Control Antisense Oligonucleotides Research Articles

Elevated apolipoprotein C3 augments diabetic kidney disease and associated atherosclerosis in type 2 diabetes.

Diabetes increases the risk of both cardiovascular disease and kidney disease. Notably, most of the excess cardiovascular risk in people with diabetes is in those with kidney disease. Apolipoprotein C3 (APOC3) is a key regulator of plasma triglycerides, and it has recently been suggested to play a role in both type 1 diabetes-accelerated atherosclerosis and kidney disease progression. To investigate if APOC3 plays a role in kidney disease in people with type 2 diabetes, we analyzed plasma levels of APOC3 from the Veterans Affairs Diabetes Trial (VADT). Elevated baseline APOC3 levels predicted a greater loss of renal function. To mechanistically test if APOC3 plays a role in diabetic kidney disease and associated atherosclerosis, we treated BTBR wildtype (WT) and leptin-deficient (OB; diabetic) mice, a model of type 2 diabetes, with an antisense oligonucleotide (ASO) to APOC3 or a control ASO (cASO), all in the setting of human-like dyslipidemia. Silencing APOC3 prevented diabetes-augmented albuminuria, renal glomerular hypertrophy, monocyte recruitment, and macrophage accumulation, partly driven by reduced ICAM1 expression. Furthermore, reduced levels of APOC3 suppressed atherosclerosis associated with diabetes. This suggests that targeting APOC3 might benefit both diabetes-accelerated atherosclerosis and kidney disease. .

Antisense oligonucleotide targeting hepatic Serum Amyloid A limits the progression of angiotensin II-induced abdominal aortic aneurysm formation

Background and aimsObesity increases the risk for abdominal aortic aneurysms (AAA) in humans and enhances angiotensin II (AngII)-induced AAA formation in C57BL/6 mice. We reported that deficiency of Serum Amyloid A (SAA) significantly reduces AngII-induced inflammation and AAA in both hyperlipidemic apoE-deficient and obese C57BL/6 mice. The aim of this study is to investigate whether SAA plays a role in the progression of early AAA in obese C57BL/6 mice. MethodsMale C57BL/6J mice were fed a high-fat diet (60% kcal as fat) throughout the study. After 4 months of diet, the mice were infused with AngII until the end of the study. Mice with at least a 25% increase in the luminal diameter of the abdominal aorta after 4 weeks of AngII infusion were stratified into 2 groups. The first group received a control antisense oligonucleotide (Ctr ASO), and the second group received ASO that suppresses SAA (SAA-ASO) until the end of the study. ResultsPlasma SAA levels were significantly reduced by the SAA ASO treatment. While mice that received the control ASO had continued aortic dilation throughout the AngII infusion periods, the mice that received SAA-ASO had a significant reduction in the progression of aortic dilation, which was associated with significant reductions in matrix metalloprotease activities, decreased macrophage infiltration and decreased elastin breaks in the abdominal aortas. ConclusionsWe demonstrate for the first time that suppression of SAA protects obese C57BL/6 mice from the progression of AngII-induced AAA. Suppression of SAA may be a therapeutic approach to limit AAA progression.

Evaluation of antisense oligonucleotide therapy targeting Hsd17b13 in a fibrosis mice model

Human genetic evidence suggests a protective role of loss-of-function variants in 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13) for liver fibrotic diseases. Although there is limited preclinical experimental data on Hsd17b13 antisense oligonucleotide (ASO) or siRNA in a fibrosis model, several ASO and siRNA approaches are being tested clinically as potential therapies for nonalcoholic steatohepatitis (NASH). The aim of this study was to assess the therapeutic potential of Hsd17b13 ASO in a preclinical advanced NASH-like hepatic fibrosis in vivo model. In vitro testing on primary hepatocytes demonstrated that Hsd17b13 ASO exhibited strong efficacy and specificity for knockdown of the Hsd17b13 gene. In choline-deficient, L-amino acid-defined, HFD (CDAHFD)-induced steatotic and fibrotic mice, therapeutic administration of Hsd17b13 ASO resulted in a significant and dose-dependent reduction of hepatic Hsd17b13 gene expression. The CDAHFD group exhibited considerably elevated liver enzyme levels, hepatic steatosis score, hepatic fibrosis, and increased fibrotic and inflammatory gene expression, indicating an advanced NASH-like hepatic fibrosis phenotype. Although Hsd17b13 ASO therapy significantly affected hepatic steatosis, it had no effect on hepatic fibrosis. Our findings demonstrate, for the first time, that Hsd17b13 ASO effectively suppressed Hsd17b13 gene expression both in vitro and in vivo, and had a modulatory effect on hepatic steatosis in mice, but did not affect fibrosis in the CDAHFD mouse model of NASH.

Histidine-rich glycoprotein attenuates catheter thrombosis.

