaling characterized. RESULTS. Seventy-nine independent KSD-associated genetic signals at 71 loci were identified. MR identified three loci affecting KSD risk via increased serum calcium or decreased serum phosphate concentrations (odds ratios for genomic regions=4.30, 11.42, and 13.83 per 1 standard deviation alteration; p<5.6x10-10). Colocalization analyses defined putative, non-coding KSD-causing variants estimated to account for 11-19% of KSD cases in proximity to diacylglycerol kinase delta (DGKD), a CaSR-signalling partner; solute carrier family 34 member 1 (SLC34A1), a renal sodium-phosphate transporter; and cytochrome P450 family 24 subfamily A member 1 (CYP24A1), which degrades 1,25-dihydroxyvitamin D. Drug- target MR indicated that reducing serum calcium by 0.08mmol/L via CASR, DGKD, or CYP24A1, or increasing serum phosphate by 0.16mmol/L via SLC34A1 may reduce KSD relative risk by up to 90%. Furthermore, reduced DGKδ expression and KSD-associated DGKD missense variants impaired CaSR-signal transduction in vitro, which was ameliorated by cinacalcet, a positive CaSR-allosteric modulator. CONCLUSION. DGKD-, SLC34A1-, and CYP24A1-associated variants linked to reduced CaSR-signal transduction, increased urinary phosphate excretion, and impaired 1,25-dihydroxyvitamin D inactivation, respectively, are common causes of KSD. Genotyping patients with KSD may facilitate personalised KSD-risk stratification and targeted pharmacomodulation of associated pathways to prevent KSD.

Authors

Catherine E. Lovegrove, Michelle Goldsworthy, Jeremy Haley, Diane Smelser, Caroline Gorvin, Fadil M. Hannan, Anubha Mahajan, Mohnish Suri, Omid Sadeghi-Alavijeh, Shabbir H. Moochhala, Daniel P. Gale, David Carey, Michael V. Holmes, Dominic Furniss, Rajesh V. Thakker, Sarah A. Howles

Activation of intestinal endogenous retroviruses by alcohol exacerbates liver disease

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Abstract

Alcohol-associated liver disease represents a significant global health challenge, with gut microbial dysbiosis and bacterial translocation playing a critical role in its pathogenesis. Patients with alcohol-associated hepatitis had increased fecal abundance of mammalian viruses including retroviruses. This study investigated the role of endogenous retroviruses (ERVs) in the development of alcohol-associated liver disease. Transcriptomic analysis of duodenal and liver biopsies revealed increased expression of several human ERVs, including HERV-K and HERV-H, in patients with alcohol-associated liver disease compared with controls. Chronic-binge ethanol feeding markedly induced ERV abundance in intestinal epithelial cells, but not the liver of mice. Ethanol increased ERV expression and activated the Z-DNA binding protein 1 (Zbp1)–mixed lineage kinase domain-like pseudokinase (Mlkl) signaling pathways to induce necroptosis in intestinal epithelial cells. Antiretroviral treatment reduced ethanol-induced intestinal ERV expression, stabilized the gut barrier, and decreased liver disease in microbiota-humanized mice. Furthermore, mice with an intestine-specific deletion of Zbp1 were protected against bacterial translocation and ethanol-induced steatohepatitis. These findings indicate that ethanol exploits this pathway by inducing ERVs and promoting innate immune responses, which results in the death of intestinal epithelial cells, gut barrier dysfunction and liver disease. Targeting the ERV-Zbp1 pathway may offer new therapies for patients with alcohol-associated liver disease.

Authors

Noemí Cabré, Marcos F. Fondevila, Wenchao Wei, Tomoo Yamazaki, Fernanda Raya Tonetti, Alvaro Eguileor, Ricard Garcia-Carbonell, Abraham S. Meijnikman, Yukiko Miyamoto, Susan Mayo, Yanhan Wang, Xinlian Zhang, Thorsten Trimbuch, Seija Lehnardt, Lars Eckmann, Derrick E. Fouts, Cristina Llorente, Hidekazu Tsukamoto, Peter Stärkel, Bernd Schnabl

