# Blood-brain barrier permeability in CKD: Link with inflammation and cognitive and mood impairment in rats

Mickaël Bobot, Amandine Bruyat, Laurent Thomas, Samantha Fernandez, Alexandre Brodovitch, José Boucraut, Stéphane Burtey, Vincent Nail, Benjamin Guillet, Guillaume Hache

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Mickaël Bobot, Amandine Bruyat, Laurent Thomas, Samantha Fernandez, Alexandre Brodovitch, et al.. Blood-brain barrier permeability in CKD: Link with inflammation and cognitive and mood impairment in rats. Behavioural Brain Research, 2025, 493, pp.115693. 10.1016/j.bbr.2025.115693. hal-05512768

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# Blood-brain barrier permeability in CKD: Link with inflammation and cognitive and mood impairment in rats

Mickaël Bobot<sup>a,b,c,*</sup>, Amandine Bruyat<sup>b,c</sup>, Laurent Thomas<sup>b,c</sup>, Samantha Fernandez<sup>b,c</sup>,
Alexandre Brodovitch<sup>d</sup>, José Boucraut<sup>d,e</sup>, Stéphane Burtey<sup>a,b</sup>, Vincent Nail<sup>b,c,f</sup>,
Benjamin Guillet<sup>b,c,f</sup>, Guillaume Hache<sup>b,c,g</sup>

## ARTICLE INFO

### Keywords:

Cognitive impairment

Blood-brain barrier

Depression

Chronic kidney disease

Imaging

Cytokines

## ABSTRACT

Chronic kidney disease (CKD) is associated with cognitive impairment. CKD is associated with increased permeability of the blood-brain barrier (BBB), resulting in increased cognitive impairment in animals and in humans. The aim of this study is to describe the inflammatory profile in blood and cerebro-spinal fluid (CSF) during a CKD model induced by adenine rich diet (ARD) in rats, in relation to BBB permeability and to explore the cognitive and mood impairment phenotypes. ARD rats displayed a 5-fold increase in BBB permeability, quantified with brain <sup>99m</sup>Tc-DTPA SPECT/CT isotopic imaging, without alteration of brain perfusion. CKD is associated with increased PDGFRβ levels in CSF (445 ± 85.6 vs. 303 ± 104.9 pg/mL, *p* = 0.03), suggesting pericyte dysfunction, but not with CSF levels of inflammatory cytokines, despite increased systemic inflammation. Neurobehavioural evaluation highlighted that ARD rats had impairment of short-term spatial memory, social memory and depressive features but not anxiety. In conclusion, CKD induces systemic inflammation and BBB permeability associated with pericyte dysfunction and alteration of memory and depressive features in rats. BBB disruption seems to be a crucial mechanism involved in cognitive and mood impairment during CKD.

## 1. Introduction

Chronic kidney disease (CKD) is associated with impaired cognition [1,2], which appears earlier than in the global population. Cognitive impairment evolves in parallel to the decline of the glomerular filtration rate, but is already present in stage 3 and 4 CKD [3], and concerns up to 30–80 % of patients with end-stage kidney disease (ESKD) [1]. Cognitive impairment particularly affects language and memory, has a major impact on the patients and their relatives, and complexify their care [4]. Specific mechanisms linked to CKD are highly suspected [5] like hydro-electrolyte imbalance, acidosis increased neuroinflammation and uremic toxicity [6]. Also, depression concerns one-quarter to half of patients with CKD, and antidepressant are poorly effective in these patients. Literature suggests that inflammation, in relation to uremic toxin

accumulation in CKD could be an important mechanism for treatment resistance in depression [7].