Factor XII (FXII) knockdown attenuates catheter thrombosis in rabbits. Because histidine-rich glycoprotein (HRG) modulates FXIIa activity, we hypothesized that HRG depletion would promote catheter thrombosis. To test this, rabbits were given either antisense oligonucleotides (ASOs) against HRG or FXII, a control ASO, or saline. The activated partial thromboplastin time (aPTT), prothrombin time (PT), and catheter-induced thrombin generation were determined in blood collected before and after treatment. Compared with the controls, the HRG- and FXII-directed ASOs reduced hepatic messenger RNA and plasma levels of HRG and FXII, respectively, by >90%. Although HRG knockdown shortened the aPTT by 2.5 fold, FXII knockdown prolonged it by fourfold; neither of the ASOs affected the PT. Catheter segments shortened the lag time and increased peak thrombin in the plasma from control rabbits; effects were significantly enhanced and attenuated in the plasma from rabbits given the HRG- and FXII-directed ASOs, respectively. Catheters were then inserted into the right external jugular vein of the rabbits, and the time for catheter occlusion was determined. The catheter occlusion times with the control ASO or saline were 62± 8minutes and 60± 11minutes, respectively. The occlusion time was significantly reduced to 34± 9minutes, with HRG knockdown and significantly prolonged to 128± 19minutes with FXII knockdown. HRG levels are decreased with sepsis or cancer, and such patients are prone to catheter thrombosis. Because HRG modulates catheter thrombosis, our findings suggest that HRG supplementation may prevent this problem.

Abstract P238: Chemerin Is Resident To Vascular Tunicas And Contributes To Vascular Tone

The adipokine chemerin has the potential to support blood pressure, evidenced by a fall in mean arterial pressure following knockdown of chemerin protein by whole-body antisense oligonucleotides (ASO) in rat models of normal and elevated blood pressure. While the liver is the greatest contributor of circulating chemerin, liver-specific (GalNAc) ASOs that abolished hepatic-derived chemerin did not change blood pressure in these models. Thus, other sites must produce the chemerin that supports blood pressure. Presently, we hypothesize that the vasculature—the blood vessel and its perivascular adipose tissue (PVAT)—is a source of chemerin that is independent of the liver and supports arterial tone. RNAScope®, Western blot, ASOs, and isometric contractility were used in the Dahl salt sensitive (SS) rat, male and female, on a normal diet. Species-specific ZZ probes detected Rarres2 mRNA in the smooth muscle, adventitia, and PVAT of the thoracic aorta. Chemerin protein was detected immunohistochemically in the endothelium, smooth muscle cells, adventitia, and PVAT. Chemerin colocalized with the vascular smooth muscle marker a-actin and the adipocyte marker perilipin. Importantly, chemerin protein in the aorta was not reduced when liver-derived chemerin was abolished by a liver-specific ASO against chemerin (thoracic aorta control ASO = 0.62 + 0.03; GalNAc ASO = 0.35 + 0.04; abdominal aorta control ASO = 0.38 ± 0.04, GalNAc ASO = 0.40 ± 0.22). Finally, inhibition of the receptor Chemerin1 by the receptor antagonist CCX832 resulted in aortic vasorelaxation [Media/PVAT + endothelium: -8.8 ± 3.3%; Media/PVAT - endothelium: -14.6 ± 4.2%; Media + endothelium: -1.5 ± 1.3%; and Media - endothelium: -5.1 ± 7.0%, quantified by percentage of initial wakeup to phenylephrine (-152 ± 67 mg of 1660 ± 121 mg; -93 ± 13 mg of 868 ± 171 mg, -20 ± 28 mg of 1906 ± 213 mg; and -59 ± 69 mg of 964 ± 70 mg, respectively)]. These data suggest that vessel-derived chemerin may support vascular tone locally through constitutive activation of Chemerin1 and highlights vascular chemerin as a potential therapeutic target in blood pressure regulation.

1569-P: Lysophosphatidic Acid Mediates Inflammation in Liver and White Adipose Tissue in a Rat Model of 1-acyl-sn-glycerol-3-phosphate Acyltransferase 2 Deficiency

