Telmisartan ameliorates adipoR1 and adipoR2 expression via PPAR-γ activation in the coronary artery and VSMCs

Modulator Effect of AT1 Receptor Knockdown on THP-1 Macrophage Proinflammatory Activity

Currently, it is known that angiotensin II (AngII) induces inflammation, and an AT1R blockade has anti-inflammatory effects. The use of an AT1 receptor antagonist promotes the inhibition of the secretion of multiple proinflammatory cytokines in macrophages, as well as a decrease in the concentration of reactive oxygen species. The aim of this study was to determine the effect of AT1 receptor gene silencing on the modulation of cytokines (e.g., IL-1β, TNF-α, and IL-10) in THP-1 macrophages and the relation to the gene expression of NF-κB.

MATERIALS AND METHODS

We evaluated the gene expression of PPAR-γ in THP-1 macrophages using PMA (60 ng/mL). For the silencing, cells were incubated with the siRNA for 72 h and telmisartan (10 µM) was added to the medium for 24 h. After that, cells were incubated during 1 and 24 h, respectively, with Ang II (1 µM). The gene expression levels of AT1R, NF-κB, and cytokines (IL-1β, TNF-α, and IL-10) were measured by RT-qPCR.

RESULTS

We observed that silencing of the AT1 receptor causes a decrease in the expression of mRNA of proinflammatory cytokines (IL-1β and TNF-α), NF-κB, and PPAR-γ.

CONCLUSIONS

We conclude that AT1R gene silencing is an alternative to modulating the production of proinflammatory cytokines such as TNF-α and IL-1β via NF-κB in macrophages and having high blood pressure decrease.

Nicotine Impairs the Anti-Contractile Function of Perivascular Adipose Tissue by Inhibiting the PPARγ-Adiponectin-AdipoR1 Axis

Nicotine is an addictive compound found in cigarette smoke that leads to vascular dysfunction and cardiovascular diseases. Perivascular adipose tissue (PVAT) exerts an anti-contractile effect on the underlying vasculature through the production of adipokines, such as adiponectin, which acts on adiponectin receptors 1 (adipoR1) to cause vasorelaxation. Peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor that regulates adiponectin gene expression and PVAT development. This study aimed to determine the effect of nicotine on the anti-contractile function of PVAT via the PPARγ-adiponectin-adipoR1 axis. Male Sprague Dawley rats were divided into a control group (given normal saline), a nicotine group (given 0.8 mg/kg of nicotine), and a nicotine + PPARγ agonist group (given nicotine and 5 mg/kg of telmisartan). Thoracic aorta PVAT was harvested after 21 days of treatment. The results showed that nicotine reduced the anti-contractile effect of PVAT on the underlying thoracic aorta. Nicotine also decreased the gene and protein expression of PPARγ, adiponectin, and adipoR1 in PVAT. Treatment with telmisartan restored the anti-contractile effect of PVAT and increased the gene and protein expression of PPARγ, adiponectin, and adipoR1 in PVAT. In conclusion, nicotine attenuates the anti-contractile function of PVAT through inhibition of the PPARγ-adiponectin-adipoR1 axis.

Nickel-Catalyzed C-S Reductive Cross-Coupling of Alkyl Halides with Arylthiosilanes toward Alkyl Aryl Thioethers

A nickel-catalyzed C-S reductive cross-coupling of alkyl halides with arylthiosilanes for producing alkyl aryl thioethers is developed. This reaction is initiated by umpolung transformations of arylthiosilanes followed by C-S reductive cross-coupling with alkyl halides to manage an electrophilic alkyl group onto the electrophilic sulfur atom and then construct a C(sp³)-S bond, and features exquisite chemoselectivity, excellent tolerance of diverse functional groups, and wide applications for late-stage modification of biologically relevant molecules.

