Hepcidin Expression Research Articles

Effect of dietary protein on serum hepcidin and iron in adults with obesity and insulin resistance: A randomized single blind clinical trial.

Background and AimsBoth obesity and iron deficiency are public health problems. The association between the two problems could be explained by chronic low-grade inflammation in obesity, which could stimulate hepcidin expression and modify iron concentration that the consumption of high-protein diets could prevent. Thus, this study aimed to compare the effects of high-protein diets with a predominance of animal or vegetable protein on serum hepcidin and iron concentrations in adults with obesity. Methods and ResultsThis randomized clinical trial involved adults with obesity and insulin resistance, who were assigned to either a high animal protein (AP) group or a high vegetable protein (VP) group for a one-month intervention. Both groups followed a calorie-restricted diet, reducing energy intake by 750 kcal/day. Baseline and final measurements included serum concentrations of hepcidin and iron, biochemical parameters, anthropometric data, and body composition. A total of 33 participants (63% female) were included in the study. Significant weight loss was observed in both groups after the intervention. Adjusted for weight loss percentage, the AP group showed a significant increase in hepcidin concentration (from 22.3 ± 14.7 to 27.5 ± 19.5 ng/mL) compared to the VP group (from 17.9 ± 15.1 to 17.2 ± 10.1 ng/mL) (p < 0.01), with no changes in serum iron concentration. Additionally, the VP diet significantly reduced serum adiponectin (p = 0.04) and C-reactive protein (p = 0.03) levels. ConclusionsIn adults with obesity following the AP diet for one month, hepcidin levels increased without affecting serum iron concentrations. Trial registrationNCT03627104

The hepcidin-ferroportin axis modulates liver endothelial cell BMP expression to influence iron homeostasis in mice

The liver hormone hepcidin regulates systemic iron homeostasis to provide enough iron for vital processes while limiting toxicity. Hepcidin acts by degrading its receptor ferroportin (encoded by Slc40a1) to decrease iron export to plasma. Iron controls hepcidin production in part by inducing liver endothelial cells (LECs) to produce bone morphogenetic proteins (BMPs), which activate hepcidin transcription in hepatocytes. Here, we used in vitro and in vivo models to investigate whether ferroportin contributes to LEC intracellular iron content to modulate BMP expression and thereby hepcidin. Quantitative proteomics of LECs from mice fed different iron diets demonstrated an inverse relationship between dietary iron and endothelial ferroportin expression. Slc40a1 knockdown primary mouse LECs and endothelial Slc40a1 knockout mice exhibited increased LEC iron and BMP ligand expression. Endothelial Slc40a1 knockout mice also exhibited altered systemic iron homeostasis with decreased serum and total liver iron but preserved erythropoiesis. Although endothelial Slc40a1 knockout mice had similar hepcidin expression as control mice, hepcidin levels were inappropriately high relative to iron levels. Moreover, when iron levels were equalized with iron treatment, hepcidin levels were higher in endothelial Slc40a1 knockout mice than controls. Finally, LEC ferroportin levels were inversely correlated with hepcidin levels in multiple mouse models, and treatment of hepcidin-deficient mice with mini-hepcidin decreased LEC ferroportin expression. Overall, these data show that LEC ferroportin modulates LEC iron and consequently BMP expression to influence hepcidin production. Furthermore, LEC ferroportin expression is regulated by hepcidin, demonstrating bidirectional communication between LECs and hepatocytes to orchestrate systemic iron homeostasis.

Role of Ferroptosis in ALD: Focusing on Hepcidin and Besides Hepcidin.

Ascending incidence and poor outcomes make Alcoholic Liver Disease (ALD) a considerable public health concern. This review concluded the iron metabolism under physiology conditions and alcohol disturbance (leading to ferroptosis in ALD) and summarized the novel treatment, diagnosis, and prognosis of ferroptosis for ALD. ALD is characterized by alcohol-induced chronic metabolism disorder, peroxidation damage, and dysfunction of the anti-oxidant system. Current animal experiments and clinical studies identified ferroptosis as a new form of regulated cell death involved in ALD. One strong evidence is that the key iron regulatory hormone, hepcidin, is downgraded in ALD through NF-κB/IL-6/STAT3, BMP/SMAD, and Jak/STAT3 pathways, which would impair iron hemostasis and induce ferroptosis in ALD. Also, imbalance metabolism and other pathological responses in ALD induce and regulate ferroptosis, which proves ferroptosis participates in the pathophysiology of ALD via oxidative stress, steatosis, and fibrosis. Inhibition of ferroptosis via regulating hepcidin expression and metabolism impairment may provide new therapies for ALD.

