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Current Atherosclerosis Reports Oct 2023To provide an insight into the new pharmacological options for the treatment of severe hypertriglyceridemia (sHTG). (Review)
Review
PURPOSE OF REVIEW
To provide an insight into the new pharmacological options for the treatment of severe hypertriglyceridemia (sHTG).
RECENT FINDINGS
sHTG is difficult to treat. The majority of the traditional pharmacological agents available have limited success in both robustly decreasing triglyceride levels and/or in reducing the incidence of acute pancreatitis (AP), the most severe complication of sHTG. Therapeutic options with novel mechanisms of action have been developed, such as antisense oligonucleotides (ASO) and small interfering RNA (siRNA) targeting APOC3 and ANGPTL3. The review discusses also 2 abandoned drugs for sHTG treatment, evinacumab and vupanorsen. The ASO targeting APOC3, volanesorsen, is approved for use in patients with familial chylomicronemia syndrome (FCS) in Europe. Olezarsen, an N-acetylgalactosamine (GalNAc)-conjugated ASO with the same target, seems to have a better safety and efficacy profile. siRNA targeting APOC3 and ANGPTL3, namely ARO-APOC3 and ARO-ANG3, are also promising for the treatment of sHTG. However, the ultimate clinical goal of any sHTG treatment, the decrease in the risk of AP, has not been definitively achieved till now by any pharmacotherapy, either approved or in development.
Topics: Humans; Acute Disease; Pancreatitis; Triglycerides; Oligonucleotides, Antisense; Hypertriglyceridemia; Apolipoprotein C-III; RNA, Small Interfering; Angiopoietin-Like Protein 3
PubMed: 37642858
DOI: 10.1007/s11883-023-01140-z -
Nature Jan 2024Although the impact of host genetics on gut microbial diversity and the abundance of specific taxa is well established, little is known about how host genetics regulates... (Meta-Analysis)
Meta-Analysis
Although the impact of host genetics on gut microbial diversity and the abundance of specific taxa is well established, little is known about how host genetics regulates the genetic diversity of gut microorganisms. Here we conducted a meta-analysis of associations between human genetic variation and gut microbial structural variation in 9,015 individuals from four Dutch cohorts. Strikingly, the presence rate of a structural variation segment in Faecalibacterium prausnitzii that harbours an N-acetylgalactosamine (GalNAc) utilization gene cluster is higher in individuals who secrete the type A oligosaccharide antigen terminating in GalNAc, a feature that is jointly determined by human ABO and FUT2 genotypes, and we could replicate this association in a Tanzanian cohort. In vitro experiments demonstrated that GalNAc can be used as the sole carbohydrate source for F. prausnitzii strains that carry the GalNAc-metabolizing pathway. Further in silico and in vitro studies demonstrated that other ABO-associated species can also utilize GalNAc, particularly Collinsella aerofaciens. The GalNAc utilization genes are also associated with the host's cardiometabolic health, particularly in individuals with mucosal A-antigen. Together, the findings of our study demonstrate that genetic associations across the human genome and bacterial metagenome can provide functional insights into the reciprocal host-microbiome relationship.
Topics: Humans; Acetylgalactosamine; Bacteria; Cohort Studies; Computer Simulation; Faecalibacterium prausnitzii; Gastrointestinal Microbiome; Genome, Human; Genotype; Host Microbial Interactions; In Vitro Techniques; Metagenome; Multigene Family; Netherlands; Tanzania
PubMed: 38172637
DOI: 10.1038/s41586-023-06893-w -
RNAi therapies: Expanding applications for extrahepatic diseases and overcoming delivery challenges.Advanced Drug Delivery Reviews Oct 2023The era of RNA medicine has become a reality with the success of messenger RNA (mRNA) vaccines against COVID-19 and the approval of several RNA interference (RNAi)... (Review)
Review
The era of RNA medicine has become a reality with the success of messenger RNA (mRNA) vaccines against COVID-19 and the approval of several RNA interference (RNAi) agents in recent years. Particularly, therapeutics based on RNAi offer the promise of targeting intractable and previously undruggable disease genes. Recent advances have focused in developing delivery systems to enhance the poor cellular uptake and insufficient pharmacokinetic properties of RNAi therapeutics and thereby improve its efficacy and safety. However, such approach has been mainly achieved via lipid nanoparticles (LNPs) or chemical conjugation with N-Acetylgalactosamine (GalNAc), thus current RNAi therapy has been limited to liver diseases, most likely to encounter liver-targeting limitations. Hence, there is a huge unmet medical need for intense evolution of RNAi therapeutics delivery systems to target extrahepatic tissues and ultimately extend their indications for treating various intractable diseases. In this review, challenges of delivering RNAi therapeutics to tumors and major organs are discussed, as well as their transition to clinical trials. This review also highlights innovative and promising preclinical RNAi-based delivery platforms for the treatment of extrahepatic diseases.