Overexpressing circ_0000831 is sufficient to inhibit neuroinflammation and vertigo in cerebral ischemia through a miR-16-5p-dependent mechanism

Circular RNAs (circRNAs) hold potential as stroke-related biomarkers due to involvement in various pathophysiological processes associated with cerebral ischemia and stability in peripheral blood. Differentially expressed circulating circRNAs were identified by preliminary sequencing analysis, through which we identified underexpressed circ_0000831 in ischemic stroke (IS). Validation was performed in peripheral blood of IS patients by quantitative polymerase chain reaction. Microglia was exposed to oxygen-glucose deprivation (OGD), where polarization phenotypes and inflammation were assessed. Middle cerebral artery occlusion was performed in mice to mimic ischemic stroke-induced vertigo, where cerebral blood flow, neurological deficits, vertigo degree, infarct area, inflammation and cell apoptosis were assayed in response to ectopic expression and knockdown of circ_0000831, miR-16-5p, and AdipoR2. Mechanically, circ_0000831 bound to miR-16-5p and downregulated miR-16-5p, and AdipoR2 was targeted by miR-16-5p and increased PPARγ expression in microglia. Furthermore, circ_0000831, AdipoR2, or PPARγ overexpression or miR-16-5p inhibition alleviated neuroinflammation, vertigo, neurological deficit, and cell apoptosis in MCAO mice. Consistently, circ_0000831, AdipoR2, or PPARγ upregulation or miR-16-5p downregulation diminished apoptosis and inflammation of OGD-induced microglia. Consequently, these findings pinpoint the circ_0000831/miR-16-5p/AdipoR2 axis as an essential signaling pathway during ischemia stroke. Thus, the circRNA circ_0000831 may work as a possible target for novel treatment in patients with ischemic stroke.

Cardioprotective effects of azilsartan compared with that of telmisartan on an in vivo model of myocardial ischemia-reperfusion injury

Azilsartan is found to be more potent than other angiotensin receptor blockers in reducing blood pressure. However, its effect on the heart following myocardial infarction remains to be established. For the first time, we investigated the peroxisome proliferator-activated receptor-γ (PPAR-γ) agonistic and cardioprotective properties of azilsartan. Computational modeling studies of interactions between azilsartan and PPAR-γ revealed azilsartan as an agonist of PPAR-γ and showed the mechanism of azilsartan in cardioprotection. Our study compared the cardioprotective potential of telmisartan to that of azilsartan in a murine model of myocardial ischemia-reperfusion injury by comparing their antioxidant, ant apoptotic, anti-inflammatory, mitogen-activated protein kinase (MAPK)-modulating ability, and PPAR-γ agonistic activity. Male Wistar rats were grouped into four to receive vehicle (dimethyl sulfoxide [0.05%] 2 ml/kg) telmisartan (10 mg/kg p.o.), azilsartan (10 mg/kg p.o.) or azilsartan with specific PPAR-γ blocker, GW 9662 for 28 days. Ischemia was induced for 45 min on the 29th day followed by 60 min of reperfusion. Telmisartan and azilsartan pretreatment significantly nearly normalized cardiac parameters and preserved structural changes. Both drugs inhibited oxidative burst, inflammation, as well as cell death by modulating apoptotic protein expression along with reduction in 4',6-diamidino-2-phenylindole/terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. An increment in pro-survival kinase ERK paralleled with a reduction in p38 and JNK was also revealed by MAPK pathway studies, after administration of these drugs. Interestingly, the aforementioned changes induced by both drugs were reversed by administration of the specific PPAR-γ antagonist, GW9662. However, we found that azilsartan upregulated PPAR-γ to a lesser extent as compared to telmisartan and the latter may be preferred in hypertensive patients at risk of myocardial infarction.

NPY1R-targeted peptide-mediated delivery of a dual PPARα/γ agonist to adipocytes enhances adipogenesis and prevents diabetes progression

Objective

PPARα/γ dual agonists have been in clinical development for the treatment of metabolic diseases including type 2 diabetes and dyslipidemia. However, severe adverse side effects led to complications in clinical trials. As most of the beneficial effects rely on the compound activity in adipocytes, the selective targeting of this cell type is a cutting-edge strategy to develop safe anti-diabetic drugs. The goal of this study was to strengthen the adipocyte-specific uptake of the PPARα/γ agonist tesaglitazar via NPY₁R-mediated internalization.

