Probes for INS

Maintenance of glucose homeostasis requires the precise regulation of hormone secretion from the endocrine pancreas. Free fatty-acid receptor 4 (FFAR4/GPR120) is a G protein-coupled receptor whose activation in islets of Langerhans promotes insulin and glucagon secretion and inhibits somatostatin secretion. However, the contribution of individual islet cell types (α, β, and δ cells) to the insulinotropic and glucagonotropic effects of GPR120 remains unclear. As gpr120 mRNA is enriched in somatostatin-secreting δ cells, we hypothesized that GPR120 activation stimulates insulin and glucagon secretion via inhibition of somatostatin release. Glucose tolerance tests were performed in mice after administration of the selective GPR120 agonist Compound A. Insulin, glucagon and somatostatin secretion were measured in static incubations of isolated mouse islets in response to endogenous (ω-3 polyunsaturated fatty acids) and/or pharmacological (Compound A and AZ-13581837) GPR120 agonists. The effect of Compound A on hormone secretion was tested further in islets isolated from mice with global or somatostatin cell-specific knockout of gpr120. Gpr120 expression was assessed in pancreatic sections by RNA in situ hybridization. Cyclic AMP (cAMP) and calcium dynamics in response to pharmacological GPR120 agonists were measured specifically in α, β and δ cells in intact islets using cAMPER and GCaMP6 reporter mice, respectively. Acute exposure to Compound A increased glucose tolerance and circulating insulin and glucagon levels in vivo. Endogenous and/or pharmacological and GPR120 agonists reduced somatostatin secretion in isolated islets and concomitantly demonstrated dose-dependent potentiation of glucose-stimulated insulin secretion and arginine-stimulated glucagon secretion. Gpr120 was enriched in δ cells. Pharmacological GPR120 agonists reduced cAMP and calcium levels in δ cells but increased these signals in α and β cells. Compound A-mediated inhibition of somatostatin secretion was insensitive to pertussis toxin. The effect of Compound A on hormone secretion was completely absent in islets from mice with either global or somatostatin cell-specific deletion of gpr120 and was partially reduced upon blockade of somatostatin receptor signaling by cyclosomatostatin. Inhibitory GPR120 signaling in δ cells contributes to both insulin and glucagon secretion in part via mitigating somatostatin release.

Prenatal exposure to excess androgens is associated with the development of polycystic ovary syndrome (PCOS). In prenatally androgenised (PNA) mice, a model of PCOS, progesterone receptor (PR) protein expression is reduced in arcuate nucleus (ARC) GABA neurons. This suggests a mechanism for PCOS-related impaired steroid hormone feedback and implicates androgen excess in inducing transcriptional repression of the PR-encoding gene _Pgr_ in the ARC. However, the androgen sensitivity of ARC neurons and the relative gene expression of progesterone receptors over development and following prenatal androgen exposure remain unknown. Here we used RT-qPCR of microdissected ARC to determine the relative androgen receptor (_Ar_) and progesterone receptor (_Pgr_) gene expression in PNA and control mice at 5 developmental timepoints. In two-way ANOVA analysis, none of the genes examined showed expression changes with a statistically significant interaction between treatment and age, although _PgrA_ showed a borderline interaction. For all genes, there was a statistically significant main effect of age on expression levels, reflecting a general increase in expression with increasing age, regardless of treatment. For _PgrB_ and _Ar_, there was a statistically significant main effect of treatment, indicating a change in expression following PNA - increased for _PgrB_ and decreased for _Ar_ - regardless of age. For _PgrA_ there was a borderline main effect of treatment, suggesting a possible change in expression following PNA, regardless of age. _PgrAB_ gene expression changes showed no significant main effect of treatment. We additionally examined androgen and progesterone responsiveness specifically in P60 ARC GABA neurons by using RNAScope _in situ_ hybridization. This analysis revealed that _Pgr_ and _Ar_ were expressed in the majority of ARC GABA neurons in normal adult females. However, our RNAScope analysis did not show significant changes in _Pgr_ or _Ar_ expression within ARC GABA neurons following PNA. Lastly, as GABA drive to GnRH neurons is increased in PNA, we hypothesised that PNA mice would show increased expression of glutamic acid decarboxylase (GAD), the rate-limiting enzyme in GABA production. However, RT-qPCR showed that the expression of GAD encoding genes (_Gad1_ and _Gad2_) was unchanged in adult PNA mice compared to controls. Our findings indicate that PNA treatment can impact _Pgr_ and _Ar_ mRNA expression in adulthood. This may reflect altered circulating steroid hormones in PNA mice or PNA-induced epigenetic changes in the regulation of _Pgr_ and _Ar_ gene expression in ARC neurons.

