The iron-regulatory hormone hepcidin is transcriptionally up-regulated by gluconeogenic signals. Recent evidence suggeststhat increases in circulating hepcidin may decrease dietary iron absorption following prolonged exercise, however evidence is limited on whether gluconeogenic signals contribute to post-exercise increases in hepcidin. Mice with genetic knockout of regulated in development and DNA response-1 (REDD1) display greater glycogen depletion following exercise, possibly indicating greater gluconeogenesis. The objective of the present study was to determine liver hepcidin, markers of gluconeogenesis and iron metabolism in REDD1 knockout and wild-type mice following prolonged exercise. Twelve-week-old male REDD1 knockout and wild-type mice were randomised to rest or 60 min treadmill running with 1, 3 or 6 h recovery (n = 5-8/genotype/group). Liver gene expression of hepcidin (Hamp) and gluconeogenic enzymes (Ppargc1a, Creb3l3, Pck1, Pygl) were determined by qRT-PCR. Effects of genotype, exercise and their interaction were assessed by two-way ANOVAs with Tukey\'s post-hoc tests, and Pearson correlations were used to assess the relationships between Hamp and study outcomes. Liver Hamp increased 1- and 4-fold at 3 and 6 h post-exercise, compared to rest (P-adjusted < 0⋅009 for all), and was 50% greater in REDD1 knockout compared to wild-type mice (P = 0⋅0015). Liver Ppargc1a, Creb3l3 and Pck1 increased with treadmill running (P < 0⋅0001 for all), and liver Ppargc1a, Pck1 and Pygl were greater with REDD1 deletion (P < 0⋅02 for all). Liver Hamp was positively correlated with liver Creb3l3 (R = 0⋅62, P < 0⋅0001) and Pck1 (R = 0⋅44, P = 0⋅0014). In conclusion, REDD1 deletion and prolonged treadmill running increased liver Hamp and gluconeogenic regulators of Hamp, suggesting gluconeogenic signalling of hepcidin with prolonged exercise.

UNASSIGNED: Acetaminophen (APAP)-induced acute liver injury (AILI) is a leading cause of acute liver failure (ALF). N-acetylcysteine (NAC) is only effective within 24 h after APAP intoxication, raising an urgent need for alternative approaches to treat this disease. This study aimed to test whether cathelicidin (Camp), which is a protective factor in chronic liver diseases, protects mice against APAP-induced liver injury and ALF.
UNASSIGNED: A clinically relevant AILI model and an APAP-induced ALF model were generated in mice. Genetic and pharmacological approaches were used to interfere with the levels of cathelicidin in vivo.
UNASSIGNED: An increase in hepatic pro-CRAMP/CRAMP (the precursor and mature forms of mouse cathelicidin) was observed in APAP-intoxicated mice. Upregulated cathelicidin was derived from liver-infiltrating neutrophils. Compared with wild-type littermates, Camp knockout had no effect on hepatic injury but dampened hepatic repair in AILI and reduced survival in APAP-induced ALF. CRAMP administration reversed impaired liver recovery observed in APAP-challenged Camp knockout mice. Delayed CRAMP, CRAMP(1-39) (the extended form of CRAMP), or LL-37 (the mature form of human cathelicidin) treatment exhibited a therapeutic benefit for AILI. Co-treatment of cathelicidin and NAC in AILI displayed a stronger hepatoprotective effect than NAC alone. A similar additive effect of CRAMP(1-39)/LL-37 and NAC was observed in APAP-induced ALF. The pro-reparative role of cathelicidin in the APAP-damaged liver was attributed to an accelerated resolution of inflammation at the onset of liver repair, possibly through enhanced neutrophil phagocytosis of necrotic cell debris in an autocrine manner.
UNASSIGNED: Cathelicidin reduces APAP-induced liver injury and ALF in mice by promoting liver recovery via facilitating inflammation resolution, suggesting a therapeutic potential for late-presenting patients with AILI with or without ALF.
UNASSIGNED: Acetaminophen-induced acute liver injury is a leading cause of acute liver failure. The efficacy of N-acetylcysteine, the only clinically approved drug against acetaminophen-induced acute liver injury, is significantly reduced for late-presenting patients. We found that cathelicidin exhibits a great therapeutic potential in mice with acetaminophen-induced liver injury or acute liver failure, which makes up for the limitation of N-acetylcysteine therapy by specifically promoting liver repair after acetaminophen intoxication. The pro-reparative role of cathelicidin, as a key effector molecule of neutrophils, in the APAP-injured liver is attributed to an accelerated resolution of inflammation at the onset of liver repair, possibly through enhanced phagocytic function of neutrophils in an autocrine manner.

