Deferoxamine alleviates liver fibrosis induced by CCl4 in rats

MitoQ protects against carbon tetrachloride-induced hepatocyte ferroptosis and acute liver injury by suppressing mtROS-mediated ACSL4 upregulation

Ferroptosis has been shown to be involved in carbon tetrachloride (CCl4)-induced acute liver injury (ALI). The mitochondrion-targeted antioxidant MitoQ can eliminate the production of mitochondrial reactive oxygen species (mtROS). This study investigated the role of MitoQ in CCl4-induced hepatocytic ferroptosis and ALI. MDA and 4HNE were elevated in CCl4-induced mice. In vitro, CCl4 exposure elevated the levels of oxidized lipids in HepG2 cells. Alterations in the mitochondrial ultrastructure of hepatocytes were observed in the livers of CCl4-evoked mice. Ferrostatin-1 (Fer-1) attenuated CCl4-induced hepatic lipid peroxidation, mitochondrial ultrastructure alterations and ALI. Mechanistically, acyl-CoA synthetase long-chain family member 4 (ACSL4) was upregulated in CCl4-exposed human hepatocytes and mouse livers. The ACSL4 inhibitor rosiglitazone alleviated CCl4-induced hepatic lipid peroxidation and ALI. ACSL4 knockdown inhibited oxidized lipids in CCl4-exposed human hepatocytes. Moreover, CCl4 exposure decreased the mitochondrial membrane potential and OXPHOS subunit levels and increased the mtROS level in HepG2 cells. Correspondingly, MitoQ pretreatment inhibited the upregulation of ACSL4 in CCl4-evoked mouse livers and HepG2 cells. MitoQ attenuated lipid peroxidation in vivo and in vitro after CCl4 exposure. Finally, MitoQ pretreatment alleviated CCl4-induced hepatocytic ferroptosis and ALI. These findings suggest that MitoQ protects against hepatocyte ferroptosis in CCl4-induced ALI via the mtROS-ACSL4 pathway.

Potential Hepatoprotective Effects of Allicin on Carbon Tetrachloride-Induced Acute Liver Injury in Mice by Inhibiting Oxidative Stress, Inflammation, and Apoptosis

The global burden of liver disease is enormous, which highlights the need for effective hepatoprotective agents. It was reported that allicin exhibits protective effects against a range of diseases. In this study, we further evaluated allicin's effect and mechanism in acute hepatic injury. Liver injury in mice was induced by intraperitoneal injection with 1% CCl4 (10 mL/kg/day). When the first dose was given, CCl4 was given immediately after administration of different doses of allicin (40, 20, and 10 mg/kg/day) as well as compound glycyrrhizin (CGI, 80 mg/kg/day), and then different doses of allicin (40, 20, and 10 mg/kg/day) as well as compound glycyrrhizin (CGI, 80 mg/kg/day) were administrated every 12 h. The animals were dissected 24 h after the first administration. The findings demonstrated a significant inhibition of CCl4-induced acute liver injury following allicin treatment. This inhibition was evidenced by notable reductions in serum levels of transaminases, specifically aspartate transaminase, along with mitigated histological damage to the liver. In this protective process, allicin plays the role of reducing the amounts or the expression levels of proinflammatory cytokines, IL-1β, IL-6. Furthermore, allicin recovered the activities of the antioxidant enzyme catalase (CAT) and reduced the production of malondialdehyde (MDA) in a dose-dependent manner, and also reduced liver Caspase 3, Caspase 8, and BAX to inhibit liver cell apoptosis. Further analysis showed that the administration of allicin inhibited the increased protein levels of Nuclear factor-erythroid 2-related factor 2 (Nrf2) and NAD(P)H:quinone oxidoreductase 1 (NQO1), which is related to inflammation and oxidative stress. The in vitro study of the LPS-induced RAW264.7 inflammatory cell model confirmed that allicin can inhibit important inflammation-related factors and alleviate inflammation. This research firstly clarified that allicin has a significant protective effect on CCl4-induced liver injury via inhibiting the inflammatory response and hepatocyte apoptosis, alleviating oxidative stress associated with the progress of liver damage, highlighting the potential of allicin as a hepatoprotective agent.

