Minocycline protects against myocardial ischemia/reperfusion injury in rats by upregulating MCPIP1 to inhibit NF-κB activation

Integrated miRNA-mRNA networks underlie attenuation of chronic β-adrenergic stimulation-induced cardiac remodeling by minocycline

Adverse cardiac remodeling contributes to heart failure development and progression, partly due to inappropriate sympathetic nervous system activation. Although β-adrenergic receptor (β-AR) blockade is a common heart failure therapy, not all patients respond, prompting exploration of alternative treatments. Minocycline, an FDA-approved antibiotic, has pleiotropic properties beyond antimicrobial action. Recent evidence suggests it may alter gene expression via changes in miRNA expression. Thus, we hypothesized that minocycline could prevent adverse cardiac remodeling induced by the β-AR agonist isoproterenol, involving miRNA-mRNA transcriptome alterations. Male C57BL/6J mice received isoproterenol (30 mg/kg/day sc) or vehicle via osmotic minipump for 21 days, along with daily minocycline (50 mg/kg ip) or sterile saline. Isoproterenol induced cardiac hypertrophy without altering cardiac function, which minocycline prevented. Total mRNA sequencing revealed isoproterenol altering gene networks associated with inflammation and metabolism, with fibrosis activation predicted by integrated miRNA-mRNA sequencing, involving miR-21, miR-30a, miR-34a, miR-92a, and miR-150, among others. Conversely, the cardiac miRNA-mRNA transcriptome predicted fibrosis inhibition in minocycline-treated mice, involving antifibrotic shifts in Atf3 and Itgb6 gene expression associated with miR-194 upregulation. Picrosirius red staining confirmed isoproterenol-induced cardiac fibrosis, prevented by minocycline. These results demonstrate minocycline's therapeutic potential in attenuating adverse cardiac remodeling through miRNA-mRNA-dependent mechanisms, especially in reducing cardiac fibrosis. NEW & NOTEWORTHY We demonstrate that minocycline treatment prevents cardiac hypertrophy and fibrotic remodeling induced by chronic β-adrenergic stimulation by inducing antifibrotic shifts in the cardiac miRNA-mRNA transcriptome.

Neuroprotective Effects of Melittin Against Cerebral Ischemia and Inflammatory Injury via Upregulation of MCPIP1 to Suppress NF-κB Activation In Vivo and In Vitro

Melittin, a principal constituent of honeybee venom, exhibits diverse biological effects, encompassing anti-inflammatory capabilities and neuroprotective actions against an array of neurological diseases. In this study, we probed the prospective protective influence of melittin on cerebral ischemia, focusing on its anti-inflammatory activity. Mechanistically, we explored whether monocyte chemotactic protein-induced protein 1 (MCPIP1, also known as ZC3H12A), a recently identified zinc-finger protein, played a role in melittin-mediated anti-inflammation and neuroprotection. Male C57/BL6 mice were subjected to distal middle cerebral artery occlusion to create a focal cerebral cortical ischemia model, with melittin administered intraperitoneally. We evaluated motor functions, brain infarct volume, cerebral blood flow, and inflammatory marker levels within brain tissue, employing quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and western blotting. In vitro, an immortalized BV-2 microglia culture was stimulated with lipopolysaccharide (LPS) to establish an inflammatory cell model. Post-melittin exposure, cell viability, and cytokine expression were examined. MCPIP1 was silenced using siRNA in LPS-induced BV-2 cells, with the ensuing nuclear translocation of nuclear factor-κB assessed through cellular immunofluorescence. In vivo, melittin enhanced motor functions, diminished infarction, fostered blood flow restoration in ischemic brain regions, and markedly inhibited the expression of inflammatory cytokines (interleukin-1β, interleukin-6, tumor necrosis factor-α, and nuclear factor-κB). In vitro, melittin augmented MCPIP1 expression in LPS-induced BV-2 cells and ameliorated inflammation-induced cell death. The neuroprotective effect conferred by melittin was attenuated upon MCPIP1 knockdown. Our findings establish that melittin-induced tolerance to ischemic injury is intrinsically linked with its anti-inflammatory capacity. Moreover, MCPIP1 is, at the very least, partially implicated in this process.

Huoluo Xiaoling Pellet promotes microglia M2 polarization through increasing MCPIP1 expression for ischemia stroke alleviation

Huoluo Xiaoling Pellet (HXP), a Chinese patent medicine, is commonly administered for the treatment of treat ischemic strokes. MCPIP1, an inducible suppressor of the inflammatory response, is a regulator of microglial M2 polarization. This study aimed to explore whether HXP can promote microglial M2 polarization by upregulating MCPIP1 expression, consequently mitigating cerebral ischemic injury. Our study involved 85 Sprague-Dawley rats (weighing 250-280 g). We established middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation-reoxygenation (OGD/R) models with MCPIP1 knockdown to assess the effects of HXP on ischemic strokes. Our findings show that HXP reduced brain water content, improved neurological function, and inhibited the expression of inflammatory factors in the brain tissues of MCAO rats. The neuroprotective effects of HXP on cerebral ischemic injuries were compromised by MCPIP1 knockdown. Immunofluorescence results indicated that the expression of microglia marker Iba1 and M2 phenotypic marker CD206 was upregulated in MCAO rats and OGD/R-treated microglia. Administration of HXP significantly reduced Iba1 expression and facilitated CD206 expression, an effect that was counteracted by sh-MCPIP1 transfection. Western blotting revealed that HXP treatment augmented the expression of MCPIP1, microglial M2 marker proteins (CD206 and Arg1), and PPARγ, while reducing the expression of microglial M1 marker proteins (CD16 and iNOS) in MCAO rats and OGD/R-induced microglia. MCPIP1 knockdown suppressed HXP-mediated upregulation of MCPIP1, CD206, Arg1, and PPARγ, as well as the downregulation of CD16 and iNOS. Our findings suggest that HXP primarily ameliorates ischemic stroke through the upregulation of MCPIP1, which in turn induces microglial M2 polarization.

