Efficacy and Safety of Inclisiran in Asian Patients: Results From ORION-18.

Background: Management of low-density lipoprotein cholesterol (LDL-C) in Asia remains suboptimal, with ∼50% of patients who are treated with lipid-lowering therapies (LLTs) unable to achieve their guideline-recommended LDL-C goals. Asian-representative studies of the use of inclisiran are needed. Objectives: The authors sought to evaluate the efficacy and safety of inclisiran in Asian patients with atherosclerotic cardiovascular disease (ASCVD) or high risk of ASCVD, as an adjunct to diet and maximally tolerated statin dose, with or without additional LLTs. Methods: The ORION-18 was a phase 3 double-blind trial in which patients were randomized 1:1 to receive either 300 mg inclisiran sodium or matching placebo on days 1, 90, and 270. Percentage change in LDL-C from baseline to day 330 was the primary endpoint. Results: A total of 345 patients (mean age 59.5 years, mean baseline LDL-C 109 mg/dL, 74.7% male) were randomized to inclisiran or placebo. Baseline characteristics were similar in both groups. The percentage decrease in LDL-C from baseline to day 330 was 57.2% (P < 0.001); proprotein convertase subtilisin/kexin type 9 was reduced by 78.3% (P < 0.001). Time-adjusted percentage reduction in LDL-C from baseline after day 90 and up to day 360 was 56.3%. At day 330, 71.7% of participants with inclisiran achieved ≥50% reduction in LDL-C compared with 1.5% with placebo. Over the study period, total cholesterol, apolipoprotein B, and non-high-density lipoprotein cholesterol (HDL-C) levels were decreased significantly, and HDL-C levels increased. The incidence of adverse events with inclisiran was similar to that with placebo. Conclusions: In Asian patients with ASCVD or high risk of ASCVD, inclisiran was effective and safe. (Study of Efficacy and Safety of Inclisiran in Asian Participants With Atherosclerotic Cardiovascular Disease [ASCVD] or ASCVD High Risk and Elevated Low-Density Lipoprotein Cholesterol [LDL-C] [ORION-18]; NCT04765657).

Iridium-catalyzed regioselective C-H sulfonamidation of 1,2,4-thiadiazoles with sulfonyl azides in water.

We have developed a regioselective C-N cross-coupling of 1,2,4-thiadiazoles with sulfonyl azides through iridium catalysis in water. This method tactically linked the 1,2,4-thiadiazoles and sulfonamides together, and the novel molecules increased the diversity of 1,2,4-thiadiazoles which may have potential applications.

Spontaneous development of hepatosteatosis in perilipin-1 null mice with adipose tissue dysfunction.

Fatty liver features triglyceride accumulation in hepatocytes and often occurs with obesity and lipodystrophy in humans. Here, we investigated the mechanism of maladaptive hepatosteatosis with adipose-tissue dysfunction. Perilipin 1 (Plin1) did not exist in hepatocytes but was expressed exclusively in adipocytes as a dual modulator for regulating two principal adipose-tissue functions, triglyceride storage and breakdown. Plin1-/- mice showed decreased fat storage but increased lipolysis and efflux of fatty acids from adipose tissue, and hepatosteatosis spontaneously developed without altered circulating inflammatory adipocytokine levels. Plin1-/- adipose dysfunction impaired insulin sensitivity and hepatic glucose metabolism, which might inhibit gluconeogenesis to produce more intermediates for hepatic lipid synthesis. Indeed, the livers of Plin1-/- mice exhibited upregulated mRNA and protein expression of key enzymes and transcriptional factors for the uptake and transport of fatty acids and for de novo synthesis of triglycerides, but the expression of key enzymes and transcriptional factors for fatty-acid oxidation was downregulated. Biochemical assays in Plin1-/- mice confirmed increased fatty acid synthase activity but decreased activity of mitochondrial carnitine palmitoyltransferase 1 and [3H]-palmitate oxidation in the liver. We concluded that dysregulation of two principal functions, adipose storage and hydrolysis, had deleterious consequences on the hepatic lipid metabolism and thereby caused maladaptive hepatosteatosis. This mouse model might mimic and explain the pathogenesis of hepatosteatosis occurring in two typical disorders of adipose tissue dysfunction, obesity and lipodystrophy, particularly in lipodystrophic patients with Plin1 mutation.

Fascia Origin of Adipose Cells.

Adipocytes might arise from vascular stromal cells, pericytes and endothelia within adipose tissue or from bone marrow cells resident in nonadipose tissue. Here, we identified adipose precursor cells resident in fascia, an uninterrupted sheet of connective tissue that extends throughout the body. The cells and fragments of superficial fascia from the rat hindlimb were highly capable of spontaneous and induced adipogenic differentiation but not myogenic and osteogenic differentiation. Fascial preadipocytes expressed multiple markers of adipogenic progenitors, similar to subcutaneous adipose-derived stromal cells (ASCs) but discriminative from visceral ASCs. Such preadipocytes resided in fascial vasculature and were physiologically active in vivo. In growing rats, adipocytes dynamically arose from the adventitia to form a thin adipose layer in the fascia. Later, some adipocytes appeared to overlay on top of other adipocytes, an early sign for the formation of three-dimensional adipose tissue in fascia. The primitive adipose lobules extended invariably along blood vessels toward the distal fascia areas. At the lobule front, nascent capillaries wrapped and passed ahead of mature adipocytes to form the distal neovasculature niche, which might replenish the pool of preadipocytes and supply nutrients and hormones necessary for continuous adipogenesis. Our findings suggest a novel model for the origin of adipocytes from the fascia, which explains both neogenesis and expansion of adipose tissue. Fascial preadipocytes generate adipose cells to form primitive adipose lobules in superficial fascia, a subcutaneous nonadipose tissue. With continuous adipogenesis, these primitive adipose lobules newly formed in superficial fascia may be the rudiment of subcutaneous adipose tissue. Stem Cells 2016;34:1407-1419.