AGPAT2 (1-acyl-sn-glycerol-3-phosphate acyltransferase 2) converts lysophosphatidic acid (LPA) into phosphatidic acid (PA) and mutations of the AGPAT2 gene are responsible for the most common form of congenital generalized lipodystrophy (CGL) which leads to diabetes and steatohepatitis. The underlying mechanism by which AGPAT2 deficiency leads to these abnormalities has not been elucidated. We explored this question using an antisense oligonucleotide (ASO) to knock down expression of AGPAT2 in liver and white adipose tissue (WAT) of adult male SD rats. AGPAT2 ASO treatment induced lipodystrophic features in which adipose and hepatic inflammation were associated with increased LPA content in WAT (Control ASO=0.4 ± 0.1 nmol/g tissue; AGPAT2 ASO=0.8 ± 0.4, P<0.05) and liver (Control ASO=2.7 ± 0.4 nmol/g tissue; AGPAT2 ASO=4.2 ± 0.9, P<0.01) whereas PA content was unchanged. We hypothesized that increased LPA content may lead to inflammation in these tissues. We tested if either a controlled-release mitochondrial protonophore (CRMP) or an ASO against glycerol-3-phosphate acyltransferase, mitochondrial (GPAM) would reduce LPA content and inflammation in these tissues in AGPAT2 ASO treated rats. CRMP treatment (20 mg/[kg-day]) primarily prevented LPA accumulation in WAT (Control ASO=0.4 ± 0.1 nmol/g tissue; AGPAT2 ASO=0.9 ± 0.1; AGPAT2 ASO+CRMP=0.6 ± 0.1) (AGPAT2 ASO vs AGPAT2+CRMP P<0.05) and prevented WAT inflammation. In contrast GPAM ASO treatment primarily prevented hepatic LPA accumulation (Control ASO=3.6 ± 0.4 nmol/g tissue; AGPAT2 ASO=4.8 ± 0.2; AGPAT2+GPAM ASO=2.7 ± 0.4) (AGPAT2 ASO vs AGPAT2+GPAM ASO P<0.01) and prevented hepatic inflammation. Conclusion: These results demonstrate a key role of LPA acid in mediating inflammation in liver and WAT in AGPAT2 deficient animals and identify novel therapeutic targets to treat CGL in patients with AGPAT2 deficiency. Disclosure I.Sakuma: None. R.C.Gaspar: None. P.Luukkonen: None. M.Kahn: None. S.Murray: Employee; Ionis Pharmaceuticals. V.Samuel: None. K.Petersen: Advisory Panel; Novo Nordisk, Research Support; Merck Sharp & Dohme Corp., Gilead Sciences, Inc. G.I.Shulman: Consultant; Novo Nordisk, DiCerna Pharmaceuticals, Inc., Bayer Consumer Care AG, Kriya Therapeutics, Arrowhead Pharmaceuticals, Inc., ESPERION Therapeutics, Inc., Other Relationship; AstraZeneca, Merck & Co., Inc., Janssen Research & Development, LLC, iMetabolic Biopharma Corporation, Maze Therapeutics, 89bio, Inc., Equator Therapeutics, Inc., Generian Pharmaceuticals, Fortress Biotech, Inc., OrsoBio, Aro Biotherapeutics Company, Stock/Shareholder; Levels Health, Inc.

CD47 antisense oligonucleotide treatment attenuates obesity and its-associated metabolic dysfunction

Previous study from our lab has revealed a new role of CD47 in regulating adipose tissue function, energy homeostasis and the development of obesity and metabolic disease in CD47 deficient mice. In this study, the therapeutic potential of an antisense oligonucleotide (ASO) targeting to CD47 in obesity and its-associated complications was determined in two obese mouse models (diet induced and genetic models). In diet induced obesity, male C57BL6 mice were fed with high fat (HF) diet to induce obesity and then treated with CD47ASO or control ASO for 8 weeks. In genetic obese mouse model, male six-week old ob/ob mice were treated with ASOs for 9 weeks. We found that CD47ASO treatment reduced HF diet-induced weight gain, decreased fat mass, prevented dyslipidemia, and improved glucose tolerance. These changes were accompanied by reduced inflammation in white adipose tissue and decreased hepatic steatosis. This protection was also seen in CD47ASO treated ob/ob mice. Mechanistically, CD47ASO treatment increased mice physical activity and energy expenditure, contributing to weight loss and improved metabolic outcomes in obese mice. Collectively, these findings suggest that CD47ASO might serve as a new treatment option for obesity and its-associated metabolic complications.

Antisense oligonucleotide therapy for KCNT1 encephalopathy.

Developmental and epileptic encephalopathies (DEEs) are characterized by pharmaco-resistant seizures with concomitant intellectual disability. Epilepsy of infancy with migrating focal seizures (EIMFS) is one of the most severe of these syndromes. De novo variants in ion channels, including gain-of-function variants in KCNT1, which encodes for sodium activated potassium channel protein KNa1.1, have been found to play a major role in the etiology of EIMFS. Here, we test a potential precision therapeutic approach in KCNT1-associated DEE using a gene-silencing antisense oligonucleotide (ASO) approach. We generated a mouse model carrying the KCNT1 p.P924L pathogenic variant; only the homozygous animals presented with the frequent, debilitating seizures and developmental compromise that are seen in patients. After a single intracerebroventricular bolus injection of a Kcnt1 gapmer ASO in symptomatic mice at postnatal day 40, seizure frequency was significantly reduced, behavioral abnormalities improved, and overall survival was extended compared with mice treated with a control ASO (nonhybridizing sequence). ASO administration at neonatal age was also well tolerated and effective in controlling seizures and extending the life span of treated animals. The data presented here provide proof of concept for ASO-based gene silencing as a promising therapeutic approach in KCNT1-associated epilepsies.