Boldine protects against carbon tetrachloride-induced chronic liver injury by regulating NF-κB signaling pathway

Sustained liver injuries predominantly promote oxidative stress and inflammation that lead to the progression of chronic liver disease (CLD), including fibrosis, cirrhosis, and hepatocellular carcinoma. Boldine, an alkaloid isolated from Peumus boldus, has been shown to have antioxidant and anti-inflammatory effects. Currently, there is no definitive treatment option available for CLD. Therefore, we investigated the hepatoprotective effect of boldine against carbon tetrachloride (CCl4 )-induced chronic liver injury in rats. CCl4 (2 mL/kg., b.w., i.p.) was administered twice weekly for 5 weeks to induce chronic liver injury in rats. Separate groups of rats were given boldine (20 mg/kg b.w., and 40 mg/kg b.w.) and silymarin (100 mg/kg b.w.) orally, daily. Serum transaminases, lipid peroxidation, and antioxidant levels were measured, and nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (cox-2), interleukin-1 β (IL-1β), and α-smooth muscle actin (α-SMA) gene and protein expressions were evaluated. CCl4 administration increased liver marker enzymes of hepatotoxicity in serum and oxidative stress markers, inflammatory genes and α-smooth muscle actin expression in liver tissue. Boldine concurrent treatment suppressed CCl4 -induced elevation of transaminase levels in serum, restored enzymic and non-enzymic antioxidants, and downregulated NF-κB, TNF-α, Cox-2 and IL-1β expressions, thereby suppressing hepatic inflammation. Boldine administration also repressed α-SMA expression. The results of this study demonstrate the antioxidant, anti-inflammatory, and antifibrotic properties of boldine, and it can be a potential therapeutic candidate in the treatment of CLD.

Water extract of earthworms mitigates mouse liver fibrosis by potentiating hepatic LKB1/Nrf2 axis to inhibit HSC activation and hepatocyte death

ETHNOPHARMACOLOGICAL RELEVANCE

When left untreated, liver fibrosis (LF) causes various chronic liver diseases. Earthworms (Pheretima aspergillum) are widely used in traditional medicine because of their capacity to relieve hepatic diseases.

AIM OF THE STUDY

This study aimed to explore the anti-LF effects of water extract of earthworms (WEE) and the underlying molecular mechanisms.

MATERIALS AND METHODS

A CCl4-induced mouse model of LF was used to study the impact of WEE on LF in vivo. The anti-LF activity of WEE in mice was compared with that of silybin, which can be clinically applied in LF intervention and was used as a positive control. Activation of LX-2 hepatic stellate cells (HSCs) and apoptosis and ferroptosis of AML-12 hepatocytes induced by TGFβ1 were used as in vitro models.

RESULTS

WEE drastically improved LF in mice. WEE reduced markers of activated HSCs in mice and inhibited TGFβ1-induced activation of LX-2 HSCs in vitro. Additionally, WEE suppressed CCl4-induced apoptosis and ferroptosis in mouse hepatocytes. Mechanistically, WEE induced Nrf2 to enter the nuclei of the mouse liver cells, and the hepatic levels of Nrf2-downstream antioxidative factors increased. LKB1/AMPK/GSK3β is an upstream regulatory cascade of Nrf2. In the LF mouse model, WEE increased hepatic phosphorylated LKB1, AMPK, and GSK3β levels. Similar results were obtained for the LX-2 cells. In AML-12 hepatocytes and LX-2 HSCs, WEE elevated intracellular Nrf2 levels, promoted its nuclear translocation, and inhibited TGFβ1-induced ROS accumulation. Knocking down LKB1 abolished the impact of WEE on the AMPK/GSK3β/Nrf2 cascade and eliminated its protective effects against TGFβ1.

CONCLUSIONS

Our findings reveal that WEE improves mouse LF triggered by CCl4 and supports its application as a promising hepatoprotective agent against LF. The potentiation of the hepatic antioxidative AMPK/GSK3β/Nrf2 cascade by activating LKB1 and the subsequent suppression of HSC activation and hepatocyte apoptosis and ferroptosis are implicated in WEE-mediated alleviation of LF.