Diabetes mellitus (DM) is a main risk factor for diastolic dysfunction (DD) and heart failure with preserved ejection fraction. High-fat diet (HFD) mice presented with diabetes mellitus, DD, higher cardiac interleukin (IL)-1β levels, and proinflammatory cardiac macrophage accumulation. DD was significantly ameliorated by suppressing IL-1β signaling or depleting macrophages. Mice with macrophages unable to adopt a proinflammatory phenotype were low in cardiac IL-1β levels and were resistant to HFD-induced DD. IL-1β enhanced mitochondrial reactive oxygen species (mitoROS) in cardiomyocytes, and scavenging mitoROS improved HFD-induced DD. In conclusion, macrophage-mediated inflammation contributed to HFD-associated DD through IL-1β and mitoROS production.

UNASSIGNED: The immune checkpoint receptor lymphocyte-activation gene 3 (LAG3) is a new target for immune checkpoint blockade (ICB), but the effects of LAG3 on atherosclerosis are not known.
UNASSIGNED: The aim of the study was to evaluate the role of LAG3 on plaque inflammation using murine hypercholesterolemic models of atherosclerosis.
UNASSIGNED: To study the role of LAG3 in atherosclerosis, we investigated both bone marrow chimeras lacking LAG3 in hematopoietic cells as well as global Lag3 -/- knockout mice. Effects of anti-LAG3 monoclonal antibody monotherapy and combination therapy with anti-programmed cell death protein 1 (PD-1) were tested in hypercholesterolemic low-density lipoprotein receptor knockout (Ldlr -/- ) mice and evaluated by histology and flow cytometry.
UNASSIGNED: LAG3-deficiency or treatment with blocking anti-LAG3 monoclonal antibodies led to increased levels of both interferon gamma-producing T helper 1 cells and effector/memory T cells, balanced by increased levels of regulatory T cells. Plaque size was affected by neither LAG3 deficiency nor LAG3 blockade, although density of T cells in plaques was 2-fold increased by loss of LAG3. Combination therapy of anti-PD-1 and anti-LAG3 had an additive effect on T cell activation and cytokine production and promoted plaque infiltration of T cells.
UNASSIGNED: Loss of LAG3 function promoted T cell activation and accumulation in plaques while not affecting plaque burden. Our report supports further clinical studies investigating cardiovascular risk in patients treated with anti-LAG3 ICB.

UNASSIGNED: Na+/Ca2+ exchanger (NCX) upregulation in cardiac diseases like heart failure promotes as an independent proarrhythmic factor early and delayed afterdepolarizations (EADs/DADs) on the single cell level. Consequently, NCX inhibition protects against EADs and DADs in isolated cardiomyocytes. We here investigate, whether these promising cellular in vitro findings likewise apply to an in vivo setup.
UNASSIGNED: Programmed ventricular stimulation (PVS) and isoproterenol were applied to a murine heterozygous NCX-knockout model (KO) to investigate ventricular arrhythmia initiation and perpetuation compared to wild-type (WT). KO displayed a reduced susceptibility towards isoproterenol-induced premature ventricular complexes. During PVS, initiation of single or double ectopic beats was similar between KO and WT. But strikingly, perpetuation of ventricular tachycardia (VT) was significantly increased in KO (animals with VT - KO: 82 %; WT: 47 %; p = 0.0122 / median number of VTs - KO: 4.5 (1.0, 6.25); WT: 0.0 (0.0, 4.0); p = 0.0039). The median VT duration was prolonged in KO (in s; KO: 0.38 (0.19, 0.96); WT: 0.0 (0.0, 0.60); p = 0.0239). The ventricular refractory period (VRP) was shortened in KO (in ms; KO: 15.1 ± 0.7; WT: 18.7 ± 0.7; p = 0.0013).
UNASSIGNED: Not the initiation, but the perpetuation of provoked whole-heart in vivo ventricular arrhythmia was increased in KO. As a potential mechanism, we found a significantly reduced VRP, which may promote perpetuation of reentrant ventricular arrhythmia. On a translational perspective, the antiarrhythmic concept of therapeutic NCX inhibition seems to be ambivalent by protecting from initiating afterdepolarizations but favoring arrhythmia perpetuation in vivo at least in a murine model.