Cardioprotective effects of minocycline against doxorubicin-induced cardiotoxicity

BACKGROUND

Doxorubicin (Dox)-induced cardiotoxicity has limited its use. Inflammation, oxidative stress, and apoptosis have important roles in Dox-induced cardiotoxicity. Minocycline (Min) is an antibiotic with anti-inflammatory, anti-oxidant and anti-apoptotic properties. Here, the cardioprotective effects of Min against Dox-induced cardiotoxicity in adult male rats were evaluated.

METHODS

Forty-two adult male rats were divided into six groups including control group (normal saline), Dox group, Min groups (Min 45 mg/kg and Min 90 mg/kg), and treatment groups (Dox + Min 45 mg/kg and Dox + Min 90 mg/kg). Dox (2.5 mg/kg) was administered three times a week for two weeks, and Min once a day for three weeks via intraperitoneal route. Cardiac tissue sections were stained with hematoxylin and eosin for histological examination. The activities of lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) in serum as well as the activity of catalase and superoxide dismutase (SOD) in cardiac tissue were measured. Cardiac tissue levels of malondialdehyde (MDA), TNF-α, and IL-1β were also measured using ELISA.

RESULTS

Compared with the Dox group, treatment with Min significantly decreased the activity of LDH and CK-MB. Min also increased the activity of catalase and SOD in the tissue samples. The results showed that the levels of MDA, TNF-α, and IL-1β in cardiac tissue samples were significantly lower in the Min groups compared with the Dox group. In addition, histopathological results showed that Min reduced the tissue damage caused by Dox.

CONCLUSION

Min reduced Dox-induced cardiotoxicity. The anti-oxidant and anti-inflammatory properties of Min may contribute to its protective effects.

Notoginsenoside R1 protects against myocardial ischemia/reperfusion injury in mice via suppressing TAK1-JNK/p38 signaling

Previous studies show that notoginsenoside R1 (NG-R1), a novel saponin isolated from Panax notoginseng, protects kidney, intestine, lung, brain and heart from ischemia-reperfusion injury. In this study we investigated the cardioprotective mechanisms of NG-R1 in myocardial ischemia/reperfusion (MI/R) injury in vivo and in vitro. MI/R injury was induced in mice by occluding the left anterior descending coronary artery for 30 min followed by 4 h reperfusion. The mice were treated with NG-R1 (25 mg/kg, i.p.) every 2 h for 3 times starting 30 min prior to ischemic surgery. We showed that NG-R1 administration significantly decreased the myocardial infarction area, alleviated myocardial cell damage and improved cardiac function in MI/R mice. In murine neonatal cardiomyocytes (CMs) subjected to hypoxia/reoxygenation (H/R) in vitro, pretreatment with NG-R1 (25 μM) significantly inhibited apoptosis. We revealed that NG-R1 suppressed the phosphorylation of transforming growth factor β-activated protein kinase 1 (TAK1), JNK and p38 in vivo and in vitro. Pretreatment with JNK agonist anisomycin or p38 agonist P79350 partially abolished the protective effects of NG-R1 in vivo and in vitro. Knockdown of TAK1 greatly ameliorated H/R-induced apoptosis of CMs, and NG-R1 pretreatment did not provide further protection in TAK1-silenced CMs under H/R injury. Overexpression of TAK1 abolished the anti-apoptotic effect of NG-R1 and diminished the inhibition of NG-R1 on JNK/p38 signaling in MI/R mice as well as in H/R-treated CMs. Collectively, NG-R1 alleviates MI/R injury by suppressing the activity of TAK1, subsequently inhibiting JNK/p38 signaling and attenuating cardiomyocyte apoptosis.

MicroRNA-155-5p in serum derived-exosomes promotes ischaemia-reperfusion injury by reducing CypD ubiquitination by NEDD4

AIMS

Recovery of blood flow is a therapeutic approach for myocardial infarction but paradoxically induces injury to the myocardium. Exosomes (exos) are pivotal mediators for intercellular communication that can be released by different cells and are involved in cardiovascular diseases. This study aimed to explore the possible effects and mechanisms of miR-155-5p loaded by serum-derived exos in myocardial infarction reperfusion injury (MIRI).

