Abstract
Cardiovascular disease, chronic kidney disease, and anemia are known to adversely affect each other. Inflammation is commonly involved in these diseases. Cardiorenal anemia syndrome (CRAS) is the name given to this mutually harmful condition. Dimethyl fumarate (DMF) is a Food and Drug Administration–approved antioxidant and anti-inflammatory agent. The purpose of this study was to investigate the effects of DMF on Dahl/salt-sensitive (DS) rats as a CRAS model. Six-week-old DS rats were divided into three groups: the control group, the high-salt (HS) group, and the HS+DMF group. The HS and HS+DMF groups were fed a high-salt diet (8% NaCl) from 6 weeks of age. In the HS+DMF group, DMF (90 mg/kg per day) was orally administered from 6 to 15 weeks of age. Systolic blood pressure was measured every 2 weeks. The heart and renal injuries were assessed with histopathological analysis. The heart and renal expression of mRNAs was assessed by reverse-transcription polymerase chain reaction. DMF significantly improved overall survival, which was shortened by HS in DS rats. Systolic blood pressure increased in the HS group compared with the control group, and DMF tended to suppress this change. DMF ameliorated the cardiac and renal abnormalities confirmed in the HS group by histopathological analysis. Furthermore, the changes in mRNA expressions associated with disease exacerbation in the HS group were suppressed by DMF. DMF also improved anemia. This study suggests that DMF improves overall survival in DS rats through organ-protective effects and is effective against cardiorenal anemia syndrome.
SIGNIFICANCE STATEMENT Dimethyl fumarate was found to improve overall survival in Dahl/salt-sensitive rats, associated with its ability to ameliorate anemia and induce cardioprotective and renoprotective effects through anti-inflammatory and antifibrotic effects.
Introduction
Patients with chronic kidney disease often develop cardiovascular disease and die before reaching end-stage renal disease (Jankowski et al., 2021). More severe renal impairment is associated with a higher incidence of cardiovascular events, and patients with heart failure have a higher degree of renal impairment than healthy individuals. Furthermore, it has been reported that anemia, which frequently complicates both, leads to reciprocal and progressive deterioration of the heart and kidney and is a poor prognostic factor for heart failure and chronic kidney disease (McCullough, 2021). Thus, cardiovascular disease, chronic kidney disease, and anemia adversely affect each other (Silverberg et al., 2006). This mutually detrimental condition, called cardiorenal anemia syndrome (CRAS), is a complex disease associated with adverse clinical outcomes, increased risk of hospitalization and death, and decreased quality of life (McCullough, 2021).
Currently, there are few satisfactory clinical treatments for CRAS. Clinical management of patients with CRAS consists of excreting toxins or artificially supplementing with organ-protective substances. Erythropoietin (EPO), which was administered as a therapeutic agent for renal anemia under the policy of supplementation of protective substances, was not effective in humans, although it was effective in restoring cardiac function in animal experiments (Swedberg et al., 2013). On the contrary, it has been reported that exogenous EPO enhances catecholamine, angiotensin II, and endothelin; increases blood pressure; and worsens prognosis (Parfrey et al., 2005; Agarwal, 2018). Recently, however, hypoxia-inducible factor and prolyl-hydroxylase inhibitors have been reported to improve renal anemia by promoting EPO production (Maxwell and Eckardt, 2016). However, the effects of hypoxia-inducible factor and prolyl-hydroxylase inhibitors on CRAS has not been reported. We focused on inflammation as a common feature of the three components of CRAS (Schiattarella et al., 2021).
Dimethyl fumarate (DMF) is a Food and Drug Administration–approved effective treatment of relapsing-remitting multiple sclerosis and is an antioxidant and anti-inflammatory agent (Grzegorzewska et al., 2017). Multiple pathways have been reported as the mechanisms of action of DMF. The most prominent is the Nrf2 pathway activator, which induces its potent anti-inflammatory response in part by directly targeting the nuclear factor κ B (NF-κB) signaling pathway (Grzegorzewska et al., 2017). Its mechanism of action includes immunomodulatory and cytoprotective effects. We hypothesized that anti-inflammatory DMF could ameliorate CRAS, an inflammatory condition common to cardiovascular disease (CVD), chronic kidney disease (CKD), and anemia. Therefore, we investigated whether DMF, an anti-inflammatory agent, is effective for CRAS.
