MiR-196a regulates heme oxygenase-1 by silencing Bach1 in the neonatal mouse lung

Alterations in sperm RNAs persist after alcohol cessation and correlate with epididymal mitochondrial dysfunction

BACKGROUND

Chronic preconception paternal alcohol use adversely modifies the sperm epigenome, inducing fetoplacental and craniofacial growth defects in the offspring of exposed males. A crucial outstanding question in the field of paternal epigenetic inheritance concerns the resilience of the male germline and its capacity to recover and correct sperm-inherited epigenetic errors after stressor withdrawal.

OBJECTIVES

We set out to determine if measures of the sperm-inherited epigenetic program revert to match the control treatment 1 month after withdrawing the daily alcohol treatments.

MATERIALS AND METHODS

Using a voluntary access model, we exposed C57BL/6J males to 6% or 10% alcohol for 10 weeks, withdrew the alcohol treatments for 4 weeks, and used RNA sequencing to examine gene expression patterns in the caput section of the epididymis. We then compared the abundance of sperm small RNA species between treatments.

RESULTS

In the caput section of the epididymis, chronic alcohol exposure induced changes in the transcriptional control of genetic pathways related to the mitochondrial function, oxidative phosphorylation, and the generalized stress response (EIF2 signaling). Subsequent analysis identified region-specific, alcohol-induced changes in mitochondrial DNA copy number across the epididymis, which correlated with increases in the mitochondrial DNA content of alcohol-exposed sperm. Notably, in the corpus section of the epididymis, increases in mitochondrial DNA copy number persisted 1 month after alcohol cessation. Analysis of sperm noncoding RNAs between control and alcohol-exposed males 1 month after alcohol withdrawal revealed a ∼100-fold increase in mir-196a, a microRNA induced as part of the nuclear factor erythroid 2-related factor 2 (Nrf2)-driven cellular antioxidant response.

DISCUSSION AND CONCLUSION

Our data reveal that alcohol-induced epididymal mitochondrial dysfunction and differences in sperm noncoding RNA content persist after alcohol withdrawal. Further, differences in mir-196a and sperm mitochondrial DNA copy number may serve as viable biomarkers of adverse alterations in the sperm-inherited epigenetic program.

Cell death or survival: Insights into the role of mRNA translational control

Cellular stress is an intrinsic part of cell physiology that underlines cell survival or death. The ability of mammalian cells to regulate global protein synthesis (aka translational control) represents a critical, yet underappreciated, layer of regulation during the stress response. Various cellular stress response pathways monitor conditions of cell growth and subsequently reshape the cellular translatome to optimize translational outputs. On the molecular level, such translational reprogramming involves an intricate network of interactions between translation machinery, RNA-binding proteins, mRNAs, and non-protein coding RNAs. In this review, we will discuss molecular mechanisms, signaling pathways, and targets of translational control that contribute to cellular adaptation to stress and to cell survival or death.

Heme oxygenase-1 determines the cell fate of ferroptotic death of alveolar macrophages in COPD

Background

Despite an increasing understanding of chronic obstructive pulmonary disease (COPD) pathogenesis, the mechanisms of diverse cell populations in the human lung remain unknown. Using single-cell RNA sequencing (scRNA-Seq), we can reveal changes within individual cell populations in COPD that are important for disease pathogenesis and characteristics.

Methods

We performed scRNA-Seq on lung tissue obtained from donors with non-COPD and mild-to-moderate COPD to identify disease-related genes within different cell types. We testified the findings using qRT-PCR, immunohistochemistry, immunofluorescence and Western blotting from 25 additional subjects and RAW 264.7 macrophages. Targeting ferroptosis with the ferroptosis inhibitor ferrostatin-1, iron chelator deferoxamine or HO-1 inhibitor zinc protoporphyrin was administered in the experimental cigarette smoke COPD mouse model.