Several studies described neurobehavioural changes in models of CKD rodents [8]: they found mainly alteration in memory [9–12], decreased motor activity [13,14], more anxious and depressive behaviours compared to control animals [15,16]. We previously demonstrated that in several models of CKD in rodents, CKD was associated with increased permeability of the blood-brain barrier (BBB), resulting in increased cognitive impairment (notably in short term memory), and linked to the activation of aryl hydrocarbon receptor (AhR) by the accumulation of the uremic toxin indoxyl sulphate (IS) [17]. This increased BBB permeability in relation to impaired cognition was then confirmed in ESKD patients compared to matched healthy volunteers in the BREIN study [18]. BBB appears to be a central mechanism explaining

<footnote><sup>a</sup> Centre de Néphrologie et Transplantation Rénale, Hôpital de la Conception, AP-HM, Marseille, France</footnote>

<footnote><sup>b</sup> Aix Marseille Univ, INSERM 1263, INRAE 1260, C2VN, Marseille, France</footnote>

<footnote><sup>c</sup> CERIMED, Aix-Marseille Univ, Marseille, France</footnote>

<footnote><sup>d</sup> Laboratoire d'Immunologie, Biogénopôle, Hôpital de la Timone, Marseille, France</footnote>

<footnote><sup>e</sup> INT UMR CNRS 7286, Aix-Marseille Université, Marseille, France</footnote>

<footnote><sup>f</sup> Radiopharmacie, AP-HM, Marseille, Marseille, France</footnote>

<footnote><sup>g</sup> Pharmacie, Hôpital de la Timone, AP-HM, Marseille, France</footnote>

<footnote>* Correspondence to: Service de Néphrologie et Transplantation Rénale, 147 boulevard Baille, Marseille 13005, France
E-mail address: mickael.bobot@ap-hm.fr (M. Bobot).</footnote>
cognitive impairment during CKD [8,19]. BBB disruption is also involved in several systemic, neurodegenerative and cerebrovascular diseases associated with cognitive impairment [20].

However, the exact mechanisms underlying the BBB permeability during CKD and its precise consequences on the different aspects of cognition are still unknown.

Persistent low-grade inflammation presents at all stages of CKD, which contributes, at least in part, to cardiovascular and all-cause mortality [21]. In the early stages of CKD, pro-inflammatory cytokines such as interleukin-6 (IL-6), and TNF-α in the blood [22] and systemic inflammation may contribute to BBB dysfunction. However, to date there is no data linking systemic inflammation to BBB dysfunction and cognitive dysfunction in the context of CKD.

In this study we aimed to describe the inflammatory profile in blood and cerebro-spinal fluid (CSF) during a CKD model induced by adenine rich diet (ARD), in relation to BBB permeability and to explore further the phenotypes of cognitive and mood impairment.

## 2. Materials and methods

All procedures using animals were approved by the institution's Animal Care and Use Committee and the French Ministry of Research (APAFIS #15636-2018122710383826VI, CE 71; Aix-Marseille University), and were conducted according to European Union Directive 2010/63/EU and to the National Institutes of Health Guide for the Care and Use of Laboratory Animals.

Experiments were conducted in 14 5-week-old male Sprague-Dawley rats (Envigo®). The animals were housed two per cage with enrichment and free access to food and water. Their welfare was daily controlled by competent personnel. The temperature and the humidity of the air were controlled, a light cycle of 7-19 h was carried out. CKD was induced by giving the rats an adenine-rich diet (ARD) at 0.5 % (Safe Nutrition®) for 28 days, as previously described [17,23].

Blood samples were collected by catheterization of the caudal vein under anesthesia by 3 % sevoflurane. The serum was extracted after centrifugation (2500 g for 15 min at 21°C) and stored at -80°C. The severity of CKD was assessed by serum urea and creatinine at D28.

CSF samples were taken by stereotaxic puncture of the magna cisterna at D28 using a rat-adapted device under 3 % sevoflurane anesthesia, and were stored at -80°C.

Dosage inflammatory cytokines were performed in blood and CSF after 28 days using V-PLEX Proinflammatory Panel 2 rat Kit (K15059D, MSD®). PDGFRβ dosage was performed in CSF by ELISA (CSB-EL017713RA, Cusabio®).

