Ligustroflavone reduces necroptosis in rat brain after ischemic stroke through targeting RIPK1/RIPK3/MLKL

OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO).Administration of ligustroflavone(10,30,60 mg·kg-1,ig)15 min before ischemia,after which neurological deficit score and infarct volume were detected by longa score and TTC stain.The cell viability and necrosis rate of hypoxia-cultured PC12 cells(O2/N2/CO2,1:94:5,8 h)were evaluated by MTS and LDH release rate.Flow cytometry further verified the mortality rate of PC12 cells.Necroptosis-associated proteins(RIPK1,RIPK3 and MLKL/p-MLKL)were detected by Western blotting.The interaction between RIPK3 and RIPK1 or MLKL were confirmed by immunoprecipitation.Operating Environ⁃ment(MOE)program demonstrated the possible combination of ligustroflavone with RIPK1,RIPK3 and MLKL.RESULTS Ischemic injury(increase in neurological deficit score and infarct volume)and upregulation of necroptosis-associated proteins were showed in rat MCAO model.Administration of ligustroflavone(30 mg·kg^-1,ig)evidently improved neurological func⁃tion,reduced infarct volume,and decreased the levels of necroptosis-associated proteins except the RIPK1.Consistently,hypoxia-cultured PC12 cells caused cellular injury(LDH release and necroposis)concomitant with up-regulation of necroptosis-associated proteins,and these phenomena were blocked in the presence of ligustroflavone(25μmol·L^-1)except the elevated RIPK1 levels.Using the Molecular Operating Environment(MOE)program,we identified RIPK1,RIPK3,and MLKL as potential targets of ligustroflavone.Further studies showed that the interaction between RIPK3 and RIPK1 or MLKL was significantly enhanced,which was blocked in the presence of ligustroflavone.CONCLUSION Ligus⁃troflavone protects rat brain from ischemic injury,and its beneficial effect is related to the prevention of necroptosis through a mechanism involving targeting RIPK1,RIPK3,and/or MLKL.

Magnolol attenuates right ventricular hypertrophy and fibrosis in hypoxia-induced pulmonary arterial hypertensive rats through inhibition of the JAK2/STAT3 signaling pathway

OBJECTIVE Right ventricular(RV)remodeling is one of the essential pathological features in pulmonary arterial hypertension(PAH).RV hypertrophy or fibrosis are the leading causes of RV remodeling.Magnolol is a compound isolated from Magnolia officinalis.It possesses multiple pharmacological activities,such as anti-oxidation and anti-inflammation.This study aims to evaluate the effects and underlying mechanisms of magnolol on RV remodeling in hypoxia-induced PAH.METHODS①Male SD rats(220 g)were randomly divided into 5 groups(n=10):the normoxia group,the hypoxia group,the hypoxia plus Magnolol(10 and 20 mg·kg^(-1)·d-1)group,and the vehicle group.Rats in the normoxia group were kept in a normoxia environment for 4 weeks,while rats in the hypoxia group were kept in a hypoxic chamber(10%O2).The rats in the hypoxia plus magnolol groups were administered with magnolol at 10 or 20 mg·kg^(-1)(ip)once a day for 4 weeks.At the end of 4 weeks,the heart function was assessed by Doppler echocardiography,and then the rats were anesthetized with sodium pentobarbital(30 mg·kg^(-1),ip).The RVSP was measured by the right heart catheterization method.The heart tissues were collected and dissected to calculate the index of RV remodeling(RV/LV+IVS,RV/tibial length,or RV/body weight).Part of the RV samples was fixed with 4%paraformaldehyde for morphological analysis,while other samples were frozen at-80℃for molecular studies(measurements of ANP,BNP,α-SMA,and collagenⅠ/ⅢmRNA expression as well as p-JAK2/JAK2 and p-STAT3/STAT3 protein levels).②To evaluate the effect of magnolol on hypoxia-induced myocardial hypertrophy and fibrosis,H9c2 or cardiac fibroblasts were divided into 7 groups:the control group,cells were cultured under normal conditions;the hypoxia group,cells were cultured under hypoxic condition(3%O2);the hypoxia plus magnolol 10 mg·kg^(-1) group,magnolol10μmol·L^(-1) was added to the culture medium before the hypoxia treatment;the hypoxia plus magnolol 30 mg·kg^(-1) group,magnolol 20μmol·L^(-1) was added to the culture medium before the hypoxia treatment;the hypoxia plus TG-101348 group,TG-101348(a specific inhibitor of JAK2)1μmol·L^(-1) was added to the culture medium before the hypoxia treatment;the hypoxia plus JSI-124 group,JSI-124(a specific inhibitor of JAK2)1μmol·L^(-1) was added to the culture medium before the hypoxia treatment;and the hypoxia plus vehicle group,an equal volume of vehicle(DMSO)was added to the culture medium before the hypoxia treatment.At the end of the experiments,the cells were collected for morphological and molecular analysis.RESULTS In vivo,male Sprang-Daley rats were exposed to 10%O2 for 4 weeks to establish an RV remodeling model,which showed hypertrophic and fibrotic features(increases of RV remodeling index,cellular size,hypertrophic and fibrotic marker expression),accompanied by an elevation in phosphorylation levels of JAK2 and STAT3;these changes were attenuated by treating rats with magnolol.In vitro,the cultured H9c2 cells or cardiac fibroblasts were exposed to 3%O2 for 48 h to induce hypertrophy or fibrosis,which showed hypertrophic(increases in cellular size as well as the expression of ANP and BNP)or fibrotic features(increases in the expression of collagenⅠ,collagenⅢandα-SMA).Administration of magnolol and TG-101348 or JSI-124 (JAK2 selective inhibitors) could prevent the process of myocardial hypertrophy and fibrosis, accompanied by the decrease in the phosphorylation level of JAK2 and STAT3. CONCLUSION Magnolol can attenuate RV hypertrophy and fibrosis in hypoxia-induced PAH rats through a mechanism involving inhibition of the JAK2/STAT3 signaling pathway.