Results

We identified two populations of alveolar macrophages (AMs) in the human lung that were dysregulated in COPD patients. We discovered that M2-like AMs modulate susceptibility to ferroptosis by disrupting lipid and iron homeostasis both in vivo and in vitro. The discrepancy in sensitivity to ferroptosis can be determined and regulated by HO-1. In contrast, M1-like AMs showed the ability to attenuate oxidative stress and exert resistance to ferroptosis. In addition, the expression of genes within M2-like AMs is also involved in defects in phagocytosis and lysosome distortion. This ferroptotic phenotype was ameliorated by antiferroptotic compounds, iron chelators and HO-1 inhibitors. During COPD, the accumulation of lipid peroxidation drives ferroptosis-sensitive M2-like AMs, while M1-like AMs show characteristics of ferroptosis resistance. Ferroptotic M2 AMs lose their anti-inflammatory and repair functions but provoke inflammatory responses, resulting in consistent inflammation and tissue damage in the presence of M1 AMs in COPD.

Conclusion

Appropriate interventions in ferroptosis can reduce the occurrence of infections and acute onset, and delay the COPD process.

Molecular mechanisms of cell death in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) in neonates is the most common pulmonary disease that causes neonatal mortality, has complex pathogenesis, and lacks effective treatment. It is associated with chronic obstructive pulmonary disease, pulmonary hypertension, and right ventricular hypertrophy. The occurrence and development of BPD involve various factors, of which premature birth is the most crucial reason for BPD. Under the premise of abnormal lung structure and functional product, newborns are susceptible to damage to oxides, free radicals, hypoxia, infections and so on. The most influential is oxidative stress, which induces cell death in different ways when the oxidative stress balance in the body is disrupted. Increasing evidence has shown that programmed cell death (PCD), including apoptosis, necrosis, autophagy, and ferroptosis, plays a significant role in the molecular and biological mechanisms of BPD and the further development of the disease. Understanding the mode of PCD and its signaling pathways can provide new therapeutic approaches and targets for the clinical treatment of BPD. This review elucidates the mechanism of BPD, focusing on the multiple types of PCD in BPD and their molecular mechanisms, which are mainly based on experimental results obtained in rodents.

MicroRNAs and Synaptic Plasticity: From Their Molecular Roles to Response to Therapy

Synaptic plasticity is the ability of synapses to weaken or strengthen over time, in response to changes in the activity of the neurons. It is orchestrated by a variety of genes, proteins, and external and internal factors, especially epigenetic factors. MicroRNAs (miRNAs) are well-acknowledged epigenetic modulators that regulate the translation and degradation of target genes in the nervous system. Increasing evidence has suggested that a number of miRNAs play important roles in modulating various aspects of synaptic plasticity. The deregulation of miRNAs could be associated with pathological alterations in synaptic plasticity, which could lead to different CNS-related diseases. Herein, we provide an update on the role of miRNAs in governing synaptic plasticity. In addition, we also summarize recent researches on the role of miRNAs in drug addiction, and their targets and mechanism of action. Understanding of the way in which miRNAs contribute to synaptic plasticity provides rational clues in establishing the novel biomarkers and new therapeutic strategies for the diagnosis and treatment of plasticity-related diseases and drug addiction.

Involvement of miRNA-34a regulated Krüppel-like factor 4 expression in hyperoxia-induced senescence in lung epithelial cells

BACKGROUND

Premature infants, subjected to supplemental oxygen and mechanical ventilation, may develop bronchopulmonary dysplasia, a chronic lung disease characterized by alveolar dysplasia and impaired vascularization. We and others have shown that hyperoxia causes senescence in cultured lung epithelial cells and fibroblasts. Although miR-34a modulates senescence, it is unclear whether it contributes to hyperoxia-induced senescence. We hypothesized that hyperoxia increases miR-34a levels, leading to cellular senescence.

METHODS

We exposed mouse lung epithelial (MLE-12) cells and primary human small airway epithelial cells to hyperoxia (95% O₂/5% CO₂) or air (21% O₂/5% CO₂) for 24 h. Newborn mice (< 12 h old) were exposed to hyperoxia (> 95% O₂) for 3 days and allowed to recover in room air until postnatal day 7. Lung samples from premature human infants requiring mechanical ventilation and control subjects who were not mechanically ventilated were employed.

