Andreyeva et al. generated a mouse model that uncovers how immune cells destroy the adrenal glands in Addison’s disease and identified IFN-γ as a promising target for future therapies. The cover image shows characteristic granuloma formation within the adrenal cortex. Immunofluorescence staining was performed for DAPI (blue) to visualize nuclei and CYP11A1 (red) to identify steroidogenic adrenocortical cells. Granulomatous lesions appear green because of the strong intrinsic autofluorescence of lipid-laden macrophages within the granulomas. Image credit: Arina Andreyeva and Ales Neuwirth.
The hypothesized cellular and molecular mechanisms underlying dystonia are broad and include mutations that perturb Ca2+ signaling, including those affecting voltage gated calcium channels (VGCC). In mice, pharmacological activation of neuronal L-type VGCCs induces dystonia in a dose dependent manner. Here we demonstrate that mice expressing a gain-of-function mutation in the L-type VGCC CaV1.2, associated with Timothy syndrome (TS), exhibit motor dysfunction consistent with dystonia. Although CaV1.2 is broadly expressed throughout peripheral tissues and across the brain, we establish that the dystonia-like behavior is driven by neuronal expression of the mutant calcium channel and observe an associated potential excitatory/inhibitory (E/I) imbalance. Because patients with TS have profound metabolic dysregulation, which is associated with some dystonias, we measured changes in circulating metabolites. The dystonia-like events are sensitive to perturbations in pyruvate metabolism, reminiscent of a subset of dystonias associated with pyruvate dysregulation. Our study provides insight into the potential convergence of previously established causes of dystonia, calcium signaling and metabolic homeostasis.
Patrick Towers, Hong-Gang Wang, Maiko Matsui, Geoffrey S. Pitt
Pneumocystis jirovecii pneumonia (PCP) remains a major cause of life-threatening respiratory failure in people with advanced HIV, yet the biological factors associated with mortality are incompletely understood. We performed integrated transcriptomic, proteomic, and metabolomic profiling of bronchoalveolar lavage fluid from 42 adults with HIV-associated PCP, relating molecular signatures to mortality. We found that fungal burden, measured by sputum immunofluorescence, Pneumocystis qPCR, and 1,3-β-D-glucan, did not differ between survivors and non-survivors or correlate with baseline gas exchange. Instead, non-survivors exhibited a bronchoalveolar immunometabolic failure signature characterised by marked depletion of immunoglobulins and complement, reduced pattern recognition receptors and fibroblast growth factor family proteins, and broad disruption of extracellular matrix organisation. Metabolomic profiling revealed enrichment of arginine-urea cycle and tricarboxylic acid pathways, with coordinated accumulation of arginine, citrulline, and TCA cycle intermediates consistent with nitrosative and mitochondrial stress. An integrated proteo-metabolomic score summarising this state was significantly higher in non-survivors and did not correlate with fungal burden or cytomegalovirus co-infection. In an immunodeficient precision-cut lung slice model, antigen-screened intravenous immunoglobulin restored macrophage-mediated Pneumocystis clearance, providing proof-of-concept for opsonic augmentation. Our findings indicate that mortality in HIV-PCP is defined by profound immunometabolic failure, highlighting humoral depletion and impaired alveolar repair as potential targets for host-directed adjunctive therapy.
Peter Rossi-Smith, Ayanda Trevor Mnguni, Dora Pungan, Robert J. Samuels, Vaishnavi R. Kumaran, Leena Syed, Trevor Ferris, Kamil Skirlo, Joseph N. Jarvis, Nelesh P. Govender, Graeme Meintjes, Sean Wasserman, Jay K. Kolls, Rachel P.J. Lai
BACKGROUND. Body weight and insulin resistance in women increase in midlife. It is not known whether this is driven by the menopause transition or solely by chronological aging. We aimed to determine the role of the menopause transition and menopause-related BMI changes in the development of insulin resistance in midlife women. METHODS. Mixed effects, linear spline modeling of longitudinal data in 1315 women, 42- to 52-years-old, pre- or early perimenopausal in 1995 to 1996 with up to 16 follow up visits by 2018. Homeostatic-model-assessed-insulin-resistance (HOMA-IR) was measured up to 12 times. Date of final menstrual period (FMP) was prospectively determined. RESULTS. HOMA-IR increased faster over a 4-year interval extending from 1.5 years prior to 2.5 years after the FMP, than in the years before or after it; p value for both slope changes < 0.0001. In the referent woman (White, age 52 years at FMP, non-smoker, body mass index [BMI] 25.6 kg/m2 at baseline, and not on sex hormone therapy or statins), the average annualized rate of HOMA-IR increase, adjusted for covariates including changes in BMI, was 1.2%, 4.3%, and 0.9% respectively, before, during, and after the 4-year transition. CONCLUSION. Consistent with an independent effect of the menopause transition, insulin resistance increased significantly faster during the transition (from 1.5 years before the to 2.5 years after the FMP) than in the years preceding or following the transition. Future studies need to investigate mechanisms underpinning this observed association and determine the impact of lifestyle on dampening menopause-associated increases in insulin resistance. FUNDING. National Institutes of Health.