Materials and Methods
Animal Experiments
For all experiments, male DS rats (DIS/EisSlc, formerly named Dahl/SS-Iwai S) were purchased from Japan SLC, Inc. (Shizuoka, Japan). Rats were housed in stainless steel cages (KN-601, Natsume Seisakusho Co., Ltd., Tokyo, Japan) with wooden bedding (White flakes, The Jackson Laboratory Japan, Inc., Tokyo, Japan) in a light-controlled room under a 12-hour light/dark cycle, were kept in the environment at a temperature of 23 ± 3°C and a humidity level of 50% ± 10%, and had free access to food and water. For urine collections, rats were housed in stainless steel rat urine collection cage (KN-646-B1, Natsume Seisakusho Co., Ltd., Tokyo, Japan) at 12 weeks of age.
Dimethyl Fumarate (>99.0% purity) was purchased from Wako Pure Chemical Industries, Ltd (Tokyo, Japan).
Five-week-old rats were fed a normal salt diet (0.3% NaCl; Oriental Yeast Co., Ltd., Tokyo, Japan) and allowed to acclimatize for a week.
At 6 weeks of age, they were randomly divided into three groups: the control group (n = 6), the high-salt (HS) group (n = 6), and the HS + DMF group (n = 10). The HS group was given a high-salt diet (8% NaCl) from 6 weeks of age. The HS+DMF group was fed a powdered high-salt diet (8% NaCl) supplemented with DMF (90 mg/kg/d) from 6 weeks of age (Grzegorzewska et al., 2017; Krishnamoorthy et al., 2017). The systolic blood pressure (SBP) was measured using a noninvasive tail-cuff method at 6, 10, 12, and 14 weeks of age (BP-98A, Softron, Tokyo, Japan). At 16 weeks of age, each group was euthanized by intraperitoneal administration of medetomidine hydrochloride (0.15 mg/kg) plus midazolam (2 mg/kg) plus butophanol tartrate (2.5 mg/kg) under deep anesthesia by severing the bilateral common carotid arteries, and the blood and each organ were collected.
All of our experimental procedures received approval by the Animal Research Committee of Hyogo Medical University. The investigation conformed to the Guidelines for Proper Conduct of Animal Experiments by the Science Council of Japan.
We have been approved by the Animal Care and Use Committee of Hyogo Medical University for conducting animal experiments.
Hematologic and Biochemical Parameters
Whole blood was analyzed within 24 hours of sampling, and serum and urine were stored at −80°C. Blood cell analysis, including reticulocyte count analysis, was performed with a blood cell analyzer XT-2000iV (Sysmex, Kobe, Japan) optimized for rats. Serum levels of creatinine were analyzed by LabAssay Creatinine (Fujifilm Wako Chemicals Corporation, Osaka, Japan).
Quantification of mRNA
Total RNA was extracted from heart and kidney using TRIzol reagent (Thermo Fisher Scientific, Tokyo, Japan). Total RNA was reverse transcribed into cDNA by the High-Capacity cDNA Reverse Transcription Kit (Thermo Fisher Scientific, Tokyo, Japan) using the GeneAmp PCR System 9700 (Thermo Fisher Scientific, Tokyo, Japan). Real-time polymerase chain reaction quantification of transcripts was performed using the TaqMan Gene Expression Master Mix and TaqMan Gene Expression Assays (Applied Biosystems) using the StepOnePlus Real-Time PCR System (Thermo Fisher Scientific, Tokyo, Japan). TaqMan Gene Expression Assays of NADPH oxidase (NOX)-4 (Nox4: Rn00585380_m1), platelet-derived growth factor (PDGF)-b (Pdgfb: Rn01502596_m1), C-C motif chemokine ligand 2 (Ccl2) (Ccl2: Rn00580555_m1), interleukin (IL)-1β (Il1b: Rn00580432_m1), intercellular adhesion molecule (ICAM)-1 (Icam1: Rn00564227_m1), transforming growth factor (TGF)-β1 (Tgfb1: Rn22572010_m1), and KIM1 (Havcr1: Rn00597703-m1) were used. mRNA levels were normalized using GAPDH mRNA as a housekeeping gene.