Critically ill patients infected with SARS-CoV-2 display adaptive immunity, but it is unknown if they develop cross-reactivity to variants of concern (VOCs). We profiled cross-immunity against SARS-CoV-2 VOCs in naturally infected, non-vaccinated, critically ill COVID-19 patients. Wave-1 patients (wild-type infection) were similar in demographics to Wave-3 patients (wild-type/alpha infection), but Wave-3 patients had higher illness severity. Wave-1 patients developed increasing neutralizing antibodies to all variants, as did patients during Wave-3. Wave-3 patients, when compared to Wave-1, developed more robust antibody responses, particularly for wild-type, alpha, beta and delta variants. Within Wave-3, neutralizing antibodies were significantly less to beta and gamma VOCs, as compared to wild-type, alpha and delta. Patients previously diagnosed with cancer or chronic obstructive pulmonary disease had significantly fewer neutralizing antibodies. Naturally infected ICU patients developed adaptive responses to all VOCs, with greater responses in those patients more likely to be infected with the alpha variant, versus wild-type.

Triosephosphate isomerase deficiency (TPI Df) is a rare, aggressive genetic disease that typically affects young children and currently has no established treatment. TPI Df is characterized by hemolytic anemia, progressive neuromuscular degeneration, and a markedly reduced lifespan. The disease has predominately been studied using invertebrate and in vitro models, which lack key aspects of the human disease. While other groups have generated mammalian Tpi1 mutant strains, specifically with the mouse mus musculus, these do not recapitulate key characteristic phenotypes of the human disease. Reported here is the generation of a novel murine model of TPI Df. CRISPR-Cas9 was utilized to engineer the most common human disease-causing mutation, Tpi1 E105D , and Tpi1 null mice were also isolated as a frame-shifting deletion. Tpi1 E105D/null mice experience a markedly shortened lifespan, postural abnormalities consistent with extensive neuromuscular dysfunction, hemolytic anemia, pathological changes in spleen, and decreased body weight. There is a ∼95% reduction in TPI protein levels in Tpi1 E105D/null animals compared to wild-type littermates, consistent with decreased TPI protein stability, a known cause of TPI Df. This work illustrates the capability of Tpi1 E105D/null mice to serve as a mammalian model of human TPI Df. This work will allow for advancement in the study of TPI Df within a model with physiology similar to humans. The development of the model reported here will enable mechanistic studies of disease pathogenesis and, importantly, efficacy testing in a mammalian system for emerging TPI Df treatments.

