The tri-peptide GHK-Cu complex ameliorates lipopolysaccharide-induced acute lung injury in mice

The Role of Bioactive Small Molecules in COPD Pathogenesis

Chronic obstructive pulmonary disease (COPD) is recognized as a predominant contributor to mortality worldwide, which causes significant burdens to both society and individuals. Given the limited treatment options for COPD, there lies a critical realization: the imperative for expeditious development of novel therapeutic modalities that can effectively alleviate disease progression and enhance the quality of life experienced by COPD patients. Within the intricate field of COPD pathogenesis, an assortment of biologically active small molecules, encompassing small protein molecules and their derivatives, assumes crucial roles through diverse mechanisms. These mechanisms relate to the regulation of redox balance, the inhibition of the release of inflammatory mediators, and the modulation of cellular functions. Therefore, the present article aims to explore and elucidate the distinct roles played by different categories of biologically active small molecules in contributing to the pathogenesis of COPD.

The glycyl-l-histidyl-l-lysine-Cu2+ tripeptide complex attenuates lung inflammation and fibrosis in silicosis by targeting peroxiredoxin 6

Silicosis is the most common type of pneumoconiosis, having a high incidence in workers chronically exposed to crystalline silica (CS). No specific medication exists for this condition. GHK, a tripeptide naturally occurring in human blood and urine, has antioxidant effects. We aimed to investigate the therapeutic effect of GHK-Cu on silicosis and its potential underlying molecular mechanism. An experimental silicosis mouse model was established to observe the effects of GHK-Cu on lung inflammation and fibrosis. Moreover, the effects of GHK-Cu on the alveolar macrophages (AM) were examined using the RAW264.7 cell line. Its molecular target, peroxiredoxin 6 (PRDX6), has been identified, and GHK-Cu can bind to PRDX6, thus attenuating lung inflammation and fibrosis in silicosis mice without significant systemic toxicity. These effects were partly related to the inhibition of the CS-induced oxidative stress in AM induced by GHK-Cu. Thus, our results suggest that GHK-Cu acts as a potential drug by attenuating alveolar macrophage oxidative stress. This, in turn, attenuates the progression of pulmonary inflammation and fibrosis, which provides a reference for the treatment of silicosis.

Research Progress on Bioactive Factors against Skin Aging

The relentless pursuit of effective strategies against skin aging has led to significant interest in the role of bioactive factors, particularly secondary metabolites from natural sources. The purpose of this study is to meticulously explore and summarize the recent advancements in understanding and utilization of bioactive factors against skin aging, with a focus on their sources, mechanisms of action, and therapeutic potential. Skin, the largest organ of the body, directly interacts with the external environment, making it susceptible to aging influenced by factors such as UV radiation, pollution, and oxidative stress. Among various interventions, bioactive factors, including peptides, amino acids, and secondary metabolites, have shown promising anti-aging effects by modulating the biological pathways associated with skin integrity and youthfulness. This article provides a comprehensive overview of these bioactive compounds, emphasizing collagen peptides, antioxidants, and herbal extracts, and discusses their effectiveness in promoting collagen synthesis, enhancing skin barrier function, and mitigating the visible signs of aging. By presenting a synthesis of the current research, this study aims to highlight the therapeutic potential of these bioactive factors in developing innovative anti-aging skin care solutions, thereby contributing to the broader field of dermatological research and offering new perspectives for future studies. Our findings underscore the importance of the continued exploration of bioactive compounds for their potential to revolutionize anti-aging skin care and improve skin health and aesthetics.

Evaluation of GHK peptide-heparin interactions in multifunctional liposomal covering

Small biospecific peptides with defined chemical structure and cellular responses are promising alternatives to full-length therapeutic proteins. Identification of these peptides solely or in combination with other bioactive factors and determination of their targets are of substantial interest in current drug delivery research. This study is aimed at the development of new liposomal formulations of ECM-derived GHK peptide known for its multiple regeneration-related activities but poorly recognized cellular targets. In situ association of membranotropic GHK derivative with unilamellar liposomes was performed to prepare GHK-modified liposomes with defined properties. According to DLS, the GHK component on the liposomal surface interacted with heparin in a specific manner compared to other polysaccharides and RGD counterpart, whereas ITC analysis of such interactions was complicated. The results provide a useful tool for screening of bio-interactions of synthetic peptide-presenting liposomes by the DLS technique. They were also employed to produce a multi-functional nanosized GHK-heparin covering for liposomes. The resulting composite liposomes possessed low size dispersity, increased anionic charge, and mechanical rigidity. The heparin component significantly promoted the accumulation of GHK-modified liposomes in 3T3 fibroblasts so that the composite liposomes exhibited the highest cell-penetrating activity. Furthermore, the latter formulation stimulated cell proliferation and strongly inhibited ROS production and GSH depletion under oxidative stress conditions. Together, the results support that cell-surface glycosaminoglycans can be involved in GHK-mediated liposomal delivery, which can be further greatly enhanced by association with heparin. The composite liposomes with GHK-heparin covering can be considered as an advanced GHK-based formulation for therapeutic and cosmeceutical applications.

Astrocytes in intracerebral hemorrhage: impact and therapeutic objectives

Intracerebral hemorrhage (ICH) manifests precipitously and profoundly impairs the neurological function in patients who are affected. The etiology of subsequent injury post-ICH is multifaceted, characterized by the intricate interplay of various factors, rendering therapeutic interventions challenging. Astrocytes, a distinct class of glial cells, interact with neurons and microglia, and are implicated in a series of pathophysiological alterations following ICH. A comprehensive examination of the functions and mechanisms associated with astrocytic proteins may shed light on the role of astrocytes in ICH pathology and proffer innovative therapeutic avenues for ICH management.

Recombinant Human Bone Morphogenetic Protein-2 Priming of Mesenchymal Stem Cells Ameliorate Acute Lung Injury by Inducing Regulatory T Cells

Mesenchymal stromal/stem cells (MSCs) possess immunoregulatory properties and their regulatory functions represent a potential therapy for acute lung injury (ALI). However, uncertainties remain with respect to defining MSCs-derived immunomodulatory pathways. Therefore, this study aimed to investigate the mechanism underlying the enhanced effect of human recombinant bone morphogenic protein-2 (rhBMP-2) primed ES-MSCs (MSCBMP2) in promoting Tregs in ALI mice. MSC were preconditioned with 100 ng/ml rhBMP-2 for 24 h, and then administrated to mice by intravenous injection after intratracheal injection of 1 mg/kg LPS. Treating MSCs with rhBMP-2 significantly increased cellular proliferation and migration, and cytokines array reveled that cytokines release by MSCBMP2 were associated with migration and growth. MSCBMP2 ameliorated LPS induced lung injury and reduced myeloperoxidase activity and permeability in mice exposed to LPS. Levels of inducible nitric oxide synthase were decreased while levels of total glutathione and superoxide dismutase activity were further increased via inhibition of phosphorylated STAT1 in ALI mice treated with MSCBMP2. MSCBMP2 treatment increased the protein level of IDO1, indicating an increase in Treg cells, and Foxp3+CD25+ Treg of CD4+ cells were further increased in ALI mice treated with MSCBMP2. In co-culture assays with MSCs and RAW264.7 cells, the protein level of IDO1 was further induced in MSCBMP2. Additionally, cytokine release of IL-10 was enhanced while both IL-6 and TNF-α were further inhibited. In conclusion, these findings suggest that MSCBMP2 has therapeutic potential to reduce massive inflammation of respiratory diseases by promoting Treg cells.