METHODS AND RESULTS

Exos were isolated from mouse serum after induction of ischaemia reperfusion (I/R) and injected into I/R-treated mice to assess cardiac function, infarction size, and cardiomyocyte apoptosis. Primary cardiomyocytes were transfected with miR-155-5p inhibitor before treatment with oxygen-glucose deprivation and re-oxygenation (OGD/R) and exos derived from the serum of I/R-treated mice (I/R-Exos), in which Bcl-2, Bax, and cleaved-caspase-3 levels were detected. The interactions among miR-155-5p, NEDD4, and CypD were evaluated. miR-155-5p level was evidently increased in I/R-Exos than in exos from the serum of sham-operated mice (P < 0.05). In comparison with the I/R group, the I/R-Exos + I/R group had increased infarct size, elevated miR-155-5p expression, and boosted apoptotic rate in mouse myocardium (P < 0.05). In mice treated with I/R-Exos and I/R, miR-155-5p inhibition reduced cardiac infarct size and apoptosis (P < 0.05). NEDD4 was a target gene of miR-155-5p and promoted CypD ubiquitination. Cardiomyocyte apoptosis was markedly increased in the miR-155-5p inhibitor + shNEDD4 + OGD/R group versus the miR-155-5p inhibitor + OGD/R group (P < 0.05), but decreased in the miR-155-5p inhibitor + shNEDD4 + shCypD + OGD/R group than in the miR-155-5p inhibitor + shNEDD4 + OGD/R group (P < 0.05).

CONCLUSIONS

miR-155-5p in I/R-Exos may facilitate MIRI by inhibiting CypD ubiquitination via targeting NEDD4.

MCPIP1 alleviated alcohol-induced immune dysfunction via the MAPK/ERK signaling pathway

RATIONALE

In recent years, monocyte chemotactic protein-induced protein 1 (MCPIP1) has been reported to control inflammation via IL-10.

OBJECTIVES

The aims of this study were to determine (1) whether MCPIP1 can repair damage to the immune system after alcohol use and (2) whether MCPIP1 can repair the immune function impaired by alcohol use through the MAPK/ERK signaling pathway. Our results will inform the treatment of immune dysfunction caused by alcohol consumption.

METHODS

Scrambled shRNA or MCPIP-1-shRNA carried by the lentiviral vector (50μl each at 1×108TU/ml) was injected retrogradely through the pancreatic duct to pretreat male C57BL/6 mice. Five days after the injection, mice were exposed to intragastric ethanol infusion (5g/kg, 25% ethanol w/v) daily or vehicle for 10 days.

RESULTS

MCPIP-1 protein was increased in the pancreas after alcohol exposure. MCPIP-1 shRNA specifically decreased MCPIP-1 protein expression and mRNA level in the pancreas. Specific knockdown of MCPIP-1 exacerbates pancreatic necrosis, interstitial edema, and inflammatory infiltrates after alcohol exposure. Meanwhile, specific knockdown of MCPIP-1 also increased pancreatic pro-inflammatory cytokine (IL-6 and IL-1β), chemokine MCP-1, and chemokine receptor 2 (CCR2) after alcohol exposure. What's more, p-JNK and p-ERK in the pancreas were all similarly increased in response to pancreas-specific knockdown of MCPIP-1 during alcohol exposure.

CONCLUSIONS

Taken together, the results above suggested that MCPIP1 repairs the immune function impaired by alcohol use via stimulating JNK and ERK pathways. Our results will inform the treatment of immune dysfunction caused by alcohol consumption.

Hypothesized neuroprotective effect of minocycline against COVID-19-induced stroke and neurological dysfunction: possible role of matrix metalloprotease signaling pathway

Severe Acute Respiratory Syndrome Coronavirus-2 (COVID-19) is a respiratory disease that causes dysfunction in respiration. Since late 2019, this virus has infected and killed millions of people around the world and imposed many medical and therapeutic problems in the form of a pandemic. According to recent data, COVID-19 disease can increase the risk of stroke, which can be deadly or cause many neurological disorders after the disease. During the last two years, many efforts have been made to introduce new therapies for management of COVID-19-related complications, including stroke. To achieve this goal, several conventional drugs have been investigated for their possible therapeutic roles. Minocycline, a broad-spectrum, long-acting antibiotic with anti-inflammatory and antioxidant properties, is one such conventional drug that should be considered for treating COVID-19-related stroke, as indirect evidence indicates that it exerts neuroprotective effects, can modulate stroke occurrence, and can play an effective and strategic role in management of the molecular signals caused by stroke and its destructive consequences. The matrix metalloprotease (MMP) signaling pathway is one of the main signaling pathways involved in the occurrence and exacerbation of stroke; however, its role in COVID-19-induced stroke and the possible role of minocycline in the management of this signaling pathway in patients with COVID-19 is unclear and requires further investigation. Based on this concept, we hypothesize that minocycline might act via MMP signaling as a neuroprotective agent against COVID-19-induced neurological dysfunction, particularly stroke.