Topics: Humans; RNAi Therapeutics; RNA, Small Interfering; COVID-19 Vaccines; COVID-19; RNA Interference; Nanoparticles
PubMed: 37657644
DOI: 10.1016/j.addr.2023.115073 -
Molecular Therapy. Nucleic Acids Sep 2023The year 2023 marks the 25th anniversary of the discovery of RNAi. RNAi-based therapeutics enable sequence-specific gene knockdown by eliminating target RNA molecules... (Review)
Review
The year 2023 marks the 25th anniversary of the discovery of RNAi. RNAi-based therapeutics enable sequence-specific gene knockdown by eliminating target RNA molecules through complementary base-pairing. A systematic review of published and ongoing clinical trials was performed. Web of Science, PubMed, and Embase were searched from January 1, 1998, to December 30, 2022 for clinical trials using RNAi. Following inclusion, data from the articles were extracted according to a predefined protocol. A total of 90 trials published in 81 articles were included. In addition, ongoing clinical trials were retrieved from ClinicalTrials.gov, resulting in the inclusion of 48 trials. We investigated how maturation of RNAi-based therapeutics and developments in delivery platforms, administration routes, and potential targets shape the current landscape of clinically applied RNAi. Notably, most contemporary clinical trials used either -acetylgalactosamine delivery and subcutaneous administration or lipid nanoparticle delivery and intravenous administration. In conclusion, RNAi therapeutics have gained great momentum during the past decade, resulting in five approved therapeutics targeting the liver for treatment of severe diseases, and the trajectory depicted by the ongoing trials emphasizes that even more RNAi-based medicines also targeting extra-hepatic tissues are likely to be available in the years to come.
PubMed: 37583575
DOI: 10.1016/j.omtn.2023.07.018 -
Clinical Therapeutics Nov 2023High plasma concentrations of LDL and lipoprotein(a) (Lp[a]) are independent and causal risk factors for atherosclerotic cardiovascular disease (ASCVD). There is an... (Review)
Review
PURPOSE
High plasma concentrations of LDL and lipoprotein(a) (Lp[a]) are independent and causal risk factors for atherosclerotic cardiovascular disease (ASCVD). There is an unmet therapeutic need for high-risk patients with elevated levels of LDL-C and/or Lp(a). Recent advances in the development of nucleic acids for gene silencing (ie, triantennary N-acetylgalactosamine conjugated antisense-oligonucleotides [ASOs] and small interfering RNA [siRNA]) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and Lp(a) offer effective and sustainable therapies.
METHODS
Related articles in the English language were identified through a search for original and review articles in the PubMed database using the following key terms: cardiovascular disease, dyslipidemia, PCSK9 inhibitors, Lp(a), LDL-cholesterol, familial hypercholesterolemia, siRNA, and antisense oligonucleotide and clinical trials (either alone or in combination).
FINDINGS
Inclisiran, the most advanced siRNA-treatment targeting hepatic PCSK9, is well tolerated, producing a >30% reduction on LDL-C levels in randomized controlled trials. Pelacarsen is the most clinical advanced ASO, whereas olpasiran and SLN360 are the 2 siRNAs directed against the mRNA of the LPA gene. Evidence suggests that all Lp(a)-targeting agents are safe and well tolerated, with robust and sustained reduction in plasma Lp(a) concentration up to 70% to 90% in individuals with elevated Lp(a) levels.
IMPLICATIONS
Cumulative evidence from clinical trials supports the value of ASO and siRNA therapies targeting the synthesis of PCSK9 and Lp(a) for lowering LDL-C and Lp(a) in patients with established ASCVD or high risk of ASCVD. Further research is needed to examine whether gene silencing therapy could improve clinical outcomes in patients with elevated LDL and/or Lp(a) levels. Confirmation of the tolerability and cost-effectiveness of long-term inhibition of PCSK9 and Lp(a) with this approach is essential.