Kidneys were fixed in 4 % formaldehyde for 48 h then kept in 70 % ethanol to be included in paraffin. The interstitial lesions were assessed with optic microscopy (station Ellipse Ni-E; Nikon) after hematoxylin-eosin staining according to a semi-quantitative score as previously described [23], for each kidney by two trained physicians blinded to the intervention group.

BBB permeability was assessed by cerebral SPECT-CT after injection of ⁹⁹mTc-coupled diethylene-triamine-penta-aceticacid (⁹⁹mTc-DTPA) as previously described [17]. Cerebral perfusion permeability was assessed by cerebral SPECT-CT after injection of ⁹⁹mTc-coupled hexamethylpropyleneamine oxime (⁹⁹mTc-HMPAO) [24]. Rats received an intravenous injection of 100 mL of ⁹⁹mTc-DTPA (20MBq) at D30, and an intravenous injection of 100 µL of ⁹⁹mTc-HMPAO at D42. SPECT-CT acquisition was done 30 min after injection of ⁹⁹mTc-DTPA or 2 h after injection of ⁹⁹mTc-HMPAO, for 25 min under anesthesia with 3 % sevoflurane using a Mediso NanoSpect camera and the Mediso Nucline 1.02 software. Radioactivity was measured in the brain using Invicro VivoQuant 3.5 and Invicro InvivoScope 2.00 reconstruction softwares. BBB permeability and cerebral perfusion were expressed as a percentage of cerebral content of ⁹⁹mTc-DTPA and ⁹⁹mTc-HMPAO, respectively, on the total amount of injected radioactivity and per gram of brain tissue (%IA/g).

The Object location task was performed to assess rat's ability to recognize that an object that it had experienced before had changed location was assessed, in order to explore a spatial memory ability [25]. The rats were placed in a 1x1x0.25 m arena. The test was conducted in three phases: 1/ habituation phase: the day before the test, the animal was placed in the southeast corner of the empty arena and was able to explore for 30 min. The arena was cleaned after each rat pass; 2/ learning phase, the rat was exposed to objects, which were placed in the far corners of the arena. The animal was allowed to explore both objects during a sample phase of 3 min, and the amount of exploration of each object was recorded by the experimenter. This sequence was repeated three times, 30 min apart; 3/ test phase, one object was placed in the same position as it had occupied in the sample phase, the second object was placed in the corner adjacent to the original position, so that the two objects were in diagonal corners. Thus, both objects in the test phase were equally familiar, but one was in a new location. The position of the moved object was counterbalanced between rats. Rats were tested at D39. Intact object location memory is evidenced by subjects spending more time investigating the object in the new location. Data were collected by video tracking software (Ethovision® XT 8.5; Noldus).

The Social Memory test assessed cognition, namely the ability to recognize novel versus familiar animals, in rodent models of CNS disorders [26]. Over the course of multiple exposures, rodents will become habituated to intruders and no longer find them as interesting as a completely novel intruder. During testing, the subject is given four 1-minute exposures in its home cage to the same intruder, ten minutes apart. In the fifth trial, the subject encounters an entirely novel intruder. All test trials were videotaped and subsequently analyzed for total body investigation, anogenital investigation, perioral investigation and body investigation.

Coat state. Dirty coats in rats often represent low self-care behavior, an indirect marker of depressive-like phenotype [27]. The observed coat state was evaluated with a quantitative scale that assessed eight different body parts: head, neck, dorsal coat, tail, forelimb, hindlimb, ventral coat, and genital region [28]. The total score of the coat status was obtained by attributing a score of 0 (clean coat) or 1 (dirty coat or in abnormal state) to each of the eight parts.