8283 Diabetes Mellitus in Patients with Hemochromatosis- A Diagnostic and Therapeutic Challenge

Abstract Disclosure: U. Rafat: None. M. Siddiqui: None. J.L. Gilden: Other; Self; Novartis Pharmaceuticals. A. Moid: Other; Self; Novartis Pharmaceuticals. Background: Primary Hemochromatosis is a genetic condition most commonly due to two sets of mutations in the Human homeostatic iron regular Protein (HFE) gene. HFE modulates the expression of hepcidin, which regulates intestinal iron absorption, plasma iron concentration and distribution of iron in tissues. Hemochromatosis patients are at high risk for developing diabetes mellitus (DM) due to iron overload in the pancreas with damage to Beta cells and impaired insulin secretory capacity. Hemochromatosis is often called Bronze Diabetes due to brown discoloration of the skin from accumulation of iron, and is characterized by hepatic fibrosis, fatigue, arthralgias, cirrhosis, DM, arthropathy, pigmentation and cardiomyopathy. Case: We present a Caucasian male with homozygous hereditary hemochromatosis, diagnosed by liver biopsy at age 40 due to transaminitis and Ferritin level of 1500 ng/mL and Genetic testing- 2 copies of HFE gene pathogenic variant (C282Y). He was later diagnosed with DM age 51, started on Metformin and referred to Endocrine clinic with abdominal bloating, and polyarticular arthralgias. Physical exam=Vital Signs normal (WT. 231lbs, BMI 34), with splenomegaly, but normal musculoskeletal exam and skin without bronze discoloration. Both parents had T2DM. Lab- Hb a1c 8.7% (0.0-5.6), Iron saturation 71% (10-50), Ferritin 66.3 ng/mL (26-388), C-Peptide 3.30 ng/ml (0.81-3.85), with glucose level of 119 mg/dL, and negative IA-2 &amp;lt;5.4 U/mL, negative Islet cell antibody, GAD 65 &amp;lt;5 IU/mL (nl &amp;lt;5), Insulin Autoantibody &amp;lt;0.4 U/mL (nl &amp;lt;0.4), and Zinc Transporter 8 antibodies &amp;lt;10 U/mL (nl &amp;lt;15). Liver tests- AST 39 U/L(10-37), ALT 77 U/L (10-65), ALP 89 U/L (45-117), total bilirubin 1.1 mg/dL(0.2-1.2). Hormonal evaluation included TSH 1.2 uIU/mL (0.55-4.78), ACTH 19 pg/mL (0-47), AM Cortisol 16.28 ug/d (5.30-22.50) IGF1 158 ng/mL (50-317) FSH 9.6 mIU/mL(l.40-18.10), LH 5.09 mIU/mL (1.50-9.30), Prolactin 7.40 ng/mL(2.10-17.70), total testosterone 374 ng/dL(250-1100), free testosterone 66.2 pg/mL (35.0-155.0). Echocardiogram-left ventricular hypertrophy and thick right ventricular wall with concerns for iron overload. Hba1c improved to 6.6% on Metformin. Fructosamine 351umol/L (151-300). In the absence of advanced cardiac, hepatic and other organ involvement, and presence of elevated C-peptide and high BMI, this patient is being managed as T2DM, with low threshold to initiate insulin therapy considering possibility of concomitant Bronze DM. Conclusion: It is important to determine type of DM, so appropriate management options can be devised. While insulin is recommended for management in Bronze Diabetes, insulin sensitizers, such as metformin and/or GLP 1 agonists can be used in type 2 DM. One must also consider therapy based upon the risk of cancer and acute pancreatitis in the setting of pancreatic iron overload, when considering antihyperglycemic therapies. Presentation: 6/2/2024

Hepcidin expression is associated with increased γ-secretase–mediated cleavage of neogenin in the liver

