Histamine H3 receptor antagonist/nitric oxide donors as novel promising therapeutic hybrid-tools for glaucoma and retinal neuroprotection.

Glaucoma is a degenerative optic neuropathy in which the degeneration of optic nerve and blindness occur. The main cause is a malfunction of ciliary processes (protrusions of the ciliary bodies) resulting in increased intraocular pressure (IOP). Ocular hypertension (OHT) causes ischemic events leading to retinal ganglion cell (RGC) depletion and blindness. Histaminergic and nitrergic systems are involved in the regulation of IOP. Therefore, we developed novel hybrid compounds that target histamine H3 receptor (H3R) with nitric oxide (NO) releasing features (ST-1989 and ST-2130). After H3R binding was proven in vitro, we investigated their effects in two OHT models in New Zealand White rabbits. Compound ST-1989 showed the highest NO elevation, together with antioxidative and anti-inflammatory features partly superior to the co-administered H3R antagonist (ciproxifan) and NO donor (molsidomine). This hybrid compound demonstrated IOP reduction in both OHT models induced by intravitreal injection of hypertonic saline and carbomer into the anterior chamber of the eye, respectively. Ocular perfusion and photoreceptor neuroprotection were evaluated in a model of ischemia/reperfusion (I/R) of the ophthalmic artery induced by repeated sub-tenon injections of endothelin-1 (ET-1), twice a week for six weeks. Compound ST-1989 counteracts retinal degeneration reducing ophthalmic artery resistance index and increasing photoreceptor responses, thus rescuing RGCs. Our results indicate that compound ST-1989 is a promising molecule with long-lasting hypotensive effects and good effectiveness in reducing inflammation, oxidative stress, and RGCs apoptosis. In conclusion, these hybrid compounds could be a novel strategy to combat glaucomatous blindness and RGC depletion for ocular diseases involving retinal damage.

Lasamide Containing Sulfonylpiperazines as Effective Agents for the Management of Glaucoma Associated Symptoms.

A series of 2,4-dichloro-5-{[4-(phenylsulfonyl)piperazin-1-yl]carbonyl}benzenesulfonamide were designed and synthesized through amidation of Lasamide 1 with substituted piperazines. The newly obtained compounds demonstrated remarkable inhibition potency and selectivity for the human (h) expressed Carbonic Anhydrase (CA; EC 4.2.1.1) II isoform. Selected compounds 7 and 9 were considered in an in vivo model of glaucoma and showed relevant performances with the latter being able to last the effect up to 4 hours. The results herein reported are in sustainment of Lasamide derivatives as a new class of compounds potentially exploitable for the management of uncontrolled IOP.

A high-affinity, cis-on photoswitchable beta blocker to optically control ß2-adrenergic receptors in vitro and in vivo.

This study introduces (S)-Opto-prop-2, a second-generation photoswitchable ligand designed for precise modulation of ß2-adrenoceptor (ß2AR). Synthesised by incorporating an azobenzene moiety with propranolol, (S)-Opto-prop-2 exhibited a high PSScis (photostationary state for cis isomer) percentage (∼90 %) and a favourable half-life (>10 days), facilitating diverse bioassay measurements. In vitro, the cis-isomer displayed substantially higher ß2AR binding affinity than the trans-isomer (1000-fold), making (S)-Opto-prop-2 one of the best photoswitchable GPCR (G protein-coupled receptor) ligands reported so far. Molecular docking of (S)-Opto-prop-2 in the X-ray structure of propranolol-bound ß2AR followed by site-directed mutagenesis studies, identified D1133.32, N3127.39 and F2896.51 as crucial residues that contribute to ligand-receptor interactions at the molecular level. In vivo efficacy was assessed using a rabbit ocular hypertension model, revealing that the cis isomer mimicked propranolol's effects in reducing intraocular pressure, while the trans isomer was inactive. Dynamic optical modulation of ß2AR by (S)-Opto-prop-2 was demonstrated in two different cAMP bioassays and using live-cell confocal imaging, indicating reversible and dynamic control of ß2AR activity using the new photopharmacology tool. In conclusion, (S)-Opto-prop-2 emerges as a promising photoswitchable ligand for precise and reversible ß2AR modulation with light. The new tool shows superior cis-on binding affinity, one of the largest reported differences in affinity (1000-fold) between its two configurations, in vivo efficacy, and dynamic modulation. This study contributes valuable insights into the evolving field of photopharmacology, offering a potential avenue for targeted therapy in ß2AR-associated pathologies.