Reactive Oxygen Species and Strategies for Antioxidant Intervention in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening pulmonary condition characterized by the sudden onset of respiratory failure, pulmonary edema, dysfunction of endothelial and epithelial barriers, and the activation of inflammatory cascades. Despite the increasing number of deaths attributed to ARDS, a comprehensive therapeutic approach for managing patients with ARDS remains elusive. To elucidate the pathological mechanisms underlying ARDS, numerous studies have employed various preclinical models, often utilizing lipopolysaccharide as the ARDS inducer. Accumulating evidence emphasizes the pivotal role of reactive oxygen species (ROS) in the pathophysiology of ARDS. Both preclinical and clinical investigations have asserted the potential of antioxidants in ameliorating ARDS. This review focuses on various sources of ROS, including NADPH oxidase, uncoupled endothelial nitric oxide synthase, cytochrome P450, and xanthine oxidase, and provides a comprehensive overview of their roles in ARDS. Additionally, we discuss the potential of using antioxidants as a strategy for treating ARDS.

New Biotinylated GHK and Related Copper(II) Complex: Antioxidant and Antiglycant Properties In Vitro against Neurodegenerative Disorders

Neurodegenerative diseases affect millions of people worldwide. The failure of the enzymatic degradation, the oxidative stress, the dyshomeostasis of metal ions, among many other biochemical events, might trigger the pathological route, but the onset of these pathologies is unknown. Multi-target and multifunctional molecules could address several biomolecular issues of the pathologies. The tripeptide GHK, a bioactive fragment of several proteins, and the related copper(II) complex have been largely used for many purposes, from cosmetic to therapeutic applications. GHK derivatives were synthesized to increase the peptide stability and improve the target delivery. Herein we report the synthesis of a new biotin-GHK conjugate (BioGHK) through orthogonal reactions. BioGHK is still capable of coordinating copper(II), as observed by spectroscopic and spectrometric measurements. The spectroscopic monitoring of the copper-induced ascorbate oxidation was used to measure the antioxidant activity Cu(II)-BioGHK complex, whereas antiglycant activity of the ligand towards harmful reactive species was investigated using MALDI-TOF. The affinity of BioGHK for streptavidin was evaluated using a spectrophotometric assay and compared to that of biotin. Finally, the antiaggregant activity towards amyloid-β was evaluated using a turn-on fluorescent dye. BioGHK could treat and/or prevent several adverse biochemical reactions that characterize neurodegenerative disorders, such as Alzheimer's disease.

Synergy of GHK-Cu and hyaluronic acid on collagen IV upregulation via fibroblast and ex-vivo skin tests

INTRODUCTION

GHK-Cu and HA are two commonly used skin care ingredients, both of which were reported to enhance collagen synthesis. This work aims to investigate their co-effect on collagen regulation.

MATERIALS AND METHODS

In cell experiments, human dermal fibroblasts were treated by a series of GHK-Cu and HA combinations, and the expressions of collagen I, IV, and VII were measured by qRT-PCR. The best formula screened out from cell experiments were further studied by ex-vivo skin model, and the content of collagen IV was quantified by immunofluorescence method.

RESULTS

The combination GHK-Cu and HA was found to promote the generation of collagen I, IV, and VII. Especially, they form a synergy on collagen IV. At the ratio of 1:9, GHK-Cu and LMW HA deliver the strongest effect to elevate collagen IV synthesis by 25.4 times in cell test and 2.03 times in ex-vivo skin test.

CONCLUSION

The co-effect of GHK-Cu and HA was revealed. Their synergy brings an insight to anti-aging technology: choosing proper molecular weight of HA and managing its ratio with GHK-Cu could enhance DEJ health via stimulating collagen IV synthesis.

Establishment of a human induced pluripotent stem cell derived alveolar organoid for toxicity assessment

Alveolar epithelial cells (AECs) are vulnerable to injury, which can result in epithelial hyperplasia, apoptosis, and chronic inflammation. In this study, we developed human induced pluripotent stem cell (hiPS) cell-derived AECs (iAECs) and the iAECs based organoids (AOs) for testing AEC toxicity after chemical exposure. HiPS cells were cultured for 14 days with differentiation medium corresponding to each step, and the iAECs-based AOs were maintained for another 14 days. SFTPC and AQP5 were expressed in the AOs, and mRNA levels of SOX9, NKX2.1, GATA6, HOPX, and ID2 were increased. The AOs were exposed for 24 h to nine chemical substances, and IC₅₀ values of the nine chemicals were determined using MTT assay. When the correlations between iAECs 2D culture and AOs 3D culture were calculated using Pearson's correlation coefficient r value, the nine chemicals that caused a significant decrease of cell viability in 3D culture were found to be highly correlated in 2D culture. The cytotoxicity and nitric oxide release in AO cultured with macrophages were then investigated. When AOs with macrophages were exposed to sodium chromate for 24 h, the IC₅₀ value and nitric oxide production were higher than when the AOs were exposed alone. Taken together, the AO-based 3D culture system provides a useful platform for understanding biological characteristics of AECs and modeling chemical exposures.

Glycyl- l-histidyl- l-lysine-Cu2+ rescues cigarette smoking-induced skeletal muscle dysfunction via a sirtuin 1-dependent pathway

BACKGROUND

Skeletal muscle dysfunction is an important co-morbidity in patients with chronic obstructive pulmonary disease (COPD) and is significantly associated with increased mortality. Oxidative stress has been demonstrated an important trigger for COPD-related skeletal muscle dysfunction. Glycine-histidine-lysine (GHK) is an active tripeptide, which is a normal component of human plasma, saliva, and urine; promotes tissue regeneration; and acts as an anti-inflammatory and antioxidant properties. The purpose of this study was to determine whether GHK is involved in COPD-related skeletal muscle dysfunction.

METHODS

The plasma GHK level in patients with COPD (n = 9) and age-paired healthy subjects (n = 11) were detected using reversed-phase high-performance liquid chromatography. The complex GHK with Cu (GHK-Cu) was used in in vitro (C2C12 myotubes) and in vivo experiments (cigarette smoking [CS]-exposure mouse model) to explore the involvement of GHK in CS-induced skeletal muscle dysfunction.