Neogenin (NEO1) is a ubiquitously expressed transmembrane protein. It interacts with hemojuvelin (HJV). Both NEO1 and HJV play pivotal roles in iron homeostasis by inducing hepcidin expression in the liver. Our previous studies demonstrated that this process depends on Neo1-Hjv interaction and showed that the Hjv-mediated hepcidin expression is correlated with the accumulation of a truncated and membrane-associated form of Neo1. In this study, we tested whether hepcidin expression is induced by increased γ-secretase-mediated cleavage of Neo1 in the liver. We found that Neo1 underwent cleavage of its ectodomain and intracellular domains by α- and γ-secretases, respectively, in hepatoma cells. Our in vitro studies suggest that γ-secretase is responsible for cleavage and release of the cytoplasmic domain of Neo1 in the Hjv-Neo1 complex. This process was enhanced by inhibition of α-secretase proteolysis and by co-expression with the Neo1-binding partner, Alk3. Further in vivo studies indicated that Neo1 induction of hepcidin expression required γ-secretase cleavage. Interestingly, neither predicted form of γ-secretase-cleaved Neo1 was able to induce hepcidin when separately expressed in hepatocyte-specific Neo1 knockout mice. These results imply that the function of Neo1 requires a de novo γ-secretase proteolysis. Additional studies revealed that in addition to the Hjv-binding domains, the function of Neo1 also required its C-terminal intracellular domain and the N-terminal immunoglobulin-like domains that are involved in Neo1 binding to Alk3. Together, our data support the idea that Neo1 induction of hepcidin is initiated as a full-length form and requires a de novo γ-secretase cleavage of Neo1's cytoplasmic domain.

Hepatocyte activation and liver injury following cerebral ischemia promote HMGB1-mediated hepcidin upregulation in hepatocytes and regulation of systemic iron levels

We previously reported that high mobility group box 1 (HMGB1), a danger-associated molecular pattern (DAMP), increases intracellular iron levels in the postischemic brain by upregulating hepcidin, a key regulator of iron homeostasis, triggering ferroptosis. Since hepatocytes are the primary cells that produce hepcidin and control systemic iron levels, we investigated whether cerebral ischemia induces hepcidin upregulation in hepatocytes. Following middle cerebral artery occlusion (MCAO) in a rodent model, significant liver injury was observed. This injury was evidenced by significantly elevated Eckhoff’s scores and increased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Additionally, total iron levels were significantly elevated in the liver, with intracellular iron accumulation detected in hepatocytes. Hepcidin expression in the liver, which is primarily localized in hepatocytes, increased significantly starting at 3 h after MCAO and continued to increase rapidly, reaching a peak at 24 h. Interestingly, HMGB1 levels in the liver were also significantly elevated after MCAO, with the disulfide form of HMGB1 being the major subtype. In vitro experiments using AML12 hepatocytes showed that recombinant disulfide HMGB1 significantly upregulated hepcidin expression in a Toll-like receptor 4 (TLR4)- and RAGE-dependent manner. Furthermore, treatment with a ROS scavenger and a peptide HMGB1 antagonist revealed that both ROS generation and HMGB1 induction contributed to hepatocyte activation and liver damage following MCAO–reperfusion. In conclusion, this study revealed that cerebral ischemia triggers hepatocyte activation and liver injury. HMGB1 potently induces hepcidin not only in the brain but also in the liver, thereby influencing systemic iron homeostasis following ischemic stroke.

Serum Iron Overload Triggers the SMAD Pathway and Induces Hepcidin Expression in Hepatocytes through SMURF1.

Serum Iron Overload Triggers the SMAD Pathway and Induces Hepcidin Expression in Hepatocytes through SMURF1.

Normalization of Fetal Cerebral and Hepatic Iron by Parental Iron Therapy to Pregnant Rats with Systemic Iron Deficiency without Anemia.