Novel Carbonic Anhydrase Inhibitors with Dual-Tail Core Sulfonamide Show Potent and Lasting Effects for Glaucoma Therapy.

Glaucoma, a leading cause of irreversible vision loss worldwide, is characterized by elevated intraocular pressure (IOP), a well-established risk factor across all its forms. We present the design and synthesis of 39 novel carbonic anhydrase inhibitors by a dual-tailed approach, strategically crafted to interact with distinct hydrophobic and hydrophilic pockets of CA active sites. The series was investigated against the CA isoforms implicated in glaucoma (hCA II, hCA IV, and hCA XII), and the X-ray crystal structures of compounds 25a, 25f, and 26a with CA II, along with 14b in complex with a hCA XII mimic, were determined. Selected compounds (14a, 25a, and 26a) underwent evaluation for their ability to reduce IOP in rabbits with ocular hypertension. Derivative 26a showed significant potency and sustained IOP-lowering effects, surpassing the efficacy of the drugs dorzolamide and bimatoprost. This positions compound 26a as a promising candidate for the development of a novel anti-glaucoma medication.

Role of histamine H4 receptor in the anti-inflammatory pathway of glucocorticoid-induced leucin zipper (GILZ) in a model of lung fibrosis.

INTRODUCTION: This study investigates the interactions between histaminergic system and glucocorticoid-induced leucin zipper (GILZ) in the inflammatory process and glucocorticoid modulation in lung fibrosis. METHODS: Wild-type (WT) and GILZ Knock-Out (KO) mice were treated with bleomycin (0.05 IU) or saline, delivered by intra-tracheal injection. After surgery, mice received a continuous infusion of JNJ7777120 (JNJ, 2 mg/kg b.wt.) or vehicle for 21 days. Lung function was studied by measuring airway resistance to air insufflation through the analysis of pressure at airway opening (PAO). Lung samples were collected to evaluate the expression of histamine H4R, Anx-A1, and p65-NF-kB, the activity of myeloperoxidase (MPO), and the production of pro-inflammatory cytokines. RESULTS: Airway fibrosis and remodeling were assessed by measuring TGF-ß production and α-SMA deposition. JNJ reduces PAO in WT but not in GILZ KO mice (from 22 ± 1 mm to 15 ± 0.5 and from 24 ± 1.5 to 19 ± 0.5 respectively), MPO activity (from 204 ± 3.13 pmol/mg to 73.88 ± 2.63 in WT and from 221 ± 4.46 pmol/mg to 107 ± 5.54 in GILZ KO), the inflammatory response, TGF-ß production, and α-SMA deposition in comparison to WT and GILZ KO vehicle groups. CONCLUSION: In conclusion, the role of H4R and GILZ in relation to glucocorticoids could pave the way for innovative therapies to counteract pulmonary fibrosis.

NCX 470 Exerts Retinal Cell Protection and Enhances Ophthalmic Artery Blood Flow After Ischemia/Reperfusion Injury of Optic Nerve Head and Retina.