The TRPM3 channel is a recently recognized noxious heat sensor that is involved in inflammatory thermal hyperalgesia. To examine its involvement in the development of hyperalgesia in interstitial cystitis/painful bladder syndrome (IC/PBS), rats with cyclophosphamide (CYP)-induced chronic cystitis were used as a model of IC/PBS. Mechanical and thermal hyperalgesia in lower abdominal region overlying the bladder in CYP rats were measured using von Frey filaments and radiant heat, respectively. TRPM3 expression at the mRNA, protein, and functional levels in dorsal root ganglion (DRG) neurons innervating the bladder was detected using RNA in situ hybridization (RNAscope), western blotting, immunohistochemistry, and Ca2+ imaging, respectively. TRPM3 channels were expressed on most of the bladder primary afferent nerve terminals containing calcitonin gene-related peptide (CGRP) and their cell bodies in L6-S1 DRGs. Activation of TRPM3 in the bladder wall by its specific agonists pregnenolone sulphate (PS) or CIM0216 induced spontaneous bladder pain, CGRP release and neurogenic inflammation which was evidenced by edema, plasma extravasation, inflammatory cell accumulation, and mast cell infiltration. In CYP rats, pretreatment with the TRPM3 antagonist primidone (2 mg/kg, i.p.) significantly alleviated the mechanical and thermal hyperalgesia, bladder submucosal edema, mast cell infiltration and bladder hyperactivity. CYP-induced cystitis was associated with TRPM3 upregulation at the mRNA, protein, and functional levels in bladder afferent neurons. Our results suggest that upregulation of TRPM3 channels is involved in the development of chronic pain in CYP-induced cystitis, and targeting TRPM3 may be a pharmacological strategy for treating bladder pain in IC/PBS.

Interferon lambda (IFN-λ) (type III IFN) is constitutively secreted from human placental cells in culture and reduces Zika virus (ZIKV) transplacental transmission in mice. However, the roles of IFN-λ during healthy pregnancy and in restricting congenital infection remain unclear. Here, we used mice lacking the IFN-λ receptor (Ifnlr1-/-) to generate pregnancies lacking either maternal or fetal IFN-λ responsiveness and found that the antiviral effect of IFN-λ resulted from signaling exclusively in maternal tissues. This protective effect depended on gestational stage, as infection earlier in pregnancy (E7 rather than E9) resulted in enhanced transplacental transmission of ZIKV. In Ifnar1-/- dams, which sustain robust ZIKV infection, maternal IFN-λ signaling caused fetal resorption and intrauterine growth restriction. Pregnancy pathology elicited by poly(I·C) treatment also was mediated by maternal IFN-λ signaling, specifically in maternal leukocytes, and also occurred in a gestational stage-dependent manner. These findings identify an unexpected effect of IFN-λ signaling, specifically in maternal (rather than placental or fetal) tissues, which is distinct from the pathogenic effects of IFN-αβ (type I IFN) during pregnancy. These results highlight the complexity of immune signaling at the maternal-fetal interface, where disparate outcomes can result from signaling at different gestational stages. IMPORTANCE Pregnancy is an immunologically complex situation, which must balance protecting the fetus from maternal pathogens with preventing maternal immune rejection of non-self fetal and placental tissue. Cytokines, such as interferon lambda (IFN-λ), contribute to antiviral immunity at the maternal-fetal interface. We found in a mouse model of congenital Zika virus infection that IFN-λ can have either a protective antiviral effect or cause immune-mediated pathology, depending on the stage of gestation when IFN-λ signaling occurs. Remarkably, both the protective and pathogenic effects of IFN-λ occurred through signaling exclusively in maternal immune cells rather than in fetal or placental tissues or in other maternal cell types, identifying a new role for IFN-λ at the maternal-fetal interface.