Iron (Fe) is a co-factor for enzymes of the developing brain necessitating sufficient supply. We investigated the effects of administering ferric derisomaltose/Fe isomaltoside (FDI) subcutaneously to Fe-deficient (ID) pregnant rats on cerebral and hepatic concentrations of essential metals and the expression of iron-relevant genes. Pregnant rats subjected to ID were injected with FDI on the day of mating (E0), 14 days into pregnancy (E14), or the day of birth (postnatal (P0)). The efficacy was evaluated by determination of cerebral and hepatic Fe, copper (Cu), and zinc (Zn) and gene expression of ferroportin, hepcidin, and ferritin H + L in pups on P0 and as adults on P70. Females fed an ID diet (5.2 mg/kg Fe) had offspring with significantly lower cerebral and hepatic Fe compared to female controls fed a standard diet (158 mg/kg Fe). Cerebral Cu increased irrespective of supplying a standard diet or administering FDI combined with the standard diet. Hepatic hepcidin mRNA was significantly lower following ID. Cerebral hepcidin mRNA was hardly detectable irrespective of iron status. In conclusion, administering FDI subcutaneously to ID pregnant rats on E0 normalizes fetal cerebral and hepatic Fe. When applied at later gestational ages, supplementation with additional Fe to the offspring is needed to normalize cerebral and hepatic Fe.

GBT1118, a Voxelotor Analog, Ameliorates Hepatopathy in Sickle Cell Disease.

Background and Objectives: In sickle cell disease (SCD), hepatopathy is a cumulative consequence of ischemia/reperfusion (I/R) injury from a vaso-occlusive crisis, tissue inflammation, and iron overload due to blood transfusion. Hepatopathy is a major contributing factor of shortened life span in SCD patients. We hypothesized that the voxelotor, a hemoglobin allosteric modifier, ameliorates sickle hepatopathy. Materials and Methods: Townes SCD mice and their controls were treated with either chow containing GBT1118, a voxelotor analog, or normal chow. We evaluated inflammation, fibrosis, apoptosis and ferroptosis in their livers using qPCR, ELISA, histology, and immunohistochemistry. Results: GBT1118 treatment resulted in reduced hemolysis, iron overload and inflammation in the liver of SCD mice. There were significant reductions in the liver enzyme levels and bile acids. Furthermore, GBT1118-treated mice exhibited reduced apoptosis, necrosis, and fibrosis. Increased ferroptosis as evident from elevated 4-hydroxynonenal (4-HNE) staining, malondialdehyde (MDA) levels, and expression of Ptgs2 and Slc7a11 mRNAs, were also significantly reduced after GBT1118 treatment. To explain the increased ferroptosis, we evaluated iron homeostasis markers in livers. SCD mice showed decreased expression of heme oxygenase-1, ferritin, hepcidin, and ferroportin mRNA levels. GBT1118 treatment significantly increased expressions of these genes. Conclusions: Our results suggest GBT1118 treatment in SCD confers the amelioration of sickle hepatopathy by reducing inflammation, fibrosis, apoptosis, iron overload and ferroptosis.

Bile from the hemojuvelin-deficient mouse model of iron excess is enriched in iron and ferritin.

Iron is an essential nutrient but is toxic in excess. Iron deficiency is the most prevalent nutritional deficiency and typically linked to inadequate intake. Iron excess is also common and usually due to genetic defects that perturb expression of hepcidin, a hormone that inhibits dietary iron absorption. Our understanding of iron absorption far exceeds that of iron excretion, which is believed to contribute minimally to iron homeostasis. Prior to the discovery of hepcidin, multiple studies showed that excess iron undergoes biliary excretion. We recently reported that wild-type mice raised on an iron-rich diet have increased bile levels of iron and ferritin, a multi-subunit iron storage protein. Given that genetic defects leading to excessive iron absorption are much more common causes of iron excess than dietary loading, we set out to determine if an inherited form of iron excess known as hereditary hemochromatosis also results in bile iron loading. We employed mice deficient in hemojuvelin, a protein essential for hepcidin expression. Mutant mice developed bile iron and ferritin excess. While lysosomal exocytosis has been implicated in ferritin export into bile, knockdown of Tfeb, a regulator of lysosomal biogenesis and function, did not impact bile iron or ferritin levels. Bile proteomes differed between female and male mice for wild-type and hemojuvelin-deficient mice, suggesting sex and iron excess impact bile protein content. Overall, our findings support the notion that excess iron undergoes biliary excretion in genetically determined iron excess.