RESULTS

Compared with healthy control, plasma GHK levels were decreased in patients with COPD (70.27 ± 38.87 ng/mL vs. 133.0 ± 54.54 ng/mL, P = 0.009). And plasma GHK levels in patients with COPD were associated with pectoralis muscle area (R = 0.684, P = 0.042), inflammatory factor TNF-α (R = -0.696, P = 0.037), and antioxidative stress factor SOD2 (R = 0.721, P = 0.029). GHK-Cu was found to rescue CSE-induced skeletal muscle dysfunction in C2C12 myotubes, as evidenced by increased expression of myosin heavy chain, reduced expression of MuRF1 and atrogin-1, elevated mitochondrial content, and enhanced resistance to oxidative stress. In CS-induced muscle dysfunction C57BL/6 mice, GHK-Cu treatment (0.2 and 2 mg/kg) reduces CS-induced muscle mass loss (skeletal muscle weight (1.19 ± 0.09% vs. 1.29 ± 0.06%, 1.40 ± 0.05%; P < 0.05) and muscle cross-sectional area elevated (1055 ± 552.4 μm² vs. 1797 ± 620.9 μm² , 2252 ± 534.0 μm² ; P < 0.001), and also rescues CS-induced muscle weakness, indicated by improved grip strength (175.5 ± 36.15 g vs. 257.6 ± 37.98 g, 339.1 ± 72.22 g; P < 0.01). Mechanistically, GHK-Cu directly binds and activates SIRT1(the binding energy was -6.1 kcal/mol). Through activating SIRT1 deacetylation, GHK-Cu inhibits FoxO3a transcriptional activity to reduce protein degradation, deacetylates Nrf2 and contribute to its action of reducing oxidative stress by generation of anti-oxidant enzymes, increases PGC-1α expression to promote mitochondrial function. Finally, GHK-Cu could protect mice against CS-induced skeletal muscle dysfunction via SIRT1.

CONCLUSIONS

Plasma glycyl- l-histidyl- l-lysine level in patients with chronic obstructive pulmonary disease was significantly decreased and was significantly associated with skeletal muscle mass. Exogenous administration of glycyl- l-histidyl- l-lysine-Cu²⁺ could protect against cigarette smoking-induced skeletal muscle dysfunction via sirtuin 1.

Synthesis and neuroprotective effects of H2S-donor-peptide hybrids on hippocampal neuronal cells

Hydrogen sulfide (H₂S) has emerged as an endogenous signaling molecule that functions in many physiological and pathological processes of human cells in health and disease, including neuromodulation and neuroprotection, inflammation, angiogenesis, and vasorelaxation. The limited clinical applications of current H₂S donors have led to the development of H₂S donor hybrid compounds that combine current H₂S donors with bioactive molecules. Finely tuned multi-targeting hybrid molecules have been shown to have complementary neuroprotective effects against reactive oxygen species (ROS)-induced oxidative stress. In this study, we developed hybrid molecules combining a dithiolethione-based slow-releasing H₂S donor that exerts neuroprotective effects, with the tripeptides glycyl-L-histidyl-l-lysine (GHK) and L-alanyl-L-cystinyl-l-glutamine (ACQ), two natural products that exhibit powerful antioxidant effects. In particular, a hybrid combination of a dithiolethione-based slow-releasing H₂S donor and ACQ exhibited significant neuroprotective effects against glutamate-induced oxidative damage in HT22 hippocampal neuronal cells. This hybrid remarkably suppressed Ca²⁺ accumulation and ROS production. Furthermore, it efficiently inhibited apoptotic neuronal cell death by blocking apoptosis-inducing factor release and its translocation to the nucleus. These results indicate that the hybrid efficiently inhibited apoptotic neuronal cell damage by complementary neuroprotective actions.

Metabolome and microbiome multi-omics integration from a murine lung inflammation model of bronchopulmonary dysplasia

BACKGROUND

Respiratory tract microbial dysbiosis can exacerbate inflammation and conversely inflammation may cause dysbiosis. Dysbiotic microbiome metabolites may lead to bronchopulmonary dysplasia (BPD). Hyperoxia and lipopolysaccharide (LPS) interaction alters lung microbiome and metabolome, mediating BPD lung injury sequence.

METHODS

C57BL6/J mice were exposed to 21% (normoxia) or 70% (hyperoxia) oxygen during postnatal days (PND) 1-14. Pups were injected with LPS (6 mg/kg) or equal PBS volume, intraperitoneally on PND 3, 5, and 7. At PND14, the lungs were collected for microbiome and metabolomic analyses (n = 5/group).

RESULTS

Microbiome alpha and beta diversity were similar between groups. Metabolic changes included hyperoxia 31 up/18 down, LPS 7 up/4 down, exposure interaction 8. Hyperoxia increased Intestinimonas abundance, whereas LPS decreased Clostridiales, Dorea, and Intestinimonas; exposure interaction affected Blautia. Differential co-expression analysis on multi-omics data identified exposure-altered modules. Hyperoxia metabolomics response was integrated with a published matching transcriptome, identifying four induced genes (ALDOA, GAA, NEU1, RENBP), which positively correlated with BPD severity in a published human newborn cohort.

CONCLUSIONS

We report hyperoxia and LPS lung microbiome and metabolome signatures in a clinically relevant BPD model. We identified four genes correlating with BPD status in preterm infants that are promising targets for therapy and prevention.

IMPACT

Using multi-omics, we identified and correlated key biomarkers of hyperoxia and LPS on murine lung micro-landscape and examined their potential clinical implication, which shows strong clinical relevance for future research. Using a double-hit model of clinical relevance to bronchopulmonary dysplasia, we are the first to report integrated metabolomic/microbiome landscape changes and identify novel disease biomarker candidates.

Glycyl-L-histidyl-L-lysine-Cu2+ attenuates cigarette smoke-induced pulmonary emphysema and inflammation by reducing oxidative stress pathway

Background: Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder manifested as chronic airway inflammation and persistent airflow limitation with the essential mechanism as inflammatory response and oxidative stress induced by toxic exposures such as cigarette smoke (CS). Glycyl-L-histidyl-L-lysine (GHK) is a nontoxic tripeptide involved in the process of healing and regeneration as a natural product. With the combination of Cu(II), glycyl-L-histidyl-L-lysine-Cu²⁺ (GHK-Cu) improves antioxidative and anti-inflammatory bioavailability, and they might offer potential therapeutic properties for COPD. Thus, the present study aimed to identify the potential effects of GHK-Cu on emphysema induced by cigarette smoke.

Methods: In the in vivo experiment, C57BL/6J mice were exposed to CS for 12 weeks to induce pulmonary emphysema. GHK-Cu was injected intraperitoneally at doses of 0.2, 2 and 20 μg/g/day in 100 µl of saline on alternative days from the 1st day after CS exposure. The effects of GHK-Cu on the morphology of CS-induced emphysema, the inflammatory response and oxidative stress were evaluated. The antioxidative effect of GHK-Cu on human alveolar epithelial A549 cells was assessed in vitro.

Results: GHK-Cu treatment attenuated the CS-induced emphysematous changes and partially reversed the matrix metalloprotein -9 (MMP-9)/tissue inhibitor of metalloproteinases-1 (TIMP-1) imbalance in the lung tissue. GHK-Cu reduced the inflammation and oxidation by decreasing the expression of inflammatory cytokines (IL-1β and TNF-α) in the bronchoalveolar lavage and the enzymatic activity of MPO and MDA in the lung homogenate while restoring the T-AOC and GSH content. Furthermore, administration of GHK-Cu reversed the increase in NF-κB expression induced by CS and increased the Nrf2 level, as an antioxidant defense component, in mice with chronic CS exposure. In CSE-exposed human alveolar epithelial A549 cells, GHK-Cu also inhibited oxidative stress by suppressing MDA levels and restoring T-AOC and GSH levels, which were modulated by upregulating Nrf2 expression.