Minocycline as heart conditioning agent in experimental type 2 diabetes mellitus - an antibacterial drug in heart protection

Cardiovascular diseases, and among them certainly myocardial infarction, remain leading cause of death worldwide. Diabetes increases risk of occurrence as well as adverse outcome of myocardial infarction. Conditioning maneuvers are the most attractive method for alleviating both the consequences of ischemia and reperfusion. Minocycline is a tetracycline derivative which exerts antioxidant, anti-inflammatory, and anti-apoptotic effects. The aim of this study was to assess the protective ability of preconditioning and postconditioning of isolated hearts from healthy and rats with experimentally induced type 2 diabetes with minocycline on functional recovery and redox status after ischemia and reperfusion. The hearts from healthy and diabetic rats were excised and retrogradely perfused according to the Langendorff technique. Using sensor in the left ventricle, the cardiodynamic parameters were recorded and in the samples of the coronary venous effluent oxidative stress biomarkers were analyzed. Minocycline was injected directly into the coronary vessels, in preconditioning 5 min before global ischemia, and in postconditioning during the first 5 min of reperfusion. Results of this study clearly show beneficial effects of minocycline applied both before ischemia and in the first minutes of reperfusion fashion in both healthy and diabetic rat hearts. The most prominent protective effect regarding oxidative stress is related to the decreased production of superoxide anion radical due postconditioning with minocycline in diabetic hearts. Cardiodynamic parameters were significantly improved in minocycline conditioned groups. Superoxide anion radical stands out as the most susceptible to changes induced by minocycline.

Cardioprotective effects of Sinomenine in myocardial ischemia/reperfusion injury in a rat model

Background

Ischemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.

Methods

Rat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.

Results

Pre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.

Conclusion

Our result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.

Attenuation in Proinflammatory Factors and Reduction in Neuronal Cell Apoptosis and Cerebral Vasospasm by Minocycline during Early Phase after Subarachnoid Hemorrhage in the Rat

Background

Subarachnoid hemorrhage (SAH) is an important subcategory of stroke due to its high mortality rate as well as severe complications such as neurological deficit. It has been suggested that cerebral inflammation is a major factor in advanced brain injury after SAH. Microglia and astrocytes are known supporting cells in the development and maintenance of inflammation in central nervous system. However, the role of microglia and astrocytes in the development of inflammation and neuronal cell apoptosis during the early phase after SAH has not been thoroughly investigated.

Materials and Methods

Sprague-Dawley rats were divided into 4 groups (n = 6/group): sham group, animals subjected to SAH without treatment, SAH animals pretreated with the microglia inhibitor minocycline (50 mg/kg, ip), and SAH animals pretreated with the astrocyte inhibitor fluorocitrate (50 mg/kg, ip). SAH was induced by injecting autologous blood (1 ml/kg) into the cistern magna on day 0. Pretreatment with minocycline or fluorocitrate was given three days prior to the induction of SAH. Rats were sacrificed 6 hr after SAH, and their cerebral spinal fluids were used to measure protein levels of neuroinflammatory cytokines IL-1β, IL-6, and TNF-α by ELISA. In addition, the cerebral cortex was utilized to determine the levels of caspase-3 by western blot and to evaluate neuronal cell apoptosis by immunohistochemistry staining and detect microglia and astrocyte by immunofluorescence staining for Iba-1 and GFAP. In this study, all SAH animals were given an injection of autologous blood and SAH rats treated with minocycline or fluorocitrate received ip injections on day 1, 2, and 3 before inducing SAH. Neurological outcome was assessed by ambulation and placing/stepping reflex responses on day 7.

Results

Immunofluorescence staining showed that SAH induced proliferation of microglia and astrocyte and minocycline inhibited the proliferation of both microglia and astrocyte. However, fluorocitrate inhibited only the proliferation of astrocyte. ELISA analysis showed that SAH upregulated TNF-α and IL-1β, but not IL-6 at 6 hr after SAH. Minocycline, but not fluorocitrate, attenuated the upregulation of TNF-α and IL-1β. Western blot analysis and immunohistochemistry staining showed that SAH induced neuronal cell apoptosis. Pretreatment with minocycline, but not fluorocitrate, decreased SAH-induced neuronal death and cerebral vasospasm. Furthermore, significant improvements in neurobehavioral outcome were seen in the minocycline treatment group, but not in animals treated with fluorocitrate.

Conclusions

Microglia may play an important role to regulate neuronal cell apoptosis and cerebral vasospasm through inhibiting inflammation at an early phase after SAH in the rat.

Cardioprotective activity of ethyl acetate extract of Cinnamomi Ramulus against myocardial ischemia/reperfusion injury in rats via inhibiting NLRP3 inflammasome activation and pyroptosis

BACKGROUND

NLRP3 inflammasome activation and pyroptosis play an important role in myocardial ischemia/reperfusion injury (MI/RI). Cinnamomi ramulus (CR), is an important folk medicinal plant in China, which derived from the dried twig of Cinnamomum cassia (L.) Presl, has function of "warming and tonifying heart yang", and traditionally utilized to treat the cold, blood-cold amenorrhea, phlegm, edema, arthralgia, and palpitations as well as improve blood circulation. The aqueous extract of C. ramulus was reported to show significant therapeutic potential for treating MI/RI. Whereas, there are no previous investigations in China or abroad has reported the cardioprotective effects and underlying mechanism of the ethyl acetate extract of C. ramulus (CREAE) and its bioactive substance cinnamic acid (CA) in triggering NLRP3 inflammasome activation and subsequent pyroptosis.

PURPOSE

The present study aimed to assess the cardioprotective function of CREAE and CA against the MI/RI in rats and involved the underlying mechanisms.