Western Blot Analysis
Rat kidney tissue was taken out from a −80°C refrigerator and weighed. Radio immunoprecipitation assay lysate was added to the specimen and ground with Polytron PT1200E (Kinematica, New York). Tissue lysate was collected and centrifuged, and the supernatant was collected. The protein concentration of the samples was determined using the bicinchoninic acid (BCA) method. The protein was electrophoretically separated by SDS-PAGE (7.5%) and transferred onto polyvinylidene fluoride membrane at a constant current of 70 mA for 60 minutes. The membranes for each blot were blocked by 5% skim milk (Nacalai Tesque, Kyoto, Japan) in Tris-buffered saline containing 0.1% Tween-20 for 1 hour at room temperature. After blocking, membranes were incubated with primary antibodies such as anti–NF-κB (1:500, GeneTex: GTX107678) and anti–β-actin antibody (1:500, GeneTex: GTX110564) overnight at 4°C. After washing with Tris-buffered saline containing 0.1% Tween-20 three times, the membranes were incubated with the secondary antibodies, Goat anti-Rabbit (1:1000, abcam: ab6721) for hours at room temperature, followed by chemical enhanced luminescence reaction. The protein bands were measured using Image J software.
Histologic Analysis
Hearts and kidneys were harvested and fixed in 10% paraformaldehyde, and sections were cut from the paraffin-embedded tissue. Sections were stained with H&E staining, periodic acid–Schiff (PAS) staining, and Masson’s trichrome (MTC) staining. For quantitative analysis, the tubular atrophy score in PAS staining was defined as follows: 0, normal tubules; 1, rare single atrophic tubule; 2, several clusters of atrophic tubules; and 3, massive atrophy (Lu et al., 2018). The fibrotic area was determined by Masson staining using ImageJ 1.53a software (National Institutes of Health, Bethesda, MD). All analyses were performed in a blinded manner.
Statistical Analysis
Data are presented as the mean ± S.D. for normally distributed continuous variables.
The Kruskal-Wallis test with the Steel-Dwass post hoc test and one-way ANOVA followed by Tukey’s HSD test were used for comparisons between groups. Differences were considered statistically significant at P < 0.05. All calculations and analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan).
Results
Characteristics of DS Rats
The effects of DMF on physiologic and hematologic parameters of DS rats are shown in Table 1. At 10 weeks of age, body weight significantly decreased in the HS and HS+DMF groups compared with the control group. The HS+DMF group showed a significant decrease compared with the HS group. At 12 and 14 weeks of age, significant decreases were observed in the HS and HS+DMF groups compared with the control group. There was significant weight gain in the HS+DMF group compared with the HS group. SBP was significantly elevated in the HS and HS+DMF groups compared with the control group at 10, 12, and 14 weeks of age (Table 2). SBP decreased in the HS+DMF group compared with the HS group at 10 and 12 weeks of age, but no significant decrease was observed at 14 weeks of age.
Body weight (g)
Systolic blood pressure (mmHg)
Red blood cell count, serum hemoglobin level, and hematocrit were significantly decreased in the HS group compared with the control group but were significantly improved by DMF (Table 3). Reticulocytes were significantly increased in the HS group compared with the control group but were significantly suppressed by DMF (Table 3). Serum creatinine was significantly increased in the HS group compared with the control group, but this increase was significantly decreased in the HS+DMF group compared with the HS group (Table 3). Heart weight increased significantly in the HS group compared with the control group but significantly decreased in the HS+DMF group compared with the HS group (Table 3). No significant difference in kidney weight was observed among the control, HS, and HS+DMF groups (Table 3). Urinary parameters showed that total protein and albumin increased significantly in the HS group but decreased significantly in the HS+DMF group (Table 4).
Physiologic and hematologic parameters at 14 weeks of age
Urinary parameters at 12 weeks of age
Effect of DMF Treatment on Cardiac Pathologic Changes in DS Rats
To further investigate the cardioprotective effect of DMF, H&E staining was performed. Deranged cellular structures and edematous cardiomyocytes were observed in the HS group. However, these abnormalities were notably ameliorated by DMF. MTC staining showed the massive areas of perivascular fibrosis in the HS group, and they were also significantly decreased in the HS+DMF group (P < 0.01; Fig. 1).
Histologic staining of heart tissues. (A) H&E staining for pathologic examination. Original magnification, 10×. (B) MTC staining for pathologic examination. Original magnification, 10×. (C) Quantitative analyses of MTC staining of heart. Kruskal-Wallis test (P = 0.008). *P < 0.05 versus control; #P < 0.05 versus HS (n = 6).
