Excessive fatty acids activate PRMT5/MDM2/Drosha pathway to regulate miRNA biogenesis and lipid metabolism.

BACKGROUND: Excessive fatty acids in the liver lead to the accumulation of lipotoxic lipids and then cellular stress to further evoke the related disease, like non-alcoholic fatty liver disease (NAFLD). As reported, fatty acid stimulation can cause some specific miRNA dysregulation, which caused us to investigate the relationship between miRNA biogenesis and fatty acid overload. METHODS: Gene expression omnibus (GEO) dataset analysis, miRNA-seq, miRNA cleavage assay, RT-qPCR, western blotting, immunofluorescence and co-immunoprecipitation (co-IP) were used to reveal the change of miRNAs under pathological status and explore the relevant mechanism. High fat, high fructose, high cholesterol (HFHFrHC) diet-fed mice transfected with AAV2/8-shDrosha or AAV2/8-shPRMT5 were established to investigate the in vivo effects of Drosha or PRMT5 on NAFLD phenotype. RESULTS: We discovered that the cleavage of miRNAs was inhibited by analysing miRNA contents and detecting some representative pri-miRNAs in multiple mouse and cell models, which was further verified by the reduction of the Microprocessor activity in the presence of palmitic acid (PA). In vitro, PA could induce Drosha, the core RNase III in the Microprocessor complex, degrading through the proteasome-mediated pathway, while in vivo, knockdown of Drosha significantly promoted NAFLD to develop to a more serious stage. Mechanistically, our results demonstrated that PA can increase the methyltransferase activity of PRMT5 to degrade Drosha through MDM2, a ubiquitin E3 ligase for Drosha. The above results indicated that PRMT5 may be a critical regulator in lipid metabolism during NAFLD, which was confirmed by the knocking down of PRMT5 improved aberrant lipid metabolism in vitro and in vivo. CONCLUSIONS: We first demonstrated the relationship between miRNA dosage and NAFLD and proved that PA can activate the PRMT5-MDM2-Drosha signalling pathway to regulate miRNA biogenesis.

Enantiomeric pairs of macrocyclic acylphloroglucinols from Syzygium szemaoense.

Two enantiomeric pairs of macrocyclic acylphloroglucinols (1a/1b and 2a/2b) with an unprecedented carbon skeleton featuring a bicyclo[12.3.1]octadecane core, together with an undescribed biogenetically related long-chain acylphloroglucinol (3), were isolated from Syzygium szemaoense. Their structures were fully established by spectroscopic method, X-ray crystallographic analysis, and ECD calculation. Compounds 1b and 2a/2b exhibited inhibition against death-associated protein kinase-related apoptosis inducing protein kinase 2 (DRAK2) and ATP citrate lyase (ACLY), respectively.

The clinical role of serum cell division control 42 in coronary heart disease.

Cell division control 42 (CDC42) regulates blood lipids, atherosclerosis, T cell differentiation and inflammation, which is involved in the process of coronary heart disease (CHD). This study aimed to evaluate the CDC42 level and its correlation with clinical features, the T-helper 17 (Th17)/regulatory-T (Treg) cell ratio and prognosis in CHD patients. In total, 210 CHD patients, 20 healthy controls and 20 disease controls were enrolled. Serum CDC42 levels of all participants were measured by enzyme-linked immunosorbent assay. In CHD patients, Th17 and Treg cells were discovered by flow cytometry; CHD patients were followed-up for a median of 16.9 months (range of 2.5-38.2 months). CDC42 level was lowest in CHD patients (median (interquartile range (IQR)): 402.5 (287.3-599.0) pg/mL), moderate in disease controls (median (IQR): 543.5 (413.0-676.3) pg/mL) and highest in healthy controls (median (IQR): 668.0 (506.5-841.3) pg/mL) (p < .001). Moreover, in CHD patients, lower CDC42 level was related to more prevalent diabetes mellitus (p = .021), and higher levels of C-reactive protein (p = .001), Gensini score (p = .006), Th17 cells (p = .001) and Th17/Treg ratio (p < .001) but was associated with lower Treg cells (p = .018). Furthermore, CDC42 low level [below the median level (402.5 pg/mL) of CDC42 in CHD patients] was correlated with higher accumulating major adverse cardiovascular event (MACE) risk (p = .029), while no correlation was found between the quartile of CDC42 level and accumulating MACE risk in CHD patients (p = .102). The serum CDC42 level is decreased and its low level is related to higher Th17/Treg ratio and increased accumulating MACE risk in CHD patients.

