Targeting heme oxygenase-1 and carbon monoxide for therapeutic modulation of inflammation

Carbon monoxide-loaded cell therapy as an exercise mimetic for sarcopenia treatment

Sarcopenia is characterized by loss of muscle strength and muscle mass with aging. The growing number of sarcopenia patients as a result of the aging population has no viable treatment. Exercise maintains muscle strength and mass by increasing peroxisome growth factor activating receptor γ-conjugating factor-1α (PGC-1α) and Akt signaling in skeletal muscle. The present study focused on the carbon monoxide (CO), endogenous activator of PGC-1α and Akt, and investigated the therapeutic potential of CO-loaded red blood cells (CO-RBCs), which is bioinspired from in vivo CO delivery system, as an exercise mimetic for the treatment of sarcopenia. Treatment of C2C12 myoblasts with the CO-donor increased the protein levels of PGC-1α which enhanced mitochondrial biogenesis and energy production. The CO-donor treatment also activated Akt, indicating that CO promotes muscle synthesis. CO levels were significantly elevated in the skeletal muscle of normal mice after intravenous administration of CO-RBCs. Furthermore, CO-RBCs restored the mRNA expression levels of PGC-1α in the skeletal muscle of two experimental sarcopenia mouse models, denervated (Den) and hindlimb unloading (HU) models. CO-RBCs also restored muscle mass in Den mice by activating Akt signaling and suppressing the muscle atrophy factors myostatin and atrogin-1, and oxidative stress. Treadmill tests further showed that the reduced running distance in HU mice was significantly restored by CO-RBC administration. These findings suggest that CO-RBCs have potential as an exercise mimetic for sarcopenia treatment.

Polyene phosphatidylcholine enhances the therapeutic response of oxaliplatin in gastric cancer through Nrf2/HMOX1 mediated ferroptosis

Oxaliplatin (OXA)-based chemotherapy is one of the first-line treatments for advanced gastric cancer. However, the potential risk for chemotherapy-induced hepatic injury can hinder its effectiveness. Polyene phosphatidylcholine (PPC) is often used as a hepatoprotective agent to counter OXA-induced hepatic injury; however, its impact on the antitumour effectiveness of OXA remains uncertain. Our retrospective study examined 98 patients with stage IV gastric cancer to assess the impact of PPC on progression-free survival (PFS) and disease control rate (DCR). Furthermore, in vitro and in vivo assays were conducted to elucidate the combined biological effects of OXA and PPC (OXA+PPC) on gastric cancer. RNA sequencing, luciferase reporter assays, live/dead cell assays, immunofluorescence, and western blotting were used to identify the activated signalling pathways and downstream factors post OXA+PPC treatment. The findings indicated that PPC served as an independent prognostic factor, correlating with prolonged PFS and improved DCR in patients with gastric cancer. The combination of OXA and PPC significantly inhibited tumour cell growth both in vitro and in vivo. RNA sequencing revealed that OXA+PPC treatment amplified reactive oxygen species and ferroptosis signalling pathways. Mechanistically, OXA+PPC upregulated the expression of haem oxygenase-1 by promoting the nuclear migration of nuclear factor erythroid 2-related factor (Nrf2), thereby enhancing its transcriptional activity. Drug-molecule docking analysis demonstrated that PPC competitively bound to the peptide structural domains of both Nrf2 and Kelch-like ECH-associated protein 1 (KEAP1), accounting for the increased translocation of Nrf2. In conclusion, our study reveals the synergistic antitumour potential of PPC and OXA while protecting patients against hepatic injury. This suggests a promising combined treatment approach for patients with advanced gastric cancer.

Precision nutrition to reset virus-induced human metabolic reprogramming and dysregulation (HMRD) in long-COVID

SARS-CoV-2, the etiological agent of COVID-19, is devoid of any metabolic capacity; therefore, it is critical for the viral pathogen to hijack host cellular metabolic machinery for its replication and propagation. This single-stranded RNA virus with a 29.9 kb genome encodes 14 open reading frames (ORFs) and initiates a plethora of virus-host protein-protein interactions in the human body. These extensive viral protein interactions with host-specific cellular targets could trigger severe human metabolic reprogramming/dysregulation (HMRD), a rewiring of sugar-, amino acid-, lipid-, and nucleotide-metabolism(s), as well as altered or impaired bioenergetics, immune dysfunction, and redox imbalance in the body. In the infectious process, the viral pathogen hijacks two major human receptors, angiotensin-converting enzyme (ACE)-2 and/or neuropilin (NRP)-1, for initial adhesion to cell surface; then utilizes two major host proteases, TMPRSS2 and/or furin, to gain cellular entry; and finally employs an endosomal enzyme, cathepsin L (CTSL) for fusogenic release of its viral genome. The virus-induced HMRD results in 5 possible infectious outcomes: asymptomatic, mild, moderate, severe to fatal episodes; while the symptomatic acute COVID-19 condition could manifest into 3 clinical phases: (i) hypoxia and hypoxemia (Warburg effect), (ii) hyperferritinemia ('cytokine storm'), and (iii) thrombocytosis (coagulopathy). The mean incubation period for COVID-19 onset was estimated to be 5.1 days, and most cases develop symptoms after 14 days. The mean viral clearance times were 24, 30, and 39 days for acute, severe, and ICU-admitted COVID-19 patients, respectively. However, about 25-70% of virus-free COVID-19 survivors continue to sustain virus-induced HMRD and exhibit a wide range of symptoms that are persistent, exacerbated, or new 'onset' clinical incidents, collectively termed as post-acute sequelae of COVID-19 (PASC) or long COVID. PASC patients experience several debilitating clinical condition(s) with >200 different and overlapping symptoms that may last for weeks to months. Chronic PASC is a cumulative outcome of at least 10 different HMRD-related pathophysiological mechanisms involving both virus-derived virulence factors and a multitude of innate host responses. Based on HMRD and virus-free clinical impairments of different human organs/systems, PASC patients can be categorized into 4 different clusters or sub-phenotypes: sub-phenotype-1 (33.8%) with cardiac and renal manifestations; sub-phenotype-2 (32.8%) with respiratory, sleep and anxiety disorders; sub-phenotype-3 (23.4%) with skeleto-muscular and nervous disorders; and sub-phenotype-4 (10.1%) with digestive and pulmonary dysfunctions. This narrative review elucidates the effects of viral hijack on host cellular machinery during SARS-CoV-2 infection, ensuing detrimental effect(s) of virus-induced HMRD on human metabolism, consequential symptomatic clinical implications, and damage to multiple organ systems; as well as chronic pathophysiological sequelae in virus-free PASC patients. We have also provided a few evidence-based, human randomized controlled trial (RCT)-tested, precision nutrients to reset HMRD for health recovery of PASC patients.

The clinical relevance of heme detoxification by the macrophage heme oxygenase system

Heme degradation by the heme oxygenase (HMOX) family of enzymes is critical for maintaining homeostasis and limiting heme-induced tissue damage. Macrophages express HMOX1 and 2 and are critical sites of heme degradation in healthy and diseased states. Here we review the functions of the macrophage heme oxygenase system and its clinical relevance in discrete groups of pathologies where heme has been demonstrated to play a driving role. HMOX1 function in macrophages is essential for limiting oxidative tissue damage in both acute and chronic hemolytic disorders. By degrading pro-inflammatory heme and releasing anti-inflammatory molecules such as carbon monoxide, HMOX1 fine-tunes the acute inflammatory response with consequences for disorders of hyperinflammation such as sepsis. We then discuss divergent beneficial and pathological roles for HMOX1 in disorders such as atherosclerosis and metabolic syndrome, where activation of the HMOX system sits at the crossroads of chronic low-grade inflammation and oxidative stress. Finally, we highlight the emerging role for HMOX1 in regulating macrophage cell death via the iron- and oxidation-dependent form of cell death, ferroptosis. In summary, the importance of heme clearance by macrophages is an active area of investigation with relevance for therapeutic intervention in a diverse array of human diseases.

Identification of potential hub genes and regulatory networks of smoking-related endothelial dysfunction in atherosclerosis using bioinformatics analysis

BACKGROUND

Endothelial dysfunction, the earliest stage of atherosclerosis, can be caused by smoking, but its molecular mechanism requires further investigation.

OBJECTIVE

This study aimed to use bioinformatics analysis to identify potential mechanisms involved in smoking-related atherosclerotic endothelial dysfunction.

METHODS

The transcriptome data used for this bioinformatics analysis were obtained from the Gene Expression Omnibus (GEO) database. The GSE137578 and GSE141136 datasets were used to identify common differentially expressed genes (co-DEGs) in endothelial cells treated with oxidized low-density lipoprotein (ox-LDL) and tobacco. The co-DEGs were annotated using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomics (KEGG) databases. Additionally, a protein-protein interaction (PPI) network was constructed to visualize their interactions and screen for hub genes. GSE120521 dataset was used to verify the expression of hub genes in unstable plaques. The miRNA expression profile GSE137580 and online databases (starBase 2.0, TargetScan 8.0 and DGIdb v4.2.0) were used to predict the related non-coding RNAs and drugs.

RESULTS

A total of 232 co-DEGs were identified, including 113 up-regulated genes and 119 down-regulated genes. These DEGs were primarily enriched in detrimental autophagy, cell death, transcription factors, and cytokines, and were implicated in ferroptosis, abnormal lipid metabolism, inflammation, and oxidative stress pathways. Ten hub genes were screened from the constructed PPI network, including up-regulated genes such as FOS, HMOX1, SQSTM1, PTGS2, ATF3, DDIT3, and down-regulated genes MCM4, KIF15, UHRF1, and CCL2. Importantly, HMOX1 was further up-regulated in unstable plaques (p= 0.034). Finally, a regulatory network involving lncRNA/circRNA-miRNA-hub genes and drug-hub genes was established.

CONCLUSION

Atherosclerotic endothelial dysfunction is associated with smoking-induced injury. Through bioinformatics analysis, we identified potential mechanisms and provided potential therapeutic targets.