Purpose: The purpose of this study was to assess the retinal protective activity and ocular hemodynamics after NCX 470 (0.1%) compared to bimatoprost administered as the US Food and Drug Administration (FDA)-approved drug (Lumigan - 0.01% ophthalmic solution, LUM) and at an equimolar dose (0.072%, BIM) to that released by NCX 470. Methods: Endothelin-1 (ET-1) induced ischemia/reperfusion injury model in rabbits was used. ET-1 was injected nearby the optic nerve head (ONH) twice/week for 6 weeks. Starting on week 3, the animals received vehicle (VEH), NCX 470, LUM, or BIM (30 µL/eye, twice daily, 6 days/week) until the end of ET-1 treatment. Intraocular pressure (IOP), ophthalmic artery resistive index (OA-RI), and electroretinogram (ERG) data were collected prior to dosing and at different time points postdosing. Reduced glutathione, 8-Hydroxy 2-deoxyguanosine, and Caspase-3 were determined in the retina of treated eyes. DNA fragmentation was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining. Results: ET-1 increased IOP (VEHIOP_Baseline = 20.5 ± 0.8 and VEHIOP_Week6 = 24.8 ± 0.3 mmHg) and OA-RI (VEHOA-RI_Baseline = 0.36 ± 0.02 and VEHOA-RI_Week6 = 0.55 ± 0.01) and reduced rod/cone responses over time. Oxidative stress, inflammation, and apoptotic markers increased in ET-1-treated eyes. NCX 470 prevented IOP (NCX 470IOP_Week6 = 18.1 ± 0.6 mmHg) and OA-RI changes (NCX 470OA-RI_Week6 = 0.33 ± 0.01) and restored ERG amplitude leaving unaltered the respective latency; these effects were only partially demonstrated by LUM or BIM. Additionally, NCX 470 reduced oxidative stress, inflammation, and apoptosis in the retinas of treated eyes. BIM and LUM were numerically less effective on these parameters. Conclusions: NCX 470 repeated ocular dosing ameliorates ocular hemodynamics and retinal cell dysfunction caused by ischemia/reperfusion via nitric oxide- and bimatoprost-mediated mechanisms. Translational Relevance: If confirmed in clinical setting our data may open new therapeutic opportunities to reduce visual field loss in glaucoma.

COVID-19 and Mixed Cryoglobulinemia Syndrome: Long-Term Survey Study on the Prevalence and Outcome, Vaccine Safety, and Immunogenicity.

PURPOSE: Mixed cryoglobulinemia syndrome (MCs) is a rare immunoproliferative systemic disorder with cutaneous and multiple organ involvement. Our multicenter survey study aimed to investigate the prevalence and outcome of COVID-19 and the safety and immunogenicity of COVID-19 vaccines in a large MCs series. METHODS: The survey included 430 unselected MCs patients (130 M, 300 F; mean age 70 ± 10.96 years) consecutively collected at 11 Italian referral centers. Disease classification, clinico-serological assessment, COVID-19 tests, and vaccination immunogenicity were carried out according to current methodologies. RESULTS: A significantly higher prevalence of COVID-19 was found in MCs patients compared to Italian general population (11.9% vs 8.0%, p < 0.005), and the use of immunomodulators was associated to a higher risk to get infected (p = 0.0166). Moreover, higher mortality rate was recorded in MCs with COVID-19 compared to those without (p < 0.01). Patients' older age (≥ 60 years) correlated with worse COVID-19 outcomes. The 87% of patients underwent vaccination and 50% a booster dose. Of note, vaccine-related disease flares/worsening were significantly less frequent than those associated to COVID-19 (p = 0.0012). Impaired vaccination immunogenicity was observed in MCs patients compared to controls either after the first vaccination (p = 0.0039) and also after the booster dose (p = 0.05). Finally, some immunomodulators, namely, rituximab and glucocorticoids, hampered the vaccine-induced immunogenicity (p = 0.029). CONCLUSIONS: The present survey revealed an increased prevalence and morbidity of COVID-19 in MCs patients, as well an impaired immunogenicity even after booster vaccination with high rate of no response. Therefore, MCs can be included among frail populations at high risk of infection and severe COVID-19 manifestations, suggesting the need of a close monitoring and specific preventive/therapeutical measures during the ongoing pandemic.

Adenosine A3 Receptor (A3AR) Agonist for the Treatment of Bleomycin-Induced Lung Fibrosis in Mice.

Adenosine receptors (ARs) are involved in the suppression and development of inflammatory and fibrotic conditions. Specifically, AR activation promotes differentiation of lung fibroblasts into myofibroblasts, typical of a fibrotic event. Pulmonary fibrosis is a severe disease characterized by inflammation and fibrosis of unknown etiology and lacking an effective treatment. The present investigation explored the action of MRS5980, a new, highly potent and selective A3AR agonist, in an established murine model of lung fibrosis. The effects of either vehicle or MRS5980 were studied in mice following intratracheal bleomycin administration. We evaluated the role of the A3AR agonist on lung stiffness, studying the airway resistance to inflation, oxidative stress (8-OHdG and MDA), inflammation, pro- and anti-inflammatory marker levels (IL-1ß, IL-6, TNF-α, IL-10 and IL-17A) and fibrosis establishment, evaluating transforming growth factor (TGF)-ß expression and α-smooth muscle actin (α-SMA) deposition in lungs. Bleomycin administration increased lung stiffness, TGF-ß levels, α-SMA deposition, and inflammatory and oxidative stress markers. The treatment with MRS5980 attenuated all the analyzed functional, biochemical and histopathological markers in a dose-dependent manner. Our findings support the therapeutic potential of A3AR agonists in lung fibrosis by demonstrating reduced disease progression, as indicated by decreased inflammation, TGF-ß expression and fibrotic remodeling.