Serum brain-derived neurotrophic factor in coronary heart disease: Correlation with the T helper (Th)1/Th2 ratio, Th17/regulatory T (Treg) ratio, and major adverse cardiovascular events.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) exerts protective roles against dyslipidemia, atherosclerosis, and inflammation in cardiovascular diseases; meanwhile, it retards CD4+ T cell differentiation into T helper (Th)1 and Th17 cells. Hence, this study aimed to investigate the linkage of serum BDNF with Th1/Th2 ratio, Th17/regulatory T (Treg) ratio, and major adverse cardiovascular events (MACE) risk in the coronary heart disease (CHD) patients. METHODS: This prospective study detected serum BDNF in 210 CHD patients, 50 disease controls (DCs), and 50 healthy controls (HCs) using an enzyme-linked immunosorbent assay. For CHD patients only, the proportion of Th1, Th2, Th17, and Treg cells in blood CD4+ T cells was calculated by flow cytometry. RESULTS: The BDNF varied among CHD patients, DC, and HC (p < 0.001). Specifically, BDNF was declined in CHD patients compared with DCs (p < 0.001) and HCs (p < 0.001). In CHD patients, BDNF was negatively related to Th1 cells (p = 0.031), Th1/Th2 ratio (p = 0.026), Th17 cells (p = 0.001), and Th17/Treg ratio (p = 0.002). Concerning the prognosis, BDNF was reduced in patients with MACE occurrence compared to patients without MACE occurrence (p = 0.006). Furthermore, BDNF showed a trend (lacked statistical significance) to relate to longer MACE-free survival (p = 0.059). Besides, BDNF was related to the absence of obesity (p = 0.019), decreased total cholesterol (p = 0.043), low-density lipoprotein cholesterol (p = 0.019), C-reactive protein (p = 0.012), and Gensini score (p = 0.005). CONCLUSION: Serum BDNF negatively correlates with Th1/Th2 ratio, Th17/Treg ratio, and estimates lower MACE risk in CHD patients.

Clinical value of long non-coding RNA KCNQ1OT1 in estimating the stenosis, lipid level, inflammation status, and prognostication in coronary heart disease patients.

OBJECTIVE: Long non-coding RNA KQT-like subfamily, member 1 opposite strand/antisense transcript 1 (KCNQ1OT1) could regulate lipid metabolism, vascular smooth muscle cell function, inflammation, and atherosclerosis. This study aimed to evaluate whether lncRNA KCNQ1OT1 could serve as a biomarker for reflecting coronary heart disease (CHD) patients' disease situation and prognosis. METHODS: LncRNA KCNQ1OT1 expression was determined in peripheral blood mononuclear cells from 267 CHD patients, 50 disease controls (DCs) (unexplained chest pain), and 50 healthy controls (HCs) by the RT-qPCR method. TNF-α, IL-17A, VCAM-1, and ICAM-1 were determined by the ELISA procedure in serum from CHD patients only. The mean (95% confidential interval) follow-up duration was 16.0 (15.3-16.8) months. RESULTS: LncRNA KCNQ1OT1 was highest in CHD patients, followed by DCs, and lowest in HCs (p < 0.001). LncRNA KCNQ1OT1 could distinguish the CHD patients from DCs (area under the curve [AUC]: 0.757) and from the HCs (AUC: 0.880). LncRNA KCNQ1OT1 was positively associated with triglyceride (p = 0.026), low-density lipoprotein cholesterol (p = 0.023), cardiac troponin I (p = 0.023), and C-reactive protein (p = 0.001). Besides, lncRNA KCNQ1OT1 was also positively linked with the Gensini score (p = 0.008). Furthermore, lncRNA KCNQ1OT1 was positively related to the TNF-α (p < 0.001), IL-17A (p = 0.008), and VCAM-1 (p = 0.003). LncRNA KCNQ1OT1 was elevated in CHD patients with MACE compared to those without MACE (p = 0.006); moreover, lncRNA KCNQ1OT1 high was associated with shorter MACE-free survival (p = 0.018). CONCLUSION: Circulating lncRNA KCNQ1OT1 expression not only reflects the stenosis degree, blood lipid level, and inflammation status but also predicts the MACE risk, while a large-scale study is needed for verification.

Rhodomeroterpene alleviates macrophage infiltration and the inflammatory response in renal tissue to improve acute kidney injury.