Methods

NPY₁R-preferring peptide tesaglitazar-[F⁷, P³⁴]-NPY (tesa-NPY) was synthesized by a combination of automated SPPS and manual couplings. Following molecular and functional analyses for proof of concept, cell culture experiments were conducted to monitor the effects on adipogenesis. Mice treated with peptide drug conjugates or vehicle either by gavage or intraperitoneal injection were characterized phenotypically and metabolically. Histological analysis and transcriptional profiling of the adipose tissue were performed.

Results

In vitro studies revealed that the tesaglitazar-[F⁷, P³⁴]-NPY conjugate selectively activates PPARγ in NPY₁R-expressing cells and enhances adipocyte differentiation and adiponectin expression in adipocyte precursor cells. In vivo studies using db/db mice demonstrated that the anti-diabetic activity of the peptide conjugate is as efficient as that of systemically administered tesaglitazar. Additionally, tesa-NPY induces adipocyte differentiation in vivo.

Conclusions

The use of the tesaglitazar-[F7, P34]-NPY conjugate is a promising strategy to apply the beneficial PPARα/γ effects in adipocytes while potentially omitting adverse effects in other tissues.

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Tesaglitazar-NPY targets adipocytes via NPY₁R receptor-mediated internalization.

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Peptide-drug conjugate is specifically delivered to NPY₁R-expressing cells.

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Release of tesaglitazar in adipocytes activates PPARγ.

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Drug delivery enhances adipocyte differentiation and adiponectin expression.

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Peptide conjugate exhibits antidiabetic activity in vivo.

Inhibition of miR-19a protects neurons against ischemic stroke through modulating glucose metabolism and neuronal apoptosis

Background

Accumulating evidence has shown that altered microRNA (miR) modulation is implicated in the pathologies of ischemic stroke. However, it is unclear whether and how hsa-miR-19a-3p mediates cerebral ischemic injury. Herein, we investigated the functional role of miR-19a-3p in cerebral ischemic injury and explored its underlying regulatory mechanism.

Methods

In vivo ischemic/reperfusion (I/R) neuronal injury and in vitro oxygen-glucose deprivation (OGD) were established. Expression of miR-19a-3p was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Glucose uptake, lactate production, and apoptosis were determined. ADIPOR2 was predicted as a target of miR-19a-3p in silico and experimentally validated by qRT-PCR, Western blot analysis and luciferase assay assays.

Results

MiR-19a expression was significantly downregulated and upregulated in rat neurons and astrocytes, respectively (P < 0.01). A significantly elevated level of miR-19a-3p was found in I/R and OGD models in comparison to sham/control groups (P < 0.01). Expression of the glycolysis enzyme markers LDHA, PKM2, HK2, Glut1 and PDK1, apoptosis-related factors levels, apoptosis, glucose uptake, and lactate production were significantly repressed by both I/R and OGD (P < 0.01 in each case). Moreover, miR-19a-3p mimic aggravated, while miR-19a-3p inhibitor alleviated, the above observations. Adipor2 was predicted and confirmed to be a direct target of miR-19a. Furthermore, restoration of Adipor2 reversed miR-19a-3p-induced effects.

Conclusions

Collectively, our results indicate that elevated miR-19a-3p mediates cerebral ischemic injury by targeting ADIPOR2. MiR-19a-3p attenuation thus might offer hope of a novel therapeutic target for ischemic stroke injury treatment.

Even Short-Term Telmisartan Treatment Ameliorated Insulin Resistance But Had No Influence on Serum Adiponectin and Tumor Necrosis Factor-Alpha Levels in Hypertensive Patients with Metabolic Syndrome

BACKGROUND

We investigated the effect of short-term telmisartan usage in addition to lifestyle changes such as diet and exercise on insulin resistance, lipid metabolism, and serum adiponectin and tumor necrosis factor-alpha (TNF-α) levels in hypertensive patients with metabolic syndrome (MetS).