Comparative study between the effect of mesenchymal stem cells microvesicles versus ozone on induced liver injury in adult male albino rats (Histological & Immunohistochemical study)

Liver disease accounts for approximately 2 million deaths er year worldwide. Liver fibrisis results from chronic injury to the liver. If not effectively treated in time, liver fibrosis may transform into liver cirrhosis. MVs are recognized as potential biomarkers and important theraputic tools for a wide sectrum of diseases. Medical ozone has the ability to protect the body against pathological conditions caused by oxidative stress. The influence of ozone and MVs on CCL4 induced liver fibrosis was investigated in this study. Forty-eight adult male albino rats were divided into four equal groups. I control, II CCL4 group, III ozone and IV microvesicles groups. Liver fibrosis was induced in group II, III & IV using 12 SC injections (0.5 ml/kg body weight) of CCL4 dissolved in olive oil twice ber week for weeks. Blood samples were obtained to estimate serum ALT & AST. Liver tissues were processed for measurment of GSH & SOD, light and electron microscopic examination. H&E staine sections og group II showed dilated congested sinusoids and centralveins, mononuclear infiltrations, vacuolations and dark nuclei. Ultrastructurally, group II revealed irregular heterochromatic nuclei of hepatocytes, small scanty mitochondria & vacuolations. Morphometric & statistical analyses were performed. Group III showed some improvement, however, group IV showed more imrovement. The results indicates that MVs caused marked improvement than ozone against CCL4 induced liver damage via antioxidant & antiinflammatory properties.

Ferroptosis as an emerging therapeutic target in liver diseases

Ferroptosis is an iron-dependently nonapoptotic cell death characterized by excessive accumulation of lipid peroxides and cellular iron metabolism disturbances. Impaired iron homeostasis and dysregulation of metabolic pathways are contributors to ferroptosis. As a major metabolic hub, the liver synthesizes and transports plasma proteins and endogenous fatty acids. Also, it acts as the primary location of iron storage for hepcidin generation and secretion. To date, although the intricate correlation between ferroptosis and liver disorders needs to be better defined, there is no doubt that ferroptosis participates in the pathogenesis of liver diseases. Accordingly, pharmacological induction and inhibition of ferroptosis show significant potential for the treatment of hepatic disorders involved in lipid peroxidation. In this review, we outline the prominent features, molecular mechanisms, and modulatory networks of ferroptosis and its physiopathologic functions in the progression of liver diseases. Further, this review summarizes the underlying mechanisms by which ferroptosis inducers and inhibitors ameliorate liver diseases. It is noteworthy that natural active ingredients show efficacy in preclinical liver disease models by regulating ferroptosis. Finally, we analyze crucial concepts and urgent issues concerning ferroptosis as a novel therapeutic target in the diagnosis and therapy of liver diseases.

Targeting ferroptosis, a novel programmed cell death, for the potential of alcohol-related liver disease therapy

Ferroptosis is a new iron-dependent cell death mode, which is different from the other types of programmed cell death, such as apoptosis, necrosis, and autophagy. Ferroptosis is characterized by a process in which fatal lipids from lipid peroxidation accumulate in cells and eventually lead to cell death. Alcohol-related liver disease (ALD) is a type of liver injury caused by excessive alcohol intake. Alcohol-related liver disease is a broad-spectrum disease category, which includes fatty liver, steatohepatitis, hepatitis, cirrhosis, and hepatocellular tumors. Recent studies have found that ferroptosis is involved in the pathological development of non-viral liver diseases. Therefore, ferroptosis may be an ideal target for the treatment of non-viral liver diseases. In this review article, we will elaborate the molecular mechanism and regulatory mechanism of ferroptosis, explore the key role of ferroptosis in the Alcohol-related liver disease process, and summarize the existing targeted ferroptosis drugs and their feasibility for the treatment of Alcohol-related liver disease.

Acute liver injury induced by carbon tetrachloride reversal by Gandankang aqueous extracts through nuclear factor erythroid 2-related factor 2 signaling pathway

The aims of this study were to evaluated the effect and underlying mechanism of Gandankang (GDK) aqueous extract in alleviating the acute liver injury induced by carbon tetrachloride (CCl₄) in vivo and in vitro. Mice were divided into 5 groups (n = 8) for acute (Groups: control, 0.3 % CCl₄, BD (Bifendate), 1.17, 2.34 and 4.68 mg/kg GDK) liver injury study. 10 µL/g CCl₄ with corn oil were injected interperitoneally (i.p) expect the control group. HepG2 cells were used in vitro study. The results showed GDK can effectively inhibit liver damage and restore the structure and function of the liver. In mechanism, GDK inhibited CCl₄-induced liver fibrosis and blocked the NF-κB pathway to effectively inhibit the hepatic inflammatory response; and inhibited CCl₄-induced oxidative stress by upregulating the Keap1/Nrf2 pathway-related proteins and promoting the synthesis of several antioxidants. Additionally, it inhibited ferroptosis in the liver by regulating the expression of ACSl4 and GPX4. GDK reduced lipid peroxide generation in vitro by downregulating the production of reactive oxygen species and Fe²⁺ aggregation, thereby inhibiting ferroptosis and alleviating CCl₄-induced hepatocyte injury. In conclusion, we describe the potential complex mechanism underlying the effect of GDK against acute liver injury.