RESULTS

Hyperoxia caused senescence as indicated by loss of nuclear lamin B1, increased p21 gene expression, and senescence-associated secretory phenotype factors. Expression of miR-34a-5p was increased in epithelial cells and newborn mice exposed to hyperoxia, and in premature infants requiring mechanical ventilation. Transfection with a miR-34a-5p inhibitor reduced hyperoxia-induced senescence in MLE-12 cells. Additionally, hyperoxia increased protein levels of the oncogene and tumor-suppressor Krüppel-like factor 4 (KLF4), which were inhibited by a miR-34a-5p inhibitor. Furthermore, KLF4 knockdown by siRNA transfection reduced hyperoxia-induced senescence.

CONCLUSION

Hyperoxia increases miR-34a-5p, leading to senescence in lung epithelial cells. This is dictated in part by upregulation of KLF4 signaling. Therefore, inhibiting hyperoxia-induced senescence via miR-34a-5p or KLF4 suppression may provide a novel therapeutic strategy to mitigate the detrimental consequences of hyperoxia in the neonatal lung.

Hyperoxia-induced miR-342-5p down-regulation exacerbates neonatal bronchopulmonary dysplasia via the Raf1 regulator Spred3

BACKGROUND AND PURPOSE

Bronchopulmonary dysplasia (BPD) is the most prevalent chronic paediatric lung disease and is linked to the development of chronic obstructive pulmonary disease. MicroRNA-based regulation of type II alveolar epithelial cell (T2AEC) proliferation and apoptosis is an important factor in the pathogenesis of BPD and warrants further investigation.

EXPERIMENTAL APPROACH

Two murine models of hyperoxic lung injury (with or without miR-342-5p or Sprouty-related, EVH1 domain-containing protein 3 [Spred3] modulation) were employed: a hyperoxia-induced acute lung injury model (100% O₂ on postnatal days 1-7) and the BPD model (100% O₂ on postnatal days 1-4, followed by room air for 10 days). Tracheal aspirate pellets from healthy control and moderate/severe BPD neonates were randomly selected for clinical miR-342-5p analysis.

KEY RESULTS

Hyperoxia decreased miR-342-5p levels in primary T2AECs, MLE12 cells and neonatal mouse lungs. Transgenic miR-342 overexpression in neonatal mice ameliorated survival rates and improved the BPD phenotype and BPD-associated pulmonary arterial hypertension (PAH). T2AEC-specific miR-342 transgenic overexpression, as well as miR-342-5p mimic therapy, also ameliorated the BPD phenotype and associated PAH. miR-342-5p targets the 3'UTR of the Raf1 regulator Spred3, inhibiting Spred3 expression. Treatment with recombinant Spred3 exacerbated the BPD phenotype and associated PAH. Notably, miR-342-5p inhibition under room air conditions did not mimic the BPD phenotype. Moderate/severe BPD tracheal aspirate pellets exhibited decreased miR-342-5p levels relative to healthy control pellets.

CONCLUSION AND IMPLICATIONS

These findings suggest that miR-342-5p mimic therapy may show promise in the treatment or prevention of BPD.

A Novel Therapeutic Target, BACH1, Regulates Cancer Metabolism

BTB domain and CNC homology 1 (BACH1) is a transcription factor that is highly expressed in tumors including breast and lung, relative to their non-tumor tissues. BACH1 is known to regulate multiple physiological processes including heme homeostasis, oxidative stress response, senescence, cell cycle, and mitosis. In a tumor, BACH1 promotes invasion and metastasis of cancer cells, and the expression of BACH1 presents a poor outcome for cancer patients including breast and lung cancer patients. Recent studies identified novel functional roles of BACH1 in the regulation of metabolic pathways in cancer cells. BACH1 inhibits mitochondrial metabolism through transcriptional suppression of mitochondrial membrane genes. In addition, BACH1 suppresses activity of pyruvate dehydrogenase (PDH), a key enzyme that converts pyruvate to acetyl-CoA for the citric acid (TCA) cycle through transcriptional activation of pyruvate dehydrogenase kinase (PDK). Moreover, BACH1 increases glucose uptake and lactate secretion through the expression of metabolic enzymes involved such as hexokinase 2 (HK2) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) for aerobic glycolysis. Pharmacological or genetic inhibition of BACH1 could reprogram by increasing mitochondrial metabolism, subsequently rendering metabolic vulnerability of cancer cells against mitochondrial respiratory inhibition. Furthermore, inhibition of BACH1 decreased antioxidant-induced glycolysis rates as well as reduced migration and invasion of cancer cells, suggesting BACH1 as a potentially useful cancer therapeutic target.