In Parkinson's disease (PD), the loss of midbrain dopaminergic cells results in severe locomotor deficits, such as gait freezing and akinesia. Growing evidence indicates that these deficits can be attributed to the decreased activity in the mesencephalic locomotor region (MLR), a brainstem region controlling locomotion. Clinicians are exploring the deep brain stimulation of the MLR as a treatment option to improve locomotor function. The results are variable, from modest to promising. However, within the MLR, clinicians have targeted the pedunculopontine nucleus exclusively, while leaving the cuneiform nucleus unexplored. To our knowledge, the effects of cuneiform nucleus stimulation have never been determined in parkinsonian conditions in any animal model. Here, we addressed this issue in a mouse model of PD, based on the bilateral striatal injection of 6-hydroxydopamine, which damaged the nigrostriatal pathway and decreased locomotor activity. We show that selective optogenetic stimulation of glutamatergic neurons in the cuneiform nucleus in mice expressing channelrhodopsin in a Cre-dependent manner in Vglut2-positive neurons (Vglut2-ChR2-EYFP mice) increased the number of locomotor initiations, increased the time spent in locomotion, and controlled locomotor speed. Using deep learning-based movement analysis, we found that the limb kinematics of optogenetic-evoked locomotion in pathological conditions were largely similar to those recorded in intact animals. Our work identifies the glutamatergic neurons of the cuneiform nucleus as a potentially clinically relevant target to improve locomotor activity in parkinsonian conditions. Our study should open avenues to develop the targeted stimulation of these neurons using deep brain stimulation, pharmacotherapy, or optogenetics.

Widespread or ectopic sensitization is a hallmark symptom of chronic pain, characterized by aberrantly enhanced pain sensitivity in multiple body regions remote from the site of original injury or inflammation. The central mechanism underlying widespread sensitization remains unidentified. The central nucleus of the amygdala (also called the central amygdala, CeA) is well situated for this role because it receives nociceptive information from diverse body sites and modulates pain sensitivity in various body regions. In this study, we examined the role of the CeA in a novel model of ectopic sensitization of rats. Injection of formalin into the left upper lip resulted in latent bilateral sensitization in the hind paw lasting >13 days in male Wistar rats. Chemogenetic inhibition of gamma-aminobutyric acid-ergic neurons or blockade of calcitonin gene-related peptide receptors in the right CeA, but not in the left, significantly attenuated this sensitization. Furthermore, chemogenetic excitation of gamma-aminobutyric acid-ergic neurons in the right CeA induced de novo bilateral hind paw sensitization in the rats without inflammation. These results indicate that the CeA neuronal activity determines hind paw tactile sensitivity in rats with remote inflammatory pain. They also suggest that the hind paw sensitization used in a large number of preclinical studies might not be simply a sign of the pain at the site of injury but rather a representation of the augmented CeA activity resulting from inflammation/pain in any part of the body or from activities of other brain regions, which has an active role of promoting defensive/protective behaviors to avoid further bodily damage.

While persistence of fear memories is essential for survival, a failure to inhibit fear in response to harmless stimuli is a feature of anxiety disorders. Extinction training only temporarily suppresses fear memory recovery in adults, but it is highly effective in juvenile rodents. Maturation of GABAergic circuits, in particular of parvalbumin-positive (PV+) cells, restricts plasticity in the adult brain, thus reducing PV+ cell maturation could promote the suppression of fear memories following extinction training in adults. Epigenetic modifications such as histone acetylation control gene accessibility for transcription and help couple synaptic activity to changes in gene expression. Histone deacetylase 2 (Hdac2), in particular, restrains both structural and functional synaptic plasticity. However, whether and how Hdac2 controls the maturation of postnatal PV+ cells is not well understood. Here, we show that PV+- cell specific Hdac2 deletion limits spontaneous fear memory recovery in adult mice, while enhancing PV+ cell bouton remodeling and reducing perineuronal net aggregation around PV+ cells in prefrontal cortex and basolateral amygdala. Prefrontal cortex PV+ cells lacking Hdac2, show reduced expression of Acan, a critical perineuronal net component, which is rescued by Hdac2 re-expression. Pharmacological inhibition of Hdac2 before extinction training is sufficient to reduce both spontaneous fear memory recovery and Acan expression in wild-type adult mice, while these effects are occluded in PV+-cell specific Hdac2 conditional knockout mice. Finally, a brief knock-down of Acan expression mediated by intravenous siRNA delivery before extinction training but after fear memory acquisition is sufficient to reduce spontaneous fear recovery in wild-type mice. Altogether, these data suggest that controlled manipulation of PV+ cells by targeting Hdac2 activity, or the expression of its downstream effector Acan, promotes the long-term efficacy of extinction training in adults.