METHODS

The MI/RI model was established in male SD rats by occlusion of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min, respectively. The rats were intragastrically administered with CREAE (74 and 37 mg/kg) and CA (45 mg/kg) for 7 successive days before vascular ligation. The cardioprotective effects of CREAE and CA against myocardial injury of rats were detected by HE staining, TTC staining, echocardiograms, and myocardial enzymes detections. Serum levels of inflammatory factors, such as IL-6, IL-1β, and TNF-α, were analyzed by ELISA kits to evaluate the effects of CREAE and CA. The protein and gene expression levels of NLRP3 and the pyroptosis-related factors in heart tissue were conducted by western blot and RT-qPCR.

RESULTS

Our results showed that CREAE and CA decrease myocardial infarct size and improve cardiac function, mitigate myocardial damage, and repress inflammatory response in rats after I/R. Mechanistically, our results revealed that CREAE and CA can dramatically suppress the activation of NLRP3 inflammasome and subsequent cardiomyocyte pyroptosis in myocardial tissues that as evidenced by downregulating the protein and gene expressions of NLRP3, ASC, IL-1β, caspase-1, gasdermin D, and N-terminal GSDMD.

CONCLUSIONS

Our data indicated that CREAE and CA may attenuate MI/RI through suppression of NLRP3 inflammasome and subsequent pyroptosis-related signaling pathways.

LncRNA 4344 promotes NLRP3-related neuroinflammation and cognitive impairment by targeting miR-138-5p

OBJECTIVE

Cognitive impairment is a common neurological disease of which NLRP3-related neuroinflammation has been demonstrated to be an essential mediator. Previous studies have indicated that long non-coding RNAs (lncRNAs) are critical for the development of neurological disorders. However, the roles and functions of lncRNA 4344 in neuroinflammation during cognitive impairment are unknown and need to be further elucidated.

METHODS

Lipopolysaccharide (LPS)-induced rat cognitive impairment and rat microglia (RM) cell inflammation models were established in vitro and in vivo. The Morris water maze test was used to evaluate the cognitive behavior of the rats. Gene expression was assessed using real-time quantitative polymerase chain reaction, and protein levels using enzyme-linked immunosorbent assay, or western blot analysis. The targeting relationship between lncRNA 4344, miR-138-5p, and NLRP3 was identified using bioinformatics analysis and a dual-luciferase reporter gene assay. Hematoxylin-Eosin and Nissl stainings, terminal deoxynucleotidyl transferase dUTP nick end labeling, or immunofluorescence staining assays were performed to detect pathological changes, neuronal apoptosis, or positive cells in hippocampal tissues, respectively.

RESULTS

The expression levels of lncRNA 4344 and NLRP3 were upregulated in the hippocampal tissues of LPS-treated rats and RM cells, and showed a strong positive correlation between each other. LncRNA 4344 overexpression further enhanced the expression of NLRP3 and its downstream genes (caspase-1, IL-1β, and IL-18), as well as neuronal apoptosis in LPS-stimulated RM cells, whereas lncRNA 4344 silencing attenuated the inflammatory injuries. Moreover, miR-138-5p was the direct target of lncRNA 4344 and was downregulated in the RM cell inflammation model. We also found that miR-138-5p directly reduced the expression of NLRP3 and its downstream genes. Subsequently, the results of the animal experiments showed that the lncRNA 4344/miR-138-5p/NLRP3 axis plays an essential role in regulating the cognitive behavior, pathological changes and apoptosis of hippocampal neurons, expression of inflammation-related factors (NLRP3, caspase-1, IL-1β, and IL-18), and microglial activation in LPS-induced cognitive impairment rats.

CONCLUSION

Our results demonstrated for the first time that lncRNA 4344 regulates NLRP3-related neuroinflammation and cognitive impairment by targeting miR-138-5p, providing a possible target for the treatment of diseases characterized by a cognitive deficit.

Monocyte Chemotactic Protein-Induced Protein 1 (MCPIP-1): A Key Player of Host Defense and Immune Regulation

Inflammatory response is a host-protective mechanism against tissue injury or infections, but also has the potential to cause extensive immunopathology and tissue damage, as seen in many diseases, such as cardiovascular diseases, neurodegenerative diseases, metabolic syndrome and many other infectious diseases with public health concerns, such as Coronavirus Disease 2019 (COVID-19), if failure to resolve in a timely manner. Recent studies have uncovered a superfamily of endogenous chemical molecules that tend to resolve inflammatory responses and re-establish homeostasis without causing excessive damage to healthy cells and tissues. Among these, the monocyte chemoattractant protein-induced protein (MCPIP) family consisting of four members (MCPIP-1, -2, -3, and -4) has emerged as a group of evolutionarily conserved molecules participating in the resolution of inflammation. The focus of this review highlights the biological functions of MCPIP-1 (also known as Regnase-1), the best-studied member of this family, in the resolution of inflammatory response. As outlined in this review, MCPIP-1 acts on specific signaling pathways, in particular NFκB, to blunt production of inflammatory mediators, while also acts as an endonuclease controlling the stability of mRNA and microRNA (miRNA), leading to the resolution of inflammation, clearance of virus and dead cells, and promotion of tissue regeneration via its pleiotropic effects. Evidence from transgenic and knock-out mouse models revealed an involvement of MCPIP-1 expression in immune functions and in the physiology of the cardiovascular system, indicating that MCPIP-1 is a key endogenous molecule that governs normal resolution of acute inflammation and infection. In this review, we also discuss the current evidence underlying the roles of other members of the MCPIP family in the regulation of inflammatory processes. Further understanding of the proteins from this family will provide new insights into the identification of novel targets for both host effectors and microbial factors and will lead to new therapeutic treatments for infections and other inflammatory diseases.