Advances in traditional Chinese medicine for cardiovascular disease therapy in 2020

Cardiovascular diseases are a major cause of morbidity and mortality worldwide and there is an urgent need to develop new pharmacotherapies for managing cardiovascular diseases.In China,traditional Chinese medicine has been used in clinical settings for thousands of years.Although traditional Chinese medicine is very popular,Western medicine experts have not yet accepted it because some ingredients and mechanisms of action for its therapeutic effect are not fully clear.Emerging evidence has established that traditional Chinese medicine inhibits oxidative stress and inflammatory response,suppresses apoptosis,promotes angiogenesis,regulates autophagy and gut microbiota,and modulates metabolomics,among others.Therefore,it has a beneficial role against cardiovascular disease occurrence and progression,such as atherosclerosis,hypertension,myocardial ischemia/reperfusion injury,myocardial infarction,cardiomyopathy,arrhythmia,cardiac remodeling,pulmonary arterial hypertension,and heart failure.In this review,we have summarized the research progress on the relevant mechanisms by which traditional Chinese medicine regulates cardiovascular diseases in 2020 to reveal its application to cardiovascular disease prevention and/or therapy.

Reactive oxygen species-based nanomaterials for the treatment of myocardial ischemia reperfusion injuries

Interventional coronary reperfusion strategies are widely adopted to treat acute myocardial infarction,but morbidity and mortality of acute myocardial infarction are still high.Reperfusion injuries are inevitable due to the generation of reactive oxygen species(ROS)and apoptosis of cardiac muscle cells.However,many antioxidant and anti-inflammatory drugs are largely limited by pharmacokinetics and route of administration,such as short half-life,low stability,low bioavailability,and side effects for treatment myocardial ischemia reperfusion injury.Therefore,it is necessary to develop effective drugs and technologies to address this issue.Fortunately,nanotherapies have demonstrated great opportunities for treating myocardial ischemia reperfusion injury.Compared with traditional drugs,nanodrugs can effectively increase the therapeutic effect and reduces side effects by improving pharmacokinetic and pharmacodynamic properties due to nanodrugs’size,shape,and material characteristics.In this review,the biology of ROS and molecular mechanisms of myocardial ischemia reperfusion injury are discussed.Furthermore,we summarized the applications of ROS-based nanoparticles,highlighting the latest achievements of nanotechnology researches for the treatment of myocardial ischemia reperfusion injury.

Nanomedicine-based treatment:An emerging therapeutical strategy for pulmonary hypertension

Pulmonary hypertension(PH)can cause breathing difficulty,a rapid decline of exercise capacity,heart failure,eventually death of the patients.The latest epidemiological study demonstrates that PH has a much higher incidence than previously thought.PH is still a highly fatal disease due to the many disadvantages of the current drugs,such as short half-life,lack of targeting,potent side effects.The PH pathological features offer great opportunities for nanomedicines for PH.Recently,emerging nanomedicines demonstrated great advantages in the therapeutic effect of PH by enhancing the accumulation of drugs in PH lesion,optimizing drug efficacy,minimizing drug side effects.However,this promising field of cross-cutting research is far from being widely explored due to the huge professional barriers.To solve this problem,we provide a comprehensive review for the latest progresses of nanomedicines in the treatment of PH.Firstly,we systematical summarized the PH pathological features and the current clinical drug treatment of PH.The advantages of nanomedicines are also deeply discussed in the treatment of PH.Subsequently,we focused on the research progresses of nanomedicines in PH through three aspects:advanced nano-drug delivery system for traditional drugs and new target drugs,gene therapy-based nanomedicines,other nanomedicines for the treatment of PH.Finally,we also discussed the prospects and challenges for the clinical application of nanomedicines in PH,provided directions for the research and development of nanomedicines for PH treatment in the future.