New Insight in Histamine Functions.

The first properties of histamine (HA) that were elucidated were vasodilation and contraction of smooth muscles in the gut after stimulating gastric acid secretion and constriction of the bronchial area during anaphylaxis [...].

B-cell activating factor (BAFF), BAFF promoter and BAFF receptor allelic variants in hepatitis C virus related Cryoglobulinemic Vasculitis and Non-Hodgkin's Lymphoma.

Cryoglobulinemic Vasculitis (CV) is an autoimmune/lymphoproliferative disorder associated with HCV infection that in 5%-10% of cases evolves into a B cell Non-Hodgkin's Lymphoma (NHL). B-cell activating factor (BAFF) is a key regulator in B-cell development and survival. Particular genetic variants are responsible for BAFF signaling impairment in autoimmune and neoplastic diseases. We evaluated BAFF and BAFF-receptor (BAFF-R) polymorphisms in order to determine if they predispose to HCV-related CV and NHL. The analysis was performed on 416 HCV-chronically infected patients: 136 HCV without signs/symptoms of lymphoproliferations/autoimmunity (HCV), 166 HCV with CV (HCV-CV) and 114 HCV with NHL (HCV-NHL). Rs9514828 SNP on BAFF promoter, rs61756766 on BAFF-R and rs12428930 on the BAFF gene were evaluated by Real-Time PCR. Concerning rs9514828, the frequency of C/T genotype was significantly higher in HCV-CV than in HCV. The difference in the distribution of the T/T mutant genotype in HCV-CV compared to HCV was significant as well as the distribution of C/T and T/T genotype in HCV-NHL versus HCV. T minor allele was more frequent in HCV-NHL and HCV-CV than in HCV. The distribution of C/T + T/T (for the dominant model of penetrance C/T + T/T vs. C/C) was significantly higher in HCV-CV and HCV-NHL than in HCV. Genotyping of rs61756766 on BAFF-R coding gene, revealed C/T heterozygosis at a frequency of 11% in HCV-NHL versus 3% in HCV. The T minor allele frequency was higher in HCV-NHL than in HCV. No differences emerged by genotyping rs12428930 SNP on BAFF coding gene. Our results reinforce the hypothesis that BAFF/BAFF-R genetic pattern has a role in the pathogenesis of HCV-related lymphoproliferations. BAFF/BAFF-R variants could identify a risk haplotype for HCV related CV and NHL and a BAFF/BAFF-R genetic profile assessment could potentially contribute to tailoring anti-BAFF therapy by identifying patients with BAFF alterations in which the treatment could be more beneficial.

Predictors of long-term cryoglobulinemic vasculitis outcomes after HCV eradication with direct-acting antivirals in the real-life.

Cryoglobulinemic vasculitis (CV) is the most frequent extrahepatic manifestation during HCV-chronic infection. An effective Direct Acting Antiviral-treatment leads to CV clinical response in the majority of CV-patients although symptoms may persist/recur despite a sustained virological response. At present, no standardized clinical predictive factors for disease maintenance/recurrence were proposed, as emerged from a complete literature review we performed and reported. Here we provided a detailed descriptive analysis of a wide population of CV patients treated with DAA-based regimes and followed-up after therapy completion for longer than 72 weeks, in order to identify clinical or laboratory predictors of disease outcome and to optimize the patient management. Together with some baseline symptoms (neuropathy, weakness and sicca syndrome), two newly created scores, CV- and Global Severity Index, emerged as reliable and standardized tools to predict CV clinical response before initiating an antiviral therapy. In addition to predictive parameters previously proposed in the world literature, these novel Indexes could fill an unmet gap in the clinical management of the complex HCV-related CV.