Extracellular vesicle miRNA-21 is a potential biomarker for predicting chronic lung disease in premature infants

Premature infants are often exposed to positive pressure ventilation and supplemental oxygen, which leads to the development of chronic lung disease (CLD). There are currently no standard serum biomarkers used for prediction or early detection of patients who go on to develop CLD. MicroRNAs (miRNAs) are a novel class of naturally occurring, short, noncoding substances that regulate gene expression at the posttranscriptional level and cause translational inhibition and/or mRNA degradation and present in body fluids packaged in extracellular vesicles (EVs), rendering them remarkably stable. Our aim was to evaluate miRNAs identified in serum EVs of premature infants as potential biomarkers for CLD. Serum EVs were extracted from premature infants at birth and on the 28th day of life (DOL). Using a human miRNA array, we identified 62 miRNAs that were universally expressed in CLD patients and non-CLD patients. Of the 62 miRNAs, 59 miRNAs and 44 miRNAs were differentially expressed on DOL0 and DOL28 in CLD and non-CLD patients, respectively. Of these miRNAs, serum EV miR-21 was upregulated in CLD patients on DOL28 compared with levels at birth and downregulated in non-CLD patients on DOL28 compared with levels at birth. In neonatal mice exposed to hyperoxia for 7days, as a model of CLD, five miRNAs (miR-34a, miR-21, miR-712, miR-682, and miR-221) were upregulated, and 7 miRNAs (miR-542-5p, miR-449a, miR-322, miR-190b, miR-153, miR-335-3p, miR-377) were downregulated. MiR-21 was detected as a common miRNA that changed in CLD patients and in the hyperoxia exposed mice. We conclude that EV miR-21 may be a biomarker of CLD.

Hyperoxia causes miR199a-5p-mediated injury in the developing lung

BACKGROUND

Hyperoxia-induced acute lung injury (HALI) is characterized by increased permeability and infiltration of inflammatory cells, impairment of alveolar development, and compromised lung function. Recent evidence has determined that microRNAs (miRs) are implicated in hyperoxia-induced lung injury, including bronchopulmonary dysplasia (BPD). However, the expression profile and functional role of miR199a-5p in developing lungs have not been reported.

METHODS

The present study was undertaken to explore the role of miR199a-5p in developing mice lungs and human neonates. We exposed neonatal mice for 7 days, mouse lung epithelial cells (MLE12), mouse lung endothelial cells (MLECs), and macrophages (RAW246.7), to hyperoxia at different time points.

RESULTS

Our results demonstrated enhanced miR199a-5p expression in hyperoxia-exposed mice lungs and cells, as well as in tracheal aspirates of infants developing BPD, with significant reduction in the expression of its target, caveolin-1. Next, we observed that miR199a-5p-mimic worsens HALI as evidenced by increased inflammatory cells, cytokines, and lung vascular markers. Conversely, miR199a-5p-inhibitor treatment attenuated HALI.

CONCLUSION

Thus, our findings suggest that miR199a-5p is a potential target for attenuating HALI pathophysiology in the developing lung. Moreover, miR199a-5p-inhibitor could be part of a novel therapeutic strategy for improving BPD in preterm neonates.

Predicting the likelihood of bronchopulmonary dysplasia in premature neonates

Introduction: Bronchopulmonary dysplasia (BPD) is the most common serious pulmonary morbidity in premature infants. Despite ongoing advances in neonatal care, the incidence of BPD has not improved. A potential explanation for this phenomenon is the limited ability for accurate early prediction of the risk of BPD. BPD continues to represent a therapeutic challenge and no single effective therapy exists for this condition. Areas covered: Here, we review risk factors of BPD derived from clinical data, biological fluid biomarkers, respiratory management data, and scientific advancements using 'omics' technologies, and their ability to predict the pathogenesis of BPD in preterm neonates. Risk factors and biomarkers were identified via literature search with a focus on the last 5 years of data. Expert opinion: The most accurate predictive tools utilize risk factors that encompass a variety of categories. Numerous predictive models have been proposed but suffer from a lack of adequate validation. An ideal model should include multiple, easily measurable variables validated across a heterogeneous population. In addition to evaluating recent BPD prediction models, we suggest approaches to enhance future models.