METHODS

A total of 36 hypertensive patients with MetS were randomized to telmisartan and control groups in an open-labeled prospective study.

RESULTS

There were significant decreases in anthropometric variables of patients according to baseline measurements in both groups at the end of the study. Serum insulin level and insulin resistance assessed by homeostasis model assessment-insulin resistance were decreased significantly in the telmisartan group (P = 0.040 and P = 0.034, respectively) compared with the controls, while there was no statistically significant change in the lipid profiles of the two groups. Serum adiponectin level was increased by 19.1% ± 41.7% in the telmisartan group, but intergroup analysis revealed no significant change. There was also no significant change in serum TNF-α level in either group.

CONCLUSION

It has been observed that even short-term telmisartan treatment had favorable effects on insulin resistance and glucose metabolism compared with lifestyle changes alone. The fundamental effect of telmisartan treatment on insulin resistance renders it a good therapeutic option for hypertensive patients with MetS.

The influence of telmisartan on metformin pharmacokinetics and pharmacodynamics

Metformin is the most widely used drug among type 2 diabetes mellitus patients. However, drug interaction on metformin will influence its glucose-lowering effect or increase its side effect of lactic acidosis. In this study, a randomized, two-stage, crossover study was conducted to unveil the potential drug interaction between metformin and the anti-hypertension drug, telmisartan. Totally, 16 healthy Chinese male volunteers were enrolled. Blood samples from various time-points after drug adminstration were analyzed for metformin quantification. Oral glucose tolerance test (OGTT) was conducted 2 h after metformin administration. The AUC_0-12 and Cmax of metformin in subjects co-administrated with telmisartan were significantly lower than with placebo. The geometric mean ratios (value of metformin plus telmisartan phase/value of metformin plus placebo phase) for Cmax and AUC_0-12 is 0.7972 (90%CI: 0.7202-0.8824) and 0.8336 (90%CI: 0.7696-0.9028), respectively. Moreover, telmisartan co-administration significantly increased the plasma concentrations of both glucose and insulin at 0.5 h since OGTT (7.64 ± 1.86 mmol/l·min vs 6.77 ± 0.83 mmol/l·min, P = 0.040; 72.91 ± 31.98 μIU/ml·min vs 60.20 ± 24.20 μIU/ml·min, P = 0.037), though the AUC of glucose and insulin after OGTT showed no significant difference. These findings suggested that telmisartan had a significant influence on the Pharmacokinetics of metformin in healthy groups, though the influence on glucose-lowering effect was moderate.

Molecular determinants of PPARγ partial agonism and related in silico/in vivo studies of natural saponins as potential type 2 diabetes modulators

The metabolic syndrome, which includes hypertension, type 2 diabetes (T2D) and obesity, has reached an epidemic-like scale. Saponins and sapogenins are considered as valuable natural products for ameliorating this pathology, possibly through the nuclear receptor PPARγ activation. The aims of this study were: to look for in vivo antidiabetic effects of a purified saponins' mixture (PSM) from Astragalus corniculatus Bieb; to reveal by in silico methods the molecular determinants of PPARγ partial agonism, and to investigate the potential PPARγ participation in the PSM effects. In the in vivo experiments spontaneously hypertensive rats (SHRs) with induced T2D were treated with PSM or pioglitazone as a referent PPARγ full agonist, and pathology-relevant biochemical markers were analysed. The results provided details on the PSM modulation of the glucose homeostasis and its potential mechanism. The in silico studies focused on analysis of the protein-ligand interactions in crystal structures of human PPARγ-partial agonist complexes, pharmacophore modelling and molecular docking. They outlined key pharmacophoric features, typical for the PPARγ partial agonists, which were used for pharmacophore-based docking of the main PSM sapogenin. The in silico studies, strongly suggest possible involvement of PPARγ-mediated mechanisms in the in vivo antidiabetic and antioxidant effects of PSM from A. corniculatus.