Diagnostic value of T2 relaxation time for hepatic iron grading in rat model of fatty and fibrotic liver

The objective of this study was to assess the quantitative diagnostic value of T2 relaxation time for determining liver iron grades in the presence of fat and fibrosis. Sixty Sprague-Dawley (SD) male rats were randomly divided into control (10 rats) and model (50 rats) groups. The model group of coexisting iron, steatosis, and liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl4) dissolved in edible vegetable oil (40% v/v). The control group received an intraperitoneal injection of 0.9% saline. All rats underwent multi-echo gradient and spin echo (M-GRASE) magnetic resonance imaging, and the T2 relaxation time of the liver was measured. The rats were killed immediately after imaging, and liver specimens were extracted for histological evaluation of steatosis, iron, and fibrosis. The relationship and differences between T2 relaxation time and liver fibrosis stage, as well as the pathological grade of hepatic steatosis, were assessed by Spearman's rank correlation coefficient, non-parametric Mann-Whitney test, and the Kruskal-Wallis test. The area under the receiver operating characteristic curve and interaction analysis were used to quantify the diagnostic performance of T2 relaxation time for detecting different degrees of liver iron grades. Six normal control rats and 34 model rats were included in this study. Fibrosis stages were F0 (n = 6), F1 (n = 6), F2 (n = 8), F3 (n = 10), and F4 (n = 10). Steatosis grades were S0 (n = 5), S1 (n = 8), S2 (n = 12), and S3 (n = 15). Hepatocyte or Kupffer cell iron grades were 0 (n = 7), 1 (n = 9), 2 (n = 12), 3 (n = 10), and 4 (n = 2). The liver fibrosis stages were positively correlated with the iron grades (P < 0.01), and the iron grades and fibrosis stages were negatively correlated with the T2 relaxation time (P < 0.01). The T2 relaxation times exhibited strongly significant differences among rats with different histologically determined iron grades (P < 0.01). Pairwise comparisons between each grade of liver iron indicated significant differences between all iron grades, except between grades 0 and 1, and between grades 1 and 2 (P > 0.05). The T2 relaxation time of the liver had an area under the receiving operating characteristic curve (AUC) of 0.965 (95% CI 0.908-0.100, P < 0.001) for distinguishing rats with a pathological grade of hepatic iron (grade ≥ 1) from those without, an AUC of 0.871 (95% CI 0.757-0.985, P < 0.001) for distinguishing rats with no iron overload (grade ≤ 1) from rats with moderate or severe iron overload (grade ≥ 2), and an AUC of 0.939 (95% CI 0.865-1.000, P < 0.001) for distinguishing rats with no to moderate iron overload (grade ≤ 2) from rats with severe iron overload (grade 3). The interaction of different pathological grades of iron, steatosis, and fibrosis has a negligible influence on the T2 relaxation time (P > 0.05). In conclusion, T2 relaxation time can assess histologically determined liver iron grades, regardless of coexisting liver steatosis or fibrosis; therefore, it is suitable for distinguishing between the presence and absence of iron deposition and it is more accurate for higher iron grading.

Emerging Roles of the Iron Chelators in Inflammation

Iron is a crucial element for mammalian cells, considering its intervention in several physiologic processes. Its homeostasis is finely regulated, and its alteration could be responsible for the onset of several disorders. Iron is closely related to inflammation; indeed, during inflammation high levels of interleukin-6 cause an increased production of hepcidin which induces a degradation of ferroportin. Ferroportin degradation leads to decreased iron efflux that culminates in elevated intracellular iron concentration and consequently iron toxicity in cells and tissues. Therefore, iron chelation could be considered a novel and useful therapeutic strategy in order to counteract the inflammation in several autoimmune and inflammatory diseases. Several iron chelators are already known to have anti-inflammatory effects, among them deferiprone, deferoxamine, deferasirox, and Dp44mT are noteworthy. Recently, eltrombopag has been reported to have an important role in reducing inflammation, acting both directly by chelating iron, and indirectly by modulating iron efflux. This review offers an overview of the possible novel biological effects of the iron chelators in inflammation, suggesting them as novel anti-inflammatory molecules.