LAG3 regulates antibody responses in a murine model of kidney transplantation

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Abstract

Lymphocyte activation gene-3 (LAG3) is a coinhibitory receptor expressed by various immune cells. While immunomodulatory potential of LAG3 is being explored in cancer and autoimmunity, there is no information on its role following organ transplantation. Our study investigated the functions of LAG3 in a mouse model of renal allograft rejection. LAG3-/- recipients rapidly reject MHC-mismatched renal allografts that are spontaneously accepted by WT recipients, with graft histology characteristic of antibody mediated rejection (ABMR). Depletion of recipient B cells but not CD8+ T cells significantly extended kidney allograft survival in LAG3-/- recipients. Treatment of WT recipients with an antagonistic LAG3 antibody enhanced anti-donor immune responses and induced kidney damage associated with chronic rejection. The studies of conditional LAG3-/- recipients and mixed bone marrow chimeras demonstrated that LAG3 expression on either T or B cells is sufficient to regulate anti-donor humoral immunity but not to induce acute allograft rejection. The numbers and proinflammatory functions of graft-infiltrating NK cells were markedly increased in LAG3-/- recipients suggesting that LAG3 also regulates the effector stage of ABMR. These results are the first to identify LAG3 as a regulator of immune responses to kidney allografts and a potential therapeutic target for ABMR prevention and treatment.

Authors

Michael Nicosia, Ran Fan, Juyeun Lee, Gabriella L. All, Victoria Gorbacheva, José Ignacio Valenzuela, Yosuke Yamamoto, Ashley Beavers, Nina Dvorina, William M. Baldwin III, Eduardo Chuluyan, Motoo Araki, Brian T. Gaudette, Robert L. Fairchild, Booki Min, Anna Valujskikh

The gut microbiome controls reactive astrocytosis during Aβ amyloidosis via propionate-mediated regulation of IL-17

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Abstract

Accumulating evidence implicates the gut microbiome (GMB) in the pathogenesis and progression of Alzheimer’s disease (AD). We recently showed that the GMB regulates reactive astrocytosis and Aβ plaque accumulation in male APPPS1-21 AD model mice. Yet, the mechanism(s) by which GMB perturbation alters reactive astrocytosis in a manner that reduces Aβ deposition remain unknown. Here, we performed metabolomics on plasma from mice treated with antibiotics (abx) and identified a significant increase in plasma propionate, a gut-derived short chain fatty acid, only in male mice. Administration of sodium propionate reduced reactive astrocytosis and Aβ plaques in APPPS1-21 mice, phenocopying the abx-induced phenotype. Astrocyte-specific RNA sequencing on abx and propionate treated mice showed reduced expression of pro-inflammatory and increased expression of neurotrophic genes. Next, we performed flow cytometry experiments where we found abx and propionate decreased peripheral RAR-related orphan receptor-γ (Rorγt)+ CD4+ (Th17) cells and IL-17 secretion, which positively correlated with reactive astrocytosis. Lastly, using an IL-17 monoclonal antibody to deplete IL-17, we found that propionate reduces reactive astrocytosis and Aβ plaques in an IL-17-dependent manner. Together, these results suggest that gut-derived propionate regulates reactive astrocytosis and Aβ amyloidosis by decreasing peripheral Th17 cells and IL-17 release. Thus, propionate treatment or strategies boosting propionate production may represent novel therapeutic strategies for AD.

Authors

Sidhanth Chandra, Jelena Popovic, Naveen K. Singhal, Elyse A. Watkins, Hemraj B. Dodiya, Ian Q. Weigle, Miranda A. Salvo, Abhirami Ramakrishnan, Zhangying Chen, James T. Watson, Aashutosh Shetti, Natalie Piehl, Xiaoqiong Zhang, Leah K. Cuddy, Katherine R. Sadleir, Steven J. Schwulst, Murali Prakriya, David Gate, Sangram S. Sisodia, Robert Vassar

SARM1 loss protects retinal ganglion cells in a mouse model of Autosomal Dominant Optic Atrophy

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Abstract

Autosomal Dominant Optic Atrophy (ADOA), the most prevalent hereditary optic neuropathy, leads to retinal ganglion cell (RGC) degeneration and vision loss. ADOA is primarily caused by mutations in the OPA1 gene, which encodes a conserved GTPase important for mitochondrial inner membrane dynamics. To date, the disease mechanism remains unclear, and no therapies are available. We generated a mouse model carrying the pathogenic Opa1R290Q/+ allele that recapitulated key features of human ADOA, including mitochondrial defects, age-related RGC loss, optic nerve degeneration, and reduced RGC functions. We identified SARM1, a neurodegeneration switch, as a key driver of RGC degeneration in these mice. Sarm1 knockout nearly completely suppressed all the degeneration phenotypes without reversing mitochondrial fragmentation. Additionally, we showed that a portion of SARM1 localized within the mitochondrial intermembrane space (IMS). These findings indicated that SARM1 was activated downstream of mitochondrial dysfunction in ADOA, highlighting it as a promising therapeutic target.