Inflammation is broadly recognized as an important factor in the pathogenesis of acute kidney injury (AKI), but pharmacological approaches to alleviate inflammation in AKI have not been proved successful in clinical trials. Macrophage infiltration into renal tissue promotes inflammatory responses that contribute to the pathogenesis of AKI. Suppression of renal tissue inflammatory responses is postulated to improve renal injury of patients and animals. Rhodomeroterpene (RMT) is a novel meroterpenoid isolated from the Rhododendron genus that was shown to exert anti-inflammatory action in vivo or in vitro in this study. We investigated the treatment effects of RMT on LPS-induced sepsis and two different AKI models. The results showed that pretreatment with RMT (30 mg kg-1  d-1 , ip, for 3 days) significantly inhibited acute inflammatory responses in LPS-induced septic mice. In both renal ischemia-reperfusion injury (I/R) and sepsis-induced AKI models, RMT (30 mg kg-1  d-1 , ip, for 3 days) ameliorated renal function and injury and alleviated inflammation by reducing the infiltration of immune cells, including macrophages and neutrophils. Furthermore, our study demonstrated that RMT inhibits inflammatory responses in macrophages. The anti-inflammatory effects of RMT may be due to the inactivation of the IKK/NF-κB and PI3K/PDK1/Akt inflammatory signaling pathways in macrophages. Collectively, our findings indicate that RMT ameliorates renal injury and alleviates the renal inflammatory state in different AKI models, suggesting that RMT may be a potential agent for the treatment of AKI.

Dimeric sesquiterpenoids and anti-inflammatory constituents of Sarcandra glabra.

Three novel dimeric sesquiterpenoids named sarglanoids A-C (1-3), two undescribed monomeric sesquiterpenoids named sarglanoids D (4) and E (5), and seven known compounds (6-12), were isolated and characterized from Sarcandra glabra. Compound 1 represents the first heterodimeric sesquiterpenoid composed of a eudesmane and an eremophilane moiety. Compound 2 possesses two eremophilane monomers featuring an undescribed dimerization pattern. Compound 3 is a symmetric eudesmane dimer with a rare 1,4-epoxy bridge. The structures of 1-5 were fully identified by spectroscopic methods and single-crystal X-ray diffraction experiments. Compounds 3 and 6 suppressed the LPS-triggered inflammatory responses in RAW 264.7 cells.

Two New Cytotoxic Maytansinoids Targeting Tubulin from Trewia nudiflora.

Two new maytansinoids, N-methyltreflorine (1: ) and methyltrewiasine (2: ), were isolated from the dried fruits of Trewia nudiflora, together with three known congeners (3:  - 5: ). Their structures were elucidated by spectroscopic methods, and the absolute configuration of 1: and 2: was determined by X-ray crystallographic analysis. Compounds 1:  - 5: exhibited strong cytotoxicity against human tumor cell lines, including HeLa, MV-4 - 11, and MCF-7, with IC50 values ranging from 0.12 to 11 nM. Compounds 1: and 4: also showed inhibitory activity against the MCF-7/ADR cell line with IC50 values of 13 and 28 nM, respectively. Compounds 1: and 2: significantly inhibited tubulin polymerization in vitro with IC50 values of 3.6 and 3.2 µM, respectively.

MicroRNA-34a in coronary heart disease: Correlation with disease risk, blood lipid, stenosis degree, inflammatory cytokines, and cell adhesion molecules.

BACKGROUND: MicroRNA-34a (miR-34a) plays an essential role in regulating blood lipid, inflammation, cell adhesion molecules, and atherosclerosis, the latter factors are closely involved in the etiology of coronary heart disease (CHD). However, the clinical value of miR-34a in CHD patients' management is rarely reported. Hence, this study aimed to assess the correlation of miR-34a with disease risk, blood lipid, coronary artery stenosis, inflammatory cytokines, and cell adhesion molecules of CHD. METHODS: A total of 203 CHD patients and 100 controls were recruited in this study, then their plasma samples were collected to detect the miR-34a by reverse transcription quantitative polymerase chain reaction. Furthermore, serum samples from CHD patients were obtained for inflammatory cytokines and cell adhesion molecule measurement by enzyme-linked immunosorbent assay. RESULTS: MiR-34a was elevated in CHD patients compared to controls (p < 0.001) and it disclosed a good diagnostic value of CHD (area under curve: 0.899, 95% confidence interval: 0.865-0.934). Besides, miR-34a positively correlated with triglyceride (p < 0.001), total cholesterol (p = 0.022) and low-density lipoprotein cholesterol (p = 0.004), but not with high-density lipoprotein cholesterol (p = 0.110) in CHD patients. Moreover, miR-34a associated with Gensini score in CHD patients (p < 0.001). As to inflammation-related indexes and cell adhesion molecules, MiR-34a expression was positively linked with C-reactive protein (p < 0.001), tumor necrosis factor alpha (p = 0.005), interleukin (IL)-1ß (p = 0.020), IL-17A (p < 0.001), vascular cell adhesion molecule-1 (p < 0.001), and intercellular adhesion molecule-1 (p = 0.010) in CHD patients, but not with IL-6 (p = 0.118) and IL-10 (p = 0.054). CONCLUSION: MiR-34a might serve as a biomarker in assistance of diagnosis and management of CHD.