UNASSIGNED: Cerebral amyloid angiopathy (CAA) is common disorder of the elderly, a prominent comorbidity of Alzheimer\'s disease, and causes vascular cognitive impairment and dementia. Previously, we generated a transgenic rat model of capillary CAA type-1 that develops many pathological features of human disease. However, a complementary rat model of larger vessel CAA type-2 disease has been lacking.
UNASSIGNED: A novel transgenic rat model (rTg-D) was generated that produces human familial CAA Dutch E22Q mutant amyloid β-protein (Aβ) in brain and develops larger vessel CAA type-2. Quantitative biochemical and pathological analyses were performed to characterize the progression of CAA and associated pathologies in aging rTg-D rats.
UNASSIGNED: rTg-D rats begin to accumulate Aβ in brain and develop varying levels of larger vessel CAA type-2, in the absence of capillary CAA type-1, starting around 18 months of age. Larger vessel CAA was mainly composed of the Aβ40 peptide and most prominent in surface leptomeningeal/pial vessels and arterioles of the cortex and thalamus. Cerebral microbleeds and small vessel occlusions were present mostly in the thalamic region of affected rTg-D rats. In contrast to capillary CAA type-1 the amyloid deposited within the walls of larger vessels of rTg-D rats did not promote perivascular astrocyte and microglial responses or accumulate the Aβ chaperone apolipoprotein E.
UNASSIGNED: Although variable in severity, the rTg-D rats specifically develop larger vessel CAA type-2 that reflects many of the pathological features of human disease and provide a new model to investigate the pathogenesis of this condition.

UNASSIGNED: Congenital pseudarthrosis of the tibia (CPT) is an uncommon congenital deformity and a special subtype of bone nonunion. The lower ability of osteogenic differentiation in CPT-derived mesenchymal stem cells (MSCs) could result in progression of CPT, and miR-30a could inhibit osteogenic differentiation. However, the role of miR-30a in CPT-derived MSCs remains unclear.
UNASSIGNED: The osteogenic differentiation of CPT-derived MSCs treated with the miR-30a inhibitor was tested by Alizarin Red S staining and alkaline phosphatase (ALP) activity. The expression levels of protein and mRNA were assessed by Western blot or quantitative reverse transcription-polymerase chain reaction (RT-qPCR), respectively. The interplay between miR-30a and HOXD8 was investigated by a dual-luciferase reporter assay. Chromatin immunoprecipitation (ChIP) was conducted to assess the binding relationship between HOXD8 and RUNX2 promoter.
UNASSIGNED: CPT-derived MSCs showed a lower ability of osteogenic differentiation than normal MSCs. miR-30a increased in CPT-derived MSCs, and miR-30a downregulation promoted the osteogenic differentiation of CPT-derived MSCs. Meanwhile, HOXD8 is a direct target for miR-30a, and HOXD8 could transcriptionally activate RUNX2. In addition, miR-30a could inhibit the osteogenic differentiation of CPT-derived MSCs by negatively regulating HOXD8.
UNASSIGNED: miR-30a inhibits the osteogenic differentiation of CPT-derived MSCs by targeting HOXD8. Thus, this study might supply a novel strategy against CPT.

UNASSIGNED: The role of osteopontin (OPN) following severe injury remains to be elucidated, especially its relationship with type I collagen (encoded by the Col1a1 gene) secretion by newly-differentiated odontoblast-like cells (OBLCs). In this study, we examined the role of OPN in the process of reparative dentin formation with a focus on reinnervation and revascularization after tooth replantation in Opn knockout (KO) and wild-type (WT) mice.
UNASSIGNED: Maxillary first molars of 2- and 3-week-old-Opn KO and WT mice (Opn KO 2W, Opn KO 3W, WT 2W, and WT 3W groups) were replanted, followed by fixation 3-56 days after operation. Following micro-computed tomography analysis, the decalcified samples were processed for immunohistochemistry for Ki67, Nestin, PGP 9.5, and CD31 and in situ hybridization for Col1a1.
UNASSIGNED: An intense inflammatory reaction occurred to disrupt pulpal healing in the replanted teeth of the Opn KO 3W group, whereas dental pulp achieved healing in the Opn KO 2W and WT groups. The tertiary dentin in the Opn KO 3W group was significantly decreased in area compared with the Opn KO 2W and WT groups, with a significantly low percentage of Nestin-positive, newly-differentiated OBLCs during postoperative days 7-14. In the Opn KO 3W group, the blood vessels were significantly decreased in area and pulp healing was disturbed with a failure of pulpal revascularization and reinnervation.
UNASSIGNED: OPN is necessary for proper reinnervation and revascularization to deposit reparative dentin following severe injury within the dental pulp of erupted teeth with advanced root development.