Authors

Chen Ding, Papa S. Ndiaye, Sydney R. Campbell, Michelle Y. Fry, Jincheng Gong, Sophia R. Wienbar, Whitney Gibbs, Philippe Morquette, Luke H. Chao, Michael Tri H. Do, Thomas Schwarz

The tumor suppressor HNRNPK induces p53-dependent nucleolar stress to drive ribosomopathies

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Abstract

The nucleolus is a membraneless organelle and an excellent stress sensor. Any changes in its architecture or composition lead to nucleolar stress, resulting in cell cycle arrest and interruption of ribosomal activity, critical factors in aging and cancer. In this study, we identified and described the pivotal role of the RNA-binding protein (RBP) HNRNPK in ribosome and nucleolar dynamics. We developed an in vitro model of endogenous HNRNPK overexpression and an in vivo mouse model of ubiquitous HNRNPK overexpression. These models showed disruptions in translation and caused alterations in the nucleolar structure, resulting in p53-dependent nucleolar stress, cell cycle arrest, senescence, and bone marrow failure phenotype, similar to what is observed in patients with ribosomopathies. Together, our findings identify HNRNPK as a master regulator of ribosome biogenesis (RiBi) and nucleolar homeostasis through p53, providing a new perspective on the orchestration of nucleolar integrity, ribosome function and cellular senescence.

Authors

Pedro Aguilar-Garrido, María Velasco-Estévez, Miguel Ángel Navarro-Aguadero, Alvaro Otero-Sobrino, Marta Ibañez-Navarro, Miguel Ángel Marugal, María Hernández-Sánchez, Prerna Malaney, Ashley Rodriguez, Oscar Benitez, Xiaorui Zhang, Marisa J.L. Aitken, Alejandra Ortiz-Ruiz, Diego Megias, Manuel Pérez-Martínez, Gadea Mata, Jesús Gomez, Miguel Lafarga, Orlando Dominguez, Osvaldo Graña-Castro, Eduardo Caleiras, Pilar Ximenez-Embun, Marta Isasa, Paloma J. de Andrés, Sandra Rodriguez-Perales, Raul Torres-Ruiz, Enrique Revilla, Rosa María García-Martín, Daniel Azorín, Josune Zubicaray, Julian Sevilla, Oleksandra Sirozh, Vanesa Lafarga, Joaquín Martinez-Lopez, Sean M. Post, Miguel Gallardo

Thrombospondin-1 inhibits alternative complement pathway activation in antineutrophil cytoplasmic antibody-associated vasculitis

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Abstract

Complement activation is a relevant driver in the pathomechanisms of vasculitis. The involved proteins in the interaction between endothelia, complement and platelets in these conditions are only partially understood. Thrombospondin-1 (TSP-1), found in platelet α-granules and released from activated endothelial cells, interacts with factor H (FH) and von Willebrand factor (vWF). However, direct regulatory interaction with the complement cascade has not yet been described. We could show that TSP-1 is a potent, FH-independent inhibitor of the alternative complement pathway. TSP-1 binds to complement proteins, inhibits cleavage of C3 and C5 and the formation of the membrane attack complex. Complement-regulatory function is validated in blood samples from patients with primary complement defects. Physiological relevance of TSP-1 is demonstrated in ANCA-associated vasculitis (AAV) patients by significantly enhanced TSP-1 staining in glomerular lesions and increased complement activity and NETosis following TSP-1 deficiency in an in vitro and in vivo model of AAV. The newly described complement-inhibiting function of TSP-1 represents an important mechanism in the interaction of endothelia and complement. In particular, the interplay between released TSP-1 and the complement system locally, especially on surfaces, influences the balance between complement activation and inhibition and may be relevant in various vascular diseases.

Authors

Swagata Konwar, Sophie Schroda, Manuel Rogg, Jessika Kleindienst, Eva L. Decker, Martin Pohl, Barbara Zieger, Jens Peter Panse, Hong Wang, Robert Grosse, Christoph Schell, Sabine Vidal, Xiaobo Liu, Christian Gorzelanny, Todor Tschongov, Karsten Häffner

NK cell activation and CD4 T cell α4β7 expression are associated with susceptibility to HIV-1