Allicin ameliorates sepsis-induced acute kidney injury through Nrf2/HO-1 signaling pathway

Acute kidney injury (AKI) is a complication that can be induced by different factors. Allicin is a class of organic sulfur compounds with anticancer and antibacterial effects, and has not been reported in sepsis-induced AKI (S-AKI). S-AKI was induced in c57BL/6 mice by cecal ligation puncture. In response to the treatment of allicin, the survival rate of mice with S-AKI was increased. Reduced levels of serum creatinine, blood urea nitrogen, UALB, KIM-1 and NGAL indicated an improvement in renal function of S-AKI mice. Allicin inhibited the inflammation and cell apoptosis, which evidenced by decreased levels of inflammatory cytokines and apoptosis-related proteins. Oxidative stress was evaluated by the levels of oxidative stress biomarkers, and suppressed by allicin. In addition, allicin-alleviated mitochondrial dysfunction was characterized by decreased JC-1 green monomer. These effects of allicin were also evidenced in HK2 cells primed with lipopolysaccharide (LPS). Both in vivo and in vitro experiments showed that the nuclear translocation of Nrf2 and the expression of HO-1 increased after allicin treatment, which was confirmed by ML385 and CDDO-Me. In summary, this study revealed the alleviating effect of allicin on S-AKI and demonstrated the promotive effect of allicin on nuclear translocation of Nrf2 for the first time. It was inferred that allicin inhibited the progression of S-AKI through Nrf2/HO-1 signaling pathway. This study makes contributions to the understanding of the roles of allicin in S-AKI.

Sargachromenol Attenuates Inflammatory Responses by Regulating NF-κB and Nrf2 Pathways in RAW 264.7 Cells and LPS-treated Mice

This study aims to explore the anti-inflammatory mechanisms of sargachromenol in both RAW 264.7 cells and lipopolysaccharide (LPS)-treated mice, as previous reports have suggested that sargachromenol possesses anti-aging, anti-inflammatory, antioxidant, and neuroprotective properties. Although the precise mechanism behind its anti-inflammatory activity remains unclear, pretreatment with sargachromenol effectively reduced the production of nitric oxide, prostaglandin E2, and interleukin (IL)-1β in LPS-stimulated RAW 264.7 cells by inhibiting cyclooxygenase-2. Moreover, sargachromenol inhibited the activation of nuclear factor-κB (NF-κB) by preventing the degradation of the inhibitor of κB-α (IκB-α) and inhibiting protein kinase B (Akt) phosphorylation in LPS-stimulated cells. We also found that sargachromenol induced the production of heme oxygenase-1 (HO-1) by activating the nuclear transcription factor erythroid-2-related factor 2 (Nrf2). In LPS-treated mice, oral administration of sargachromenol effectively reduced the levels of IL-1β, IL-6, and tumor necrosis factor-α (TNF-α) in the serum, suggesting its ability to suppress the production of inflammatory mediators by inhibiting the Akt/NF-κB pathway and upregulating the Nrf2/HO-1 pathway.

Food-derived peptides as novel therapeutic strategies for NLRP3 inflammasome-related diseases: a systematic review

NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3), a member of the nucleotide-binding domain (NOD) and leucine-rich repeat sequence (LRR) protein (NLR) family, plays an essential role in the inflammation initiation and inflammatory mediator secretion, and thus is also associated with many disease progressions. Food-derived bioactive peptides (FDBP) exhibit excellent anti-inflammatory activity in both in vivo and in vitro models. They are encrypted in plant, meat, and milk proteins and can be released under enzymatic hydrolysis or fermentation conditions, thereby hindering the progression of hyperuricemia, inflammatory bowel disease, chronic liver disease, neurological disorders, lung injury and periodontitis by inactivating the NLRP3. However, there is a lack of systematic review around FDBP, NLRP3, and NLRP3-related diseases. Therefore, this review summarized FDBP that exert inhibiting effects on NLRP3 inflammasome from different protein sources and detailed their preparation and purification methods. Additionally, this paper also compiled the possible inhibitory mechanisms of FDBP on NLRP3 inflammasomes and its regulatory role in NLRP3 inflammasome-related diseases. Finally, the progress of cutting-edge technologies, including nanoparticle, computer-aided screening strategy and recombinant DNA technology, in the acquisition or encapsulation of NLRP3 inhibitory FDBP was discussed. This review provides a scientific basis for understanding the anti-inflammatory mechanism of FDBP through the regulation of the NLRP3 inflammasome and also provides guidance for the development of therapeutic adjuvants or functional foods enriched with these FDBP.

A Pilot Study About the Role of PANoptosis-Based Genes in Atherosclerosis Development

Background

As a chronic inflammatory disease, atherosclerosis (AS) and ischemia events are primarily affected by inflammation in AS. PANoptosis has been implicated in many human systemic disorders, including infection, cancer, neurodegeneration, and inflammation. On the other hand, little is understood about PANoptosis's function in AS.

Methods

We used consensus clustering to divide the GSE100927 dataset into two panoptosis-related subgroups. PANoptosis-associated genes were screened by differential analysis and weighted gene co-expression network analysis (WGCNA) and enriched by ClueGO software. Investigating LASSO regression and MCODE to identify AS Diagnostic Markers. Immunoinfiltration analysis and single-cell analysis were used to search for cell types associated with the diagnostic genes. Final validation was performed by polymerase chain reaction (PCR).

Results

We classified the GSE100927 dataset into two PANoptosis-related subtypes based on the expression of PANoptosis-related genes (PRGs) using consensus clustering. A total of 36 PANoptosis-associated genes were screened in the differentially expressed genes and WGCNA-related module. 4 hub genes were identified by MCODE and LASSO regression, and 3 AS diagnostic markers (ACP5, CCL3, HMOX1) were screened by external validation set. Immunoinfiltration analysis and single-cell analysis showed that the three diagnostic markers were associated with macrophages, and PCR results demonstrated that ACP5 and HMOX1 could be used as AS diagnostic markers.

Conclusion

Our study identified ACP5 and HMOX1 as diagnostic genes for AS that may be associated with PANoptosis. ACP5 and HMOX1 may be involved in the pathogenesis of AS by regulating macrophage PANoptosis.

SNP (A > G - rs13057211) but not GT(n) polymorphism in HMOX-1 promotor gene is associated with COVID-19 mortality

INTRODUCTION

COVID-19 causes severe inflammatory respiratory distress syndrome. The global pandemic caused millions of cases of morbidity and mortality worldwide. Patients may present with variable symptoms including dyspnea, fever, and GIT manifestations. The HMOX-1 gene is located on the long (q) arm of chromosome 22 at position 12.3. HMOX-1 is expressed in all mammalian tissues at basal levels and is considered as a stress response enzyme. HMOX-1 has a specific polymorphic site with variable GT(n) repeats at the promotor region. Several authors evaluated the HMOX-1 GT(n) promoter polymorphism in different inflammatory conditions. We evaluated HMOX-1 promoter polymorphism in relation to serum Hemoxygenase level and inflammatory makers (CRP, Ferritin, PCT, IL-6 and D-dimer) in patients affected by SARS-COV-2 disease.

SUBJECTS AND METHODS

Ninety patients confirmed to be infected with COVID-19 were followed up till the study end point (recovery and discharge or death). HMOX-1 promotor GT(n) polymorphism was evaluated using Sanger sequencing. HMOX-1 enzyme serum level was measured by ELISA and the level of different inflammatory markers was assessed by available commercial kits.

RESULTS

A novel Single nucleotide polymorphism (SNP) (A > G) - rs13057211 in the GT(n) region of HMOX-1 promoter gene was found in 40 (61.5%) COVID-19 patients out of the studied 65 patients. This (A > G) SNP was associated with higher mortality rate in COVID-19 as it was detected in 27 patients (75% of the patients who succumbed to the disease) (p = 0.021, Odds ratio = 3.7; 95% CI:1.29-10.56). Serum IL-6 (Interleuken-6) was positively correlated the length of Hospital Stay (LOHS) and procalcitonin (PCT); (p = 0.014, r: 0.651 and p < 0.001, r:0.997) respectively while negatively correlated with levels of HMOX-1 enzyme serum level (p = 0.013, r: -0.61). CRP correlated positively with LOHS (p = 0.021, r = 0.4), PCT (p = 0.044, r = 0.425) and age (p < 0.001, r = 0.685). Higher levels of D-Dimer and PCT were observed in patients with the long repeat. There was no significant difference between patients who recovered and those who died from COVID-19 as regards HMOX-1 level and GT(n) polymorphism.

CONCLUSION

We report a novel SNP (A > G, rs13057211) in the GT(n) region of HMOX-1 promoter gene that was associated with mortality in COVID-19 patients, however no significant difference was found in HMOX-1 serum level or HMOX-1 (GT)n repeats within the studied groups.

Galangin attenuates doxorubicin-induced cardiotoxicity via activating nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling pathway to suppress oxidative stress and inflammation

Doxorubicin (DOX) has aroused contradiction between its potent anti-tumor capacity and severe cardiotoxicity. Galangin (Gal) possesses antioxidant, anti-inflammatory, and antiapoptotic activities. We aimed to explore the role and underlying mechanisms of Gal on DOX-induced cardiotoxicity. Mice were intraperitoneally injected with DOX (3 mg/kg, every 2 days for 2 weeks) to generate cardiotoxicity model and Gal (15 mg/kg, 2 weeks) was co-administered via gavage daily. Nuclear factor erythroid 2-related factor 2 (Nrf2) specific inhibitor, ML385, was employed to explore the underlying mechanisms. Compared to DOX-insulted mice, Gal effectively improved cardiac dysfunction and ameliorated myocardial damage. DOX-induced increase of reactive oxygen species, malondialdehyde, and NADPH oxidase activity and downregulation of superoxide dismutase (SOD) activity were blunted by Gal. Gal also markedly blocked increase of IL-1β, IL-6, and TNF-α in DOX-insulted heart. Mechanistically, Gal reversed DOX-induced downregulation of Nrf2, HO-1, and promoted nuclear translocation of Nrf2. ML385 markedly blunted the cardioprotective effects of Gal, as well as inhibitive effects on oxidative stress and inflammation. Gal ameliorates DOX-induced cardiotoxicity by suppressing oxidative stress and inflammation via activating Nrf2/HO-1 signaling pathway. Gal may serve as a promising cardioprotective agent for DOX-induced cardiotoxicity.