Conclusion: GHK-Cu treatment attenuated CS-induced emphysema by anti-inflammation by downregulating NF-κB and antioxidation via upregulation of the Nrf2/Keap1 in lung tissues.

Exogenous Bioactive Peptides Have a Potential Therapeutic Role in Delaying Aging in Rodent Models

In recent years, some exogenous bioactive peptides have been shown to have promising anti-aging effects. These exogenous peptides may have a mechanism similar to endogenous peptides, and some can even regulate the release of endogenous active peptides and play a synergistic role with endogenous active peptides. Most aging studies use rodents that are easy to maintain in the laboratory and have relatively homogenous genotypes. Moreover, many of the anti-aging studies using bioactive peptides in rodent models only focus on the activity of single endogenous or exogenous active peptides, while the regulatory effects of exogenous active peptides on endogenous active peptides remain largely under-investigated. Furthermore, the anti-aging activity studies only focus on the effects of these bioactive peptides in individual organs or systems. However, the pathological changes of one organ can usually lead to multi-organ complications. Some anti-aging bioactive peptides could be used for rescuing the multi-organ damage associated with aging. In this paper, we review recent reports on the anti-aging effects of bioactive peptides in rodents and summarize the mechanism of action for these peptides, as well as discuss the regulation of exogenous active peptides on endogenous active peptides.

Gas explosion-induced acute blast lung injury assessment and biomarker identification by a LC-MS-based serum metabolomics analysis

The objective of this study was to evaluate the histopathological effect of gas explosion on rats, and to explore the metabolic alterations associated with gas explosion-induced acute blast lung injury (ABLI) in real roadway environment using metabolomics analyses. All rats were exposed to the gas explosion source at different distance points (160 m and 240 m) except the control group. Respiratory function indexes were monitored and lung tissue analysis was performed to correlate histopathological effect to serum metabolomics. Their sera samples were collected to measure the metabolic alterations by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). HE staining in lung showed that the gas explosion caused obvious inflammatory pulmonary injury, which was consistent with respiratory function monitoring results and the serum metabolomics analysis results. The metabolomics identified 9 significantly metabolites different between the control- and ABLI rats. 2-aminoadipic acid, L-methionine, L-alanine, L-lysine, L-threonine, cholic acid and L-histidine were significantly increased in the exposed groups. Citric acid and aconitic acid were significantly decreased after exposure. Pathway analyses identified 8 perturbed metabolic pathways, which provided novel potential mechanisms for the gas explosion-induced ABLI. Therefore, metabolomics analysis identified both known and unknown alterations in circulating biomarkers, adding an integral mechanistic insight into the gas explosion-induced ABLI in real roadway environment.

Copper(ii) complex of N-truncated amyloid-β peptide bearing a His-2 motif as a potential receptor for phosphate anions

Electrochemical and spectroscopic studies demonstrated that the N-truncated amyloid β peptide Aβ_5-9 (Arg-His-Asp-Ser-Gly-NH₂) possessing histidine at position 2 (His-2) formed ternary complexes with copper(ii) and phosphate anions or phosphate groups of biomolecules. The recognition ability of Cu(ii)-Aβ_5-9 toward phosphate species provided a new perspective on designing phosphate-selective molecular receptors.

Transcription factor NF-κB promotes acute lung injury via microRNA-99b-mediated PRDM1 down-regulation

Acute lung injury (ALI), is a rapidly progressing heterogenous pulmonary disorder that possesses a high risk of mortality. Accumulating evidence has implicated the activation of the p65 subunit of NF-κB [NF-κB(p65)] activation in the pathological process of ALI. microRNAs (miRNAs), a group of small RNA molecules, have emerged as major governors due to their post-transcriptional regulation of gene expression in a wide array of pathological processes, including ALI. The dysregulation of miRNAs and NF-κB activation has been implicated in human diseases. In the current study, we set out to decipher the convergence of miR-99b and p65 NF-κB activation in ALI pathology. We measured the release of pro-inflammatory cytokines (IL-1β, IL-6, and TNFα) in bronchoalveolar lavage fluid using ELISA. MH-S cells were cultured and their viability were detected with cell counting kit 8 (CCK8) assays. The results showed that miR-99b was up-regulated, while PRDM1 was down-regulated in a lipopolysaccharide (LPS)-induced murine model of ALI. Mechanistic investigations showed that NF-κB(p65) was enriched at the miR-99b promoter region, and further promoted its transcriptional activity. Furthermore, miR-99b targeted PRDM1 by binding to its 3'UTR, causing its down-regulation. This in-creased lung injury, as evidenced by increased wet/dry ratio of mouse lung, myeloperoxidase activity and pro-inflammatory cytokine secretion, and enhanced infiltration of inflammatory cells in lung tissues. Together, our findings indicate that NF-κB(p65) promotion of miR-99b can aggravate ALI in mice by down-regulating the expression of PRDM1.

Glycine-Histidine-Lysine (GHK) Alleviates Astrocytes Injury of Intracerebral Hemorrhage via the Akt/miR-146a-3p/AQP4 Pathway

Intracerebral hemorrhage (ICH) is a major type of cerebrovascular disease with poor prognosis. Recent studies have shown that Glycyl-l-histidyl-l-lysine (GHK) is a kind of natural human tripeptide which could inhibit inflammation and against neurodegenerative diseases, but neither its role nor the mechanisms in ICH have yet been explicit. Currently, we investigated the possible strategies of GHK on ICH injury. Neurological deficit scores, brain water content, Nissl staining, and aquaporin 4 (AQP4) immunohistochemistry were detected in different groups of rats. The expression of microRNAs (miRNAs) was examined by real-time PCR. Inflammatory factors were detected using enzyme-linked immunosorbent assay (ELISA). Cell viability and cell proliferation were detected by Cell Counting Kit-8 (CCK-8). Matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitors of metalloproteinase-1 (TIMP1), AQP4 expression were detected/assessed using western blot. We observed that 5 and 10 μg/g of GHK improved neurological recovery by significantly reducing brain water content, improving neurological deficits, and promoting neuron survival. Besides, GHK alleviated inflammatory reaction and downregulated AQP4 expression. Furthermore, the effects of GHK on astrocyte were associated with the upregulation of miRNA-146a-3p, which partially regulated the expression of AQP4. Our results demonstrated that the phosphatidylinositol 3-kinase (PI3K)/AKT pathway participated in the GHK-induced upregulation of miR-146a-3p and miR-146a-3p/AQP4 interaction plays a role in the injury following ICH. These findings suggested that GHK could provide a novel therapeutic strategy for ICH.

Ternary Cu(II) Complex with GHK Peptide and Cis-Urocanic Acid as a Potential Physiologically Functional Copper Chelate

The tripeptide NH₂–Gly–His–Lys–COOH (GHK), cis-urocanic acid (cis-UCA) and Cu(II) ions are physiological constituents of the human body and they co-occur (e.g., in the skin and the plasma). While GHK is known as Cu(II)-binding molecule, we found that urocanic acid also coordinates Cu(II) ions. Furthermore, both ligands create ternary Cu(II) complex being probably physiologically functional species. Regarding the natural concentrations of the studied molecules in some human tissues, together with the affinities reported here, we conclude that the ternary complex [GHK][Cu(II)][cis-urocanic acid] may be partly responsible for biological effects of GHK and urocanic acid described in the literature.