Protective role of Siberian onions against toxin-induced liver dysfunction: an insight into health-promoting effects

Siberian onions (SOs) are delicious wild vegetables. Their taste is most unique, not only like scallions but also like leeks or garlic. They also have a traditional medicinal value for anti-inflammation, anti-oxidation, and anti-pyretic analgesia, particularly facilitating hepatoprotective effects. The current study investigates the potential mechanism of SOs against toxin-induced liver dysfunction. BALB/c mice were administrated with SO or silymarin by oral gavage for one week, followed by injecting carbon tetrachloride (CCl₄) to induce hepatic fibrosis. The effect of SO against hepatic fibrosis was evaluated by examining the liver tissue for serum transaminase, oxidative stress, extracellular matrix, histological alterations, cytokine levels, and apoptosis. In vitro, HSC-T6 cells were cultured with the supernatant from Raw 264.7 cells stimulated with lipopolysaccharides, followed by SO extracts or Niclosamide (Signal Transducer and Activator of Transcription 3 (STAT3) inhibitor) at indicated time periods and doses. SO decreased serum transaminase levels and oxidative stress, and regulated the balance of ECM in CCl₄-induced mice, including α-SMA, collagen-I and TIMP-1. SO reduced the release of inflammatory factors and regulated apoptosis-associated proteins, which is related to the inhibition of STAT3 phosphorylation. Moreover, SO reduced the positive expressions of α-SMA and NLRP3 by inhibiting STAT3 phosphorylation in activated HSCs. SO could show health-promoting effects for liver dysfunction by alleviating hepatic fibrogenesis, apoptosis and inflammation in the development of hepatic fibrosis potential depending on the STAT3 signaling pathway.

Fibrosis in the central nervous system: from the meninges to the vasculature

Formation of a collagenous connective tissue scar after penetrating injuries to the brain or spinal cord has been described and investigated for well over 100 years. However, it was studied almost exclusively in the context of penetrating injuries that resulted in infiltration of meningeal fibroblasts, which raised doubts about translational applicability to most CNS injuries where the meninges remain intact. Recent studies demonstrating the perivascular niche as a source of fibroblasts have debunked the traditional view that a fibrotic scar only forms after penetrating lesions that tear the meninges. These studies have led to a renewed interest in CNS fibrosis not only in the context of axon regeneration after spinal cord injury, but also across a spectrum of CNS disorders. Arising with this renewed interest is some discrepancy about which perivascular cell gives rise to the fibrotic scar, but additional studies are beginning to provide some clarity. Although mechanistic studies on CNS fibrosis are still lacking, the similarities to fibrosis of other organs should provide important insight into how CNS fibrosis can be therapeutically targeted to promote functional recovery.

Inhibition of Oxidative Stress and ALOX12 and NF-κB Pathways Contribute to the Protective Effect of Baicalein on Carbon Tetrachloride-Induced Acute Liver Injury

This study investigates the protective effect of baicalein on carbon tetrachloride (CCl₄)-induced acute liver injury and the underlying molecular mechanisms. Mice were orally administrated baicalein at 25 and 100 mg/kg/day for 7 consecutive days or ferrostatin-1 (Fer-1) at 10 mg/kg was i.p. injected in mice at 2 and 24 h prior to CCl₄ injection or the vehicle. Our results showed that baicalein or Fer-1 supplementation significantly attenuated CCl₄ exposure-induced elevations of serum alanine aminotransferase and aspartate aminotransferase, and malondialdehyde levels in the liver tissues and unregulated glutathione levels. Baicalein treatment inhibited the nuclear factor kappa-B (NF-κB) pathway, activated the erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway in liver tissues, and markedly improved CCl₄-induced apoptosis, inflammation and ferroptosis in liver tissues exposed with CCl₄. In vitro, baicalein treatment improved CCl₄ -induced decreases of cell viabilities and knockdown of Nrf2 and arachidonate 12-lipoxygenase (ALOX12) genes partly abolished the protective effect of baicalein on CCl₄ -induced cytotoxicity in HepG2 cells. In conclusion, our results reveal that baicalein supplementation ameliorates CCl₄-induced acute liver injury in mice by upregulating the antioxidant defense pathways and downregulating oxidative stress, apoptosis, inflammation and ferroptosis, which involved the activation of Nrf2 pathway and the inhibition of ALOX12 and NF-κB pathways.