Major evidence of nutritional and metabolic management in the context of bariatric surgery: a systematic review

Introduction: Approximately $315 billion is spent annually on the medical cost of obesity in adult patients in the United States alone. According to the American Society for Metabolic and Bariatric Surgery (ASMBS), the rate of bariatric surgery (BS) increased from 158,000 in 2011 to 196,000 in 2015. This increase in invasive techniques does not eliminate unhealthy habits, therefore, lifestyle modifications, such as healthy eating and correct physical activity programs, can improve surgical results. Objective: To establish the main nutritional and metabolic management strategies in the context of bariatric surgery, to modulate and reduce the problems caused by nutrient deficit. Methods: The systematic review rules of the PRISMA Platform were followed. The search was conducted from May to June 2024 in the Web of Science, Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 135 articles were found. 42 articles were fully evaluated and 18 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 22 studies with a high risk of bias and 24 that did not meet GRADE and AMSTAR-2. Most studies presented homogeneity in their results, with X2=79.7%&gt;50%. It was concluded that the recommendations were gathered to assist in individualized clinical practice in the nutritional management of patients with obesity. In general, patients with obesity have significantly lower concentrations of serum iron, folic acid, vitamins A, B6, B12, C, 25-hydroxyvitamin D, and lipid-standardized vitamin E. Before bariatric surgery, nutritional status should be analyzed and preoperative weight loss can be attempted. Very low-calorie diets and very low-calorie ketogenic diets are prescribed in the last months before surgery. It was noted that the recommendations were gathered to assist in individualized clinical practice in the nutritional management of patients with obesity, including nutritional management. Iron status may be affected by adipose tissue inflammation and increased expression of the systemic iron regulatory protein hepcidin. The postoperative recommendation for vitamin B12 (cobalamin) should be 350-500 micrograms/1000 micrograms monthly, and for folate (folic acid) in the postoperative period should be 1000 micrograms per day.

RGM Family Involved in the Regulation of Hepcidin Expression in Anemia of Chronic Disease

The persistent production of inflammatory cytokines causes anemia of chronic disease (ACD). Playing a central role in the pathophysiology of ACD is hepcidin, a key regulator of iron metabolism. The regulation of hepcidin expression is a complex process intricately controlled by multiple pathways. These include the BMP/SMAD, the HFE–TFR2, and the IL-6/STAT3 pathway, each playing a significant role in this regulation. We detail the critical role of the repulsive guidance molecule (RGM) family, especially hemojuvelin (HJV/RGMc), in regulating hepcidin expression in ACD. HJV functions as a co-receptor for BMPs and positively regulates hepcidin expression. RGMa and RGMb may also regulate hepcidin expression and inflammatory responses. RGM family proteins play essential roles in the interplay between inflammation, iron metabolism, and the immune system, and elucidating them could lead to a better understanding of the pathophysiology of ACD and the development of new therapeutic strategies.

Visceral adiposity is associated with iron deposition and myelin loss in the brains of aged mice

Iron deposition and myelin loss are observed in the brain with aging, and iron accumulation is suggested to be involved in myelin damage. However, the exact mechanism of iron deposition with aging remains unclear. This study was aimed to determine whether expanded visceral adipose tissue contributes to iron deposition and myelin loss by inducing hepcidin in the brains of aged male mice. Compared with young adult mice, levels of hepcidin in the brain, epididymal adipose tissue, and circulation were increased in aged mice, which had expanded visceral adipose tissue with inflammation. An increase in expressions of ferritin, an indicator of intracellular iron status, was accompanied by decreased levels of proteins related to myelin sheath in the brains of aged mice. These age-related changes in the brain were improved by visceral fat removal. In addition, IL-6 level, activation of microglia/macrophages, and nuclear translocation of phosphorylated Smad1/5 (pSmad1/5) inducing hepcidin expression were reduced in the brains of aged mice after visceral fat removal, accompanied by decreases of pSmad1/5- and ferritin-positive microglia/macrophages and mature oligodendrocytes. These findings indicate that visceral adiposity contributes to hepcidin-mediated iron deposition and myelin loss with inflammation in the aged brain. Our results support the importance of preventing visceral adiposity for maintaining brain health in older individuals.

Reduced Plasma Bone Morphogenetic Protein 6 Levels in Sepsis and Septic Shock Patients.