Dimethyl fumarate ameliorates erectile dysfunction in bilateral cavernous nerve injury rats by inhibiting oxidative stress and NLRP3 inflammasome-mediated pyroptosis of nerve via activation of Nrf2/HO-1 signaling pathway

OBJECTIVE

To investigate the therapeutic potential of dimethyl fumarate (DMF) in improving erectile function of bilateral cavernous nerve injury (BCNI) rats, along with elucidating its underlying mechanisms.

METHODS

A BCNI rat model was established by clamping bilateral cavernous nerve (CN). DMF was given by gavage at low (20 mg/kg/day) and high (40 mg/kg/day) dosages for a duration of 4 weeks. Erectile function was assessed by electrical stimulation of CN. Penis and CN tissues were collected for subsequent analysis. Additionally, PC-12 cell line was used to verify the mechanism of DMF in vitro. Nfe2l2 or Ho-1 gene knockdown PC-12 cell lines were constructed by lentiviral transfection, respectively. A damaged cell model was induced using H2O2. And then molecular biological methods were employed to analyze cellular molecules and proteins.

RESULTS

DMF administration for 4 weeks led to improvements in erectile function, reduced fibrosis of penis corpus cavernosum in BCNI rats. The morphology of CN was improved and the number of nerve fibers increased. Furthermore, the levels of nNOS, NO, and cGMP were increased, while Ca2+ was decreased in penis corpus cavernosum. Notably, the levels of ROS, 3-NT and NLRP3 inflammasomes production were reduced, alongside increased expression of Nrf2 and HO-1 proteins in the dorsal penile nerve (DPN) and CN. In vitro, DMF increased cell viability, reduced ROS level, promoted SOD, diminished 3-NT, MDA and DNA damage markers, and inhibited the activation of NLRP3 inflammasomes in H2O2 induced PC-12 cells. Nfe2l2 knockdown and Ho-1 knockdown significantly attenuated the protective effect of DMF, respectively. Furthermore, inhibition of ROS production by N-acetylcysteine led to a reduction in NLRP3 inflammasome activation in H2O2 induced PC-12 cells.

CONCLUSIONS

DMF improved erectile function of BCNI rats by protecting nerves through inhibiting oxidative stress and the activation of NLRP3 inflammasome-mediated pyroptosis via activation of Nrf2/HO-1 pathway.

Nrf2/HO-1 as a therapeutic target in renal fibrosis

Chronic kidney disease (CKD) is one of the most prevalent chronic diseases and affects between 10 and 14 % of the world's population. The World Health Organization estimates that by 2040, the disease will be fifth in prevalence. End-stage CKD is characterized by renal fibrosis, which can eventually lead to kidney failure and death. Renal fibrosis develops due to multiple injuries and involves oxidative stress and inflammation. In the human body, nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in the expression of antioxidant, anti-inflammatory, and cytoprotective genes, which prevents oxidative stress and inflammation damage. Heme oxygenase (HO-1) is an inducible homolog influenced by heme products and after exposure to cellular stress inducers such as oxidants, inflammatory chemokines/cytokines, and tissue damage as an outcome or downstream of Nrf2 activation. HO-1 is known for its antioxidative properties, which play an important role in regulating oxidative stress. In renal diseases-induced tissue fibrosis and xenobiotics-induced renal fibrosis, Nrf2/HO-1 has been targeted with promising results. This review summarizes these studies and highlights the interesting bioactive compounds that may assist in attenuating renal fibrosis mediated by HO-1 activation. In conclusion, Nrf2/HO-1 signal activation could have a renoprotective effect strategy against CKD caused by oxidative stress, inflammation, and consequent renal fibrosis.

HO-1-Mediated Autophagic Restoration Protects Lens Epithelial Cells Against Oxidative Stress and Cellular Senescence

Purpose

Oxidative stress and cellular senescence are risk factors for age-related cataract. Heme oxygenase 1 (HO-1) is a critical antioxidant enzyme and related to autophagy. Here, we investigate the crosstalk among HO-1, oxidative stress, and cellular senescence in mouse lens epithelial cells (LECs).

Methods

The gene expression of HO-1, p21, LC3, and p62 was measured in human samples. The protective properties of HO-1 were examined in hydrogen peroxide (H2O2)-damaged LECs. Autophagic flux was examined by Western blot and mRFP-GFP-LC3 assay. Western blotting and lysotracker staining were used to analyze lysosomal function. Flow cytometry was used to detect intracellular reactive oxygen species and analyze cell cycle. Senescence-associated β-galactosidase assay was used to determine cellular senescence. The crosstalk between HO-1 and transcription factor EB (TFEB) was further observed in TFEB-knockdown cells. The TFEB binding site in the promoter region of Hmox1 was predicted by the Jasper website and was confirmed by chromatin immunoprecipitation assay.

Results

HO-1 gene expression decreased in LECs of patients with age-related nuclear cataract, whereas mRNA expression levels of p21, LC3, and p62 increased. Upon H2O2-induced oxidative stress, LECs showed the characteristics of autophagic flux blockade, lysosomal dysfunction, and premature senescence. Interestingly, HO-1 significantly restored the impaired autophagic flux and lysosomal function and delayed cellular senescence. TFEB gene silencing greatly reduced the HO-1-mediated autophagic restoration, leading to a failure to prevent LECs from oxidative stress and premature senescence.

Conclusions

We demonstrated HO-1 effects on restoring autophagic flux and delaying cellular senescence under oxidative stress in LECs, which are dependent on TFEB.

Induction of heme oxygenase-1 antagonizes PM2.5-induced pulmonary VEGFA expression through regulating HIF-1α

Particulate matter (PM) 2.5 has long been regarded as a major risk factor of the respiratory system, which constitutes a threat to human health. Although the positive relationship between PM2.5 exposure and the development of respiratory diseases has been well established, limited studies investigate the intrinsic self-protection mechanisms against PM2.5-induced respiratory injuries. Excessive pulmonary inflammation served as a key pathogenic mechanism in PM2.5-induced airway dysfunction, and we have previously shown that PM2.5 induced the production of vascular endothelial growth factor A (VEGFA) in the bronchial epithelial cells, which subsequently led to pulmonary inflammatory responses. In the current study, we found that PM2.5 also concurrently induced the expression of the stress-responsive protein heme oxygenase-1 (HO-1) along with VEGFA in the bronchial epithelial cells both in vivo and in vitro. Importantly, knocking down of HO-1 expression significantly increased the synthesis and secretion of VEGFA; while overexpression of HO-1 showed the opposite effects, indicating that HO-1 induction can antagonize VEGFA production in the bronchial epithelial cells upon PM2.5 exposure. Mechanistically, HO-1 inhibited PM2.5-evoked VEGFA induction through modulating hypoxia-inducible factor 1 alpha (HIF-1α), which was the upstream transcriptional factor of VEGFA. More specifically, HO-1 could not only inhibit HIF-1α expression, but also suppress its transactivity. Taken together, our results suggested that HO-1 was an intrinsic protective factor against PM2.5-induced pulmonary VEGFA production with a mechanism relating to HIF-1α, thus providing a potential treatment strategy against PM2.5 triggered airway injuries.

Astrocytic Nrf2 Mediates the Neuroprotective and Anti-Inflammatory Effects of Nootkatone in an MPTP-Induced Parkinson's Disease Mouse Model

This study aims to investigate the neuroprotective effects of nootkatone (NKT), a sesquiterpenoid compound isolated from grapefruit, in an MPTP-induced Parkinson's disease (PD) mouse model. NKT restored MPTP-induced motor impairment and dopaminergic neuronal loss and increased the expression of neurotrophic factors like BDNF, GDNF, and PGC-1α. In addition, NKT inhibited microglial and astrocyte activation and the expression of pro-inflammatory markers like iNOS, TNF-α, and IL-1β and oxidative stress markers like 4-HNE and 8-OHdG. NKT increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)-driven antioxidant enzymes like HO-1 and NQO-1 in astrocytes, but not in neurons or microglia in MPTP-treated mice. To investigate whether Nrf2 mediates the anti-inflammatory, antioxidant, or neuroprotective effects of NKT, mice were pretreated with Nrf2-specific inhibitor brusatol (BT) prior to NKT treatment. BT attenuated the NKT-mediated inhibition of 4-HNE and 8-OHdG and the number of Nrf2+/HO-1+/NQO1+ cells co-localized with GFAP+ astrocytes in the substantia nigra of MPTP-treated mice. In addition, BT reversed the effects of NKT on dopaminergic neuronal cell death, neurotrophic factors, and pro-/anti-inflammatory cytokines in MPTP-treated mice. Collectively, these data suggest that astrocytic Nrf2 and its downstream antioxidant molecules play pivotal roles in mediating the neuroprotective and anti-inflammatory effects of NKT in an MPTP-induced PD mouse model.

Betaine regulates steroidogenesis, endoplasmic reticulum stress response and Nrf2/HO-1 antioxidant pathways in mouse Leydig cells under hyperglycaemia condition

We studied the effects of betaine on steroidogenesis, endoplasmic reticulum stress and Nrf2 antioxidant pathways of mice Leydig cells under hyperglycaemia conditions. Leydig cells were grown in low and high glucose concentrations (5 mM and 30 mM) in the presence of 5 mM of betaine for 24 h. Gene expression was determined using a real-time PCR method. The protein levels were determined by Western blot analysis. The testosterone production was evaluated by the ELISA method. Cellular contents of reduced and oxidised glutathione were measured by colorimetric method. Hyperglycaemia caused impaired steroidogenesis and ERS in Leydig cells associated with the down-regulation of 3β-HSD, StAR, P450scc, LH receptor and increased expression of GRP78, CHOP, ATF6 and IRE1. Betaine could improve cell viability, attenuate the ERS, and restore testosterone production in Leydig cells under hyperglycaemia conditions. Betaine can protect Leydig cells against the adverse effects of hyperglycaemia by regulating steroidogenesis, antioxidants, and ERS.