Polycystic ovary syndrome (PCOS) is a female endocrine disorder that is associated with prenatal exposure to excess androgens. In prenatally androgenized (PNA) mice that model PCOS, GABAergic neural transmission to and innervation of GnRH neurons is increased. Evidence suggests that elevated GABAergic innervation originates in the arcuate nucleus (ARC). We hypothesised that GABA-GnRH circuit abnormalities are a direct consequence of PNA, resulting from DHT binding to androgen receptor (AR) in the prenatal brain. However, whether prenatal ARC neurons express AR at the time of PNA treatment is presently unknown. We used RNAScope _in situ_ hybridization to localize AR mRNA (_Ar_)-expressing cells in healthy gestational day (GD) 17.5 female mouse brains and to assess co-expression levels in specific neuronal phenotypes. Our study revealed that less than 10% of ARC GABA cells expressed _Ar_. In contrast, we found that ARC kisspeptin neurons, critical regulators of GnRH neurons, were highly co-localised with _Ar_. Approximately 75% of ARC _Kiss1_-expressing cells also expressed _Ar_ at GD17.5, suggesting that ARC kisspeptin neurons are potential targets of PNA. Investigating other neuronal populations in the ARC we found that approximately 50% of pro-opiomelanocortin (_Pomc_) cells, 22% of tyrosine hydroxylase (_Th_) cells, 8% of agouti-related protein (_Agrp_) cells and 8% of somatostatin (_Sst_) cells express _Ar_. Lastly, RNAscope in coronal sections showed _Ar_ expression in the medial preoptic area (mPOA), and the ventral part of the lateral septum (vLS). These _Ar_-expressing regions were highly GABAergic, and 22% of GABA cells in the mPOA and 25% of GABA cells in the vLS also expressed _Ar_. Our findings identify specific neuronal phenotypes in the ARC, mPOA and vLS that are androgen sensitive in late gestation. PNA-induced functional changes in these neurons may be related to the development of impaired central mechanisms associated with PCOS-like features.

Background Patients with advanced squamous-cell lung cancer (SQCLC) frequently (46%) exhibit tumor overexpression of fibroblast growth factor receptor (FGFR) messenger ribonucleic acid (mRNA). Rogaratinib is a novel oral pan-FGFR inhibitor with a good safety profile and anti-tumor activity in early clinical trials as a single agent in FGFR pathway-addicted tumors. SAKK 19/18 determined clinical activity of rogaratinib in patients with advanced SQCLC overexpressing FGFR1-3 mRNA. Methods Patients with advanced SQCLC failing standard systemic treatment and with FGFR1-3 mRNA tumor overexpression as defined in the protocol received rogaratinib 600 mg BID until disease progression or intolerable toxicity. A 6-months progression-free survival rate (6mPFS) ≤15% was considered uninteresting (H0), whereas a 6mPFS ≥38% was considered promising (H1). According to a Simon 2-stage design, 2 out of 10 patients of the first stage were required to be progression-free at 6 months. Comprehensive Genomic Profiling was performedusing the Oncomine Comprehensive Assay Plus (Thermo Fisher Scientific). Results Between July 2019 and November 2020, 49 patients were screened and 20 were classified FGFR-positive. Among a total of 15 patients, 6mPFS was reached in 1 patient (6.7%), resulting in trial closure for futility after the first stage. There were 7 (46.7%) patients with stable disease and 5 (33.3%) patients with progressive disease. Median PFS was 1.6 (95% CI 0.9-3.5) months and median overall survival (OS) 3.5 (95% CI 1.0-5.9) months. Most frequent treatment-related adverse events (TRAEs) included hyperphosphatemia in 8 (53%), diarrhea in 5 (33%), stomatitis in 3 (20%) and nail changes in 3 (20%) patients. Grade ≥3 TRAEs occurred in 6 (40%) patients. No associations between mutational profile and treatment outcome were observed. Conclusion Despite preliminary signals of activity, rogaratinib failed to improve PFS in patients with advanced SQCLC overexpressing FGFR mRNA. FGFR inhibitors in SQCLC remain a challenging field, and more in-depth understanding of pathway crosstalks may lead to the development of drug combinations with FGFR inhibitors resulting in improved outcomes.