Infectious diseases are associated with low iron levels and the induction of hepcidin, the primary protein regulating cellular iron export. Bone morphogenetic protein 6 (BMP6), a key regulator of hepcidin expression, has not yet been analyzed in the plasma of patients with systemic inflammatory response syndrome (SIRS) or sepsis. An analysis of 38 SIRS, 39 sepsis, and 78 septic shock patients revealed similar levels of BMP6 in sepsis and septic shock, which were lower compared to patients with SIRS and healthy controls. Plasma BMP6 levels did not correlate with procalcitonin and C-reactive protein levels in patients with SIRS or sepsis/septic shock. Neither bacterial nor SARS-CoV-2 infections affected plasma BMP6 levels. There was no difference in BMP6 levels between ventilated and non-ventilated patients, or between patients with and without dialysis. Vasopressor therapy did not alter BMP6 levels. Survivors had plasma BMP6 levels similar to non-survivors. Due to the high variability of plasma BMP6 levels, these analyses have limited clinical relevance. Iron, ferritin, and transferrin levels were known in at least 50% of patients but did not correlate with plasma BMP6 levels. In conclusion, this study showed normal BMP6 plasma levels in SIRS, which are reduced in patients with sepsis and septic shock. This suggests that the commonly observed increase in hepcidin levels and the decline in iron levels in SIRS, sepsis, and septic shock are not due to higher BMP6.

Erythropoietin enhances iron bioavailability in HepG2 cells by downregulating hepcidin through mTOR, C/EBPα and HIF-1α

The regulation of iron (Fe) levels is essential to maintain an adequate supply for erythropoiesis, among other processes, and to avoid possible toxicity. The liver-produced peptide hepcidin is regarded as the main regulator of Fe absorption in enterocytes and release from hepatocytes and macrophages, as it impairs Fe export through ferroportin. The glycoprotein erythropoietin (Epo) drives erythroid progenitor survival and differentiation in the bone marrow, and has been linked to the mobilization of Fe reserves necessary for hemoglobin production. Herein we show that Epo inhibits hepcidin expression directly in the HepG2 hepatic cell line, thus leading to a decrease in intracellular Fe levels. Such inhibition was dependent on the Epo receptor-associated kinase JAK2, as well as on the PI3K/AKT/mTOR pathway, which regulates nutrient homeostasis. Epo was also found to decrease binding of the C/EBP-α transcription factor to the hepcidin promoter, which could be attributed to an increased expression of its inhibitor CHOP. Epo did not only hinder the stimulating effect of C/EBP-α on hepcidin transcription, but also favored hepcidin inhibition by HIF-1α, by increasing is nuclear translocation as well as its protein levels. Moreover, in assays with the inhibitor genistein, this transcription factor was found necessary for Epo-induced hepcidin suppression. Our findings support the involvement of the PI3K/AKT/mTOR pathway in the regulation of Fe levels by Epo, and highlight the contrasting roles of the C/EBP-α and HIF-1α transcription factors as downstream effectors of the cytokine in this process.

Genetic Correlation of HBB, HFE and HAMP Genes to Endocrinal Complications in Egyptian Beta Thalassemia Major Patients.

Iron loading is regarded as the primary cause of endocrine abnormalities in thalassemia major patients. Thus, the purpose of the current research was to explore the impact of thalassemia genotypes, hepcidin antimicrobial peptide (HAMP) and hereditary hemochromatosis (HFE) gene variants, and hepcidin expression on serum ferritin and endocrinal complications in thalassemia patients. The study comprised fifty beta-thalassemia cases and fifty age- and sex-matched controls. Genotyping of the Beta-globin gene (HBB), HAMP, and exon 2 of the HFE gene was performed using Sanger sequencing. C282Y (c.845G > A) variant of the HFE gene was determined by PCR-RFLP. Hepcidin mRNA expression was assessed by qRT-PCR. Biochemical and hormonal studies were done for all patients. Hypogonadism and short stature were found in 56% and 20% of the investigated cases, respectively. Molecular studies reported a statistically higher frequency of the HAMP variant c.-582A > G in thalassemic patients than controls. Significant downregulation of hepcidin expression was found in cases compared to healthy subjects that was significantly associated with short stature. Considering the thalassemia alleles, the IVSI.1G > A (β0) allele was statistically related to hypogonadism. Our results proposed that thalassemia genotypes and downregulated hepcidin expression were the potential risk factors for endocrinopathies in our cases. We also demonstrated an increased incidence of the HAMP promoter variant c.-582A > G that might have a role in the pathogenesis of iron overload in thalassemic cases. Significant downregulation of hepcidin expression, that contributes to increased iron burden, could be used as a future therapeutic target in these patients.