The critical role of microRNAs in stress response: Therapeutic prospect and limitation

Stress response refers to the systemic nonspecific response upon exposure to strong stimulation or chronic stress, such as severe trauma, shock, infection, burn, major surgery or improper environment, which disturb organisms and damage their physical and psychological health. However, the pathogenesis of stress induced disorder remains complicated and diverse under different stress exposure. Recently, studies have revealed a specific role of microRNAs (miRNAs) in regulating cellular function under different types of stress, suggesting a significant role in the treatment and prevention of stress-related diseases, such as stress ulcer, posttraumatic stress disorder, stress-induced cardiomyopathy and so on. This paper have reviewed the literature on microRNA related stress diseases in different databases including PubMed, Web of Science, and the MiRbase. It considers only peer-reviewed papers published in English between 2004 and 2018. This review summarizes new advances in principles and mechanisms of miRNAs regulating stress signalling pathway and the role of miRNAs in human stress diseases. This comprehensive review is to provide an integrated account of how different stresses affect miRNAs and how stress-miRNA pathways may, in turn, be linked with disease, which offers some potential strategies for stress disorder treatment. Furthermore, the limitation of current studies and challenges for clinical use are discussed.

MicroRNA-98-5p ameliorates oxygen-glucose deprivation/reoxygenation (OGD/R)-induced neuronal injury by inhibiting Bach1 and promoting Nrf2/ARE signaling

MicroRNA-98-5p (miR-98-5p) is a stress-related microRNA (miRNA) that plays an important role in regulating cell survival, apoptosis, and oxidative stress in multiple cell types and diseases. However, little is known about the role of miR-98-5p in cerebral ischemia/reperfusion injury. In this study, we investigated the role and mechanism of miR-98-5p in regulating neuronal injury induced by oxygen-glucose deprivation/reoxygenation (OGD/R), an in vitro model of cerebral ischemia/reperfusion injury. We found that miR-98 expression was significantly altered in neurons in response to OGD/R treatment. Functional experiments showed that overexpression of miR-98-5p inhibited OGD/R-induced apoptosis and reactive oxygen species (ROS) production in neurons, whereas inhibition of miR-98-5p showed the opposite effect. Interestingly, bioinformatics analysis predicted that BTB and CNC homology 1 (Bach1) was a potential target gene of miR-98-5p, that was verified by dual-luciferase reporter assay. Moreover, overexpression of miR-98-5p inhibited Bach1 expression while suppression of miR-98-5p promoted Bach1 expression in neurons. Notably, miR-98-5p was shown to regulate the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the activity of the antioxidant response element (ARE). However, overexpression of Bach1 or silencing of Nrf2 significantly abolished the miR-98-5p-mediated neuroprotective effect. Overall, these results demonstrate that miR-98-5p ameliorates OGD/R-induced neuronal injury in vitro through targeting to promote activation of Nrf2/ARE signaling. Our study suggests that miR-98-5p may play a potential role in cerebral ischemia/reperfusion injury and represents a potential therapeutic target for neuroprotection.

Recent advances in the pathogenesis of BPD

Bronchopulmonary dysplasia (BPD) continues to be one of the most common complications of preterm birth and is characterized histopathologically by impaired lung alveolarization. Extremely preterm born infants remain at high risk for the development of BPD, highlighting a pressing need for continued efforts to understand the pathomechanisms at play in affected infants. This brief review summarizes recent progress in our understanding of the how the development of the newborn lung is stunted, highlighting recent reports on roles for growth factor signaling, oxidative stress, inflammation, the extracellular matrix and proteolysis, non-coding RNA, and fibroblast and epithelial cell plasticity. Additionally, some concerns about modeling BPD in experimental animals are reviewed, as are new developments in the in vitro modeling of pathophysiological processes relevant to impaired lung alveolarization in BPD.