Minocycline attenuates oxidative and inflammatory injury in a intestinal perforation induced septic lung injury model via down-regulating lncRNA MALAT1 expression

BACKGROUND

Oxidative stress and inflammatory responses play an important role in acute lung injury (ALI). Although minocycline (MINO) has anti-inflammatory effects and is a promising candidate in treating inflammatory diseases, the effect of MINO on ALI during sepsis is still unclear.

METHODS

In the present study, a mouse model with intestinal perforation was established. C57BL/6 mice received cecal ligation and puncture (CLP) to induce sepsis-associated ALI. MINO was used to treat the mice via intraperitoneal injection at different doses (negative control, 20 mg/kg, 50 mg/kg and 100 mg/kg, respectively) 24 h after CLP. The severity of lung injury was evaluated by pathological examination, and lung wet / dry weight ratio was calculated to evaluate the severity of pulmonary edema. The changes of TNF-α, IL-1β, IL-6, PGE2, MDA, NF-κB, Nrf2, Keap1 and lncRNA MALAT1 levels in lung tissues of the mice were detected with ELISA, chemical colorimetry, Western blot or qRT-PCR.

RESULTS

MINO ameliorated the lung edema and lung injury of the mice induced by CLP in a dose-dependent manner. MINO administration could significantly down-regulate expressions of TNF-α, IL-6, IL-1β, PGE2 and MDA in lung tissues of the mice. Mechanistically, MINO exerted the effects of anti-inflammation and anti-oxidative stress through down-regulating the expression of MALAT1 and regulating Nrf2/Keap1 and NF-κB signaling pathways.

CONCLUSION

MINO represses oxidative stress and inflammatory response during sepsis-induced ALI via down-regulating MALAT1 expression, and it has the potential to treat septic ALI.

Multifunctional RNase MCPIP1 and its Role in Cardiovascular Diseases

Monocyte chemoattractant protein-1 induced protein 1 (MCPIP1), one of the MCPIP family members, is characterized by the presence of both C-x8-C-x5-C-x3-H (CCCH)- type zinc finger and PilT-N-terminal domains. As a potent regulator of innate immunity, MCPIP1 exerts anti-inflammatory effects through its ribonuclease (RNase) and deubiquitinating enzyme activities to degrade cytokine mRNAs and inhibit nuclear factor- kappa B (NF-κB), respectively. MCPIP1 is expressed not only in immune cells but also in many other cell types, including cardiomyocytes, vascular endothelial cells (ECs) and smooth muscle cells (SMCs). Increasing evidence indicates that MCPIP1 plays a role in the regulation of cardiac functions and is involved in the processes of vascular diseases, such as ischemia-reperfusion (I/R) and atherosclerosis. To better understand the emerging roles of MCPIP1 in the cardiovascular system, we reviewed the current literature with respect to MCPIP1 functions and discussed its association with the pathogenesis of cardiovascular diseases and the implication as a therapeutic target.

Pleiotropic Effects of Tetracyclines in the Management of COVID-19: Emerging Perspectives

Coronavirus disease 2019 (COVID-19) is a global infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Approximately 15% of severe cases require an intensive care unit (ICU) admission and mechanical ventilation due to development of acute respiratory distress syndrome (ARDS). Tetracyclines (TCs) are a group of bacteriostatic antibiotics, like tetracycline, minocycline, and doxycycline, effective against aerobic and anaerobic bacteria as well as Gram-positive and Gram-negative bacteria. Based on available evidences, TCs may be effective against coronaviruses and thus useful to treat COVID-19. Thus, this review aims to provide a brief overview on the uses of TCs for COVID-19 management. SARS-CoV-2 and other coronaviruses depend mainly on the matrix metalloproteinases (MMPs) for their proliferation, cell adhesion, and infiltration. The anti-inflammatory mechanisms of TCs are linked to different pathways. Briefly, TCs inhibit mitochondrial cytochrome c and caspase pathway with improvement of lymphopenia in early COVID-19. Specifically, minocycline is effective in reducing COVID-19-related complications, through attenuation of cytokine storm as apparent by reduction of interleukin (IL)-6, IL-1, and tumor necrosis factor (TNF)-α. Different clinical trials recommend the replacement of azithromycin by minocycline in the management of COVID-19 patients at high risk due to two main reasons: 1) minocycline does not prolong the QT interval and even inhibits ischemia-induced arrhythmia; 2) minocycline displays synergistic effect with chloroquine against SARS-CoV-2. Taken together, the data presented here show that TCs, mainly doxycycline or minocycline, may be potential partners in COVID-19 management, derived pneumonia, and related complications, such as acute lung injury (ALI) and ARDS.