The Intersection of Hepcidin and Polycystic Ovary Syndrome: A Review of Current Understanding

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder affecting up to 13% of reproductive-age women. It is characterized by a constellation of symptoms including menstrual irregularities, hyperandrogenism, and polycystic ovaries, often intertwined with metabolic disturbances such as insulin resistance and dyslipidemia. Hepcidin is a liver-produced peptide hormone that regulates iron homeostasis, with a significant role in the pathophysiology of PCOS. Hepcidin controls iron absorption and storage by binding to ferroportin, leading to its degradation and reducing iron export from enterocytes and macrophages. In PCOS patients, hepcidin dysregulation is linked to underlying hormonal and metabolic abnormalities, including insulin resistance and hyperandrogenism. Studies consistently demonstrate decreased hepcidin levels in PCOS patients, resulting in altered iron metabolism parameters, such as increased serum iron and ferritin concentrations, leading to iron overload. This iron overload can exacerbate complications like anemia. The relationship between hepcidin, anemia, and PCOS is influenced by several mechanisms. Hyperandrogenism in PCOS inhibits hepcidin synthesis, reducing iron sequestration and increasing serum iron levels, contributing to erythropoiesis and potentially mitigating anemia, while also posing a risk of iron overload. Hyperinsulinemia associated with insulin resistance further decreases hepcidin levels, enhancing dietary iron absorption and increasing serum iron levels. Despite the chronic low-grade inflammation typical in PCOS, which usually increases hepcidin levels, the inflammation may not be sufficient to override the suppressive effects of hyperandrogenism and hyperinsulinemia on hepcidin expression. Oligomenorrhea or amenorrhea in PCOS leads to reduced menstrual blood loss, contributing to iron retention and further influencing hepcidin regulation. Genetic and epigenetic factors also significantly impact hepcidin expression and iron metabolism in PCOS.

Foxo1 is an iron-responsive transcriptional factor regulating systemic iron homeostasis

AbstractThe liver plays a crucial role in maintaining systemic iron homeostasis by secreting hepcidin, which is essential for coordinating iron levels in the body. Imbalances in iron homeostasis are associated with various clinical disorders related to iron deficiency or iron overload. Despite the clinical significance, the mechanisms underlying how hepatocytes sense extracellular iron levels to regulate hepcidin synthesis and iron storage are not fully understood. In this study, we identified Foxo1, a well-known regulator of macronutrient metabolism, which translocates to the nucleus of hepatocytes in response to high-iron feeding, holo-transferrin, and bone morphogenetic protein 6 (BMP6) treatment. Furthermore, Foxo1 plays a crucial role in mediating hepcidin induction in response to both iron and BMP signals by directly interacting with evolutionally conserved Foxo binding sites within the hepcidin promoter region. These binding sites were found to colocalize with Smad-binding sites. To investigate the physiological relevance of Foxo1 in iron metabolism, we generated mice with hepatocyte-specific deletion of Foxo1. These mice exhibited reduced hepatic hepcidin expression and serum hepcidin levels, accompanied by elevated serum iron and liver nonheme iron concentrations. Moreover, high-iron diet further exacerbated these abnormalities in iron metabolism in mice lacking hepatic Foxo1. Conversely, hepatocyte-specific Foxo1 overexpression increased hepatic hepcidin expression and serum hepcidin levels, thereby ameliorating iron overload in a murine model of hereditary hemochromatosis (Hfe−/− mice). In summary, our study identifies Foxo1 as a critical regulator of hepcidin and systemic iron homeostasis. Targeting Foxo1 may offer therapeutic opportunities for managing conditions associated with aberrant iron metabolism.