Lung omics signatures in a bronchopulmonary dysplasia and pulmonary hypertension-like murine model

Bronchopulmonary dysplasia (BPD), the most common chronic lung disease in infants, is associated with long-term morbidities, including pulmonary hypertension (PH). Importantly, hyperoxia causes BPD and PH; however, the underlying mechanisms remain unclear. Herein, we performed high-throughput transcriptomic and proteomic studies using a clinically relevant murine model of BPD with PH. Neonatal wild-type C57BL6J mice were exposed to 21% oxygen (normoxia) or 70% oxygen (hyperoxia) during postnatal days (PNDs) 1-7. Lung tissues were collected for proteomic and genomic analyses on PND 7, and selected genes and proteins were validated by real-time quantitative PCR and immunoblotting analysis, respectively. Hyperoxia exposure dysregulated the expression of 344 genes and 21 proteins. Interestingly, hyperoxia downregulated genes involved in neuronal development and maturation in lung tissues. Gene set enrichment and gene ontology analyses identified apoptosis, oxidoreductase activity, plasma membrane integrity, organ development, angiogenesis, cell proliferation, and mitophagy as the predominant processes affected by hyperoxia. Furthermore, selected deregulated proteins strongly correlated with the expression of specific genes. Collectively, our results identified several potential therapeutic targets for hyperoxia-mediated BPD and PH in infants.

Recent advances in our understanding of the mechanisms of late lung development and bronchopulmonary dysplasia

The objective of lung development is to generate an organ of gas exchange that provides both a thin gas diffusion barrier and a large gas diffusion surface area, which concomitantly generates a steep gas diffusion concentration gradient. As such, the lung is perfectly structured to undertake the function of gas exchange: a large number of small alveoli provide extensive surface area within the limited volume of the lung, and a delicate alveolo-capillary barrier brings circulating blood into close proximity to the inspired air. Efficient movement of inspired air and circulating blood through the conducting airways and conducting vessels, respectively, generates steep oxygen and carbon dioxide concentration gradients across the alveolo-capillary barrier, providing ideal conditions for effective diffusion of both gases during breathing. The development of the gas exchange apparatus of the lung occurs during the second phase of lung development-namely, late lung development-which includes the canalicular, saccular, and alveolar stages of lung development. It is during these stages of lung development that preterm-born infants are delivered, when the lung is not yet competent for effective gas exchange. These infants may develop bronchopulmonary dysplasia (BPD), a syndrome complicated by disturbances to the development of the alveoli and the pulmonary vasculature. It is the objective of this review to update the reader about recent developments that further our understanding of the mechanisms of lung alveolarization and vascularization and the pathogenesis of BPD and other neonatal lung diseases that feature lung hypoplasia.

Differentiation impairs Bach1 dependent HO-1 activation and increases sensitivity to oxidative stress in SH-SY5Y neuroblastoma cells

Neuronal adaptation to oxidative stress is crucially important in order to prevent degenerative diseases. The role played by the Nrf2/HO-1 system in favoring cell survival of neuroblastoma (NB) cells exposed to hydrogen peroxide (H₂O₂) has been investigated using undifferentiated or all-trans retinoic acid (ATRA) differentiated SH-SY5Y cells. While undifferentiated cells were basically resistant to the oxidative stimulus, ATRA treatment progressively decreased cell viability in response to H₂O₂. HO-1 silencing decreased undifferentiated cell viability when exposed to H₂O₂, proving the role of HO-1 in cell survival. Conversely, ATRA differentiated cells exposed to H₂O₂ showed a significantly lower induction of HO-1, and only the supplementation with low doses of bilirubin (0,5-1 μM) restored viability. Moreover, the nuclear level of Bach1, repressor of HO-1 transcription, strongly decreased in undifferentiated cells exposed to oxidative stress, while did not change in ATRA differentiated cells. Furthermore, Bach1 was displaced from HO-1 promoter in undifferentiated cells exposed to H₂O₂, enabling the binding of Nrf2. On the contrary, in ATRA differentiated cells treated with H₂O₂, Bach1 displacement was impaired, preventing Nrf2 binding and limiting HO-1 transcription. In conclusion, our findings highlight the central role of Bach1 in HO-1-dependent neuronal response to oxidative stress.