Dimeric clerodane diterpenoids and antiviral constituents of Dodonaea viscosa.

Three unprecedented dimeric clerodane diterpenoids, dodovisdimers A-C (1-3), along with six known clerodane monomers (4-9), were isolated from Dodonaea viscosa. Compounds 1-3 may be biosynthetically formed via an intermolecular Diels-Alder [4+2] cycloaddition between the coexisting monomers 4-7. The structures of these clerodanes were characterized by spectroscopic techniques, X-ray crystallographic study, and ECD calculations. Some isolates exerted antiviral effects on human influenza A virus (H3N2) in vitro.

Two New Oleanane-Triterpenoid Saponins from Clinopodium gracile.

Two new oleanane-triterpenoid saponins, clinograsaponins A (1) and B (2), together with twelve known ones (3-14), were isolated from the whole herb of Clinopodium gracile (Bentham) Matsumura. Their structures were determined by spectroscopic analysis and chemical method. All the isolated compounds were evaluated for their activities against ATP-citrate lyase (ACLY) and nuclear factor kappa B (NF-κB).

[Studies on alkaloid constituents of Fritillaria yuminensis].

Twelve alkaloids were isolated from the bulbs of Fritillaria yuminensis by column chromatography over silica gel, ODS, and Sephadex LH-20, as well as RP-HPLC. Their structures were identified mainly by NMR and MS analyses as yubeinine(1), imperialine(2), delavinone(3), tortifoline(4), hupehenizioiside(5), imperialine-ß-D-glucoside(6), kuroyurinidine(7), pengbeisine A(8), walujewine A(9), peimisine-3-O-ß-D-glucopyranoside(10), solanidine-3-O-α-L-rhamnopyranosyl-(1→2)-ß-D-glucopyranoside(11), and solanidine-3-O-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→4)]-ß-D-glucopyranoside(12). Compounds 4-12 were obtained from F. yuminensis for the first time.

[Flavonoids with PTP1B inhibition from Broussonetia papyrifera].

Eleven flavonoids were isolated from the twigs of Broussonetia papyrifera by column chromatography over silica gel,ODS,MCI gel,and Sephadex LH-20,as well as RP-HPLC.Their structures were identified by spectroscopic methods including NMR,MS,UV,and IR as broupapyrin A(1),5,7,3',4'-tetrahydroxy-3-methoxy-8-geranylflavone(2),8-prenylquercetin-3-methyl ether(3),broussonol D(4),broussoflavonol B(5),uralenol(6),broussonol E(7),8-(1,1-dimethylallyl)-5'-(3-methylbut-2-enyl)-3',4',5,7-tetrahydroxyflanvonol(8),broussoflavonol E(9),4,2',4'-trihydroxychalcone(10),and butein(11).Compound 1 is a new isoprenylated flavonol.Compounds 3,6,10,and 11 were obtained from the genus Broussonetia for the first time,and 4 and 7 were firstly discovered in B.papyrifera.Compounds 1-5 and 7-9 showed significant inhibitory effects on PTP1 B with IC50 values ranging from(0.83±0.30) to(4.66±0.83) µmol·L-1.

Enantiomeric Pairs of Meroterpenoids with Diverse Heterocyclic Systems from Rhododendron nyingchiense.

Eight enantiomeric pairs of new meromonoterpenoids (1a/1b-8a/8b) and four known compounds (9-12) were isolated from Rhododendron nyingchiense. Their structures were established by spectroscopic methods, quantum chemical calculations, and X-ray crystallography. The enantiomeric pairs were acquired from scalemic mixtures by chiral-phase HPLC and showed diverse heterocyclic frameworks. Compounds 1a/1b possess a rare 6/7/5/5 heterocyclic system, and 2a/2b incorporate a new 6/6/3/5 heterocyclic system featuring a quinone motif. Compounds 3a/3b represent the first meroterpenoids with a 6/6/5 ring system from the Rhododendron genus. Putative biosynthetic pathways of these compounds are proposed. Compounds 1b, 2a-4a, 8a, 8b, and 11 exhibited weak inhibitory effects on PTP1B, with IC50 values ranging from 5.7 ± 0.5 to 61.0 ± 4.8 µM.