Proteomic analysis of murine testes lipid droplets.

Testicular Leydig cells contain abundant cytoplasmic lipid droplets (LDs) as a cholesteryl-ester store for releasing cholesterols as the precursor substrate for testosterone biosynthesis. Here, we identified the protein composition of testicular LDs purified from adult mice by using mass spectrometry and immunodetection. Among 337 proteins identified, 144 were previously detected in LD proteomes; 44 were confirmed by microscopy. Testicular LDs contained multiple Rab GTPases, chaperones, and proteins involved in glucuronidation, ubiquination and transport, many known to modulate LD formation and LD-related cellular functions. In particular, testicular LDs contained many members of both the perilipin family and classical lipase/esterase superfamily assembled predominately in adipocyte LDs. Thus, testicular LDs might be regulated similar to adipocyte LDs. Remarkably, testicular LDs contained a large number of classical enzymes for biosynthesis and metabolism of cholesterol and hormonal steroids, so steroidogenic reactions might occur on testicular LDs or the steroidogenic enzymes and products could be transferred through testicular LDs. These characteristics differ from the LDs in most other types of cells, so testicular LDs could be an active organelle functionally involved in steroidogenesis.

Defective differentiation of adipose precursor cells from lipodystrophic mice lacking perilipin 1.

Perilipin 1 (Plin1) localizes at the surface of lipid droplets to regulate triglyceride storage and hydrolysis in adipocytes. Plin1 defect leads to low adiposity in mice and partial lipodystrophy in human. This study investigated the roles of Plin1 in adipocyte differentiation. Plin1 null (-/-) mice showed plenty of multilocular adipocytes and small unilocular adipocytes in adipose tissue, along with lack of a subpopulation of adipose progenitor cells capable of in vivo adipogenesis and along with downregulation of adipogenic pathway. Before initiation of differentiation, adipose stromal-vascular cells (SVCs) from Plin1-/- mice already accumulated numerous tiny lipid droplets, which increased in number and size during the first 12-h induction but thereafter became disappeared at day 1 of differentiation. The adipogenic signaling was dysregulated despite protein level of PPARγ was near normal in Plin1-/- SVCs like in Plin1-/- adipose tissue. Heterozygous Plin1+/- SVCs were able to develop lipid droplets, with both the number and size more than in Plin1-/- SVCs but less than in Plin1+/+ SVCs, indicating that Plin1 haploinsufficiency accounts for attenuated adipogenesis. Aberrant lipid droplet growth and differentiation of Plin1-/- SVCs were rescued by adenoviral Plin1 expression and were ameliorated by enhanced or prolonged adipogenic stimulation. Our finding suggests that Plin1 plays an important role in adipocyte differentiation and provides an insight into the pathology of partial lipodystrophy in patients with Plin1 mutation.

Development of hypertrophic cardiomyopathy in perilipin-1 null mice with adipose tissue dysfunction.

AIMS: Perilipin-1 (Plin1), exclusively located on the surface of lipid droplets in adipocytes, regulates the storage and hydrolysis of adipose triglycerides. Plin1 deficiency primarily causes low adiposity and aberrant lipolysis in rodents and humans. Here, we investigated whether adipose tissue dysfunction in perilipin-1 null (Plin1⁻/⁻) mice has maladaptive consequences for the heart and an association with hypertrophic cardiomyopathy. METHODS AND RESULTS: Perilipin-1 was expressed specifically in adipocytes but was undetectable in cardiomyocytes. Plin1⁻/⁻ mice were histologically lipodystrophic, with reduced body fat. Paradoxically, the adipocytes of Plin1⁻/⁻ mice, like those of obese and diabetic mammals, showed robust basal lipolysis and fatty acid efflux to the plasma. Such adipose tissue dysfunctions accounted for the ectopic lipid accumulation and enhanced fatty acid transport and oxidation in Plin1⁻/⁻ mouse hearts. Excessive fatty acid ß-oxidation and lipotoxicity induced excessive production of reactive oxygen species and oxidative stress because antioxidative capacity was reduced in cardiomyocytes, These malefactors injured the myocardial structure and function, as evidenced by disorganized myofilaments as well as irregular and swollen mitochondria with disrupted cristae. Finally, Plin1⁻/⁻ mice showed grossly visible cardiac hypertrophy, with progressively up-regulated expression of hypertrophy and dysfunction marker genes, leading to heart failure, particularly with left ventricular diastolic dysfunction at 20 weeks of age. CONCLUSIONS: Adipose tissue dysfunction may have deleterious effects on the heart and contribute to the development of hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy in Plin1⁻/⁻ mice with adipose tissue dysfunction may mimic and mechanistically explain the cardiomyopathies occurring in two typical adipose tissue disorders in humans, lipodystrophy and obesity.