Expression and Purification of Recombinant GHK Tripeptides Are Able to Protect against Acute Cardiotoxicity from Exposure to Waterborne-Copper in Zebrafish

In this study, an alternative method is developed to replace chemical synthesis to produce glycyl-histidyl-lysine (GHK) tripeptides with a bacterial fermentation system. The target GHK tripeptides are cloned into expression plasmids carrying histidine-glutathione-S-transferase (GST) double tags and TEV (tobacco etch virus) cleavage sites at the N-terminus. After overexpression in Escherichia coli (E. coli) BL21 cells, the recombinant proteins are purified and recovered by high-pressure liquid chromatography (HPLC). UV-vis absorption spectroscopy was used to investigate the chemical and biological properties of the recombinant GHK tripeptides. The results demonstrated that one recombinant GHK tripeptide can bind one copper ion to form a GHK-Cu complex with high affinity, and the recombinant GHK peptide to copper ion ratio is 1:1. X-ray absorption near-edge spectroscopy (XANES) of the copper ions indicated that the oxidation state of copper in the recombinant GHK-Cu complexes here was Cu(II). All of the optical spectrum evidence suggests that the recombinant GHK tripeptide appears to possess the same biophysical and biochemical features as the GHK tripeptide isolated from human plasma. Due to the high binding affinity of GHK tripeptides to copper ions, we used zebrafish as an in vivo model to elucidate whether recombinant GHK tripeptides possess detoxification potential against the cardiotoxicity raised by waterborne Cu(II) exposure. Here, exposure to Cu(II) induced bradycardia and heartbeat irregularity in zebrafish larvae; however, the administration of GHK tripeptides could rescue those experiencing cardiotoxicity, even at the lowest concentration of 1 nM, where the GHK-Cu complex minimized CuSO4-induced cardiotoxicity effects at a GHK:Cu ratio of 1:10. On the other hand, copper and the combination with the GHK tripeptide did not significantly alter other cardiovascular parameters, including stroke volume, ejection fraction, and fractional shortening. Meanwhile, the heart rate and cardiac output were boosted after exposure with 1 nM of GHK peptides. In this study, recombinant GHK tripeptide expression was performed, along with purification and chemical property characterization, which revealed a potent cardiotoxicity protection function in vivo with zebrafish for the first time.

Lipopolysaccharide-Induced Acute Lung Injury Is Associated with Increased Ran-Binding Protein in Microtubule-Organizing Center (RanBPM) Molecule Expression and Mitochondria-Mediated Apoptosis Signaling Pathway in a Mouse Model

Background

Acute lung injury (ALI) is a severe and life-threatening disorder treated in intensive care units. This study aimed to determine molecules or associated signaling pathways that are involved in lipopolysaccharide (LPS)-induced inflammation in an ALI model.

Material/Methods

An ALI mouse model was established by administering LPS (25 mg/kg via intratracheal instillation). Thirty-two ALI mice were divided into Model-4 h, Model-8 h, Model-12 h, and Model-24 h groups, while another 8 mice without LPS treatment were assigned as the Control group. Hematoxylin-eosin (HE) staining was used to evaluate inflammation of lung tissues. Wet weight/dry weight (W/D) ratio and myeloperoxidase (MPO) activity of lung tissue in ALI mice were evaluated. Expressions of Bcl-2, Bcl-XL, Bak, Bax, cleaved caspase-3 (C-caspase-3), and Ran-binding protein in microtubule-organizing center (RanBPM) were determined using Western blot analysis.

Results

LPS administration caused obvious inflammatory cell infiltration of lung tissues in ALI mice. The W/D ratio of ALI mouse lung tissues was significantly higher in Model groups than in the Control group (p<0.05). MPO activity of ALI mice was remarkably higher in Model groups compared to the Control group (p<0.05). LPS-induced ALI model mice exhibited significantly higher levels of C-caspase 3 lung tissues compared to the Control group (p<0.05). LPS-induced ALI model mice had significantly lower Bcl-XL/Bcl-2 and remarkably higher Bak/Bax expression compared with the Control group (p<0.05). LPS-induced ALI model mice displayed obviously higher RanBPM expression than in the Control group (p<0.05).

Conclusions

Lipopolysaccharide-induced acute lung injury is associated with increased RanBPM molecule expression and with mitochondria-mediated apoptosis signaling pathway in a mouse model.

The potential of GHK as an anti-aging peptide

GHK (glycyl-L-histidyl-L-lysine) is a naturally occurring peptide found in human serum with levels averaging 200 ng/ml at age 20 but declining to an average of 80 ng/ml by age 60. The molecule has a very high affinity for copper and forms the chelate GHK-Cu. The peptide as well as its Cu (II) chelate have anti-inflammatory and tissue remodeling properties. GHK-Cu has been shown to promote skin remodeling, wound healing and regeneration, and has prominent antioxidant and anti-inflammatory effects in in vitro and in vivo studies. In addition, preliminary observations suggest GHK can partially reverse cognitive impairment in aging mice by targeting anti-inflammatory and epigenetic pathways. The evidence as presented provides the rationale to further investigate this naturally occurring peptide in preclinical and clinical aging studies.

Anti-inflammatory effect of octyl gallate in alveolar macrophages cells and mice with acute lung injury

Acute lung injury (ALI) is an inflammatory process, and has high incidence and mortality. ALI and the acute respiratory distress syndrome are two common complications worldwide that result in acute lung failure, sepsis, and death. Pro-inflammatory substances, such as cytokines and chemokines, are responsible for activating the body's defense mechanisms and usually mediate inflammatory processes. Therefore, the research of substances that decrease the uncontrolled response of organism is seen as potential for patients with ALI. Octyl gallate (OG) is a phenolic compound with therapeutic actions namely antimicrobial, antiviral, and antifungal. In this study, we evaluated its action on lipopolysaccharide (LPS)-activated alveolar macrophages RAW 264.7 cells and ALI in male mice. Our results demonstrated protective effects of OG in alveolar macrophages activated with LPS and mice with ALI. The OG treatment significantly decreased the inflammatory markers in both studies in vitro and in vivo. The data suggested that OG can act as an anti-inflammatory agent for ALI.

Protective effects of GHK-Cu in bleomycin-induced pulmonary fibrosis via anti-oxidative stress and anti-inflammation pathways

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a serious lung problem with advancing and diffusive pulmonary fibrosis as the pathologic basis, and with oxidative stress and inflammation as the key pathogenesis. Glycyl-L-histidyl-l-lysine (GHK) is a tripeptide participating into wound healing and regeneration. GHK-Cu complexes improve GHK bioavailability. Thus, the current study aimed to explore the therapeutic role of GHK-Cu on bleomycin (BLM)-induced pulmonary fibrosis in a mouse model.

METHODS

BLM (3 mg/kg) was administered via tracheal instillation (TI) to induce a pulmonary fibrosis model in C57BL/6j mice 21 days after the challenge of BLM. GHK-Cu was injected intraperitoneally (i.p.) at different dosage of 0.2, 2 and 20 μg/g/day in 0.5 ml PBS on alternate day. The histological changes, inflammation response, the collagen deposition and epithelial-mesenchymal transition (EMT) was evaluated in the lung tissue. EMT was evaluated by ɑ-SMA and fibronectin expression in the lung tissue. NF-κB p65, Nrf2 and TGFβ1/Smad2/3 signalling pathways were detected by immunoblotting analysis.