Antisense oligonucleotides targeting miR‐29b binding site increase translation of progranulin protein: potential therapeutic strategy for progranulin‐deficient frontotemporal dementia

AbstractBackground GRN mutations cause frontotemporal dementia (FTD) due to haploinsufficiency of progranulin. Several microRNAs (miRs), including miR‐29b, have been reported to negatively regulate progranulin protein levels. Here, we tested if antisense oligonucleotides (ASOs) – which are versatile modulators of target mRNA/protein levels – can be used to increase progranulin levels by sterically blocking the miR‐29b binding site.MethodWe designed 48 ASOs targeting the miR‐29b binding site in the 3’ UTR of the human GRN mRNA. We treated H4 neuroglioma cells and iPSC‐derived neurons with these ASOs and subsequently measured progranulin protein levels by western blot and ELISA. We performed further studies to determine the mechanism of action of these ASOs using ribosomal profiling, metabolic labeling, and FRET assays.ResultsWe identified 16 ASOs that increased progranulin protein levels in a dose‐dependent manner. Ribosomal profiling experiments revealed that cells treated with ASOs had marked enrichment in GRN mRNA in heavy polyribosome fractions, compared to cells treated with a scrambled control ASO, suggesting that the ASOs increase the rate of progranulin translation. Consistent with this, ASO treatment resulted in increased levels of newly synthesized progranulin protein. FRET‐based assays showed that ASOs can effectively compete miR‐29b from its binding site in the GRN 3’ UTR RNA under in vitro conditions.ConclusionsTogether, our results demonstrate that ASOs can be used to effectively increase target protein levels by partially blocking miR binding sites. This strategy may be therapeutically feasible for progranulin‐deficient FTD as well as other conditions of haploinsufficiency.

EXTH-07. AN ANTISENSE OLIGONUCLEOTIDE AGAINST TUMOR MICROTUBES IN GLIOBLASTOMA AS A NEW THERAPEUTIC OPTION TO IMPROVE TUMOR SPECIFIC THERAPY

Abstract Glioblastomas are known to be highly therapy resistant tumors. The description of tumor microtubes (TMs) as long cellular protrusions that connect glioblastoma cells to a network resistant against all standard therapies advanced the basic biological understanding of the disease and offers a new therapeutic target. An antisense oligonucleotide (ASO) against the production of a protein involved in formation and function of TMs was developed and tested in a xenograft mouse model of human glioblastoma cells. After the implantation of fluorescent tumor cells under a chronic cranial window and the establishment of the tumor, the ASO treatment was started with a continuous micropump application directly into the central nervous system (CNS) and treatment effects were observed in a two-photon microscope. Furthermore, co-treatment with irradiation was tested and tumor size as well as protein expression evaluated in and ex vivo. This led to the conclusion that the setup of combined continuous pump application and two photon microscopy is technically feasible and tolerable. It offers the possibility of applying compounds directly into the CNS under live and longitudinal readouts. The fluorescently tagged ASO was traced in the brain parenchyma over weeks proving a high stability of the compound. In combination with radiotherapy, animals treated with the active ASO against the protein of formation and function of TMs showed a smaller tumor size than animals treated with radiotherapy and the non-targeting ASO. The targeted protein was expressed less in the treated animals then the animals receiving the control ASO and the extend of protein expression correlated with tumor size. Hence, after successful therapies with ASOs in other neurologic diseases and the need for better therapeutic options for glioblastoma patients, the development of an ASO against a protein involved in the TM formation and function offers a new therapeutic option with high translational potential.

Abstract P003: Chemerin Supports Basal Blood Pressure In Both Male And Female Dahl SS Rats