Minocycline alleviates peripheral nerve adhesion by promoting regulatory macrophage polarization via the TAK1 and its downstream pathway

AIMS

Inflammation plays a key role in peripheral nerve adhesion and often leads to severe pain and nerve dysfunction. Minocycline was reported to have potent anti-inflammatory effects and might be a promising drug to prevent or attenuate peripheral nerve adhesion. The present study aimed to clarify whether minocycline contributes to nerve adhesion protection and its underlying mechanism.

MATERIALS AND METHODS

Rats with sciatic nerve adhesion induced by glutaraldehyde glue (GG) were intraperitoneally injected with minocycline or saline every 12 h for 7 consecutive days. After that, the adhesion score, Ashcroft score, demyelination, macrophage polarization and inflammatory factors in peripheral nerve adhesion tissues or tissues in sham group were determined with histological staining, western blot and real time-PCR. Murine macrophage RAW264.7 cells were stimulated by LPS alone or together with minocycline at different concentrations and time duration to study the mechanism of minocycline in alleviating nerve adhesion.

KEY FINDINGS

We found that minocycline treatment reduced the adhesion score, Ashcroft score, the growth of scar tissue, demyelination, and macrophage recruitment. Moreover, minocycline significantly and dose-dependently promoted regulatory macrophage polarization but decreased pro-inflammatory macrophage polarization. Furthermore, mechanism studies showed that TAK1 and its downstream pathway p38/JNK/ERK1/2/p65 were inhibited by minocycline, which led to lower IL-1β and TNFα expression, but increased IL-10 expression.

SIGNIFICANCE

Altogether, these results suggest that minocycline is highly effective against peripheral nerve adhesion through anti-fibrosis, anti-inflammation, and myelination protection, making it a highly promising candidate for treating adhesion-related disorders.

Global gene expression analysis using RNA-seq reveals the new roles of Panax notoginseng Saponins in ischemic cardiomyocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng saponins (PNS), the main active ingredients of Panax notoginseng (Burkill) F.H.Chen, have been clinically used for cardiovascular diseases treatment in China as the Traditional Chinese Medicine (TCM) (Duan et al., 2017). Evidence demonstrated that PNS protected cardiomyocytes from myocardial ischemia, but the more underlying molecular mechanisms of the protective effect are still unclear. The aims of this study are to systematically know the function of PNS and discover new roles of PNS in ischemic cardiomyocytes.

MATERIALS AND METHODS

To confirm PNS function on ischemic cardiomyopathy, we established in vitro myocardial ischemia model on H9C2 cardiomyocyte line, which was induced by oxygen-glucose depletion (OGD). Then RNA-seq was carried out to systematically analyze global gene expression. This study was aimed to systematically investigate the protective effect and more potential molecular mechanisms of PNS on H9C2 cardiomyocytes in vitro through whole-transcriptome analysis with total RNA sequencing (RNA-Seq).

RESULTS

PNS exhibited anti-apoptotic effect in H9C2 cardiomyocytes in OGD-induced myocardial ischemia model. Through RNA-seq, we found that OGD affected expression profiling of many genes, including upregulated and downregulated genes. PNS inhibited cardiomyocyte apoptosis and death through rescuing cell cycle arrest, the DNA double-strand breakage repair process and chromosome segregation. Interestingly, for the canonical signaling pathways regulation, RNA-seq showed PNS could inhibit cardiac hypertrophy, MAPK signaling pathway, and re-activate PI3K/AKT and AMPK signaling pathways. Experimental data also confirmed the PNS could protect cardiomyocytes from OGD-induced apoptosis through activating PI3K/AKT and AMPK signaling pathways. Moreover, RNA-seq demonstrated that the expression levels of many non-coding RNAs, such as miRNAs and lncRNAs, were significantly affected after PNS treatment, suggesting that PNS could protect cardiomyocytes through regulating non-coding RNAs.

CONCLUSION

RNA-seq systematically revealed different novel roles of Panax Notoginseng Saponins (PNS) in protecting cardiomyocytes from apoptosis, induced by myocardial ischemia, through rescuing cell cycle arrest and cardiac hypertrophy, re-activating the DNA double-strand breakage repair process, chromosome segregation, PI3K/Akt and AMPK signaling pathways and regulating non-coding RNAs.

Concomitant use of dexamethasone and tetracyclines: a potential therapeutic option for the management of severe COVID-19 infection?

Introduction: The global coronavirus disease-2019 (COVID-19) pandemic has posed a critical challenge to the research community as well as to the healthcare systems. Severe COVID-19 patients are at a higher risk of developing serious complications and mortality. There is a dire need for safe and effective pharmacotherapy for addressing unmet needs of these patients. Concomitant use of dexamethasone and tetracyclines, by virtue of their immunomodulatory and other relevant pharmacological properties, offers a potential strategy for synergy aimed at improving clinical outcomes.Areas covered: Here we review the potential benefits of combining dexamethasone and tetracyclines (minocycline or doxycycline) for the management of severe COVID-19 patients. We have critically examined the evidence obtained from in silico, experimental, and clinical research. We have also discussed the plausible mechanisms, advantages, and drawbacks of this proposed combination therapy for managing severe COVID-19.Expert opinion: The concomitant use of dexamethasone and one of the tetracyclines among severe COVID-19 patients offers several advantages in terms of additive immunomodulatory effects, cost-effectiveness, wide-availability, and well-known pharmacological properties including adverse-effect profile and contraindications. There is an urgent need to facilitate pilot studies followed by well-designed and adequately-powered multicentric clinical trials to generate conclusive evidence related to utility of this approach.