Hepatoprotective effect of bone marrow-derived mesenchymal stromal cells in CCl4-induced liver cirrhosis

Bone marrow mesenchymal stromal cells (BM-MSCs) are multipotent stem cells which are ideal candidates for use in regenerative medicine. The objectives of this study were to evaluate the hepatoprotective effect of BM-MSC and its combination treatment with silymarin in carbon tetrachloride (CCl₄)-induced liver cirrhosis animal model and to investigate whether tail vein or portal vein infusion was the ideal route for BM-MSC transplantation. 36 female Wistar rats were randomly divided into six groups (n = 6): Group 1 (normal control), Group 2 (received only CCl₄, disease model), Group 3 (CCl₄ + BM-MSCs through tail vein), Group 4 (CCl₄ + BM-MSCs through portal vein), Group 5 (CCl₄ + silymarin), Group 6 (CCl₄ + BM-MSCs + silymarin). On the 21st day after treatment, blood samples were collected for biochemical estimations. After the experiment, the rats were sacrificed. Liver was dissected out and processed for histopathology and scanning electron microscopy studies. Liver enzyme and marker analysis, histopathological studies indicated that the combination of BM-MSCs and silymarin was effective in treating liver cirrhosis. Transplanted BM-MSCs in combination with silymarin ameliorated the liver tissue damage through their immunoregulatory activities. Among the two routes, the intravenous administration of cells through the tail vein was found to be more effective and safe.

Protective effects of deferoxamine on lead-induced cardiotoxicity in rats

Because of the numerous industrial applications of lead (Pb), Pb poisoning is an important public health threat in the world particularly in developing and industrialized countries. Oxidative stress is one of the important mechanisms of Pb-mediated toxicity. Deferoxamine (DFO) is an iron chelating agent that has recently shown antioxidant and antiapoptotic effects. This study investigated the protective capacity of DFO against Pb-induced cardiotoxicity in rats. We used five groups in this study: control, DFO (300 mg/kg), Pb (50 mg/kg), DFO (150 mg/kg) + Pb, DFO (300 mg/kg) + Pb. DFO was administered intraperitoneally 30 min before intraperitoneal injection of Pb for 5 days. After drug treatment, the levels of lactate dehydrogenase (LDH), lipid peroxidation (LPO), glutathione (GSH), and antioxidant enzymes were measured in serum and heart samples. The results showed that pretreatment with DFO reduced Pb-induced oxidative stress markers in serum and cardiac tissues. We found that LDH and LPO levels were significantly increased in Pb-treated rats and decreased with DFO pre-administration. Furthermore, the decreased activities of total antioxidant capacity, and GSH were observed after Pb treatment. However, DFO administration effectively prevented the Pb-induced alterations of these antioxidant enzymes activities. In conclusion, the results presented here indicate that DFO has protective effects in Pb-induced cardiotoxicity in rats, probably due to its antioxidant action and inhibition of oxidative stress.

COVID-19 as part of the hyperferritinemic syndromes: the role of iron depletion therapy

SARS-CoV-2 infection is characterized by a protean clinical picture that can range from asymptomatic patients to life-threatening conditions. Severe COVID-19 patients often display a severe pulmonary involvement and develop neutrophilia, lymphopenia, and strikingly elevated levels of IL-6. There is an over-exuberant cytokine release with hyperferritinemia leading to the idea that COVID-19 is part of the hyperferritinemic syndrome spectrum. Indeed, very high levels of ferritin can occur in other diseases including hemophagocytic lymphohistiocytosis, macrophage activation syndrome, adult-onset Still's disease, catastrophic antiphospholipid syndrome and septic shock. Numerous studies have demonstrated the immunomodulatory effects of ferritin and its association with mortality and sustained inflammatory process. High levels of free iron are harmful in tissues, especially through the redox damage that can lead to fibrosis. Iron chelation represents a pillar in the treatment of iron overload. In addition, it was proven to have an anti-viral and anti-fibrotic activity. Herein, we analyse the pathogenic role of ferritin and iron during SARS-CoV-2 infection and propose iron depletion therapy as a novel therapeutic approach in the COVID-19 pandemic.