Topics: Humans; Proprotein Convertase 9; Cholesterol, LDL; Cardiovascular Diseases; Lipoprotein(a); Oligonucleotides, Antisense; Atherosclerosis; RNA, Small Interfering
PubMed: 37524569
DOI: 10.1016/j.clinthera.2023.07.008 -
Blood Nov 2023The acute hepatic porphyrias (AHPs) are inherited disorders of heme biosynthesis characterized by life-threatening acute neurovisceral attacks precipitated by factors...
The acute hepatic porphyrias (AHPs) are inherited disorders of heme biosynthesis characterized by life-threatening acute neurovisceral attacks precipitated by factors that upregulate hepatic 5-aminolevulinic acid synthase 1 (ALAS1) activity. Induction of hepatic ALAS1 leads to the accumulation of porphyrin precursors, in particular 5-aminolevulinic acid (ALA), which is thought to be the neurotoxic mediator leading to acute attack symptoms such as severe abdominal pain and autonomic dysfunction. Patients may also develop debilitating chronic symptoms and long-term medical complications, including kidney disease and an increased risk of hepatocellular carcinoma. Exogenous heme is the historical treatment for attacks and exerts its therapeutic effect by inhibiting hepatic ALAS1 activity. The pathophysiology of acute attacks provided the rationale to develop an RNA interference therapeutic that suppresses hepatic ALAS1 expression. Givosiran is a subcutaneously administered N-acetylgalactosamine-conjugated small interfering RNA against ALAS1 that is taken up nearly exclusively by hepatocytes via the asialoglycoprotein receptor. Clinical trials established that the continuous suppression of hepatic ALAS1 mRNA via monthly givosiran administration effectively reduced urinary ALA and porphobilinogen levels and acute attack rates and improved quality of life. Common side effects include injection site reactions and increases in liver enzymes and creatinine. Givosiran was approved by the US Food and Drug Administration and European Medicines Agency in 2019 and 2020, respectively, for the treatment of patients with AHP. Although givosiran has the potential to decrease the risk of chronic complications, long-term data on the safety and effects of sustained ALAS1 suppression in patients with AHP are lacking.
Topics: Humans; Aminolevulinic Acid; RNA Interference; Quality of Life; Porphyrias, Hepatic; Pain; Heme; Porphyrias
PubMed: 37027823
DOI: 10.1182/blood.2022018662 -
International Journal of Molecular... Sep 2023Lipoprotein(a) [Lp(a)] is a well-established risk factor for cardiovascular disease, predisposing to major cardiovascular events, including coronary heart disease,... (Review)
Review
Lipoprotein(a) [Lp(a)] is a well-established risk factor for cardiovascular disease, predisposing to major cardiovascular events, including coronary heart disease, stroke, aortic valve calcification and abdominal aortic aneurysm. Lp(a) is differentiated from other lipoprotein molecules through apolipoprotein(a), which possesses atherogenic and antithrombolytic properties attributed to its structure. Lp(a) levels are mostly genetically predetermined and influenced by the size of LPA gene variants, with smaller isoforms resulting in a greater synthesis rate of apo(a) and, ultimately, elevated Lp(a) levels. As a result, serum Lp(a) levels may highly vary from extremely low to extremely high. Hyperlipoproteinemia(a) is defined as Lp(a) levels > 30 mg/dL in the US and >50 mg/dL in Europe. Because of its association with CVD, Lp(a) levels should be measured at least once a lifetime in adults. The ultimate goal is to identify individuals with increased risk of CVD and intervene accordingly. Traditional pharmacological interventions like niacin, statins, ezetimibe, aspirin, PCSK-9 inhibitors, mipomersen, estrogens and CETP inhibitors have not yet yielded satisfactory results. The mean Lp(a) reduction, if any, is barely 50% for all agents, with statins increasing Lp(a) levels, whereas a reduction of 80-90% appears to be required to achieve a significant decrease in major cardiovascular events. Novel RNA-interfering agents that specifically target hepatocytes are aimed in this direction. Pelacarsen is an antisense oligonucleotide, while olpasiran, LY3819469 and SLN360 are small interfering RNAs, all conjugated with a N-acetylgalactosamine molecule. Their ultimate objective is to genetically silence LPA, reduce apo(a) production and lower serum Lp(a) levels. Evidence thus so far demonstrates that monthly subcutaneous administration of a single dose yields optimal results with persisting substantial reductions in Lp(a) levels, potentially enhancing CVD risk reduction. The Lp(a) reduction achieved with novel RNA agents may exceed 95%. The results of ongoing and future clinical trials are eagerly anticipated, and it is hoped that guidelines for the tailored management of Lp(a) levels with these novel agents may not be far off.