RESULTS

GHK-Cu complex inhibited BLM-induced inflammatory and fibrotic pathological changes, alleviated the inflammatory response in the BALF by reducing the levels of the inflammatory cytokines, TNF-ɑ and IL-6 and the activity of MPO as well as reduced collagen deposition. In addition, the GHK-Cu treatment significantly reversed the MMP-9/TIMP-1 imbalance and partially prevented EMT via Nrf2, NF-κB and TGFβ1 pathways, as well as Smad2/3 phosphorylation.

CONCLUSIONS

GHK-Cu presented a protective effect in BLM-induced inflammation and oxidative stress by inhibiting EMT progression and suppressing TGFβ1/Smad2/3 signalling in pulmonary fibrosis.

Effect of oligoarginine conjugation on the antiwrinkle activity and transdermal delivery of GHK peptide

GHK (Gly-His-Lys), a natural peptide found in human skin and plasma, has been widely used in the cosmeceutical and pharmaceutical fields. The hydrophilic GHK and GHK-Cu are limited in their abilities to penetrate deeply into skin; because of this, various strategies for their skin delivery have been developed. In this investigation, Arg₄ was conjugated with GHK to get heptapeptide, GHK-R4, and then in vitro antiwrinkle activity and transdermal delivery were compared between GHK and GHK-R4. Notably, Arg₄ conjugation accelerated the cellular penetration of GHK both in vitro and in vivo. Furthermore, higher in vitro antiwrinkle activity and collagen biosynthesis was obtained with GHK-R4 at much lower doses than with control R4-free GHK. The enhanced activity and delivery of GHK-R4 might be due to the cell penetrating ability and matrix metalloproteinase (MMP) inhibitory activity of R4 itself.

Procyanidin B2 Suppresses Lipopolysaccharides-Induced Inflammation and Apoptosis in Human Type II Alveolar Epithelial Cells and Lung Fibroblasts

Acute lung injury (ALI) is characterized by acute lung inflammation and apoptosis of alveolar epithelial cells (AECs) with a high morbidity and mortality. Procyanidin B2 (PCB2) is a naturally occurring flavonoid with anti-inflammatory activity. Our previous study demonstrated that PCB2 inhibited NLRP3 inflammasome signaling and ameliorated paraquat-induced ALI in rat, indicating the protective role of PCB2. As lipopolysaccharide (LPS) induced acute cell injury and dysfunction, we continued to evaluate the protective effects of PCB2 using LPS-treated human AECs and lung fibroblasts (LFs) model. We tested the effects of PCB2 on cell permeability, viability, apoptosis, nuclear factor-kappaB (NF-κB) activation, NLRP3 inflammasome activation, and proinflammatory cytokines production in LPS-treated human AECs and LFs. PCB2 prevented LPS-induced cell apoptosis, and increased the cell viability in LPS-treated human AECs and LFs. PCB2 inhibited LPS-induced Bax and active caspase-3 expression, and promoted Bcl-2 expression. PCB2 prevented LPS-induced tumor necrosis factor-α, interleukin-1β expression, NF-κB activation, and NLRP3 inflammasome activation. PCB2 suppressed LPS-induced inflammation and apoptosis in human AECs and LFs by inhibiting NF-κB and NLRP3 inflammasome.

Extracellular Matrix Component Remodeling in Respiratory Diseases: What Has Been Found in Clinical and Experimental Studies?

Changes in extracellular matrix (ECM) components in the lungs are associated with the progression of respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome (ARDS). Experimental and clinical studies have revealed that structural changes in ECM components occur under chronic inflammatory conditions, and these changes are associated with impaired lung function. In bronchial asthma, elastic and collagen fiber remodeling, mostly in the airway walls, is associated with an increase in mucus secretion, leading to airway hyperreactivity. In COPD, changes in collagen subtypes I and III and elastin, interfere with the mechanical properties of the lungs, and are believed to play a pivotal role in decreased lung elasticity, during emphysema progression. In ARDS, interstitial edema is often accompanied by excessive deposition of fibronectin and collagen subtypes I and III, which can lead to respiratory failure in the intensive care unit. This review uses experimental models and human studies to describe how inflammatory conditions and ECM remodeling contribute to the loss of lung function in these respiratory diseases.

Metal-dependent hormone function: the emerging interdisciplinary field of metalloendocrinology

For over 100 years, there has been an incredible amount of knowledge amassed concerning hormones in the endocrine system and their central role in human health. Hormones represent a diverse group of biomolecules that are released by glands, communicate signals to their target tissue, and are regulated by feedback loops to maintain organism health. Many disease states, such as diabetes and reproductive disorders, stem from misregulation or dysfunction of hormones. Increasing research is illuminating the intricate roles of metal ions in the endocrine system where they may act advantageously in concert with hormones or deleteriously catalyze hormone-associated disease states. As the critical role of metal ions in the endocrine system becomes more apparent, it is increasingly important to untangle the complex mechanisms underlying the connections between inorganic biochemistry and hormone function to understand and control endocrinological phenomena. This tutorial review harmonizes the interdisciplinary fields of endocrinology and inorganic chemistry in the newly-termed field of "metalloendocrinology". We describe examples linking metals to both normal and aberrant hormone function with a focus on highlighting insight to molecular mechanisms. Hormone activities related to both essential metal micronutrients, such as copper, iron, zinc, and calcium, and disruptive nonessential metals, such as lead and cadmium are discussed.

Carnosol suppresses interleukin-6 production in mouse lungs injured by ischemia–reperfusion operation and in RAW264.7 macrophages treated with lipopolysaccharide

Carnosol is a naturally occurring herbal compound, known for its antioxidative properties. We previously found that carnosol protected mouse lungs from ischemia–reperfusion injury in ex vivo cultures. To elucidate the molecular mechanisms underpinning carnosol-mediated lung protection, we analyzed modes of interleukin-6 (IL-6) gene expression, which is associated with lung ischemia–reperfusion injury. Microarray analysis of mouse lungs suggested that IL-6 mRNA levels were elevated in the mouse lungs subjected to clamp-reperfusion, which was associated with elevated levels of other inflammatory modulators, such as activating transcription factor 3 (ATF3). Carnosol pretreatment lowered the IL-6 protein levels in mouse lung homogenates prepared after the clamp-reperfusion. On the other hand, the ATF3 gene expression was negatively correlated with that of IL-6 in RAW264.7 cells. IL-6 mRNA levels and gene promoter activities were suppressed by carnosol in RAW264.7 cells, but rescued by ATF3 knockdown. When RAW264.7 cells were subjected to hypoxia–reoxygenation, carnosol treatment lowered oxygen consumption after reoxygenation, which was coupled with a correlation with a transient production of mitochondrial reactive oxygen species and following ATF3 gene expression. These results suggest that carnosol treatment could be a new strategy for protecting lungs from ischemia–reperfusion injury by modulating the ATF3–IL-6 axis.