Collagenase loaded chitosan nanoparticles for digestion of the collagenous scar in liver fibrosis: The effect of chitosan intrinsic collagen binding on the success of targeting

A variety of hepatic insults result in the accumulation of collagen-rich new extracellular matrix in the liver, ultimately culminating in liver fibrosis and cirrhosis. For such reasons, approaches looking into digestion of the collagen-rich extracellular matrix present an interesting therapeutic approach for cases of chronic liver disease, where the fibrotic scar is well established. Portal collagenase administration has recently led to the successful reversion of cirrhosis in an experimental rabbit model. Notwithstanding, the question of how such a sensitive therapeutic macromolecule could be administered in a less invasive manner, and in a way that preserves its functionality and avoids digestion of other non-hepatic vital collagen presents itself. Chitosan is a biodegradable polymer that has been reported to interact and bind to collagen. Chitosan nanoparticles (CS NPs) have also been reported to encapsulate therapeutic proteins, maintaining their functional form and protecting them from in-vivo degradation. For such reasons, CS NPs were loaded with collagenase and evaluated in-vitro and in-vivo for their ability to target and digest collagen. CS NPs were able to encapsulate collagenase (≈ 60% encapsulation efficiency) and release its content in active form. To determine whether chitosan's collagen interaction would enable NP collagen binding or whether the modification with collagen binding peptides (CBPs) is necessary, CS NPs were modified with the CBP; CCQDSETRTFY. Since the density of targeting ligand and the length of tether play a significant role in the success of active targeting, the surface of NPs was modified with different densities of the CBP either directly or using a polyethylene glycol (PEG) spacer. PEGylated NPs showed higher levels of CBP tagging; high, intermediate and low density of CBPs corresponded to 585.8 ± 33, 252.9 ± 25.3 and 56.5 ± 8.8 µg/mL for PEGylated NPs and 425.56 ± 12.67, 107.91 ± 10.3 and 49.86 ± 3.2 µg/mL for unPEGylated NPs, respectively. In-vitro collagen binding experiments showed that unmodified CS NPs were able to bind collagen and that modification with CBPs either directly or via PEG did not enhance collagen binding. In-vivo experiments demonstrated that unmodified CS NPs were able to reverse fibrosis with a survival rate of 100% at the end of the study, indicating the ability of CS NPs to deliver functional collagenase to the fibrotic liver and making the use of CBPs unnecessary.

Deferoxamine: An Angiogenic and Antioxidant Molecule for Tissue Regeneration

Deferoxamine (DFO) has been in use for half a century as a Food and Drug Administration-approved iron chelator, but recent studies indicate a variety of properties that could expand this drug's application into the fields of tissue and regenerative engineering. DFO has been implicated as an angiogenic agent in studies on ischemia, wound healing, and bone regeneration because of its ability to upregulate hypoxia-inducible factor-1 alpha (HIF-1α) and other key downstream angiogenic factors. DFO has also demonstrated antioxidant capabilities unrelated to its iron-chelating properties, making it a potential modulator of the oxidative stress involved in the inflammation response. Together, these properties make DFO a potential bioactive molecule to promote wound healing and enhance tissue integration of biomaterials in vivo. Impact Statement Deferoxamine (DFO) is approved by the Food and Drug Administration as an iron chelator and is been used to treat iron overload. Recent studies indicate that DFO may have important applications in the growing field of tissue regeneration because of its unique properties of downregulating inflammation while promoting vascularization, thereby enhancing wound healing in vivo.

Iron chelation by deferasirox confers protection against concanavalin A-induced liver fibrosis: A mechanistic approach

Hepatic iron overload is one of the causative factors for chronic liver injury and fibrosis. The present study aimed to investigate the potential antifibrotic effect of the iron chelator; deferasirox (DFX) in experimentally-induced liver fibrosis in rats. Male Sprague-Dawley rats were administered concanavalin A (Con A) and/or DFX for 6 consecutive weeks. Con A injection induced significant hepatotoxicity as was evident by the elevated transaminases activity, and decreased albumin level. Also, it disturbed the iron homeostasis through increasing C/EBP homologous protein (CHOP), decreasing phosphorylated cAMP responsive element binding protein(P-CREB) and hepcidin levels leading to significant serum and hepatic iron overload. In addition, it induced an imbalance in the oxidative status of the liver via upregulating NADPH oxidase 4 (NOX4), together with a marked decrease in anti-oxidant enzymes' activities. As a consequence, upregulation of nuclear factor-kappa b (NF-κB) and the downstream inflammatory mediators was observed. Those events all together precipitated in initiation of liver fibrosis as confirmed by the elevation of alpha-smooth muscle actin (α-SMA) and liver collagen content. Co-treatment with DFX protected against experimentally-induced liver fibrosis in rats via its iron chelating, anti-oxidant, and anti-inflammatory properties. These findings imply that DFX can attenuate the progression of liver fibrosis.