Introduction: Pulmonary arterial hypertension (PAH) is a lethal condition lacking curative pharmacotherapy. Expansion of the extracellular matrix occurs in early stages of pulmonary angiopathy, but the presence of individual matrix components warrants further investigation. Accumulation of the osmotically active matrix proteoglycan aggrecan has been associated with swelling and disruption of vessel wall integrity in systemic arteries. Whether aggrecan is present to any significant extent in PAH tissue, and what potential role it may have, is not known. Methods: Paraffin-embedded lung tissue from 11 patients with idiopathic PAH was imaged using synchrotron-based phase contrast micro-CT at the TOMCAT beamline, Swiss Light Source. Image analysis was performed in Fiji and Amira. Imaged blocks were subsequently sectioned for histology, immunohistochemistry with an aggrecan core protein antibody and RNAscope in situ hybridization. qPCR was performed to investigate gene expression. Failed donor lungs were used as controls. Results: Aggrecan core protein was identified in vascular lesions of all 11 patients with idiopathic PAH, localized to cellular rather than fibrotic or collagenous lesions. RNAscope in situ hybridization confirmed local production of ACAN mRNA in diseased vessels. Quantification of repeated immunohistochemistry demonstrated significantly increased accumulation of aggrecan in patients with idiopathic PAH compared to failed donor lung controls. ACAN and ADAMTS15 mRNA were also found to be up-regulated in pulmonary arteries from patients with IPAH, indicating ongoing proteolytic turnover. Image analysis and three-dimensional renderings of pulmonary arteries identified aggrecan in lumen-reducing lesions containing cellular connective tissue, at sites of intrapulmonary bronchopulmonary shunting and at sites of elevated pulmonary blood pressure. Conclusions: Our findings indicate local production and accumulation of aggrecan in pressure-related lesions of idiopathic PAH. This work strengthens the hypothesis that aggrecan plays a role in arterial adaptations to altered hemodynamics and is the first to suggest a role for aggrecan in pulmonary arterial homeostasis and idiopathic PAH.

Exon 2 duplications of the DMD gene, encoding the dystrophin protein, account for around 6-11% of all duplication mutations associated with X-linked Duchenne muscular dystrophy (DMD). As part of the preclinical development of a U7snRNA vector currently in a clinical trial (ClinicalTrials.gov NCT04240314), we have previously evaluated the therapeutic efficacy, absence of off-target splicing effects in AAV9.U7snRNA-mediated skipping of exon 2 in a murine Dmd model, and lack of toxicity in non-human primates. Here we report that 3-month-old Dup2 mice systemically injected with scAAV9.U7.ACCA vector, containing four copies of U7snRNA targeted to the exon 2 splice acceptor and splice donor sites, showed efficient exon 2 skipping, long-term dystrophin expression, and skeletal muscle function correction 18-months post vector administration. The RT-PCR data showed that a single vector injection (3E13 vg/kg) resulted in significant exon 2 skipping in tibialis anterior (TA), diaphragm (Dia) and heart tissues, showing an average of 46%, 32% and 73% total therapeutic transcripts, respectively. To determine the degree of functional rescue, in situ and in vitro physiology studies on TA and Dia muscles were performed. Both Dia and TA from 21-month-old control Dup2 mice exhibited a functional deficit with a significant reduction in specific force output (45-61%) compared with Bl6 mice. The significant force drop was also observed in those mice compared with Bl6 following a rigorous fatigue protocol. The single vector infusion resulted in a dramatic improvement in specific force output up to 64-76% in Dia and TA, and better protection of the TA muscle (up to 73%) from repeated fatigue. Overall, our results confirm that scAAV9.U7.ACCA provides long-term protection by restoring the disrupted dystrophin reading frame in straight muscles from Dup2 mice and functional recovery of TA and Dia muscles 18-month post vector administration.