Glycine-Histidine-Lysine (GHK) Alleviates Neuronal Apoptosis Due to Intracerebral Hemorrhage via the miR-339-5p/VEGFA Pathway

Glycine-histidine-lysine (GHK) is a human tripeptide that enhances wound healing, exerts neuroprotective effects against neurodegenerative disease, and improves tissue regeneration. This study examined whether GHK can alleviate injury due to intracerebral hemorrhage (ICH). Briefly, adult Wistar rats in GHK pretreatment groups were injected with GHK (1 or 10 mg/kg, i.p.) every 24 h for 3 days. Water content and intact neurons were detected in the rats 3 days after ICH, and the neurological deficit scores were examined in the rats at 4, 24, 72, and 168 h after ICH. Apoptosis was evaluated via caspase-3 immunohistochemistry, Nissl staining, and TUNEL assay. We also examined the effect of GHK on the expression of related proteins in SH-SY5Y cells via Western blotting. The expression of miR-339-5p was examined via real-time polymerase chain reaction analyses. GHK improved neurological deficits, reduced water content in the brain and inhibited neuronal apoptosis in ICH rats. It also prevented the apoptosis of SH-SY5Y cells with hemin treatment. Furthermore, GHK downregulated miR-339-5p expression, and overexpression of miR-339-5p partially reversed the anti-apoptotic effects of GHK in SH-SY5Y cells. Our findings suggest that the p38 MAPK pathway is involved in the GHK-induced downregulation of miR-339-5p, and that the miR-339-5p/VEGFA axis plays a role in preventing neuronal apoptosis following ICH injury. These findings indicate that GHK may represent a novel therapeutic strategy for ICH.

miR-34b-5p inhibition attenuates lung inflammation and apoptosis in an LPS-induced acute lung injury mouse model by targeting progranulin

Inflammation and apoptosis play important roles in the initiation and progression of acute lung injury (ALI). Our previous study has shown that progranulin (PGRN) exerts lung protective effects during LPS-induced ALI. Here, we have investigated the potential roles of PGRN-targeting microRNAs (miRNAs) in regulating inflammation and apoptosis in ALI and have highlighted the important role of PGRN. LPS-induced lung injury and the protective roles of PGRN in ALI were first confirmed. The function of miR-34b-5p in ALI was determined by transfection of a miR-34b-5p mimic or inhibitor in intro and in vivo. The PGRN level gradually increased and subsequently significantly decreased, reaching its lowest value by 24 hr; PGRN was still elevated compared to the control. The change was accompanied by a release of inflammatory mediators and accumulation of inflammatory cells in the lungs. Using bioinformatics analysis and RT-PCR, we demonstrated that, among 12 putative miRNAs, the kinetics of the miR-34b-5p levels were closely associated with PGRN expression in the lung homogenates. The gain- and loss-of-function analysis, dual-luciferase reporter assays, and rescue experiments confirmed that PGRN was the functional target of miR-34b-5p. Intravenous injection of miR-34b-5p antagomir in vivo significantly inhibited miR-34b-5p up-regulation, reduced inflammatory cytokine release, decreased alveolar epithelial cell apoptosis, attenuated lung inflammation, and improved survival by targeting PGRN during ALI. miR-34b-5p knockdown attenuates lung inflammation and apoptosis in an LPS-induced ALI mouse model by targeting PGRN. This study shows that miR-34b-5p and PGRN may be potential targets for ALI treatments.

Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data

The human peptide GHK (glycyl-l-histidyl-l-lysine) has multiple biological actions, all of which, according to our current knowledge, appear to be health positive. It stimulates blood vessel and nerve outgrowth, increases collagen, elastin, and glycosaminoglycan synthesis, as well as supports the function of dermal fibroblasts. GHK&rsquo;s ability to improve tissue repair has been demonstrated for skin, lung connective tissue, boney tissue, liver, and stomach lining. GHK has also been found to possess powerful cell protective actions, such as multiple anti-cancer activities and anti-inflammatory actions, lung protection and restoration of chronic obstructive pulmonary disease (COPD) fibroblasts, suppression of molecules thought to accelerate the diseases of aging such as NFκB, anti-anxiety, anti-pain and anti-aggression activities, DNA repair, and activation of cell cleansing via the proteasome system. Recent genetic data may explain such diverse protective and healing actions of one molecule, revealing multiple biochemical pathways regulated by GHK.

GHK Peptide Inhibits Bleomycin-Induced Pulmonary Fibrosis in Mice by Suppressing TGFβ1/Smad-Mediated Epithelial-to-Mesenchymal Transition

Objective: Idiopathic pulmonary fibrosis is an irreversible and progressive fibrotic lung disease that leads to declines in pulmonary function and, eventually, respiratory failure and has no effective treatment. Gly-His-Lys (GHK) is a tripeptide involved in the processes of tissue regeneration and wound healing and has significant inhibitory effects on transforming growth factor (TGF)-β1 secretion. The effect of GHK on fibrogenesis in pulmonary fibrosis and the exact underlying mechanism have not been studied previously. Thus, this study investigated the effects of GHK on bleomycin (BLM)-induced fibrosis and identified the pathway that is potentially responsible for these effects.

Methods: Intratracheal injections of 3 mg/kg BLM were administered to induce pulmonary fibrosis in C57BL/6 mice. GHK was administered intraperitoneally at doses of 2.6, 26, and 260 μg/ml/day every other day from the 4th to the 21st day after BLM instillation. Three weeks after BLM instillation, pulmonary injury and pulmonary fibrosis was evaluated by the hematoxylin-eosin (HE) and Masson’s trichrome (MT) staining. Chronic inflammation index was used for the histological assessments by two pathologists blindly to each other. Tumor necrosis factor (TNF)-α and IL-6 levels in BALF and myeloperoxidase (MPO) activity in lung extracts were measured. For the pulmonary fibrosis evaluation, the fibrosis index calculated based on MT staining, collagen deposition and active TGF-β1 expression detected by ELISA, and the expression of TGF-β1, α-smooth muscle actin (SMA), fibronectin, MMP-9, and TIMP-1 by western blotting. The epithelial mesenchymal transition index, E-cadherin, and vimentin was also detected by western blot. The statistical analysis was performed by one-way ANOVA and the comparison between different groups were performed.

Results: Treatment with GHK at all three doses reduced inflammatory cell infiltration and interstitial thickness and attenuated BLM-induced pulmonary fibrosis in mice. GHK treatment significantly improved collagen deposition, and MMP-9/TIMP-1 imbalances in lung tissue and also reduced TNF-α, IL-6 expression in bronchoalveolar lavage fluid (BALF) and MPO in lung extracts. Furthermore, GHK reversed BLM-induced increases in TGF-β1, p-Smad2, p-Smad-3 and insulin-like growth factor-1 (IGF-1) expression.

Conclusion: GHK inhibits BLM-induced fibrosis progression, the inflammatory response and EMT via the TGF-β1/Smad 2/3 and IGF-1 pathway. Thus, GHK may be a potential treatment for pulmonary fibrosis.