Assessing the cardioprotective effect of necrosulfonamide in doxorubicin-induced cardiotoxicity in mice

This study aimed to determine the cardioprotective effect of necrosulfonamide (NSA), a pyroptosis and necroptosis inhibitor, against acute doxorubicin cardiotoxicity. Fifteen male mice were divided into three groups (n=5/group). Cardiotoxicity was induced by a single intraperitoneal injection of 20 mg/kg of DOX on the 3rd day of the experiment. The control group received daily intraperitoneal (i.p.) injections of 5% DMSO for five consecutive days. The second group, the DOX group, received a single i.p. injection of 20 mg/kg DOX on the third day of the experiment. The third group, the DOX plus necrosulfonamide (NSA) group, received DOX injections like the second group and 5 mg/kg of NSA i.p. daily for five days, starting two days before the DOX injection. At the end of the study, animals were euthanized, and blood and tissue samples were collected. Various parameters, including cardiac troponin I (cTnI), TNF-α, IL-1β, caspase-1, glutathione peroxidase-4 (GPX-4), and hemeoxygenase 1 (Hmox-1), were measured using ELISA. Cardiac expression of the NF-κB gene was determined by RT-qPCR. A histopathological assessment of myocardial lesions was also performed. DOX administration significantly increased serum cTnI levels and tissue inflammatory biomarkers (TNF-α, IL-1β, caspase-1) while reducing tissue antioxidant enzymes (GPX-4, Hmox-1). In addition, it significantly increased nuclear factor-κB (NF-κB) gene expression compared to the control (about 10.5-fold elevation). Histopathological analysis revealed marked vacuolization and necrosis. However, pretreatment with NSA dramatically altered these findings, with serum cTnI levels significantly lower in this group compared to DOX. Inflammatory indicators decreased, and antioxidant enzymes were restored to varying degrees. NSA pretreatment downregulated NF-κβ gene expression and preserved near-normal myocardial morphology. Our results showed that NSA protected against DOX-induced cardiotoxicity, an effect likely mediated by its anti-pyroptotic, anti-necroptotic, and antioxidant properties.

Gomariz R, Muñoz-Calleja C, Fernández-Ruiz E, González-Álvaro I, Cardeñoso L. Occurrence of SARS-CoV-2 viremia is associated with genetic variants of genes related to COVID-19 pathogenesis

Introduction

SARS-CoV-2 viral load has been related to COVID-19 severity. The main aim of this study was to evaluate the relationship between SARS-CoV-2 viremia and SNPs in genes previously studied by our group as predictors of COVID-19 severity.

Materials and methods

Retrospective observational study including 340 patients hospitalized for COVID-19 in the University Hospital La Princesa between March 2020 and December 2021, with at least one viremia determination. Positive viremia was considered when viral load was above the quantifiable threshold (20 copies/ml). A total of 38 SNPs were genotyped. To study their association with viremia a multivariate logistic regression was performed.

Results

The mean age of the studied population was 64.5 years (SD 16.6), 60.9% patients were male and 79.4% white non-Hispanic. Only 126 patients (37.1%) had at least one positive viremia. After adjustment by confounders, the presence of the minor alleles of rs2071746 (HMOX1; T/T genotype OR 9.9 p < 0.0001), rs78958998 (probably associated with SERPING1 expression; A/T genotype OR 2.3, p = 0.04 and T/T genotype OR 12.9, p < 0.0001), and rs713400 (eQTL for TMPRSS2; C/T + T/T genotype OR 1.86, p = 0.10) were associated with higher risk of viremia, whereas the minor alleles of rs11052877 (CD69; A/G genotype OR 0.5, p = 0.04 and G/G genotype OR 0.3, p = 0.01), rs2660 (OAS1; A/G genotype OR 0.6, p = 0.08), rs896 (VIPR1; T/T genotype OR 0.4, p = 0.02) and rs33980500 (TRAF3IP2; C/T + T/T genotype OR 0.3, p = 0.01) were associated with lower risk of viremia.

Conclusion

Genetic variants in HMOX1 (rs2071746), SERPING1 (rs78958998), TMPRSS2 (rs713400), CD69 (rs11052877), TRAF3IP2 (rs33980500), OAS1 (rs2660) and VIPR1 (rs896) could explain heterogeneity in SARS-CoV-2 viremia in our population.

Gasotransmitters in non-alcoholic fatty liver disease: just the tip of the iceberg

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by fatty lesions and fat accumulation in hepatic parenchymal cells, which is in the absence of excessive alcohol consumption or definite liver damage factors. The exact pathogenesis of NAFLD is not fully understood, but it is now recognized that oxidative stress, insulin resistance, and inflammation are essential mechanisms involved in the development and treatment of NAFLD. NAFLD therapy aims to stop, delay or reverse disease progressions, as well as improve the quality of life and clinical outcomes of patients with NAFLD. Gasotransmitters are produced by enzymatic reactions, regulated through metabolic pathways in vivo, which can freely penetrate cell membranes with specific physiological functions and targets. Three gasotransmitters, nitric oxide, carbon monoxide, and hydrogen sulfide have been discovered. Gasotransmitters exhibit the effects of anti-inflammatory, anti-oxidant, vasodilatory, and cardioprotective agents. Gasotransmitters and their donors can be used as new gas-derived drugs and provide new approaches to the clinical treatment of NAFLD. Gasotransmitters can modulate inflammation, oxidative stress, and numerous signaling pathways to protect against NAFLD. In this paper, we mainly review the status of gasotransmitters research on NAFLD. It provides clinical applications for the future use of exogenous and endogenous gasotransmitters for the treatment of NAFLD.

The emergence and advancement of Tsuji-Trost reaction triggered carbon monoxide recognition and bioimaging

Considering that carbon monoxide is both a vital gasotransmitter and an obnoxious gas, tremendous efforts have been dedicated toward its recognition through various methods. However, the fluorescent light-up approach through the exploration of optical markers remains one of the most convenient methods owing to its several advantages. Amongst the different approaches towards the development of CO responsive optically active molecular markers, the Tsuji-Trost reaction-based CO recognition strategy has remained one of the most significant areas of interest across researchers working in this field. However, there have been no attempts to exclusively summarize the commendable work done in this area yet. The current review, therefore, attempts to summarize the developments of various optical probes following this reaction strategy until the year 2022. This review provides detailed mechanistic insights into the Tsuji-Trost mediated CO detection strategy. Besides, discussions on the strategic development and employment of probes based on various allyl derivatives - allyl carbamate/carbonate/ethers - will provide a thorough understanding of the detection method. The significant advancements of the Tsuji-Trost reaction as an interesting strategy that is accepted and extensively explored for monitoring CO in various media including air, aqueous solutions and living systems have been elaborately discussed. Various potential applications and utilization of these developed fluorogenic probes for tracing CO in different living systems have been examined systematically. Moreover, monitoring of exogenous/endogenous CO levels, modulation of intracellular CO concentration under various induced conditions and bioimaging of CO in in vivo models have also been detailed here. Briefly, this review summarizes the current prospects of this detection method and the future directions in related fields.

CEACAM6 as a Novel Therapeutic Target to Boost HO-1-mediated Antioxidant Defense in COPD

Rationale: Tobacco smoking and air pollution are primary causes of chronic obstructive pulmonary disease (COPD). However, only a minority of smokers develop COPD. The mechanisms underlying the defense against nitrosative/oxidative stress in nonsusceptible smokers to COPD remain largely unresolved. Objectives: To investigate the defense mechanisms against nitrosative/oxidative stress that possibly prevent COPD development or progression. Methods: Four cohorts were investigated: 1) sputum samples (healthy, n = 4; COPD, n = 37), 2) lung tissue samples (healthy, n = 13; smokers without COPD, n = 10; smoker+COPD, n = 17), 3) pulmonary lobectomy tissue samples (no/mild emphysema, n = 6), and 4) blood samples (healthy, n = 6; COPD, n = 18). We screened 3-nitrotyrosine (3-NT) levels, as indication of nitrosative/oxidative stress, in human samples. We established a novel in vitro model of a cigarette smoke extract (CSE)-resistant cell line and studied 3-NT formation, antioxidant capacity, and transcriptomic profiles. Results were validated in lung tissue, isolated primary cells, and an ex vivo model using adeno-associated virus-mediated gene transduction and human precision-cut lung slices. Measurements and Main Results: 3-NT levels correlate with COPD severity of patients. In CSE-resistant cells, nitrosative/oxidative stress upon CSE treatment was attenuated, paralleled by profound upregulation of heme oxygenase-1 (HO-1). We identified carcinoembryonic antigen cell adhesion molecule 6 (CEACAM6) as a negative regulator of HO-1-mediated nitrosative/oxidative stress defense in human alveolar type 2 epithelial cells (hAEC2s). Consistently, inhibition of HO-1 activity in hAEC2s increased the susceptibility toward CSE-induced damage. Epithelium-specific CEACAM6 overexpression increased nitrosative/oxidative stress and cell death in human precision-cut lung slices on CSE treatment. Conclusions: CEACAM6 expression determines the hAEC2 sensitivity to nitrosative/oxidative stress triggering emphysema development/progression in susceptible smokers.

Carboxyhemoglobin (COHb): Unavoidable Bystander or Protective Player?

Carbon monoxide (CO) is a cytoprotective endogenous gas that is ubiquitously produced by the stress response enzyme heme-oxygenase. Being a gas, CO rapidly diffuses through tissues and binds to hemoglobin (Hb) increasing carboxyhemoglobin (COHb) levels. COHb can be formed in erythrocytes or in plasma from cell-free Hb. Herein, it is discussed as to whether endogenous COHb is an innocuous and inevitable metabolic waste product or not, and it is hypothesized that COHb has a biological role. In the present review, literature data are presented to support this hypothesis based on two main premises: (i) there is no direct correlation between COHb levels and CO toxicity, and (ii) COHb seems to have a direct cytoprotective and antioxidant role in erythrocytes and in hemorrhagic models in vivo. Moreover, CO is also an antioxidant by generating COHb, which protects against the pro-oxidant damaging effects of cell-free Hb. Up to now, COHb has been considered as a sink for both exogenous and endogenous CO generated during CO intoxication or heme metabolism, respectively. Hallmarking COHb as an important molecule with a biological (and eventually beneficial) role is a turning point in CO biology research, namely in CO intoxication and CO cytoprotection.