Passively-targeted mitochondrial tungsten-based nanodots for efficient acute kidney injury treatment

Acute kidney injury(AKI)can lead to loss of kidney function and a substantial increase in mortality.The burst of reactive oxygen species(ROS)plays a key role in the pathological progression of AKI.Mitochondrial-targeted antioxidant therapy is very promising because mitochondria are the main source of ROS in AKI.Antioxidant nanodrugs with actively targeted mitochondria have achieved encouraging success in many oxidative stress-induced diseases.However,most strategies to actively target mitochondria make the size of nanodrugs too large to pass through the glomerular system to reach the renal tubules,the main damage site of AKI.Here,an ultra-small Tungsten-based nanodots(TWNDs)with strong ROS scavenging can be very effective for treatment of AKI.TWNDs can reach the tubular site after crossing the glomerular barrier,and enter the mitochondria of the renal tubule without resorting to complex active targeting strategies.To our knowledge,this is the first time that ultra-small negatively charged nanodots can be used to passively target mitochondrial therapy for AKI.Through in-depth study of the therapeutic mechanism,such passive mitochondria-targeted TWNDs are highly effective in protecting mitochondria by reducing mitochondrial ROS and increasing mitophagy.In addition,TWNDs can also reduce the infiltration of inflammatory cells.This work provides a new way to passively target mitochondria for AKI,and give inspiration for the treatment of many major diseases closely related to mitochondria,such as myocardial infarction and cerebral infarction.

Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

Currently,there are no clinical drugs available to treat acute kidney injury(AKI).Given the high prevalence and high mortality rate of AKI,the development of drugs to effectively treat AKI is a huge unmet medical need and a research hotspot.Although existing evidence fully demonstrates that reactive oxygen and nitrogen species(RONS)burst at the AKI site is a major contributor to AKI progression,the heterogeneity,complexity,and unique physiological structure of the kidney make most antioxidant and anti-inflammatory small molecule drugs ineffective because of the lack of kidney targeting and side effects.Recently,nanodrugs with intrinsic kidney targeting through the control of size,shape,and surface properties have opened exciting prospects for the treatment of AKI.Many antioxidant nanodrugs have emerged to address the limitations of current AKI treatments.In this review,we systematically summarized for the first time about the emerging nanodrugs that exploit the pathological and physiological features of the kidney to overcome the limitations of traditional small-molecule drugs to achieve high AKI efficacy.First,we analyzed the pathological structural characteristics of AKI and the main pathological mechanism of AKI:hypoxia,harmful substance accumulation-induced RONS burst at the renal site despite the multifactorial initiation and heterogeneity of AKI.Subsequently,we introduced the strategies used to improve renal targeting and reviewed advances of nanodrugs for AKI:nano-RONS-sacrificial agents,antioxidant nanozymes,and nanocarriers for antioxidants and anti-inflammatory drugs.These nanodrugs have demonstrated excellent therapeutic effects,such as greatly reducing oxidative stress damage,restoring renal function,and low side effects.Finally,we discussed the challenges and future directions for translating nanodrugs into clinical AKI treatment.

MoS_(2)-based nanocomposites for cancer diagnosis and therapy

Molybdenum is a trace dietary element necessary for the survival of humans.Some molybdenum-bearing enzymes are involved in key metabolic activities in the human body(such as xanthine oxidase,aldehyde oxidase and sulfite oxidase).Many molybdenum-based compounds have been widely used in biomedical research.Especially,MoS_(2)-nanomaterials have attracted more attention in cancer diagnosis and treatment recently because of their unique physical and chemical properties.MoS_(2)can adsorb various biomolecules and drug molecules via covalent or non-covalent interactions because it is easy to modify and possess a high specific surface area,improving its tumor targeting and colloidal stability,as well as accuracy and sensitivity for detecting specific biomarkers.At the same time,in the near-infrared(NIR)window,MoS_(2)has excellent optical absorption and prominent photothermal conversion efficiency,which can achieve NIR-based phototherapy and NIR-responsive controlled drug-release.Significantly,the modified MoS_(2)-nanocomposite can specifically respond to the tumor microenvironment,leading to drug accumulation in the tumor site increased,reducing its side effects on non-cancerous tissues,and improved therapeutic effect.In this review,we introduced the latest developments of MoS_(2)-nanocomposites in cancer diagnosis and therapy,mainly focusing on biosensors,bioimaging,chemotherapy,phototherapy,microwave hyperthermia,and combination therapy.Furthermore,we also discuss the current challenges and prospects of MoS_(2)-nanocomposites in cancer treatment.