Direct and macrophage stimulation mediated effects of active, inactive, and cell-free supernatant forms of Akkermansia muciniphila and Faecalibacterium duncaniae on hepcidin gene expression in HepG2 cells.

Hepcidin is a crucial regulator of iron homeostasis with protective effects on liver fibrosis. Additionally, gut microbiota can also affect liver fibrosis and iron metabolism. Although the hepatoprotective potential of Akkermansia muciniphila and Faecalibacterium duncaniae, formerly known as F. prausnitzii, has been reported, however, their effects on hepcidin expression remain unknown. We investigated the direct and macrophage stimulation-mediated effects of active, heat-inactivated, and cell-free supernatant (CFS) forms of A. muciniphila and F. duncaniae on hepcidin expression in HepG2 cells by RT-qPCR analysis. Following stimulation of phorbol-12-myristate-13-acetate (PMA) -differentiated THP-1 cells with A. muciniphila and F. duncaniae, IL-6 concentration was assessed via ELISA. Additionally, the resulting supernatant was treated with HepG2 cells to evaluate the effect of macrophage stimulation on hepcidin gene expression. The expression of genes mediating iron absorption and export was also examined in HepG2 and Caco-2 cells via RT-qPCR. All forms of F. duncaniae increased hepcidin expression while active and heat-inactivated/CFS forms of A. muciniphila upregulated and downregulated its expression, respectively. Active, heat-inactivated, and CFS forms of A. muciniphila and F. duncaniae upregulated hepcidin expression, consistent with the elevation of IL-6 released from THP-1-stimulated cells as a macrophage stimulation effect in HepG2 cells. A. muciniphila and F. duncaniae in active, inactive, and CFS forms altered the expression of hepatocyte and intestinal iron-mediated absorption /exporter genes, namely dcytb and dmt1, and fpn in HepG2 and Caco-2 cells, respectively. In conclusion, A. muciniphila and F. duncaniae affect not only directly but also through macrophage stimulation the expression of hepcidin gene in HepG2 cells. These findings underscore the potential of A. muciniphila and F. duncaniae as a potential therapeutic target for liver fibrosis by modulating hepcidin and intestinal and hepatocyte iron metabolism mediated gene expression.

Nisin-preconditioned mesenchymal stem cells combatting nosocomial Pseudomonas infections

BackgroundNosocomial infections caused by multidrug-resistant Pseudomonas aeruginosa are a considerable public health threat, requiring innovative therapeutic approaches. ObjectivesThis study explored preconditioning mesenchymal stem cells (MSCs) with the antimicrobial peptide Nisin to enhance their antibacterial properties while maintaining regenerative capacity. MethodsHuman MSCs were preconditioned with varying concentrations of Nisin (0.1–1000 IU/mL) to determine an optimal dose. MSCs preconditioned with Nisin were characterized using microscopy, flow cytometry, gene expression analysis, and functional assays. The effects of preconditioning on the viability, phenotype, differentiation capacity, antimicrobial peptide expression, and antibacterial activity of MSCs against Pseudomonas aeruginosa were tested in vitro. The therapeutic efficacy was evaluated by topically applying conditioned media from Nisin-preconditioned versus control MSCs to infected wounds in a rat model, assessing bacterial burden, healing, host response, and survival. ResultsAn optimal Nisin dose of 500 IU/mL was identified, which increased MSC antibacterial gene expression and secretome activity without compromising viability or stemness. Nisin-preconditioned MSCs showed upregulated expression of LL37 and hepcidin. Conditioned media from Nisin-preconditioned MSCs exhibited about 4-fold more inhibition of P. aeruginosa growth compared to non-preconditioned MSCs. In the wound infection model, the secretome of Nisin-preconditioned MSCs suppressed bacterial load, accelerated wound closure, modulated inflammation, and improved survival compared to standard MSC treatments. ConclusionThis study explores the effect of preconditioning MSCs with the antimicrobial peptide Nisin on enhancing their antibacterial properties while maintaining regenerative capacity. Secreted factors from Nisin-preconditioned MSCs have the potential to attenuate infections and promote healing in vivo. The approach holds translational promise for managing antibiotic-resistant infections and warrants further development. Preconditioned MSCs with Nisin may offer innovative, multifaceted therapies for combating nosocomial pathogens and promoting tissue regeneration.