Role of the Nrf2/HO-1 axis in bronchopulmonary dysplasia and hyperoxic lung injuries

Bronchopulmonary dysplasia (BPD) is a chronic illness that usually originates in preterm newborns. Generally, BPD is a consequence of respiratory distress syndrome (RDS) which, in turn, comes from the early arrest of lung development and the lack of pulmonary surfactant. The need of oxygen therapy to overcome premature newborns' compromised respiratory function generates an increasing amount of reactive oxygen species (ROS), the onset of sustained oxidative stress (OS) status, and inflammation in the pulmonary alveoli deputies to respiratory exchanges. BPD is a severe and potentially life-threatening disorder that in the most serious cases, can open the way to neurodevelopmental delay. More importantly, there is no adequate intervention to hamper or treat BPD. This perspective article seeks to review the most recent and relevant literature describing the very early stages of BPD and hyperoxic lung injuries focussing on nuclear factor erythroid derived 2 (Nrf2)/heme oxygenase-1 (HO-1) axis. Indeed, Nrf2/HO1 activation in response to OS induced lung injury in preterm concurs to the induction of certain number of antioxidant, anti-inflammatory, and detoxification pathways that seem to be more powerful than the activation of one single antioxidant gene. These elicited protective effects are able to counteract/mitigate all multifaceted aspects of the disease and may support novel approaches for the management of BPD.

miR-196a Enhances Neuronal Morphology through Suppressing RANBP10 to Provide Neuroprotection in Huntington's Disease

MicroRNAs (miRNAs) play important roles in several neurobiological processes, including the development and progression of diseases. Previously, we identified that one specific miRNA, miR-196a, provides neuroprotective effects on Huntington's disease (HD), although the detailed mechanism is still unclear. Based on our bioinformatic analyses, we hypothesize miR-196a might offer neuroprotective functions through improving cytoskeletons of brain cells. Here, we show that miR-196a could enhance neuronal morphology, further ameliorating intracellular transport, synaptic plasticity, neuronal activity, and learning and memory abilities. Additionally, we found that miR-196a could suppress the expression of RAN binding protein 10 (RANBP10) through binding to its 3' untranslated region, and higher expression of RANBP10 exacerbates neuronal morphology and intracellular transport. Furthermore, miR-196a enhances neuronal morphology through suppressing RANBP10 and increasing the ability of β-tubulin polymerization. Most importantly, we observed higher expression of RANBP10 in the brains of HD transgenic mice, and higher expression of RANBP10 might exacerbate the pathological aggregates in HD. Taken together, we provide evidence that enhancement of neuronal morphology through RANBP10 is one of the neuroprotective mechanisms for miR-196a. Since miR-196a has also been reported in other neuronal diseases, this study might offer insights with regard to the therapeutic use of miR-196a in other neuronal diseases.

Heme Oxygenase 1 as a Therapeutic Target in Acute Kidney Injury

A common clinical condition, acute kidney injury (AKI) significantly influences morbidity and mortality, particularly in critically ill patients. The pathophysiology of AKI is complex and involves multiple pathways, including inflammation, autophagy, cell-cycle progression, and oxidative stress. Recent evidence suggests that a single insult to the kidney significantly enhances the propensity to develop chronic kidney disease. Therefore, the generation of effective therapies against AKI is timely. In this context, the cytoprotective effects of heme oxygenase 1 (HO-1) in animal models of AKI are well documented. HO-1 modulates oxidative stress, autophagy, and inflammation and regulates the progression of cell cycle via direct and indirect mechanisms. These beneficial effects of HO-1 induction during AKI are mediated in part by the by-products of the HO reaction (iron, carbon monoxide, and bile pigments). This review highlights recent advances in the molecular mechanisms of HO-1-mediated cytoprotection and discusses the translational potential of HO-1 induction in AKI.