Evidence supports that Antisense oligonucleotides (ASO) against the adipokine chemerin reduce the blood pressure of the normal male Sprague Dawley rat and, to a greater magnitude, the hypertensive Dahl SS rat fed a high fat diet. In the Dahl SS rat, chemerin protein concentration in white adipose tissue [mesenteric perivascular adipose tissue (Mes PVAT)] was significantly higher in females vs males. We hypothesized that female Dahl SS rats would be more dependent on chemerin for blood pressure maintenance than males because of the Mes PVAT’s proximity to blood vessels that control total peripheral resistance. Age-matched male and female Dahl SS rats on a standard chow (0.2% NaCl, 6.2% fat) diet were used. Radiotelemeters were implanted to measure blood pressure (MAP) and heart rate (bpm). Following a two-week recovery period after implantation, one week of baseline measures were collected. Knockdown of whole body chemerin was achieved by subcutaneous injections of scrambled control ASO or whole-body ASO against chemerin (both 25 mg/kg) on days 0, 7, 14, and 21. On day 23, the rats were euthanized, and samples were collected for western blot and qPCR of the chemerin gene Rarres2 . Plasma chemerin was abolished in both male and female rats given the ASO against chemerin vs that of rats receiving the control ASO. In males and females, respectively, chemerin mRNA expression (2 -ΔCT ) was reduced from 0.53 to 0.001 ± 0.002 and 0.23 to 0.001 ± 0.02 in liver, 0.05 to 0.01 ± 0.005 and 0.07 to 0.005 ± 0.02 in RP fat, and 0.09 to 0.01 ± 0.003 and 0.05 to 0.001 ± 0.02 in epididymal/uterine fat. MAP in control ASO rats showed no significant change from baseline measurements (M:137.4 ± 3.0 /F: 130.6 ± 1.5 mmHg), while males and females treated with whole-body ASO dropped by 10.7 ± 1.6 and 10.9 ± 2.1 mmHg respectively after four injections, with no significant change in heart rate. Pulse pressure also decreased by 5.6 ± 1.3 and 6.8 ± 1.3 mmHg in whole-body ASO males and females, respectively, with no significant changes from baseline in the control animals. These data suggest, contrary to our hypothesis, that chemerin plays a similar role in basal blood pressure regulation in males and females. This indicates that males and females may be equally dependent on chemerin for high fat diet-induced hypertension.

Abstract 6250: Investigating the immunomodulatory mechanisms of Smyd3 depletion in HPV-negative head and neck squamous cell carcinoma

Abstract Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer type in the world, with Human Papilloma virus (HPV)-negative patients having a ~50% recurrence rate and poor median overall survival of ~13 months in the recurrent/metastatic setting. Pembrolizumab, a programmed-death-1 (PD-1) checkpoint inhibitor is active but with a response rate as low as 19%. Our preliminary work has identified SET and MYND Domain containing 3 (SMYD3) as a chromatin modifier that is significantly overexpressed in HPV-negative HNSCC tumor tissues compared to normal epithelium and is associated with low CD8+ T-cell infiltration in HPV-negative HNSCC. Furthermore, we have shown that knockdown of human SMYD3 upregulates the expression of multiple type I IFN response and antigen presentation machinery (APM) genes. This study aims to investigate whether Smyd3 depletion potentiates immune-mediated antitumor efficacy in anti-PD-1 resistant syngeneic mouse models of HPV-negative HNSCC (MOC1), as well as relevant mechanisms. SiRNA-mediated knockdown of Smyd3 in mouse HPV-negative MOC1 cells followed by RNA-seq revealed upregulation of multiple type I IFN response and APM genes in vitro. Multicolor flow cytometry of MOC1 tumors treated with control anti-sense oligonucleotides (ASOs) or Smyd3 ASOs showed that Smyd3 depletion in a syngeneic, heterotopic mouse model (C57BL/6) of flank MOC1 tumors induced intratumoral infiltration of CD8+ T-cells, as well as upregulation of H2-Kb (MHC class I) and mouse Pd-l1 in MOC1 cells. Combined treatment of Smyd3 ASOs with anti-PD-1 induced complete regressions of flank MOC1 tumors in 4/8 treated mice and significant tumor growth restriction in 2/8 mice, while 2/8 tumors “escaped” the treatment effect. Single-cell RNA seq of MOC1 tumors treated with control or Smyd3 ASOs is ongoing to evaluate the effects of Smyd3 depletion on MOC1 cancer cells and immune cell subsets of the tumor microenvironment and to identify potential mechanisms of resistance of Smyd3 ASO + anti-PD-1 combination treatment. Genome-wide mapping of Smyd3 and the repressive mark H4K20me3, which is known to be written by Smyd3, in MOC1 cells using CUT&RUN assays is also ongoing and aims to decipher whether Smyd3 directly binds to and regulates the expression of immune-related genes through H4K20me3. Ex-vivo cytotoxicity assays aim to evaluate whether CRISPR Smyd3 KO in MOC1 cells sensitizes cancer cells to TIL-mediated cytotoxicity. Smyd3 depletion induces an inflamed tumor microenvironment and may potentiate the immune-mediated antitumor efficacy of anti-PD-1 in syngeneic mouse models of HPV-negative HNSCC. This work may lay the biological rationale to combine SMYD3 inhibition with T-cell based immunotherapeutic approaches in HPV-negative HNSCC. Citation Format: Daniel E. Tsai, Yvette Robbins, Angel Huynh, Andrew Sinkoe, Cem Sievers, Madhavi Murali, Xiaolin Luo, Clint T. Allen, Vassiliki Saloura. Investigating the immunomodulatory mechanisms of Smyd3 depletion in HPV-negative head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6250.