Rapid improvement of psychiatric stigmata after IFN-free treatment in HCV patients with and without cryoglobulinemic vasculitis.

OBJECTIVE: Hepatitis C virus (HCV) causes neuropsychiatric disorders and quality of life impairment, especially in patients with cryoglobulinemic vasculitis (CV). Direct acting antivirals (DAAs) are effective in most extrahepatic HCV diseases, but limited information exists regarding the outcome of psychiatric disorders in patients with and without CV, after therapy. We aimed to evaluate psychiatric outcomes, in HCV-patients with and without CV, before and after successful DAA therapy. METHODS: We prospectively studied DAA-treated HCV-patients, stratified into presence (CV) or absence of CV (NON-CV). Four psychometric scales were administered to assess depression (HAM-D and MADRS), anxiety (HAM-A), and mania (MRS). Short-Form-36 questionnaires evaluated quality of life. RESULTS: Seventy-six patients were recruited, and 47 CV and 29 NON-CV were treated with antivirals. At baseline, depression and anxiety, from mild to severe, were frequently shown, with the most advanced cases in thee CV group; no patients achieved the scores for mania. A significant improvement emerged for all the psychometric scales in the entire population and in the subgroups, after viral eradication even in the short-term outcome. The Short-Form-36 summary components showed benefits. CONCLUSIONS: After HCV eradication, the depression and anxiety scores significantly improved and severity grade generally lowered. DAA-positive effects on mental disorders should be considered part of the therapy outcome, being beneficial especially in CV patients who usually have worse baseline mental scores. Key Points • HCV frequently causes psychiatric disorders and an often-invalidating autoimmune/lymphoproliferative disease called cryoglobulinemic vasculitis. • The new direct acting antivirals (DAAs) are very effective and well tolerated by HCV-patients. • This study shows DAA-induced benefits on depression and anxiety in HCV-patients that are especially evident in CV patients who usually have worse baseline mental scores. • DAA-induced benefits are observed in the short-term post-therapy follow-up, in contrast with data previously obtained in HCV patients treated with IFN-based anti-HCV therapy.

Impact of direct acting antivirals on hepatitis C virus-related cryoglobulinemic syndrome.

INTRODUCTION: Mixed cryoglobulinemia (MC) is a B-cell lymphoproliferative disorder largely attributable to Hepatitis C virus (HCV) infection. MC clinical manifestations are determined by systemic vasculitis of low/medium sized vessels (mixed cryoglobulinemia syndrome or cryoglobulinemic vasculitis [CV]) caused by the deposition of cryoglobulins in blood vessels. EVIDENCE ACQUISITION: A systematic review was performed via the Medline and Scopus databases to evaluate studies concerning CV treatment with new direct antiviral agents (DAAs) and their effect on the syndrome. EVIDENCE SYNTHESIS: The introduction of interferon-free protocols has led to more evident positive effects than those observed in the treatment of hepatitis C. In fact, IFN-free, DAA-based therapy minimized side effects permitting the treatment of previously contraindicated patients and led to a particularly high SVR rate and to a clinical/immunological response in the majority of patients, even if at different levels in different patients, from restitutio ad integrum to partial response. In view of the clearly positive evolution in CV management, the persistence of CV manifestations, in partial or non-responders continues to pose problems in the clinical approach to patients who represent a new condition that is still not completely known. CONCLUSIONS: Results of DAA-based therapy strongly confirm the use of anti-HCV therapy as the first-line therapeutic option in CV patients. However, growing evidence of a possible persistence or late relapse of CV suggests the need for longer/more accurate post-DAA follow-ups as well as biomarkers that are capable of predicting the risk of clinical relapse/persistence to allow for the design of rational post-HCV eradication clinical flow-charts.

Hematological and Genetic Markers in the Rational Approach to Patients With HCV Sustained Virological Response With or Without Persisting Cryoglobulinemic Vasculitis.