Topics: Adult; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Apoprotein(a); Lipoprotein(a); Apolipoproteins A; Hyperlipoproteinemias; Aortic Valve Stenosis
PubMed: 37686428
DOI: 10.3390/ijms241713622 -
International Journal of Molecular... Nov 2023Mucopolysaccharidosis IVA (MPS IVA) is a rare disorder caused by mutations in the N-acetylgalactosamine-6-sulfate-sulfatase () encoding gene. GALNS leads to the... (Review)
Review
Mucopolysaccharidosis IVA (MPS IVA) is a rare disorder caused by mutations in the N-acetylgalactosamine-6-sulfate-sulfatase () encoding gene. GALNS leads to the lysosomal degradation of the glycosaminoglyccreasans keratan sulfate and chondroitin 6-sulfate. Impaired GALNS enzymes result in skeletal and non-skeletal complications in patients. For years, the MPS IVA pathogenesis and the assessment of promising drugs have been evaluated using in vitro (primarily fibroblasts) and in vivo (mainly mouse) models. Even though value information has been raised from those studies, these models have several limitations. For instance, chondrocytes have been well recognized as primary cells affected in MPS IVA and responsible for displaying bone development impairment in MPS IVA patients; nonetheless, only a few investigations have used those cells to evaluate basic and applied concepts. Likewise, current animal models are extensively represented by mice lacking GALNS expression; however, it is well known that MPS IVA mice do not recapitulate the skeletal dysplasia observed in humans, making some comparisons difficult. This manuscript reviews the current in vitro and in vivo MPS IVA models and their drawbacks.
Topics: Humans; Mice; Animals; Mucopolysaccharidosis IV; Keratan Sulfate; Chondroitin Sulfates; Chondrocytes; Disease Models, Animal; Chondroitinsulfatases
PubMed: 38003337
DOI: 10.3390/ijms242216148 -
Current Opinion in Lipidology Dec 2023The aim of this study was to discuss the potential mechanisms and implications of the opposing liver safety results from recent angiopoietin-like 3 (ANGPTL3) inhibition... (Review)
Review
PURPOSE OF REVIEW
The aim of this study was to discuss the potential mechanisms and implications of the opposing liver safety results from recent angiopoietin-like 3 (ANGPTL3) inhibition studies.
RECENT FINDINGS
The clinical development of vupanorsen, a N-acetylgalactosamine (GalNAc) antisense targeting hepatic ANGPTL3, was recently discontinued due to a significant signal of liver transaminase increase. Vupanorsen elicited a dose-dependent increase in hepatic fat fraction up to 75%, whereas the small interfering RNA (siRNA) ARO-ANG3, has reported preliminary evidence of a dose-dependent decrease in hepatic fat fraction up to 30%.
SUMMARY
ANGPTL3 inhibition is an attractive therapeutic target to reduce all apoB-containing lipoproteins. The discrepancy in liver signal results between the antisense and siRNA approach may be explained by the level of target inhibition. An alternative explanation may relate to off-target effects of vupanorsen, which have a molecule- and/or platform-specific origin. For intrahepatic strategies, highly potent ANGPTL3 inhibition will for now require special attention for liver safety.
Topics: Humans; Angiopoietin-like Proteins; Angiopoietin-Like Protein 3; Liver; RNA, Small Interfering; Angiopoietins
PubMed: 37820081
DOI: 10.1097/MOL.0000000000000898 -
Cell Surface (Amsterdam, Netherlands) Dec 2023Half a century after their discovery, polymers of -acetylgalactosamine produced by the Aspergilli have garnered new interest as mediators of fungal virulence. Recent... (Review)
Review
Half a century after their discovery, polymers of -acetylgalactosamine produced by the Aspergilli have garnered new interest as mediators of fungal virulence. Recent work has focused on the secreted and cell wall-associated heteropolymer, galactosaminogalactan (GAG). This polymer, composed of galactose (Gal) and partially deacetylated -acetylgalactosamine (GalNAc), plays a role in a variety of pathogenic processes including biofilm formation, immune modulation and evasion, and resistance to antifungals. Given its many potential contributions to fungal pathogenesis, GAG is a promising therapeutic target for novel antifungal strategies. As such, several studies have sought to elucidate the biosynthetic pathways required for GAG production and secretion. Herein we review the progress made in the understanding of the molecular mechanisms underlying GAG synthesis and identify several gaps in our understanding of this process.
PubMed: 36691652
DOI: 10.1016/j.tcsw.2023.100095