Mitochondrial dysfunction, oxidative stress, ER stress and mitochondria-ER crosstalk alterations in a chemical rat model of Huntington's disease: potential benefits of bezafibrate

Redox homeostasis, mitochondrial functions, and mitochondria-endoplasmic reticulum (ER) communication were evaluated in the striatum of rats after 3-nitropropionic acid (3-NP) administration, a recognized chemical model of Huntington's disease (HD). 3-NP impaired redox homeostasis by increasing malondialdehyde levels at 28 days, decreasing glutathione (GSH) concentrations at 21 and 28 days, and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione S-transferase at 7, 21, and 28 days, catalase at 21 days, and glutathione reductase at 21 and 28 days. Impairment of mitochondrial respiration at 7 and 28 days after 3-NP administration was also observed, as well as reduced activities of succinate dehydrogenase (SDH) and respiratory chain complexes. 3-NP also impaired mitochondrial dynamics and the interactions between ER and mitochondria and induced ER-stress by increasing the levels of mitofusin-1, and of DRP1, VDAC1, Grp75 and Grp78. Synaptophysin levels were augmented at 7 days but reduced at 28 days after 3-NP injection. Finally, bezafibrate prevented 3-NP-induced alterations of the activities of SOD, GPx, SDH and respiratory chain complexes, DCFH oxidation and on the levels of GSH, VDAC1 and synaptophysin. Mitochondrial dysfunction and synaptic disruption may contribute to the pathophysiology of HD and bezafibrate may be considered as an adjuvant therapy for this disorder.

Molecular profiling of the stroke-induced alterations in the cerebral microvasculature reveals promising therapeutic candidates

Stroke-induced cerebral microvascular dysfunction contributes to aggravation of neuronal injury and compromises the efficacy of current reperfusion therapies. Understanding the molecular alterations in cerebral microvessels in stroke will provide original opportunities for scientific investigation of novel therapeutic strategies. Toward this goal, using a recently optimized method which minimizes cell activation and preserves endothelial cell interactions and RNA integrity, we conducted a genome-wide transcriptomic analysis of cerebral microvessels in a mouse model of stroke and compared these transcriptomic alterations with the ones observed in human, nonfatal, brain stroke lesions. Results from these unbiased comparative analyses have revealed the common alterations in mouse stroke microvessels and human stroke lesions and identified shared molecular features associated with vascular disease (e.g., Serpine1/Plasminogen Activator Inhibitor-1, Hemoxygenase-1), endothelial activation (e.g., Angiopoietin-2), and alterations in sphingolipid metabolism and signaling (e.g., Sphigosine-1-Phosphate Receptor 2). Sphingolipid profiling of mouse cerebral microvessels validated the transcript data and revealed the enrichment of sphingomyelin and sphingoid species in the cerebral microvasculature compared to brain and the stroke-induced increase in ceramide species. In summary, our study has identified novel molecular alterations in several microvessel-enriched, translationally relevant, and druggable targets, which are potent modulators of endothelial function. Our comparative analyses have revealed the presence of molecular features associated with cerebral microvascular dysfunction in human chronic stroke lesions. The results shared here provide a detailed resource for therapeutic discovery of candidates for neurovascular protection in stroke and potentially, other pathologies exhibiting cerebral microvascular dysfunction.

N6-methyladenosine mediates Nrf2 protein expression involved in PM2.5-induced pulmonary fibrosis

It has been reported that particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) could induce epithelial-mesenchymal transition (EMT)- and extracellular matrix (ECM)-related pulmonary fibrosis (PF). The transcription factor Nrf2 alleviated PM2.5-induced PF by antagonizing oxidative stress. The N⁶-methyladenosine (m⁶A) modification plays a significant role in the stress response. However, the effect of m⁶A modification on the mechanisms of Nrf2-mediated defense against PM2.5-induced PF remained unknown. Here, we explored the role and the underlying molecular mechanisms of m⁶A methylation of Nrf2 mRNA in PM2.5-induced PF. We established filtered air (FA), unfiltered air (UA), and concentrated PM2.5 air (CA) group mice model and 0, 50, and 100 μg/mL PM2.5-treated 16HBE cell models. The extent of lung fibrosis in mice and fibrosis indicators were detected by histopathological analysis, immunohistochemical staining and western blotting. The molecular mechanism of m⁶A-modified Nrf2 was demonstrated by m⁶A-methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), qRT-PCR and T3 ligase-based PCR. Our data showed that PM2.5 exposure for 16 weeks could induce pulmonary fibrosis and activate Nrf2 signaling pathway. m⁶A methyltransferase METTL3 was upregulated after PM2.5 treatment in vivo and in vitro. Moreover, METTL3 mediated m⁶A modification of Nrf2 mRNA and promoted Nrf2 translation in mice and 16HBE cells after PM2.5 exposure. Mechanistically, three m⁶A-modified sites (1317, 1376 and 935; numbered relative to the first nucleotide of 3'UTR) of Nrf2 mRNA were identified in PM2.5-treatment 16HBE cells. Furthermore, the m⁶A binding proteins YTHDF1/IGF2BP1 promoted Nrf2 translation by binding to m⁶A residues of Nrf2 mRNA. Our results revealed the mechanism of m⁶A mediated Nrf2 signaling pathway against oxidative stress, which affected the development of PM2.5-induced PF.

Acute Intermittent Porphyria Attack Triggered by COVID-19 Infection

A 45-year-old male patient who was diagnosed with acute intermittent porphyria (AIP) four years ago and had his last episode two years prior presented to our clinic with an AIP attack complicated with rhabdomyolysis triggered by coronavirus disease 2019 (COVID-19) infection. Although there are well-known factors that might trigger an AIP attack, some studies also showed an association of COVID-19 with porphyria. These studies suggest that the accumulation of by-products in the heme synthesis pathway during COVID-19 infection may cause attacks mimicking acute intermittent porphyria. In respect to that, in the early phases of the pandemic, hypotheses emerged arguing the treatment of severe COVID-19 infections with hemin as the treatment of an AIP attack. In our instance, after a two-year period during which there had not been an episode, there was no evident cause other than COVID-19 infection. We believe that patients with porphyria are particularly prone to exacerbations during a COVID-19 infection and should be monitored carefully.

Lighting up trace carbon monoxide and residual palladium species by a low cytotoxic mitochondria targetable red fluorescent probe: Its large scaled applications

High levels of residual palladium can lead to serious negative health effects. Carbon monoxide (CO) is a significant gasotransmitter in transporting intermolecular and intramolecular signals to balance several physiological processes. Therefore, there is a need for rapid detection of CO and palladium residue. To address these issues, we have designed a novel light-up fluorescent probe for the detection of Pd and CO. It can not only detect Pd and CO selectively with a remarkable chromogenic and red fluorescent response over other metal ions allowing detection with naked eyes but also discriminate Pd⁰ and Pd²⁺/Pd⁴⁺ species. The detection reaction is confirmed by HPLC analysis. The probe demonstrates biocompatibility and mitochondrial target ability for potential biological applications. The practical applications based on drug residue and soil analysis, and smartphone have been successfully performed. Bioimaging of the concentration change of Pd and CO in HeLa cells using the probe is successfully applied. Therefore, the present approach can provide early diagnosis of Pd and CO with low detection limit, low cytotoxicity, high selectivity, and sensitivity.

The mitigating effect of exogenous carbon monoxide on chronic allograft rejection and fibrosis post-lung transplantation

BACKGROUND

Small airway inflammation and fibrosis or bronchiolitis obliterans (BO) is the predominant presentation of chronic lung allograft dysfunction (CLAD) post-lung transplantation. Carbon monoxide (CO) is a critical endogenous signaling transducer with known anti-inflammatory and anti-fibrotic effects but its therapeutic potential in CLAD remains to be fully elucidated.

METHODS

Here we investigate the effect of inhaled CO in modulating chronic lung allograft rejection pathology in a murine orthotopic lung transplant model of BO (B6D2F1/J→DBA/2J). Additionally, the effects of CO on the activated phenotype of mesenchymal cells isolated from human lung transplant recipients with CLAD were studied.

RESULTS

Murine lung allografts treated with CO (250 ppm × 30 minutes twice daily from days 7 to 40 post-transplantation) demonstrated decreased immune cell infiltration, fibrosis, and airway obliteration by flow cytometry, trichrome staining, and morphometric analysis, respectively. Decreased total collagen, with levels comparable to isografts, was noted in CO-treated allografts by quantitative hydroxyproline assay. In vitro, CO (250 ppm × 16h) was effective in reversing the fibrotic phenotype of human CLAD mesenchymal cells with decreased collagen I and β-catenin expression as well as an inhibitory effect on ERK1/2 MAPK, and mTORC1/2 signaling. Sildenafil, a phosphodiesterase 5 inhibitor, partially mimicked the effects of CO on CLAD mesenchymal cells and was partially effective in decreasing collagen deposition in murine allografts, suggesting the contribution of cGMP-dependent and -independent mechanisms in mediating the effect of CO.

CONCLUSION

These results suggest a potential role for CO in alleviating allograft fibrosis and mitigating chronic rejection pathology post-lung transplant.

CircFNDC3B regulates osteoarthritis and oxidative stress by targeting miR-525-5p/HO-1 axis

Osteoarthritis (OA) is a common chronic degenerative joint disease associated with a variety of risk factors including aging, genetics, obesity, and mechanical disturbance. This study aimed to elucidate the function of a newly discovered circular RNA (circRNA), circFNDC3B, in OA progression and its relationship with the NF-κB signaling pathway and oxidative stress. The circFNDC3B/miR-525-5p/HO-1 axis and its relationship with the NF-κB signaling pathway and oxidative stress were investigated and validated using fluorescence in situ hybridization, real-time PCR, western blotting, immunofluorescence analysis, luciferase reporter assays, pull-down assays, and reactive oxygen species analyses. The functions of circFNDC3B in OA was investigated in vitro and in vivo. These evaluations demonstrated that circFNDC3B promotes chondrocyte proliferation and protects the extracellular matrix (ECM) from degradation. We also revealed that circFNDC3B defends against oxidative stress in OA by regulating the circFNDC3B/miR-525-5p/HO-1 axis and the NF-κB signaling pathway. Further, we found that overexpression of circFNDC3B alleviated OA in a rabbit model. In summary, we identified a new circFNDC3B/miR-525-5p/HO-1 signaling pathway that may act to relieve OA by alleviating oxidative stress and regulating the NF-κB pathway, resulting in the protection of the ECM in human chondrocytes, highlighting it as a potential therapeutic target for the treatment of OA.