ANGPTL4 silencing via antisense oligonucleotides reduces plasma triglycerides and glucose in mice without causing lymphadenopathy

Angiopoietin-like 4 (ANGPTL4) is an important regulator of plasma triglyceride (TG) levels and an attractive pharmacological target for lowering plasma lipids and reducing cardiovascular risk. Here, we aimed to study the efficacy and safety of silencing ANGPTL4 in the livers of mice using hepatocyte-targeting GalNAc-conjugated antisense oligonucleotides (ASOs). Compared with injections with negative control ASO, four injections of two different doses of ANGPTL4 ASO over 2 weeks markedly downregulated ANGPTL4 levels in liver and adipose tissue, which was associated with significantly higher adipose LPL activity and lower plasma TGs in fed and fasted mice, as well as lower plasma glucose levels in fed mice. In separate experiments, injection of two different doses of ANGPTL4 ASO over 20 weeks of high-fat feeding reduced hepatic and adipose ANGPTL4 levels but did not trigger mesenteric lymphadenopathy, an acute phase response, chylous ascites, or any other pathological phenotypes. Compared with mice injected with negative control ASO, mice injected with ANGPTL4 ASO showed reduced food intake, reduced weight gain, and improved glucose tolerance. In addition, they exhibited lower plasma TGs, total cholesterol, LDL-C, glucose, serum amyloid A, and liver TG levels. By contrast, no significant difference in plasma alanine aminotransferase activity was observed. Overall, these data suggest that ASOs targeting ANGPTL4 effectively reduce plasma TG levels in mice without raising major safety concerns.

Abstract 500: Silencing Apolipoprotein C3 Prevents Diabetic Kidney Disease And Atherosclerosis In A Mouse Model Of Type 2 Diabetes

Diabetes increases the risk of both cardiovascular disease and kidney disease. Notably, most of the excess cardiovascular risk in people with diabetes is in those with kidney disease. Apolipoprotein C3 (APOC3) is a small apolipoprotein that is elevated by insulin-insufficiency and regulates plasma triglyceride levels. To test if APOC3, and the dyslipidemia it represents, play a role in diabetic kidney disease (DKD) and associated atherosclerosis, we treated BTBR wildtype (WT) and leptin-deficient (OB; diabetic) mice with an antisense oligonucleotide (ASO) to APOC3 or a control ASO (cASO), all in the setting of human-like dyslipidemia (accomplished by administration of an ASO targeting the LDLR). APOC3 ASO treatment reduced triglycerides, triglyceride-rich lipoproteins. It prevented diabetes-accelerated atherosclerosis in the aortic sinus, brachiocephalic artery, and aorta (sinus lesion: 67926 ± 8486 μm 2 lesion in cASO-treated OB mice compared to 38589 ± 9507 μm 2 in APOC3 ASO-treated OB mice, p<0.05, n=12-15). The reduction in lesion size with APOC3 treatment was associated with fewer macrophages and reduced perilipin 2 staining (a marker for lipid droplet formation). In the kidney, diabetes resulted in a dramatic increase in glomerular hypertrophy, neutral lipid accumulation, APOC3, and APOE-accumulation, which APOC3 ASO-treatment attenuated. Furthermore, diabetes resulted in monocyte recruitment, macrophage accumulation, and macrophage lipid loading in the glomeruli, all of which was dramatically suppressed in the setting of APOC3 silencing (36% of glomerular macrophages were lipid loaded in OB cASO mice whereas only 9% were lipid loaded in APOC3-ASO treated mice, p<0.0001). The recruitment was driven by increased endothelial cell ICAM1 expression, but monocyte lipid loading may also contribute. Intriguingly, APOC3-ASO treatment reduced diabetes-associated urinary albumin creatinine ratio but did not affect it in non-diabetic mice (WT mice: 374 ± 71 μg albumin/mg creatinine, OB cASO mice: 4648 ± 1021 μg/mg and OB mice with APOC3 ASO: 2341 ± 439 μg/mg, p<0.05, n=12-14). Together, this suggests that targeting APOC3 and diabetic dyslipidemia might be beneficial for both diabetes-accelerated atherosclerosis and kidney disease.

Direct targeting of FOXP3 in Tregs with AZD8701, a novel antisense oligonucleotide to relieve immunosuppression in cancer

BackgroundThe Regulatory T cell (Treg) lineage is defined by the transcription factor FOXP3, which controls immune-suppressive gene expression profiles. Tregs are often recruited in high frequencies to the tumor microenvironment...

Abstract 14035: IL-4Ra-Mediated CD206 + Macrophage Activation Promotes Adverse Remodeling in the Failing Heart