Mechanistic basis for impaired ferroptosis in cells expressing the African-centric S47 variant of p53

A population-restricted single-nucleotide coding region polymorphism (SNP) at codon 47 exists in the human TP53 gene (P47S, hereafter P47 and S47). In studies aimed at identifying functional differences between these variants, we found that the African-specific S47 variant associates with an impaired response to agents that induce the oxidative stress-dependent, nonapoptotic cell death process of ferroptosis. This phenotype is manifested as a greater resistance to glutamate-induced cytotoxicity in cultured cells as well as increased carbon tetrachloride-mediated liver damage in a mouse model. The differential ferroptotic responses associate with intracellular antioxidant differences between P47 and S47 cells, including elevated abundance of the low molecular weight thiols coenzyme A (CoA) and glutathione in S47 cells. Importantly, the disparate ferroptosis phenotypes related to the P47S polymorphism are reversible. Exogenous administration of CoA provides protection against ferroptosis in cultured mouse and human cells, as well as in a mouse model. The combined data support a positive role for p53 in ferroptosis and identify CoA as a regulator of this cell death process. Together, these findings provide mechanistic insight linking redox regulation of p53 to small molecule antioxidants and stress signaling pathways. They also identify potential therapeutic approaches to redox-related pathologies.

Effects of iron chelating agent on Schistosoma mansoni infected murine model

Schistosomiasis is one of the major health problems in many tropical and developing countries. Infection takes place once cerceriae penetrate human skin, then it changed into schistosomules. The schistosomules takes iron in the form of heme from host's haemoglobin, ferritin and transferrin. Iron is a vital element not only for growth and sexual maturity of schistosomules to adults but also for oogenesis. Since the trapped eggs are the pathological causative agent for most of pathogenesis and complications, the current work was designed to study the effects of early deprivation of schistosomules from iron in the host (in vivo) by chelating it with deferoxamine (DFO). The iron chelation has effects on growth, maturity and egg deposition, as well as it has ameliorative effects on liver pathology such as hepatic fibrosis. Mice were classified into four groups, normal control, DFO treated only, Schistosoma mansoni (S. mansoni) infected DFO untreated and S. mansoni infected DFO treated. The infected DFO treated mice showed significant reduction in fecal egg excretion with increased percentage of dead eggs and this was accompanied with a significant reduction of both total worm burden and hepatic egg load and increased dead egg percentage compared to the infected DFO untreated group. There was also a significant reduction in both serum and hepatic tissue ferritin concentrations in the infected DFO treated mice in comparison to the infected DFO untreated group. Additionally, a significant decrease in number and size of granulomas with subsequent improvement of liver fibrosis was recorded in the infected DFO treated group. This immunopathology was also associated with significant up regulation of Interlukine12 (IL12), Interferon gamma (IFN γ) and significant down regulation in interleukin4 (IL4), interleukin10 (IL10) in both serum and hepatic tissue in the infected DFO treated compared to other groups. Entirely, DFO succeeded in diminishing the growth, maturity and fecundity of S. mansoni with a subsequent improvement of hepatic pathology. As a result of the above findings, it can be concluded that DFO could be considered as a useful treatment against schistosomal infection.

Screening for the protective effect target of deproteinized extract of calf blood and its mechanisms in mice with CCl4-induced acute liver injury

Liver injury is a common pathological basis of various liver diseases, and long-term liver injury is often an important initiation factor leading to liver fibrosis and even liver cirrhosis and hepatocellular carcinoma (HCC). It has been reported that deproteinized extract of calf blood (DECB) can inhibit the replication of hepatitis B virus and confers a protective effect on the liver after traumatic liver injury. However, few studies on the regulatory factors and mechanisms of DECB have been reported. In this current study, an acute mouse liver injury model was established with carbon tetrachloride (CCl₄). The differentially expressed genes and related cell signal transduction pathways were screened using mRNA expression microarray. STEM software V1.3.6 was used for clustering gene functions, and the DAVID and KEGG databases were applied for the analysis. A total of 1355 differentially expressed genes were selected, among which nine were validated by RT-qPCR. The results showed that the Fas, IL1b, Pik3r1, Pik3r5, Traf2, Traf2, Csf2rb2, Map3k14, Pik3cd and Ppp3cc genes were involved in the regulation of DECB in an acute mouse liver injury model. Targets of the protective effects of DECB and its related mechanisms were found in mice with acute liver injury induced by carbon tetrachloride, which may provide an important theoretical basis for further DECB research.