ASSESSMENT OF CARDIOPROTECTIVE EFFECT OF NECROSTATIN-1 STABLE IN A MICE MODEL OF ACUTE DOXORUBICIN-INDUCED CARDIOTOXICITY

OBJECTIVE

The aim: To evaluate the effect of Necrostatin-1s (Nec-1s), an inhibitor of necroptosis, on acute Dox-induced cardiotoxicity in a mice model.

PATIENTS AND METHODS

Materials and methods: Fifteen male mice were used. The animals were allocated into three groups. On the third day of the experiment, a single intraper¬itoneal dose of 20 mg/kg Dox was used to induce cardiotoxicity. Mice in the control group were given vehicle (DMSO) intraperitoneally, whereas mice in the third group were given 5 mg/kg Nec-1s two days before Dox treatment and continued for a total of five days. Animals were euthanized at the conclusion of the research. ELISA was used to assess the following parameters: cTnI, TNF-α, IL-1β, GPX-4, and Hmox-1. The expression of TNF-R1 and phosphorylated NF-κβ p65 was measured using immunohistochemistry. In addition, a histopathologic evaluation of the cardiac lesions was conducted.

RESULTS

Results: Our results showed that Dox treatment substantially elevated serum cTnI levels, increased tissue inflammatory biomarkers (TNF-α, IL-1β, phospho NF-κβ p65 and TNF-R1), and reduced tissue antioxidant enzymes (GPX-4, Hmox-1). A histopathological analysis showed pronounced necrosis and vacuolization. These results were drastically changed by pretreatment with Nec-1s, with serum cTnI levels in this group being much lower than in the Dox group. In addition to a significant decrease in inflammatory markers, antioxidant enzymes were partially recovered. Moreover, there was preservation of the cardiac morphology to a level that was roughly normal.

CONCLUSION

Conclusions: Our findings demonstrate that pretreatment with Nec-1s protected against acute Dox-induced cardiotoxicity. This cardioprotective effect was mainly due to amelioration of inflammation that reflected by inhibition of NF-κβ/TNF-α/TNF-R1 pathway, with partial restoration of antioxidant enzymes, GPX-4 and Hmox1.

Heme oxygenase-1 protects against PM2.5 induced endothelial dysfunction through inhibition of HIF1α

PM2.5 has been accepted as a strong risk factor for cardiovascular diseases. Activation of the renin-angiotensin system (RAS) has been proved to be a key factor in triggering vascular endothelial dysfunction upon PM2.5 exposure in our previous reports. In the current study, we observed the concurrent induction of hemoxygenase (HO)- 1 and RAS components (ANGII and AT1R) expression both in the vascular endothelial cell lines and in rat lung tissue after PM2.5 exposure. Furthermore, HO-1 inhibited RAS activation by suppressing the expression and activity of HIF1α, the upstream transcriptional activator of ANGII and AT1R. In addition, HO-1 blocked significantly increased the release of cell adhesion molecules and chemokines (VCAM-1, E-Selectin, P-Selectin, IL-8, MCP-1) that drive monocyte-endothelium adhesion, along with the enhanced the generation of oxidative stress response mediators in the vascular endothelium. These data together indicate that PM2.5 induced HO-1 upregulation functions as a self-defense response to antagonize endothelial dysfunction by inhibiting HIF1α-mediated RAS activation. Targeting endogenous protective pathway might be helpful to protect from PM2.5-induced cardiovascular injury.

Dose-dependent effects of human umbilical cord-derived mesenchymal stem cell treatment in hyperoxia-induced lung injury of neonatal rats

Background

Mesenchymal stem cells (MSCs) are multipotent stromal cells that have been reported to possess great potential for the treatment of bronchopulmonary dysplasia (BPD).

Objective

Our study aims to assess the effects of three different doses of intraperitoneal administration of human umbilical cord-derived MSCs (hUC-MSCs) on a hyperoxia-induced BPD model of newborn rat.

Methods

Neonatal Sprague Dawley (SD) rats were reared in either hyperoxia (75% O2) or room air (RA) from postnatal days (PN) 1-14. At PN5, hUC-MSCs (1 × 106, 5× 106,or 1× 107 cells per pup) were given intraperitoneally to newborn rats exposed to 75% O2 from birth; the controls received an equal volume of normal saline (NS). At PN14, the lung tissues, serum, and bronchoalveolar fluid (BALF) were collected for histologic examination, wet/dry (W/D) weight ratio analysis, engraftment, myeoloperoxidase (MPO) activity analysis, cytokine analysis, and western blot analysis of protein expression.

Results

Compared to rat pups reared in RA, rat pups reared in hyperoxia had a significant lower survival rate (53.3%) (P < 0.01). Hyperoxia-exposed rats exhibited pulmonary inflammation accompanied by alveolar-capillary leakage, neutrophile infiltration, augmented myeloperoxidase (MPO) activity, prominent alveolar simplification, and increased mean linear intercept (MLI), which was ameliorated by hUC-MSCs treatment. Increased oxidative stress and inflammatory cytokine production were also reduced. Importantly, the expression of Fas, an apoptosis-associated protein that was increasingly expressed in hyperoxia-exposed rats (P < 0.05), was downregulated after administration of hUC-MSCs (P < 0.05).

Conclusions

Our results suggest that intraperitoneal administration of high number hUC-MSCs (1 × 107 cells) may represent an effective modality for the treatment of hyperoxia-induced BPD in neonatal rats.

SARS-CoV-2 Infection Dysregulates Host Iron (Fe)-Redox Homeostasis (Fe-R-H): Role of Fe-Redox Regulators, Ferroptosis Inhibitors, Anticoagulants, and Iron-Chelators in COVID-19 Control

Severe imbalance in iron metabolism among SARS-CoV-2 infected patients is prominent in every symptomatic (mild, moderate to severe) clinical phase of COVID-19. Phase-I - Hypoxia correlates with reduced O₂ transport by erythrocytes, overexpression of HIF-1α, altered mitochondrial bioenergetics with host metabolic reprogramming (HMR). Phase-II - Hyperferritinemia results from an increased iron overload, which triggers a fulminant proinflammatory response - the acute cytokine release syndrome (CRS). Elevated cytokine levels (i.e. IL6, TNFα and CRP) strongly correlates with altered ferritin/TF ratios in COVID-19 patients. Phase-III - Thromboembolism is consequential to erythrocyte dysfunction with heme release, increased prothrombin time and elevated D-dimers, cumulatively linked to severe coagulopathies with life-threatening outcomes such as ARDS, and multi-organ failure. Taken together, Fe-R-H dysregulation is implicated in every symptomatic phase of COVID-19. Fe-R-H regulators such as lactoferrin (LF), hemoxygenase-1 (HO-1), erythropoietin (EPO) and hepcidin modulators are innate bio-replenishments that sequester iron, neutralize iron-mediated free radicals, reduce oxidative stress, and improve host defense by optimizing iron metabolism. Due to its pivotal role in 'cytokine storm', ferroptosis is a potential intervention target. Ferroptosis inhibitors such as ferrostatin-1, liproxstatin-1, quercetin, and melatonin could prevent mitochondrial lipid peroxidation, up-regulate antioxidant/GSH levels and abrogate iron overload-induced apoptosis through activation of Nrf2 and HO-1 signaling pathways. Iron chelators such as heparin, deferoxamine, caffeic acid, curcumin, α-lipoic acid, and phytic acid could protect against ferroptosis and restore mitochondrial function, iron-redox potential, and rebalance Fe-R-H status. Therefore, Fe-R-H restoration is a host biomarker-driven potential combat strategy for an effective clinical and post-recovery management of COVID-19.

Deep-Depth Imaging of Hepatic Ischemia/Reperfusion Injury Using a Carbon Monoxide-Activated Upconversion Luminescence Nanosystem

Exploring a chemical imaging tool for visualizing the endogenous CO biosignaling molecule is of great importance in understanding the pathophysiological functions of CO in complex biological systems. Most of the existing CO fluorescent probes show excitation and emission in the region of ultraviolet and visible light, which are not suitable for application in in vivo deep-depth imaging of CO. Herein, a new near-infrared (NIR) to NIR upconversion luminescence (UCL) nanosystem for in vivo visualization of CO was developed, which possesses the merits of high selectivity and sensitivity, a deep tissue penetration depth, and a high signal-to-noise ratio. In this design, upon interaction with CO, the maxima absorption peak of the nanosystem showed a significant blue shift from 795 nm to 621 nm and triggered a remarkable turn-on NIR UCL signal due to the luminescence resonance energy transfer process. Leveraging this nanosystem, we achieved an NIR UCL visualization of the generation of CO biosignals caused by hypoxic, acute inflammation, or ischemic injury in living cells, zebrafish, and mice. Moreover, the protective effect of CO in zebrafish models of oxygen and glucose deprivation/reperfusion (OGD/R) and mice models of lipopolysaccharide-induced oxidative stress (LOS) and hepatic ischemia/reperfusion (HI/R) was also further verified. Therefore, this work discloses that the nanosystem not only serves as a promising nanoplatform to study biological signaling pathways of CO in pathophysiological events, but may also provide a powerful tool for HI/R injury diagnosis.