Monocyte chemotactic protein-inducing protein 1 negatively regulating asthmatic airway inflammation and mucus hypersecretion involving γ-aminobutyric acid type A receptor signaling pathway in vivo and in vitro

BACKGROUND

Mounting evidence, consistent with our previous study, showed that γ-aminobutyric acid type A receptor (GABAAR) played an indispensable role in airway inflammation and mucus hypersecretion in asthma. Monocyte chemotactic protein-inducing protein 1 (MCPIP1) was a key negative regulator of inflammation. Recent studies showed that inflammation was largely suppressed by enhanced MCPIP1 expression in many inflammatory diseases. However, the role and potential mechanism of MCPIP1 in airway inflammation and mucus hypersecretion in asthma were still not well studied. This study was to explore the role of MCPIP1 in asthmatic airway inflammation and mucus hypersecretion in both mice and BEAS-2B cells, and its potential mechanism.

METHODS

In vivo, mice were sensitized and challenged by ovalbumin (OVA) to induce asthma. Airway inflammation and mucus secretion were analyzed. In vitro, BEAS-2B cells were chosen. Interleukin (IL)-13 was used to stimulate inflammation and mucus hypersecretion in cells. MCPIP1 Lentiviral vector (LA-MCPIP1) and plasmid-MCPIP1 were used to up-regulate MCPIP1 in lung and cells, respectively. MCP-1, thymic stromal lymphopoietin (TSLP), mucin 5AC (MUC5AC), MCPIP1, and GABAARβ2 expressions were measured in both lung and BEAS-2B cells. Immunofluorescence staining was performed to observe the expression of GABAARβ2 in cells.

RESULTS

MCPIP1 was up-regulated by LA-MCPIP1 (P < 0.001) and plasmid-MCPIP1 (P < 0.001) in lung and cells, respectively. OVA-induced airway inflammation and mucus hypersecretion, OVA-enhanced MCP-1, TSLP, MUC5AC, and GABAARβ2 expressions, and OVA-reduced MCPIP1 were significantly blunted by LA-MCPIP1 in mice (all P < 0.001). IL-13-enhanced MCP-1, TSLP, MUC5AC, and GABAARβ2 expressions, and IL-13-reduced MCPIP1 were markedly abrogated by plasmid-MCPIP1 in BEAS-2B cells (all P < 0.001).

CONCLUSION

The results of this study suggested that OVA and IL-13-induced airway inflammation and mucus hypersecretion were negatively regulated by MCPIP1 in both lung and BEAS-2B cells, involving GABAAR signaling pathway.

Shuxuening injection protects against myocardial ischemia-reperfusion injury through reducing oxidative stress, inflammation and thrombosis

Background

Shuxuening injection (SXNI) has a good effect on cardiovascular and cerebrovascular diseases. Here, our study aims to investigate whether SXNI have the protective effect on myocardial ischemia-reperfusion injury (MIRI) and elucidate the mechanism of SXNI's cardiac protection.

Methods

In this experiment, the coronary arteries of Sprague-Dawley (SD) rats were ligated for the induction of a MIRI model. TTC staining and haematoxylin-eosin (HE), as well as troponin I (TnI), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK) and CK-MB levels, were used to detect the protective effect of SXNI. In rat cardiac tissue, superoxide dismutase, catalase, glutathione and malondialdehyde (MDA) activities and glucose-regulated protein 78 (GRP78), calreticulin (CRT), CCAAT/enhancer binding protein homologous protein (CHOP) and caspase-12 expression levels were detected. In rat serum, the levels of inflammatory factors, including high-sensitivity C-reactive protein, monocyte chemoattractant protein-1, tumour necrosis factor-α, interleukin-6 (IL-6) and IL-1β, were measured by Elisa. In the rat arterial tissue, Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) expression was measured by western blot. In the rat plasma, ELISA was used to assay the levels of coagulation and plasmin system indicators, including platelet activating factor, endothelin, tissue factor (TF), plasminogen inhibitor, thromboxane B2, plasma fibrinogen.

Results

The results showed that SXNI can reduce the infarct size of myocardial tissue, decrease the myocardial enzyme and TnI levels and decrease the degree of myocardial damage compared with the model group. Additionally, SXNI can increase the activity of antioxidant enzymes, reduce the MDA level and decrease the GRP78, CRT, CHOP and caspase-12 expression levels. SXNI also decreased the levels of inflammatory cytokines in rat serum, lowered the level of procoagulant molecules in plasma and reduced the TLR4/NF-κB expression.

Conclusions

SXNI has protective effect on MIRI mainly by inhibiting oxidative stress and endoplasmic reticulum stress (ERS), thereby regulating TLR4/NF-κB pathway to reduce inflammation, and lowing procoagulant-related factors levels to reduce the risk of thrombosis.