5,4'-Dihydroxy-7,8-dimethoxyflavanone and Aliarin from Dodonaea viscosa Are Activators of PPARγ.

PPARγ agonists are widely used medications in diabetes mellitus therapy. Their role in improving adipose tissue function contributes to antidiabetic effects. The extracts of Dodonaea viscosa have been reported to exert antidiabetic activity. However, the effective mediators and the underlying mechanisms were largely unknown. In this study, we investigated the action on PPARγ transactivation and adipocyte modulation of two typical flavonoid constituents from D. viscosa, 5,4'-dihydroxy-7,8-dimethoxyflavanone and aliarin. Our results showed that 5,4'-dihydroxy-7,8-dimethoxyflavanone and aliarin were potential partial PPARγ agonists. The compounds induced adipogenesis in 3T3-L1 cells, with an upregulated adiponectin mRNA level and enhanced insulin sensitivity. The favorable effects of 5,4'-dihydroxy-7,8-dimethoxyflavanone, aliarin, and other flavonoid constituents on adipocytes might contribute to the antidiabetic efficacy of D. viscosa.

Vistriterpenoids A and B, Two New 24-Nor-oleanane Triterpenoids from Dodonaea viscosa.

Two new triterpenoids, vistriterpenoids A (1) and B (2), and four known ones, were acquired from Dodonaea viscosa. Compounds 1 and 2 represent the 24-nor-oleanane triterpenoids isolated from the genus Dodonaea for the first time. Their structures were identified based on extensive spectroscopic methods. Compounds 1, 2, 5, and 6 exerted inhibitory activities against PTP1B in vitro.

Isoprenylated phenolic compounds with tyrosinase inhibition from Morus nigra.

A new isoprenylated sanggenon-type flavanone, nigrasin K (1), together with three known analogs (2-4) and five known Diels-Alder adducts (5-9), were isolated from the twigs of Morus nigra. Their structures were elucidated by spectroscopic methods. Sanggenon M (2), chalcomoracin (5), sorocein H (6), kuwanon J (7), sanggenon C (8), and sanggenon O (9) showed significant inhibitory effects on mushroom tyrosinase.

Five Pairs of Meroterpenoid Enantiomers from Rhododendron capitatum.

Chemical investigation on the aerial parts of Rhododendron capitatum resulted in the discovery of five enantiomeric pairs of new meroterpenoids, (+)-/(-)-rhodonoids C (1a and 1b), E (3a and 3b), F (4a and 4b), and (-)-/(+)-rhodonoids D (2a and 2b) and G (5a and 5b). These enantiomeric pairs existed as partial racemates in a plant and were obtained by chiral HPLC separation. Their structures with absolute configurations were assigned by spectroscopic data, single-crystal X-ray diffraction, and ECD analysis. Compounds 1a and 1b are the first pair of meromonoterpenes incorporating an unprecedented 6/6/6/5 ring system, and 1a showed antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro. Compounds 2a and 2b are the first examples of meromonoterpenes featuring a unique 6/6/5/5 ring system.

New Cytotoxic Alkylated Chalcones from Fatoua villosa.

Three new alkylated chalcones, villosins A - C (1 - 3), five known analogues, together with ten known coumarins, were isolated from Fatoua villosa. The structures of the new compounds were elucidated by extensive spectroscopic analysis, including 1D-, 2D-NMR, and MS data. Compounds 1 - 3 showed cytotoxicity against five kinds of human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) with IC50 values ranging from 1.4 ± 0.1 to 5.7 ± 0.3 µm.

New Alkaloids and α-Glucosidase Inhibitory Flavonoids from Ficus hispida.

Two new pyrrolidine alkaloids, ficushispimines A (1) and B (2), a new ω-(dimethylamino)caprophenone alkaloid, ficushispimine C (3), and a new indolizidine alkaloid, ficushispidine (4), together with the known alkaloid 5 and 11 known isoprenylated flavonoids 6 - 16, were isolated from the twigs of Ficus hispida. Their structures were elucidated by spectroscopic methods. Isoderrone (8), 3'-(3-methylbut-2-en-1-yl)biochanin A (11), myrsininone A (12), ficusin A (13), and 4',5,7-trihydroxy-6-[(1R*,6R*)-3-methyl-6-(1-methylethenyl)cyclohex-2-en-1-yl]isoflavone (14) showed inhibitory effects on α-glucosidase in vitro.