Arun S. Karlamangla, Wei Juan Han, Preethi Srikanthan, Albert Shieh, Duncan Thomas, Barbara Sternfeld, Monique M. Hedderson, Gail A. Greendale
Chronic liver disease affects over a billion people worldwide. Despite diverse etiologies, a unifying feature of chronic liver disease is the liver’s impaired ability to regenerate during progression to cirrhosis, but no common molecular mechanism has been identified. Hepatocyte proliferation and liver regeneration depend on nucleoplasmic calcium (Ca2+) signals, and Ca2+ signals in hepatocytes depend on the type 2 inositol trisphosphate receptor (ITPR2) calcium release channel. Here, we found that ITPR2 was localized in part to the hepatocyte nucleus, and this localization depended on the presence of nucleoporin 62 (NUP62). Loss of either ITPR2 or NUP62 disrupted nuclear Ca2+ signaling, and impaired Ca2+ signals in the nucleus blunted nuclear entry of β-catenin. Remarkably, both ITPR2 and NUP62 are progressively lost from hepatocytes in patients with the four most common types of chronic liver disease. These findings identify a microdomain regulating Ca2+ signaling in the hepatocyte nucleus that becomes progressively disrupted as liver disease progresses. Preservation of this nuclear microdomain may be a novel approach to maintain liver regeneration and slow the progression to cirrhosis in chronic liver disease.
Jittima Weerachayaphorn, Mateus T. Guerra, Naotaka Kugiyama, Emma Kruglov, Dejian Zhao, Piyachat Chansela, Vitoon Saengsirisuwan, Marie E. Robert, Teruo Utsumi, Yasuko Iwakiri, Michael H. Nathanson
Persistent production of type I interferons (IFN-Is) is a hallmark of cutaneous lupus erythematosus (CLE). Ultraviolet (UV) light stimulates IFN-I response in the skin and exacerbates CLE. Here, we identify V-type immunoglobulin domain-containing suppressor of T cell activation (VISTA) as a negative regulator of both basal and UV-induced IFN-I response in the skin and show that VISTA limits skin photosensitivity in an IFN-I-dependent manner, in part through Stimulator of Interferon Genes (STING). Furthermore, we demonstrate a novel role for VISTA in keratinocytes both at steady state and in response to UV light. Conditional deletion of VISTA in epidermal keratinocytes results in a ~10-fold increase in basal skin IFN-I scores and a heightened UV-induced skin injury score, both of which are dependent on IFN-I signaling. VISTA-targeting monoclonal antibodies suppress the UV-induced IFN-I response in human keratinocytes and in mice expressing human VISTA in vivo, thereby reducing UV-induced skin injury scores. Together, these findings identify VISTA as a keratinocyte-intrinsic checkpoint that restrains STING-associated IFN-I response in the skin and suggest VISTA agonism as a therapeutic strategy to limit photosensitivity in CLE.
Zachary T. Peters, Lindsay K. Mendyka, J'Voughnn A. Blake, Himanshu B. Goswami, Angelique N. Cortez, Grace E. Crossland, Sicong Shan, Elizabeth C. Nowak, Myana Keusch, Mrinal K. Sarkar, Johann E. Gudjonsson, Christopher M. Burns, Dorothea T. Barton, Bruce R. Blazar, Tyler J. Curiel, Rodwell Mabaera, Victoria P. Werth, Andrea Kalus, Keith B. Elkon, Randolph J. Noelle, Sladjana Skopelja-Gardner