Geraniol alleviates LPS-induced acute lung injury in mice via inhibiting inflammation and apoptosis

Geraniol (GOH), a special type of acyclic monoterpene alcohol, has been widely used to treat many diseases associated with inflammation and apoptosis. Acute lung injury (ALI) is a common clinical disease in humans characterized by pulmonary inflammation and apoptosis. In the present study, we investigated the protective effects of GOH in a mouse model of ALI induced by the intranasal administration of lipopolysaccharide (LPS) and elucidated the underlying molecular mechanisms in RAW 264.7 cells. In vivo, GOH treatment markedly ameliorated pathological injury and pulmonary cell apoptosis and reduced the wet/dry (W/D) weight ratio of lungs, myeloperoxidase (MPO) activity and the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). In vitro, the levels of pro-inflammatory cytokines, iNOS and COX-2 were significantly increased in LPS-stimulated RAW 264.7 cells, an effect that was decreased by GOH treatment. Moreover, GOH treatment dramatically reduced the expression of Toll-like receptor 4 (TLR4) and then prevented the nuclear factor-κB (NF-κB) activation. GOH treatment also promoted anti-apoptotic Bcl-2 expression and inhibited pro-apoptotic Bax and Caspase-3 expression. Furthermore, knockdown of TLR4 expression exerted a similar effect and inhibited the phosphorylation of p65, as well as the Bax and Caspase-3 expression. Taken together, these results suggest that GOH treatment alleviates LPS-induced ALI via inhibiting pulmonary inflammation and apoptosis, a finding that might be associated with the inhibition of TLR4-mediated NF-κB and Bcl-2/Bax signalling pathways.

Effects of Lysine deficiency and Lys-Lys dipeptide on cellular apoptosis and amino acids metabolism

SCOPE

Lysine (Lys) is a common limiting amino acids (AA) for humans and animals and plays an important role in cell proliferation and metabolism, while metabolism of Lys deficiency and its dipeptide is still obscure. Thus, this study mainly investigated the effects of Lys deficiency and Lys-Lys dipeptide on apoptosis and AA metabolism in vitro and in vivo models.

METHODS AND RESULTS

Lys deficiency induced cell-cycle arrest and apoptosis and upregulated Lys transporters in vitro and in vivo. SLC7A11, a cystine-glutamate antiporter, was markedly upregulated by Lys deficiency and then further mediated cystine uptake and glutamate release, which was negatively regulated by cystine and glutamate transporters. Meanwhile, Lys deprivation upregulated pept1 expression, which might improve Lys-Lys dipeptide absorption to compensate for the reduced Lys availability. Lys-Lys dipeptide alleviated Lys deficiency induced cell-cycle arrest and apoptosis and influenced AA metabolism. Furthermore, the mammalian target of rapamycin signal might be involved in sensing cellular Lys starvation and Lys-Lys dipeptide.

CONCLUSIONS

Altogether, these studies suggest that Lys deficiency impairs AA metabolism and causes apoptosis. Lys-Lys dipeptide serves as a Lys source and alleviates Lys deficiency induced cellular imbalance.

Oridonin attenuates the release of pro-inflammatory cytokines in lipopolysaccharide-induced RAW264.7 cells and acute lung injury

Acute lung injury (ALI) is a life-threatening inflammatory disease owing to the lack of specific and effective therapies. Oridonin (Ori) is an active diterpenoid isolated from Rabdosiarubescens (R.rubescens) that has been shown to possess a broadspectrum pharmacological properties including anti-inflammatory, antitumour, antioxidative and neuroregulatory effects. However, its potential protective mechanism in ALI is not well characterized. In this study, we demonstrated that Ori reduces the mortality of mice with ALI induced by a high dose of lipopolysaccharide (LPS), which suggests that Ori has a protective effect on LPS induced ALI. Next, our results confirmed that Ori improves LPS-induced localized pulmonary pathology and decreased the concentration of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in the serum. Nuclear factor-kappa B (NF-κB) is capable of regulating the transcription of pro-inflammatory factors. Interestingly, our results showed that Ori inhibits the expression of TLR4/MyD88 and phosphorylation of NF-κB p65 in lung tissues. To confirm this, we further validated the possible regulatory anti-inflammatory mechanisms of Ori in vitro. LPS-induced RAW264.7 cells, which are widely used as an inflammation model to evaluate the potential protective effect of drugs in vitro, were chosen for this study. Similar results were observed, that is, pre-treatment with Ori, markedly inhibited the nuclear translocation and phosphorylation of NF-κB p65 induced by LPS and subsequently decreased the release of pro-inflammatory cytokines that were increased by LPS. Overall, these results demonstrated that Ori exerts a therapeutic effect on ALI by inhibiting the release of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, through the TLR4/MyD88/NF-κB axis.

Polydatin reduces Staphylococcus aureus lipoteichoic acid-induced injury by attenuating reactive oxygen species generation and TLR2-NFκB signalling

Staphylococcus aureus (S. aureus) causes severe inflammation in various infectious diseases, leading to high mortality. The clinical application of antibiotics has gained a significant curative effect. However, it has led to the emergence of various resistant bacteria. Therefore, in this study, we investigated the protective effect of polydatin (PD), a traditional Chinese medicine extract, on S. aureus lipoteichoic acid (LTA)-induced injury in vitro and in vivo. First, a significant improvement in the pathological conditions of PD in vivo was observed, suggesting that PD had a certain protective effect on LTA-induced injury in a mouse model. To further explore the underlying mechanisms of this protective effect of PD, LTA-induced murine macrophages were used in this study. The results have shown that PD could reduce the NF-κB p65, and IκBα phosphorylation levels increased by LTA, resulting in a decrease in the transcription of pro-inflammatory factors, such as TNF-α, IL-1β and IL-6. However, LTA can not only activate NF-κB through the recognition of TLR2 but also increase the level of intracellular reactive oxygen species (ROS), thereby activating NF-κB signalling. We also detected high levels of ROS that activate caspases 9 and 3 to induce apoptosis. In addition, using a specific NF-κB inhibitor that could attenuate apoptosis, namely NF-κB p65, acted as a pro-apoptotic transcription factor in LTA-induced murine macrophages. However, PD could inhibit the generation of ROS and NF-κB p65 activation, suggesting that PD suppressed LTA-induced injury by attenuating ROS generation and TLR2-NFκB signalling.

The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline

Neurodegeneration, the progressive death of neurons, loss of brain function, and cognitive decline is an increasing problem for senior populations. Its causes are poorly understood and therapies are largely ineffective. Neurons, with high energy and oxygen requirements, are especially vulnerable to detrimental factors, including age-related dysregulation of biochemical pathways caused by altered expression of multiple genes. GHK (glycyl-l-histidyl-l-lysine) is a human copper-binding peptide with biological actions that appear to counter aging-associated diseases and conditions. GHK, which declines with age, has health promoting effects on many tissues such as chondrocytes, liver cells and human fibroblasts, improves wound healing and tissue regeneration (skin, hair follicles, stomach and intestinal linings, boney tissue), increases collagen, decorin, angiogenesis, and nerve outgrowth, possesses anti-oxidant, anti-inflammatory, anti-pain and anti-anxiety effects, increases cellular stemness and the secretion of trophic factors by mesenchymal stem cells. Studies using the Broad Institute Connectivity Map show that GHK peptide modulates expression of multiple genes, resetting pathological gene expression patterns back to health. GHK has been recommended as a treatment for metastatic cancer, Chronic Obstructive Lung Disease, inflammation, acute lung injury, activating stem cells, pain, and anxiety. Here, we present GHK's effects on gene expression relevant to the nervous system health and function.