Background: In heart failure (HF), cardiac macrophages are largely comprised of CD206 + cells that locally self-renew independent of the blood monocyte pool. We tested the hypothesis that cardiac CD206 + macrophages expressing interleukin (IL)-4Rα are key mediators of adverse left ventricular (LV) remodeling in HF. Methods and Results: Adult male C57BL/6 mice underwent non-reperfused myocardial infarction (MI) to induce HF. HF mice (vs. sham mice) exhibited progressive expansion of cardiac CD206 + macrophages up to 8 w post-MI (accounting for ~80% total macrophages), whereas cardiac CD206 - macrophages peaked at 48 h and then decreased by 90% at 1 w post-MI and beyond. Cardiac CD206 + macrophage levels negatively correlated with LV ejection fraction, and positively correlated with remote zone fibrosis. These cells were predominantly CCR2 - and nearly half expressed IL-4Rα, whereas CD206 - macrophages, monocytes, neutrophils, and T-cells had markedly lower IL-4Rα expression. Bone marrow-derived macrophages (BMDMs) polarized with IL-4 (M[IL-4]) induced myofibroblast activation in vitro . Intramyocardial adoptive transfer of M[IL-4] macrophages (1 x 10 6 cells) into naïve mice induced progressive LV chamber dilation and dysfunction, and augmented cardiac fibrosis over 4 w. Next, sham and HF mice with similar LV remodeling at 4 w post-MI were given IL-4Rα-specific or control antisense oligonucleotides (ASOs) 40 mg/kg i.p. every 3 d for 4 w. HF mice receiving IL-4Rα ASOs exhibited profoundly diminished cardiac CD206 + IL-4Rα + (and total CD206 + ) macrophage levels, substantially less macrophage proliferation and phagocytosis, and improvement of LV dysfunction, hypertrophy, and fibrosis. Moreover, both M[IL-4] CD206 + BMDMs and CD206 + IL-4Rα + macrophages in failing hearts expressed high levels of Fizz1 (found in inflammatory zone 1). Blocking FIZZ1 expression and/or secretion blunted the profibrotic capacity of M[IL-4] CD206 + BMDMs in vitro . Conclusion: CD206 + IL-4Rα + macrophages proliferate and expand in the failing heart and are key drivers of pathological remodeling and fibrosis, in part through the secretion of FIZZ1. Inhibition of CD206 + macrophage IL-4Rα signaling may be a fruitful therapeutic approach for alleviating LV remodeling in HF.

Hepatic Mitochondrial SAB Deletion or Knockdown Alleviates Diet-Induced Metabolic Syndrome, Steatohepatitis, and Hepatic Fibrosis.

The hepatic mitogen-activated protein kinase (MAPK) cascade leading to c-Jun N-terminal kinase (JNK) activation has been implicated in the pathogenesis of nonalcoholic fatty liver (NAFL)/NASH. In acute hepatotoxicity, we previously identified a pivotal role for mitochondrial SH3BP5 (SAB; SH3 homology associated BTK binding protein) as a target of JNK, which sustains its activation through promotion of reactive oxygen species production. Therefore, we assessed the role of hepatic SAB in experimental NASH and metabolic syndrome. In mice fed high-fat, high-calorie, high-fructose (HFHC) diet, SAB expression progressively increased through a sustained JNK/activating transcription factor 2 (ATF2) activation loop. Inducible deletion of hepatic SAB markedly decreased sustained JNK activation and improved systemic energy expenditure at 8weeks followed by decreased body fat at 16weeks of HFHC diet. After 30weeks, mice treated with control-antisense oligonucleotide (control-ASO) developed steatohepatitis and fibrosis, which was prevented by Sab-ASO treatment. Phosphorylated JNK (p-JNK) and phosphorylated ATF2 (p-ATF2) were markedly attenuated by Sab-ASO treatment. After 52weeks of HFHC feeding, control N-acetylgalactosamine antisense oligonucleotide (GalNAc-Ctl-ASO) treated mice fed the HFHC diet exhibited progression of steatohepatitis and fibrosis, but GalNAc-Sab-ASO treatment from weeks 40 to 52 reversed these findings while decreasing hepatic SAB, p-ATF2, and p-JNK to chow-fed levels. Hepatic SAB expression increases in HFHC diet-fed mice. Deletion or knockdown of SAB inhibited sustained JNK activation and steatohepatitis, fibrosis, and systemic metabolic effects, suggesting that induction of hepatocyte Sab is an important driver of the interplay between the liver and the systemic metabolic consequences of overfeeding. In established NASH, hepatocyte-targeted GalNAc-Sab-ASO treatment reversed steatohepatitis and fibrosis.

The choice of negative control antisense oligonucleotides dramatically impacts downstream analysis depending on the cellular background

BackgroundThe lymphatic and the blood vasculature are closely related systems that collaborate to ensure the organism’s physiological function. Despite their common developmental origin, they present distinct functional fates in adulthood that rely on robust lineage-specific regulatory programs. The recent technological boost in sequencing approaches unveiled long noncoding RNAs (lncRNAs) as prominent regulatory players of various gene expression levels in a cell-type-specific manner.ResultsTo investigate the potential roles of lncRNAs in vascular biology, we performed antisense oligonucleotide (ASO) knockdowns of lncRNA candidates specifically expressed either in human lymphatic or blood vascular endothelial cells (LECs or BECs) followed by Cap Analysis of Gene Expression (CAGE-Seq). Here, we describe the quality control steps adopted in our analysis pipeline before determining the knockdown effects of three ASOs per lncRNA target on the LEC or BEC transcriptomes. In this regard, we especially observed that the choice of negative control ASOs can dramatically impact the conclusions drawn from the analysis depending on the cellular background.ConclusionIn conclusion, the comparison of negative control ASO effects on the targeted cell type transcriptomes highlights the essential need to select a proper control set of multiple negative control ASO based on the investigated cell types.