Effect of DMF Treatment on Cardiac Gene Expression in DS Rats
Figure 2 shows the mRNA expression levels in the hearts of each group. The IL1β, Ccl2, ICAM1, NOX4, and TGF-β1 mRNA expression was significantly higher in the HS group than in the control group, but in the HS+DMF group, it decreased to the level of the control group (P < 0.05).
mRNA expression of IL1b, Ccl2, ICAM1, NOX4, and TGF-β in heart tissue. Messenger RNA expression of (A) IL1b, (B) Ccl2, (C) ICAM1, (D) NOX4, and (E) TGF-β1 in the heart tissue. All data were analyzed with the Kruskal-Wallis test. *P < 0.05 versus control; #P < 0.05 versus HS (n = 6).
Effect of DMF Treatment on Kidney Pathologic Changes in DS Rats
To investigate the renal protective effect of DMF, PAS staining was performed. There was significantly more tubular damage in the HS group than in the control group (Fig. 3). However, these abnormalities were notably ameliorated by DMF. MTC staining showed that the area of fibrosis was significantly higher in the HS group than in the control group. However, the increase in the area of fibrosis was significantly suppressed in the HS+DMF group (P < 0.01; Fig. 3). Western blot assay illustrated that NF-κB was increased in the HS group compared with the control group (Fig. 3, E and F). The increased expression of NF-κB was significantly reversed by DMF.
Histologic staining of renal tissues. (A) PAS staining for pathologic examination. Original magnification, 40×. (B) MTC staining for pathologic examination. Original magnification, 40×. (C) The bar graph shows the tubular atrophy score in each case. Quantitative analyses of Masson staining of kidney. Kruskal-Wallis test (P = 0.0229). (D) The bar graph shows the area of fibrosis (%). (E) Representative images of the western blot results. (F) Quantitative densitometric analysis of proteins. n = 6 in each group. Quantitative analyses of western blots were one-way ANOVAs (P = 0.00758) followed by Tukey’s HSD test. *P < 0.05 versus control; #P < 0.05 versus HS.
Effect of DMF Treatment on Renal Gene Expression in DS Rats
Figure 4 shows the mRNA expression levels in the kidneys of each group. The results showed that the mRNA expression of IL1b, Ccl2, NOX4, ICAM1, PDGF, TGF-β1, and Kim1 was increased in the HS group, whereas it decreased significantly in the HS+DMF group.
mRNA expression of IL1b, Ccl2, ICAM1, Nox4, and TGF-β in kidney tissue. Messenger RNA expression of (A) IL1b, (B) Ccl2, (C) ICAM1, (D) Nox4, (E) PDGFb, (F) TGF-β1, and (G) Kim1. All data were analyzed with the Kruskal-Wallis test. *P < 0.05 versus control; #P < 0.05 versus HS (n = 6).
Effect of DMF on the Survival of DS Rats
We examined the overall survival in these groups (Fig. 5). Compared with the control group, the overall survival decreased in the HS group, whereas the DMF treatment significantly improved compared with the HS group.
Kaplan-Meier curves for the overall survival of DS rats in the control group, HS group, and HS+DMF group. *P < 0.05 versus control; #P < 0.05 versus HS (n = 6).
Discussion
Focusing on the inflammation that occurs commonly in CRAS, we hypothesized that DMF, an anti-inflammatory drug, could suppress CRAS. The results showed that DMF significantly ameliorated anemia, provided cardiac and renal protection, and prolonged overall survival. Therefore, DMF was suggested to be effective in CRAS.
Since the DS rats used this time are a model of CRAS due to hypertension, the trend of blood pressure was investigated. A previous study reported that DMF has a blood pressure–lowering effect (Ahmed et al., 2018). In this experiment, a significant decrease was observed in the HS+DMF group compared with the HS group at 10 and 12 weeks of age. At 14 weeks of age, there was a decreasing trend, but no significant difference was observed. The reason why there was a significant difference in the previous study but not in the current study may be because the models used were different. In this model, the increase in blood pressure was greater than in the previous model, so it might not be possible to lower it completely. In this study, sampling was performed at week 14, when no significant difference in antihypertensive effect was observed, suggesting that DMF might affect other effects than just antihypertensive effects.
A previous study reported that DMF increased fetal hemoglobin, provided heme detoxification, and corrected anemia in sickle cell disease (Pierini et al., 2017). In this study, red blood cell count, serum hemoglobin level, and hematocrit were significantly decreased in the HS group compared with the control group but significantly improved by DMF. Since the kidney is the site of erythropoietin production, the effect of DMF on renal injury in this model might have affected erythropoietin production function and contributed to the improvement of red blood cell numbers. On the other hand, reticulocytes were significantly increased in the HS group compared with the control group but were significantly suppressed by DMF. We previously reported that anemia in DS rats fed an HS diet is caused by shortened red blood cell lifespan (Manabe et al., 2020). These findings suggest that DMF might improve anemia.