Hydrogen-Rich Water as a Novel Therapeutic Strategy for the Affective Disorders Linked with Chronic Neuropathic Pain in Mice

Neuropathic pain manifested with allodynia and hyperalgesia usually becomes a chronic condition accompanied with mood disorders. Clinical therapies for neuropathic pain are still unsatisfactory with notable side effects. Recent studies have reported the protective role of molecular hydrogen (H₂) in different diseases including neurological disorders, such as Alzheimer's as well as its antidepressant activities in animals with chronic stress. This study explored the effects of treatment with hydrogen-rich water (HRW) in male mice with neuropathic pain induced by the chronic constriction of the sciatic nerve (CCI) and the accompanying affective deficits. The likely pathways implied in the HRW analgesic activity, as well as the interaction between heme oxygenase 1 (HO-1) enzyme and H₂ during neuropathic pain were also studied. The results showed: (i) the inhibitory effects of the repetitive treatment with HRW on the allodynia and hyperalgesia provoked by CCI; (ii) the anxiolytic and antidepressant actions of HRW in animals with neuropathic pain; (iii) the contribution of the antioxidant enzymes (HO-1 and NAD(P)H: quinone oxidoreductase 1) and the ATP sensitive potassium channels in the painkiller activities of HRW during neuropathic pain; (iv) a positive interaction between the HO-1 and H₂ systems in inhibiting the CCI-induced neuropathy; and (v) the antioxidant, antinociceptive, anti-inflammatory and/or antiapoptotic features of HRW treatment in the dorsal root ganglia and/or amygdala of sciatic nerve-injured mice. This study demonstrates new protective actions of H₂ and suggests that treatment with HRW might be an interesting therapeutic strategy for chronic neuropathic pain and its associated mood disorders.

Controlled therapeutic delivery of CO from carbon monoxide-releasing molecules (CORMs)

Carbon monoxide (CO) has been regarded as a "silent killer" for its toxicity toward biological systems. However, a low concentration of endogenously produced CO has shown a number of therapeutic benefits such as anti-inflammatory, anti-proliferative, anti-apoptosis, and cytoprotective activities. Carbon monoxide-releasing molecules (CORMs) have been developed as alternatives to direct CO inhalation, which requires a specialized setting for strict dose control. CORMs are efficient CO donors, with central transition metals (such as ruthenium, iron, cobalt, and manganese) surrounded by CO as a ligand. CORMs can stably store and subsequently release their CO payload in the presence of certain triggers including solvent, light, temperature, and ligand substitution. However, CORMs require appropriate delivery strategies to improve short CO release half-life and target specificity. Herein, we highlighted the therapeutic potential of inhalation and CORMs-delivered CO. The applications of conjugate and nanocarrier systems for controlling CO release and improving therapeutic efficacy of CORMs are also described in detail. The review concludes with some of the hurdles that limit clinical translation of CORMs. Keeping in mind the tremendous potential and growing interest in CORMs, this review would be helpful for designing controlled CO release systems for clinical applications.

Carbon monoxide (CO) correlates with symptom severity, autoimmunity, and responses to probiotics treatment in a cohort of children with autism spectrum disorder (ASD): a post-hoc analysis of a randomized controlled trial

BACKGROUND

Inflammation, autoimmunity, and gut-brain axis have been implicated in the pathogenesis of autism spectrum disorder (ASD). Carboxyhemoglobin (SpCO) as a non-invasive measurement of inflammation has not been studied in individuals with ASD. We conducted this post-hoc study based on our published clinical trial to explore SpCO and its association with ASD severity, autoimmunity, and response to daily Lactobacillus plantarum probiotic supplementation.

METHODS

In this study, we included 35 individuals with ASD aged 3-20 years from a previously published clinical trial of the probiotic Lactobacillus plantarum. Subjects were randomly assigned to receive daily Lactobacillus plantarum probiotic (6 × 10¹⁰ CFUs) or a placebo for 16 weeks. The outcomes in this analysis include Social Responsiveness Scale (SRS), Aberrant Behavior Checklist second edition (ABC-2), Clinical Global Impression (CGI) scale, SpCO measured by CO-oximetry, fecal microbiome by 16 s rRNA sequencing, blood serum inflammatory markers, autoantibodies, and oxytocin (OT) by ELISA. We performed Kendall's correlation to examine their interrelationships and used Wilcoxon rank-sum test to compare the means of all outcomes between the two groups at baseline and 16 weeks.

RESULTS

Elevated levels of serum anti-tubulin, CaM kinase II, anti-dopamine receptor D1 (anti-D1), and SpCO were found in the majority of ASD subjects. ASD severity is correlated with SpCO (baseline, R = 0.38, p = 0.029), anti-lysoganglioside GM1 (R = 0.83, p = 0.022), anti-tubulin (R = 0.69, p = 0.042), and anti-D1 (R = 0.71, p = 0.045) in treatment group.

CONCLUSIONS

The findings of the present study suggests that the easily administered and non-invasive SpCO test offers a potentially promising autoimmunity and inflammatory biomarker to screen/subgroup ASD and monitor the treatment response to probiotics. Furthermore, we propose that the associations between autoantibodies, gut microbiome profile, serum OT level, GI symptom severity, and ASD core symptom severity scores are specific to the usage of probiotic treatment in our subject cohort. Taken together, these results warrant further studies to improve ASD early diagnosis and treatment outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03337035 , registered November 8, 2017.

Intratracheal administration of umbilical cord-derived mesenchymal stem cells attenuates hyperoxia-induced multi-organ injury via heme oxygenase-1 and JAK/STAT pathways

BACKGROUND

Bronchopulmonary dysplasia (BPD) is not merely a chronic lung disease, but a systemic condition with multiple organs implications predominantly associated with hyperoxia exposure. Despite advances in current management strategies, limited progress has been made in reducing the BPD-related systemic damage. Meanwhile, although the protective effects of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) or their exosomes on hyperoxia-induced lung injury have been explored by many researchers, the underlying mechanism has not been addressed in detail, and few studies have focused on the therapeutic effect on systemic multiple organ injury.

AIM

To investigate whether hUC-MSC intratracheal administration could attenuate hyperoxia-induced lung, heart, and kidney injuries and the underlying regulatory mechanisms.

METHODS

Neonatal rats were exposed to hyperoxia (80% O₂), treated with hUC-MSCs intratracheal (iT) or intraperitoneal (iP) on postnatal day 7, and harvested on postnatal day 21. The tissue sections of the lung, heart, and kidney were analyzed morphometrically. Protein contents of the bronchoalveolar lavage fluid (BALF), myeloperoxidase (MPO) expression, and malondialdehyde (MDA) levels were examined. Pulmonary inflammatory cytokines were measured via enzyme-linked immunosorbent assay. A comparative transcriptomic analysis of differentially expressed genes (DEGs) in lung tissue was conducted via RNA-sequencing. Subsequently, we performed reverse transcription-quantitative polymerase chain reaction and western blot analysis to explore the expression of target mRNA and proteins related to inflammatory and oxidative responses.

RESULTS

iT hUC-MSCs administration improved pulmonary alveolarization and angiogenesis (P < 0.01, P < 0.01, P < 0.001, and P < 0.05 for mean linear intercept, septal counts, vascular medial thickness index, and microvessel density respectively). Meanwhile, treatment with hUC-MSCs iT ameliorated right ventricular hypertrophy (for Fulton’s index, P < 0.01), and relieved reduced nephrogenic zone width (P < 0.01) and glomerular diameter (P < 0.001) in kidneys. Among the beneficial effects, a reduction of BALF protein, MPO, and MDA was observed in hUC-MSCs groups (P < 0.01, P < 0.001, and P < 0.05 respectively). Increased pro-inflammatory cytokines tumor necrosis factor-alpha, interleukin (IL)-1β, and IL-6 expression observed in the hyperoxia group were significantly attenuated by hUC-MSCs administration (P < 0.01, P < 0.001, and P < 0.05 respectively). In addition, we observed an increase in anti-inflammatory cytokine IL-10 expression in rats that received hUC-MSCs iT compared with rats reared in hyperoxia (P < 0.05). Transcriptomic analysis showed that the DEGs in lung tissues induced by hyperoxia were enriched in pathways related to inflammatory responses, epithelial cell proliferation, and vasculature development. hUC-MSCs administration blunted these hyperoxia-induced dysregulated genes and resulted in a shift in the gene expression pattern toward the normoxia group. hUC-MSCs increased heme oxygenase-1 (HO-1), JAK2, and STAT3 expression, and their phosphorylation in the lung, heart, and kidney (P < 0.05). Remarkably, no significant difference was observed between the iT and iP administration.

CONCLUSION

iT hUC-MSCs administration ameliorates hyperoxia-induced lung, heart, and kidney injuries by activating HO-1 expression and JAK/STAT signaling. The therapeutic benefits of local iT and iP administration are equivalent.

Inflammatory gene expression during acute high‐altitude exposure

Abstract

The molecular signalling pathways that regulate inflammation and the response to hypoxia share significant crosstalk and appear to play major roles in high‐altitude acclimatization and adaptation. Several studies demonstrate increases in circulating candidate inflammatory markers during acute high‐altitude exposure, but significant gaps remain in our understanding of how inflammation and immune function change at high altitude and whether these responses contribute to high‐altitude pathologies, such as acute mountain sickness. To address this, we took an unbiased transcriptomic approach, including RNA sequencing and direct digital mRNA detection with NanoString, to identify changes in the inflammatory profile of peripheral blood throughout 3 days of high‐altitude acclimatization in healthy sea‐level residents (n = 15; five women). Several inflammation‐related genes were upregulated on the first day of high‐altitude exposure, including a large increase in HMGB1 (high mobility group box 1), a damage‐associated molecular pattern (DAMP) molecule that amplifies immune responses during tissue injury. Differentially expressed genes on the first and third days of acclimatization were enriched for several inflammatory pathways, including nuclear factor‐κB and Toll‐like receptor (TLR) signalling. Indeed, both TLR4 and LY96, which encodes the lipopolysaccharide binding protein (MD‐2), were upregulated at high altitude. Finally, FASLG and SMAD7 were associated with acute mountain sickness scores and peripheral oxygen saturation levels on the first day at high altitude, suggesting a potential role of immune regulation in response to high‐altitude hypoxia. These results indicate that acute high‐altitude exposure upregulates inflammatory signalling pathways and might sensitize the TLR4 signalling pathway to subsequent inflammatory stimuli.