Abstract P101: Suppression Of Serum Amyloid A Limits Progression Of Obesity Associated Abdominal Aortic Aneurysms

Obesity increases the risk for abdominal aortic aneurysms (AAA) in humans, and enhances angiotensin II (AngII)-induced AAA formation in C57BL/6 mice. Obesity is also associated with increases in serum amyloid A (SAA). We previously reported that deficiency of SAA significantly reduces AngII-induced inflammation and AAA in apoE-deficient mice. In this study we investigated whether SAA plays a role in progression of an established AAA in obese C57BL/6 mice. Approach and Results: Male C57BL/6 mice were fed a high fat diet (60% kcal as fat) throughout the study. After 4 months of diet the mice were infused with angiotensin II (AngII) at 1000ng/kg/min until the end of the study. Ultrasound (US) was performed in all mice before and after 28 days of AngII infusion, and mice that had at least a 25% increase in the luminal diameter of the abdominal aorta were stratified by luminal diameter into 3 groups. Group 1 was killed to establish baseline AAA. Groups 2 and 3 continued to receive AngII for a further 8 weeks along with an antisense oligonucleotide (ASO) that suppresses all 3 acute phase SAA isoforms (SAA-ASO), or a control ASO (5 mg/kg/wk). US was repeated at study end to assess AAA progression. Plasma SAA at the end of the experiment was 89.2±83.2 mg/L in the control ASO group, and 18.6±0.7 mg/L in the SAA-ASO group (mean±SD , p=0.008). There was no impact of SAA suppression on body weight, body fat, or blood pressure. After the first 4 weeks of AngII infusion, the average luminal diameter in all mice was 1.81±0.40 mm (mean±SD). Mice that received the control ASO had continued aortic dilation (average luminal aortic diameter 2.06±0.42 mm), whereas the mice that received the SAA-ASO had a significant reduction in progression of aortic dilation (average luminal diameter 1.64±0.43 mm, p=0.0015 for interaction between time and group). Conclusions: We demonstrate for the first time that suppression of SAA protects obese C57BL/6 mice from progression of AngII-induced AAA. Suppression of SAA may be a therapeutic approach to limit AAA progression.

Abstract MP09: MLKL (Mixed Lineage Kinase Domain-like Protein) Is A Novel Regulator Of The Splenic Microenvironment That Restricts Hematopoiesis During Atherosclerosis

During atherosclerosis, macrophages within the aorta undergo necroptosis, a mode of pro-inflammatory cell death that is triggered by the phosphorylation of RIPK1 & RIPK3 and leads to the activation of the mixed lineage kinase domain-like protein (MLKL) and cell lysis. Our previous work demonstrated that while inhibition of MLKL decreased necroptosis and necrotic core in the plaque, unlike RIPK1 & RIPK3 this inhibition did not lead to overall decrease in plaque area, suggesting that MLKL may in fact participate in other processes that drive atherosclerotic plaque development. Because circulating leukocytes are recruited and contribute to the growing atheroma, and these leukocytes are derived from hematopoietic stem and progenitor cells (HSPCs) found in both the bone marrow (BM) and the spleen, we investigated whether these hematopoietic reservoirs became dysregulated upon loss of MLKL during atherogenesis. To induce atherogenesis, Apoe -knockout mice ( Apoe -/-) were fed a high fat-high cholesterol diet for 16 weeks while receiving weekly subcutaneous administration of antisense oligonucleotides (ASOs) to knockdown MLKL expression. In the Apoe -/- mice receiving MLKL ASO we observed a 3.1-fold increase in splenomegaly compared to the control ASO, specifically with an expansion of the splenic red pulp, the area of splenic hematopoiesis. Furthermore, flow cytometry revealed a significant increase in myeloid HSPCs and mature myeloid populations in the spleen, but not the BM, after MLKL knockdown. However, no changes were observed in these hematopoietic measures after transplantation of Ldlr -knockout mice with MLKL-knockout BM, indicating that MLKL restricts hematopoiesis through its regulation of non-hematopoietic cells of the splenic niche. Indeed, upon MLKL knockdown in the Apoe -/- mice we observed a >50% reduction in splenic endothelial cells, which are required to promote HSPC quiescence and repress hematopoiesis. These data therefore demonstrate a novel role for MLKL on preserving splenic endothelial cells to limit immune cell development during atherosclerosis, and more generally, highlight the importance of the dysregulation of the splenic microenvironment to contributing to the inflammatory processes that drive atherosclerosis.