Although few reports have examined the effects of DMF on heart failure, several studies have reported cardioprotective effects. DMF has been shown to prevent cardiovascular disease by inhibiting dendritic cell maturation and may exert protective effects on myocardial ischemia/reperfusion models (Kuang et al., 2020; Sun et al., 2022). Myocardial remodeling, which is the cause of heart failure, is thought to be formed by the degeneration and necrosis of myocardial cells, the infiltration of inflammatory cells, and tissue fibrosis (Szekely and Arbel, 2018). In this study, we investigated cardiomyocyte degeneration and fibrosis. H&E staining showed disorganized cellular structure and edematous cardiomyocytes in the HS group. Furthermore, when fibrosis was evaluated by MTC staining, significant fibrosis occurred in the HS group. These abnormalities were significantly inhibited by DMF. In addition, TGF-β1 mRNA expression in heart tissue was also examined, and TGF-β1 was increased in the HS group, but DMF suppressed it. These findings suggest that suppression of fibrosis in cardiac tissue was associated with suppression of TGF-β1.
We examined cytokines in cardiac tissue. Regardless of the underlying etiology, the development and progression of heart failure are closely associated with inflammation, and the induction and activation of chemokines are one of the hallmarks of the inflammatory response in heart failure. IL-1β is known to induce fibrosis and cardiac remodeling after acute myocarditis in mice. Inflammation is involved in the pathogenesis of many heart diseases, and IL-1β is one of the major mediators in this inflammatory process (Szekely and Arbel, 2018). Ccl2 functions in the development and progression of cardiovascular diseases such as heart failure. ICAM1 is an immunoglobulin-like adhesion molecule that mediates leukocyte arrest and transendothelial migration from the bloodstream to the sites of inflammation. ICAM1 regulates cardiac inflammation and pathologic cardiac remodeling by mediating T-cell recruitment to the left ventricle, contributing to cardiac dysfunction and heart failure (Salvador et al., 2016). In this study, DMF suppressed the increase in IL-1β, Ccl2, and ICAM1 mRNA expression, suggesting that DMF may have suppressed inflammation in heart tissue. NOX4 is known to be the major source of reactive oxygen species (ROS) in myocardial remodeling (Matsushima et al., 2016). In this study, NOX4, which increased in the HS group, was suppressed in the HS+DMF group, suggesting the possibility that ROS production was suppressed and cardiomyocyte abnormalities were suppressed. From the above, DMF has been shown to exert anti-inflammatory and antifibrotic effects and to have cardioprotective effects associated with the suppression of various cytokines.
Recent studies strongly support a protective effect of DMF against renal damage (Yang et al., 2021). In the present study, serum creatinine was significantly higher in the HS group compared with the control group, but this increase was significantly decreased in the HS+DMF group compared with the HS group. This suggested that DMF has a renal protective effect.
Furthermore, in renal tissues, PAS staining revealed an increase in tubular atrophy in the HS group, but it was suppressed in the HS+DMF group. In addition, according to the results of MTC staining for evaluating fibrosis, fibrosis significantly increased in the HS group but was significantly suppressed by DMF. A previous study reported that DMF, which plays an important role in the development of renal fibrosis, prevents renal fibrosis through suppression of TGF-β1 signaling (Oh et al., 2012). In addition, PDGFb is an important factor involved in renal interstitial fibrosis (Floege et al., 2008). In the present results, the TGF-β1 and PDGFb mRNA expression that increased in the HS group was suppressed by DMF. We examined the mRNA expression of KIM1. KIM1 is highly expressed in renal tubular cells after injury and is commonly considered an early biomarker of acute kidney injury (Vaidya et al., 2006). As a result, a significant increase was observed in the HS group and a significant suppression in the HS+DMF group. Furthermore, DMF significantly decreased urinary total protein and albumin, which were significantly increased in the HS group. These findings suggested that DMF inhibits renal tissue damage such as fibrosis and tubular damage.