Key points

Inflammation plays a crucial role in the physiological response to hypoxia.

High‐altitude hypoxia exposure causes alterations in the inflammatory profile that might play an adaptive or maladaptive role in acclimatization.

In this study, we characterized changes in the inflammatory profile following acute high‐altitude exposure.

We report upregulation of novel inflammation‐related genes in the first 3 days of high‐altitude exposure, which might play a role in immune system sensitization.

These results provide insight into how hypoxia‐induced inflammation might contribute to high‐altitude pathologies and exacerbate inflammatory responses in critical illnesses associated with hypoxaemia.

Low-dose carbon monoxide suppresses metastatic progression of disseminated cancer cells

Low-dose carbon monoxide (CO) is under investigation in clinical trials to treat non-cancerous diseases and has excellent safety profiles. Due to the early detection and cancer awareness, increasing cancer patients are diagnosed at early stages and potentially curative surgical resection can be done. However, many patients ultimately experience recurrence. Here, we evaluate the therapeutic effect of CO on cancer metastatic progression. We show that 250 ppm CO inhibits migration of multiple types of cancer cell lines including breast, pancreatic, colon, prostate, liver, and lung cancer and reduces the ability to adhere to fibronectin. We demonstrate that in mouse models, 250 ppm inhaled CO inhibits lung metastasis of breast cancer and liver metastasis of pancreatic cancer. Moreover, low-dose CO suppresses recurrence and increases survival after surgical removal of primary pancreatic cancer in mice. Mechanistically, low-dose CO blocks transcription of heme importers, leading to diminished intracellular heme levels and a heme-regulated enzyme, cytochrome P4501B1 (CYP1B1). Either supplementing heme or overexpressing CYP1B1 reverses the anti-migration effect of low-dose CO. Taken together, low-dose CO therapy inhibits cell migration, reduces adhesion to fibronectin, prevents disseminated cancer cells from expanding into gross metastases, and improves survival in pre-clinical mouse models of metastasis.

Naphthalimide derivatives as fluorescent probes for imaging endogenous gasotransmitters

Gasotransmitters have gained significant recognition attributed to their evident biological impacts, and is accepted as a promising and less-explored area with immense research scope. The three-member family comprising of nitric oxide, carbon monoxide and hydrogen sulphide as endogenous gaseous signaling molecules have been found to elicit a plethora of crucial biological functions, spawning a new research area. The sensing of these small molecules is vital to gain deeper insights into their functions, as they can act both as a friend or a foe in mammalian systems. The initial sections of the review present the physiological and pathophysiological roles of these endogenous gas transmitters and their synergistic interactions. Further, various detection approaches, especially the usage of fascinating features of 1,8-naphthalimide as fluorescent probe in the detection and monitoring of these small signaling molecules are highlighted. The current limitations and the future scope of improving the sensing of the three gasotransmitters are also discussed.

Protective effect of naringin against oxaliplatin-induced peripheral neuropathy in rats: A behavioral and molecular study

Oxaliplatin (OXL) is a chemotherapeutic drug used for metastatic and other types of cancer, but it causes peripheral neuropathy as a dose-limiting side effect. Herein, we used the rat model of OXL-induced peripheral neuropathy to demonstrate the protective effects of naringin (NRG) in this neuropathy. In this study, rats were injected with OXL (4 mg/kg, body weight, i.p.) in 5% glucose solution 30 min after oral administration of NRG (50 and 100 mg/kg, body weight) on the 1st, 2nd, 5th, and 6th days. OXL caused sensory and motor neuropathy (as revealed by the hot plate, tail flick, rota-rod, and cold hyperalgesia tests) in the sciatic nerve of rats. Coadministration of oral NRG alleviated OXL-induced sensory and motor neuropathy. Levels of superoxide dismutase, catalase, glutathione peroxidase, nuclear factor erythroid 2-related factor 2, Heme oxygenase-1, nuclear factor-κ B, tumor necrosis factor-α, interleukin-1β, Bax, Bcl-2, caspase-3, paraoxonase, mitogen-activated protein kinase 14, neuronal nitric oxide synthase (nNOS), acetylcholinesterase, and arginase 2 in the sciatic nerve tissues were assessed by real-time polymerase chain reaction. Moreover, the protein levels of caspase-3, Bax, Bcl-2, intercellular adhesion molecules-1, glial fibrillary acidic protein, and nNOS were examined by Western blot analysis. NRG treatment significantly improved all the above-mentioned parameters and reduced OXL-induced oxidative stress, inflammation, and apoptosis in the sciatic nerve tissue. In conclusion, this study demonstrated that NRG significantly attenuated OXL-induced peripheral neuropathy and might be considered as a new protective agent to prevent the OXL-induced peripheral neuropathy.

Activatable Fluorescent-Photoacoustic Integrated Probes with Deep Tissue Penetration for Pathological Diagnosis and Therapeutic Evaluation of Acute Inflammation in Mice

Inflammation is associated with many diseases, so the development of an excellent near infrared fluorescent (NIRF) and photoacoustic (PA) dual-modality probe is crucial for the accurate diagnosis and efficacy evaluation of inflammation. However, most of the current NIRF/PA scaffolds are based on repurposing existing fluorescent dye platforms that exhibit non-optimal properties for both NIRF and PA signal outputs. Herein, we developed a novel dye scaffold QL-OH by optimizing the NIRF and PA signal of classical hemicyanine dyes. Based on this optimized dye, we developed the first NIRF/PA dual-mode carbon monoxide (CO) probe QL-CO for noninvasive and sensitive visualization of CO levels in deep inflammatory lesions in vivo. The novel probe QL-CO exhibited rapid and sensitive NIRF₇₇₅/PA₇₃₀ dual activation responses toward CO. In addition, the CO-activated probe QL-CO was successfully used for the diagnosis of inflammation and evaluation of anti-inflammation drug efficacy in living mice though the NIRF/PA dual-mode imaging technology for the first time. More importantly, the probe QL-CO could accurately locate the deep inflammatory lesion tissues (≈1 cm) in mice and obtain 3D PA diagnostic images with deep penetration depth and spatial resolution. Therefore, the new NIRF/PA dual-mode probe QL-CO has high potential for deep-tissue diagnosis imaging of CO in vivo. These findings may provide a new tool and approach for future research and diagnosis of CO-associated diseases.

Paeoniflorin Can Improve Acute Lung Injury Caused by Severe Acute Pancreatitis through Nrf2/ARE Pathway

Objective

To evaluate the potential therapeutic effect of paeoniflorin on acute lung injury induced by severe acute pancreatitis (SAP) and to initially explore the possible protective mechanisms of paeoniflorin.

Method

The SAP lung injury rat model was established by retrograde injection of 5% sodium taurocholate to the cholangiopancreatic duct. H&E staining was used to detect pathological changes in rat lung tissue. W/D ratio method, serum amylase (AMY), and lipase activity were used to assess the degree of lung injury in rats. Oxidation indicators such as LDH, MDA, and SOD in lung tissue were measured. Levels of inflammatory factors TNF-α, IL-6, and IL-10 were measured in bronchoalveolar lavage fluid (BALF). At the same time, Western blot was used to detect the expression of related proteins in the Nrf2/ARE signaling pathway.

Results

In SAP rats, paeoniflorin treatment could significantly alleviate lung injury conditions such as pulmonary edema and inflammatory cell infiltration in lung tissue and reduce serum amylase and lipase activities. Paeoniflorin can reduce the content of LDH and MDA in lung tissue and increase the content of SOD. In addition, ELISA results showed that paeoniflorin could inhibit the levels of TNF-α and IL-6 in BALF and upregulate the levels of IL-10. Paeoniflorin could upregulate the expression of Nrf2/ARE signaling pathway proteins Cyt-Nrf2, HO-1, and NQO1 in lung tissue of SAP rats.

Conclusion

Paeoniflorin may improve acute lung injury in rats with severe pancreatitis by inhibiting inflammation and oxidative stress response. These effects may be related to activating the Nrf2/ARE signaling pathway.

Carbon monoxide (CO)/heme oxygenase (HO)-1 in gastrointestinal tumors pathophysiology and pharmacology - possible anti- and pro-cancer activities

Gastrointestinal (GI) tract cancers pose a significant pharmacological challenge for researchers in terms of the discovery of molecular agents and the development of targeted therapies. Although many ongoing clinical trials have brought new perspectives, there is still a lack of successful long-term treatment. Several novel pharmacological and molecular agents are being studied in the prevention and treatment of GI cancers. On the other hand, pharmacological tools designed to release an endogenous gaseous mediator, carbon monoxide (CO), were shown to prevent the gastric mucosa against various types of injuries and exert therapeutic properties in the treatment of GI pathologies. In this review, we summarized the current evidence on the role of CO and heme oxygenase 1 (HO-1) as a CO producing enzyme in the pathophysiology of GI tumors. We focused on a beneficial role of HO-1 and CO in biological systems and common pathological conditions. We further discussed the complex and ambiguous function of the HO-1/CO pathway in cancer cells with a special emphasis on molecular and cellular pro-cancerous and anti-cancer mechanisms. We also focused on the role that HO-1/CO plays in GI cancers, especially within upper parts such as esophagus or stomach.

Reactive Oxygen Species and Oxidative Stress in Vascular-Related Diseases

Oxidative stress (OS) refers to the enhancement of oxidation and the decreased of related antioxidant enzymes activity under pathological conditions, resulting in relatively excess reactive oxygen species (ROS), causing cytotoxicity, which leads to tissue damage and is linked to neurodegenerative diseases, cardiovascular diseases, diabetes, cancers, and many other pathologies. As an important intracellular signaling molecule, ROS can regulate numerous physiological actions, such as vascular reactivity and neuronal function. According to several studies, the uncontrolled production of ROS is related to vascular injury. The growing evidence revealing how traditional risk factors translate into ROS and lead to vasculitis and other vascular diseases. In this review, we sought to mainly discuss the role of ROS and antioxidant mechanisms in vascular-related diseases, especially cardiovascular and common macrovascular diseases.