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Abstract

We leveraged specimens from the RV217 prospective study that enrolled participants at high risk of HIV-1 acquisition to investigate how NK, conventional T cells, and unconventional T cells influence HIV-1 acquisition. We observed low levels of α4β7 expression on memory CD4 T cells and iNKT cells, two cell types highly susceptible to HIV-1 infection, in highly exposed seronegative (HESN) compared to highly exposed seroconverter (HESC) participants. NK cells from HESN had higher levels of α4β7 compared to HESC, presented a quiescent phenotype, and had a higher capacity to respond to opsonized target cells. We also measured translocated microbial products in plasma and found differences in phylum distribution between HESN and HESC that were associated with the immune phenotypes impacting the risk of HIV-1 acquisition. Finally, a logistic regression model combining features of NK cells activation, α4β7 expression on memory CD4 T cells, and Tbet expression by iNKT cells achieved the highest accuracy in identifying HESN and HESC participants. This immune signature comprised of increased α4β7 on cells susceptible to HIV infection combined with higher NK cells activation and lower gut homing potential could impact the efficacy of HIV-1 prevention strategies such as vaccines.

Authors

Kawthar Machmach, Kombo F. N'guessan, Rohit Farmer, Sucheta Godbole, Dohoon Kim, Lauren McCormick, Noemia S. Lima, Amy R. Henry, Farida Laboune, Isabella Swafford, Sydney K. Mika, Bonnie M. Slike, Jeffrey R. Currier, Leigh Anne Eller, Julie A. Ake, Sandhya Vasan, Merlin L. Robb, Shelly J. Krebs, Daniel C. Douek, Dominic Paquin-Proulx

PPIL2 is a target of the JAK2/STAT5 pathway and promotes myeloproliferation via p53-mediated degradation

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Abstract

The activated JAK2/STAT pathway is characteristic of myeloproliferative neoplasms (MPNs). Pleckstrin-2 (PLEK2) signalosome is downstream of the JAK2/STAT5 pathway and plays an important role in MPN development. The detailed molecular composition of this signalosome is unclear. Here, we revealed peptidylprolyl isomerase-like 2 (PPIL2) as a critical component of the complex in regulating human and murine erythropoiesis. PPIL2 was a direct target of STAT5 and was upregulated in MPN patients and a Jak2V617F MPN mouse model. Mechanistically, PPIL2 interacted with and catalyzed p53 polyubiquitination and proteasome-mediated degradation to promote cell growth. Ppil2 deficiency, or inhibition by cyclosporin A, led to a marked upregulation of p53 in vivo and ameliorated myeloproliferative phenotypes in Jak2V617F mice. Cyclosporin A also markedly reduced JAK2 mutated erythroid and myeloid proliferation in an induced pluripotent stem cell-derived human bone marrow organoid model. Our findings revealed PPIL2 as a critical component of the PLEK2 signalosome in driving MPN pathogenesis through negatively regulating p53, thus providing a target and an opportunity for drug repurposing by using cyclosporin A to treat MPNs.

Authors

Pan Wang, Xu Han, Kehan Ren, Ermin Li, Honghao Bi, Inci Aydemir, Madina Sukhanova, Yijie Liu, Jing Yang, Peng Ji

GluN2B suppression restores phenylalanine-induced neuroplasticity and cognition impairments in a mouse model of phenylketonuria

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Abstract

Phenylketonuria (PKU), an inborn error of phenylalanine (Phe) metabolism, is a common cause of intellectual disability. However, the mechanisms by which elevated phenylalanine (Phe) levels cause cognitive impairment remain unclear. Here, we show that submillimolar Phe perturbs synaptic plasticity through the hyperactivation of GluN2B-containing NMDARs. PahEnu2 PKU model mice exhibited submillimolar and supramillimolar concentrations of Phe in the cerebrospinal fluid (CSF) and serum, respectively. L-Phe produced concentration-dependent bidirectional effects on NMDA-induced currents, without affecting synaptic NMDARs in hippocampal CA1 neurons. L-Phe-induced hyperactivation of extrasynaptic GluN2B resulted in activity-dependent downregulation of AMPARs during burst or sustained synaptic activity. Administration of L-Phe in mice decreased neural activity and impaired memory, which were blocked by pretreatment with GluN2B inhibitors. Furthermore, pharmacological and virus-mediated suppression of GluN2B reversed the impaired learning in PahEnu2 mice. Collectively, these results suggest that the concentration of Phe in the CSF of patients with PKU perturbs extrasynaptic NMDARs and synaptic plasticity, and that suppression of GluN2B may have the potential to improve cognitive function in patients with PKU.

Authors

Woo Seok Song, Young Sook Kim, Young-Soo Bae, Sang Ho Yoon, Jae Min Lim, Myoung-Hwan Kim