We examined mRNA expression of cytokines associated with inflammation in renal tissue. Inflammation plays an important role in the pathogenesis of kidney disease (Kashyap et al., 2018). Stimulation of IL-1β signaling within the kidney itself is also already known to exacerbate the progression of renal injury via activation of the NLRP3 inflammasome (McKnight et al., 2020). ICAM1 has also been shown to be expressed in renal tubular cells during inflammation (Wu et al., 2007). Ccl2 is an important mediator of interstitial inflammation, fibrosis, and tubular atrophy in chronic kidney disease (Kashyap et al., 2018; Xu et al., 2019). In this study, IL-1β, ICAM1, and Ccl2, which were increased in the HS group, were suppressed in the HS+DMF group. These findings suggest that DMF exerts a protective effect on the kidneys by suppressing inflammation at the genetic level. In addition, we examined the expression of NF-κB in renal tissue by western blot and found that DMF suppressed the elevated expression in the HS group. This suggests that inflammation is suppressed even at the protein level. In the present study, NOX4 mRNA expression, which increased in the HS group, was suppressed in the HS+DMF group. NOX4 is involved in ROS generation. Increased ROS causes oxidative stress and contributes to anemia. These findings suggest that DMF suppresses ROS generation and may also be involved in suppressing anemia symptoms. These support the results of previous studies that DMF can act as a nephroprotectant in part through regulation of oxidative stress, mitochondrial function, and inflammation (Ashari et al., 2023).
In the present study, damage occurred to vascular endothelial cells, vascular smooth muscle cells, and renal secretory cells in the HS group, which may impair some of the inflammatory cytokines and growth factors that we measured. This leads to immune cell chemoattraction and transmigration, enabled by ICAM. A high-salt diet can also stimulate immune cells such as macrophages, dendritic cells, and T cells, which ultimately amplify inflammation, oxidative stress, and injury in chronic kidney disease (CKD) and cardiovascular disease (CVD). DMF is thought to have cardiorenal protective effects by inhibiting these damaging mechanisms.
There are several limitations to this study. The lack of a DMF monotherapy control group is a potential weakness in the study design. We did not establish a DMF alone group in this study because we believed that DMF monotherapy had little effect in the absence of disease. Therefore, we believe that this absence does not unduly compromise the interpretation of the results. Although cytokines were examined in this research, it was not possible to examine them one by one using knockout mice. Therefore, it was not possible to investigate what kind of changes would be caused by the deficiency of each cytokine. Regarding heart failure, this study was limited to histologic analysis and cytokine mRNA analysis, and an echo examination was not performed, so further examination is necessary.t
Conclusion
DMF was found to improve the overall survival of DS rats. This was suggested to be related to the ability of DMF to ameliorate anemia and cause cardioprotective and renal protective effects through its anti-inflammatory and antifibrotic effects.
Acknowledgments
The authors thank Kazutake Tsujikawa and Kazuto Nunomura (Graduate School of Pharmaceutical Sciences, Osaka University) for measurements of complete blood counts and differential white blood cell counts. The authors would like to thank Sachi Ito for excellent technical assistance.
Data Availability
The authors declare that all the data supporting the findings of this study are contained within the paper.
Authorship Contributions
Participated in research design: Ito, Tsujino.
Conducted experiments: Ito. Yamatani, Arai.
Performed data analysis: Ito, Manabe, Tsujino.
Wrote or contributed to the writing of the manuscript: Ito, Yamatani, Arai, Manabe, Tsujino.
Footnotes
- Received April 18, 2023.
- Accepted September 11, 2023.
This study was supported by JSPS KAKENHI [Grant JP15K09148] (to T.T.) and [Grant JP18K08055] (to T.T. and S.I.). A portion of this research was supported by the Platform Project for Supporting Drug Discovery and Life Science Research [Basis for Supporting Innovative Drug Discovery and Life Science Research (BINDS)] from AMED [Grant JP21am0101123].
No author has an actual or perceived conflict of interest with the contents of this article.
Abbreviations
- Ccl2
- C-C motif chemokine ligand 2
- CRAS
- cardiorenal anemia syndrome
- DMF
- dimethyl fumarate
- DS
- Dahl/salt-sensitive
- EPO
- erythropoietin
- HS
- high salt
- ICAM
- intercellular adhesion molecule
- IL
- interleukin
- KIM
- kidney injury molecule
- MTC
- Masson’s trichrome
- NF-κB
- nuclear factor κ B
- NOX
- NADPH oxidase
- PAS
- periodic acid–Schiff
- PDGF
- platelet-derived growth factor
- ROS
- reactive oxygen species
- SBP
- systolic blood pressure
- TGF
- transforming growth factor
- Copyright © 2023 by The Author(s)
This is an open access article distributed under the CC BY-NC Attribution 4.0 International license.