BACKGROUND AND AIMS: Direct-acting antivirals (DAAs) usually lead to improvement/remission of cryoglobulinemic vasculitis (CV), although symptoms may persist/recur after a sustained virological response (SVR). We evaluated hematological and genetic markers in patients with HCV-SVR vasculitis with and without persisting/recurring symptoms to early predict the CV outcome. APPROACH AND RESULTS: Ninety-eight patients with HCV-CV were prospectively enrolled after a DAA-induced SVR: Group A: 52 with complete clinical response; Group B: 46 with symptom maintenance/recurrence. Monoclonal B-cell lymphocytosis, t(14;18) translocation, and abnormal free light chains κ/λ ratios were detected by flow cytometry or nested-PCR or nephelometry in 4% Group A versus 17% Group B (P = 0.04) patients, 17% Group A versus 40% Group B patients (P = 0.02), and 17% Group A versus 47% Group B (P = 0.003) patients, respectively. At least 1 out of 3 clonality markers was altered/positive in 29% of Group A versus 70% of Group B patients (P < 0.0001). When available, pretherapy samples were also tested for t(14;18) translocation (detected in 12/37 [32%] Group A and 21/38 [55%] Group B) and κ/λ ratios (abnormal in 5/35 [14%] Group A and 20/38 [53%] Group B) (P = 0.0006), whereas at least one clonality marker was detected/altered in 16/37 (43%) Group A and 30/38 (79%) Group B (P = 0.002). CV-associated single-nucleotide polymorphisms were tested by real-time PCR. Among them, notch4 rs2071286 T minor allele and TT genotype showed a higher frequency in Group B versus Group A (46% vs. 29%, P = 0.01, and 17% vs. 2%, P = 0.006, respectively). CONCLUSIONS: Hematological or genetic analyses could be used to foresee the CV clinical response after DAA therapy and could be valuable to assess a rational flowchart to manage CV during follow-up.

Solving the mystery of HBV-related mixed cryoglobulinemia: potential biomarkers of disease progression.

OBJECTIVES: The biomarkers of an immunological dysregulation due to a chronic HBV infection are indeed understudied. If untreated, this condition may evolve into liver impairment co-occurring with extrahepatic involvements. Here, we aim to identify a new panel of biomarkers [including immunoglobulin G (IgG) subclasses, RF, and Free Light Chains (FLCs)] that may be useful and reliable for clinical evaluation of HBV-related cryoglobulinemia. METHODS: We retrospectively analysed clinical data from 44 HBV-positive patients. The patients were stratified (according to the presence/absence of mixed cryoglobulinemia) into two groups: 22 with cryoglobulins (CGs) and 22 without CGs. Samples from 20 healthy blood donors (HDs) were used as negative controls. Serum samples were tested for IgG subclasses, RF (-IgM, -IgG, and -IgA type), and FLCs. RESULTS: We detected a strikingly different distribution of serum IgG subclasses between HDs and HBV-positive patients, together with different RF isotypes; in addition, FLCs were significantly increased in HBV-positive patients compared with HDs, while no significant difference was shown between HBV-positive patients with/without mixed cryoglobulinemia. CONCLUSION: The immune-inflammatory response triggered by HBV may be monitored by a peculiar profile of biomarkers. Our results open a new perspective in the precision medicine era; in these challenging times, they could also be employed to monitor the clinical course of those COVID-19 patients who are at high risk of HBV reactivation due to liver impairment and/or immunosuppressive therapies.

Role of Notch Receptors in Hematologic Malignancies.

Notch receptors are single-pass transmembrane proteins that play a critical role in cell fate decisions and have been implicated in the regulation of many developmental processes. The human Notch family comprises of four receptors (Notch 1 to 4) and five ligands. Their signaling can regulate extremely basic cellular processes such as differentiation, proliferation and death. Notch is also involved in hematopoiesis and angiogenesis, and increasing evidence suggests that these genes are involved and frequently deregulated in several human malignancies, contributing to cell autonomous activities that may be either oncogenic or tumor suppressive. It was recently proposed that Notch signaling could play an active role in promoting and sustaining a broad spectrum of lymphoid malignancies as well as mutations in Notch family members that are present in several disorders of T- and B-cells, which could be responsible for altering the related signaling. Therefore, different Notch pathway molecules could be considered as potential therapeutic targets for hematological cancers. In this review, we will summarize and discuss compelling evidence pointing to Notch receptors as pleiotropic regulators of hematologic malignancies biology, first describing the physiological role of their signaling in T- and B-cell development and homeostasis, in order to fully understand the pathological alterations reported.