The Forced swimming test (FST) is centered on a rodent's response to the threat of drowning, the results of which have been interpreted as a measure of susceptibility to negative mood [29]. We performed the FST as previously described [30]. Briefly, rats were forced to swim in a vertical plastic cylinder (diameter 40 cm, height 40 cm) containing 30 cm of water maintained at 25 ± ²°C. The day before the test, the rats were allowed to become used water cylinder for 10 min. The test was performed for 5 min, the duration of immobility time for every rat was measured. All trials were videotaped and subsequently analyzed by two observers who were blinded to treatment. The animal was dried with a towel and the water was changed after each swimming test.

The open field test is validated for evaluating anxiety in rodents [31]. These behaviors are induced by removing the animal from its cage and placing it in an open and novel environment. An arena measuring 1x1x0.25 m was used. The floor and walls of the enclosure were black. The animals were placed in the middle of a wall, with their head facing the wall. The test lasted 10 min. The number of entries into the center zone (25cmx25cm) were recorded using the tracking software.

The elevated plus maze (EPM) consisted of two open arms (50 × 10 cm) and two closed arms (50 × 10 cm, surrounded by 50-cm plastic walls) that originated from a common central platform (10 × 10 cm). The apparatus was elevated to a height of 50 cm above the floor. This test was performed in a dark environment. The rat was placed on the central platform with the head facing towards an open arm and allowed to explore for 5 min [32]. The proportion of time spent in the open arms (the time spent in the open arms / 5 min) and the number of entries into the open arms were calculated. The rat was considered as entering a new arm when it introduced its four paws in the arm. The maze was rinsed and dried between each rat.
Results are expressed in mean ± standard derivation. Comparisons of quantitative values were done by non-parametric Mann-Whitney test. All tests were two-tailed. Statistical analysis was done using GraphPad Prism 8.0 software; a p value below 0.05 was considered significant.

### 3. Results

Rats fed with ARD had impaired kidney function with increased serum urea 62.5 ± 19.8 vs. 7.3 ± 0.5 mmol/L (p < 0.0001), and creatinine 193.3 ± 41.5 vs. 43.8 ± 2.6 µmol/L (p < 0.0001) levels (n = 6), compared to control rats (n = 8) at D28.

#### 3.1. ARD-induced CKD was associated with inflammation

At D28, ARD rats displayed increased serum levels of pro-inflammatory cytokines IL-10 (16.7 ± 2.6 vs. 12.9 ± 1.7 ng/mL, p = 0.03), IL-13 (8.22 ± 2.37 vs. 0.06 ± 0.12 ng/mL, p = 0.009), IL-4 (4.0 ± 1.3 vs. 2.3 ± 1.7, p = 0.057), IFN-g (6.8 ± 0.4 vs. 3.5 ± 2.4 ng/mL, p = 0.009), and TNFα (34.3 ± 11.1 vs. 8.6 ± 4.5 ng/mL, p = 0.009) compared to control rats. Serum levels of IL-1b, IL-4, IL-6 and KC/GRO (Cxcl1) were not different between the two groups of animals (Fig. 1).

In CSF, levels of cytokines were not statistically different in the two groups of animals, although there was a non-significant increase in concentrations of IL-1b (49.9 ± 37.4 vs. 19.2 ± 25.4 ng/mL, n = 13, p = 0.09) and TNFα (3.5 ± 2.1 vs. 1.4 ± 1.0 ng/mL, n = 13, p = 0.07) in CKD rats (Fig. 2).

#### 3.2. ARD-induced CKD was associated with pericyte dysfunction and increased BBB permeability

CSF concentration of PDGFRβ was increased in CKD rats, compared to controls: 445 ± 85.6 vs. 303 ± 104.9 pg/mL, n = 13, p = 0.03 (Fig. 3a), in favor of pericyte dysfunction.

<figure><img src="image_5.png" /><figcaption>**Fig. 1.** Serum levels of cytokines in rats fed with adenine rich (ard) and control (ctrl) diets. A: interferon gamma, B: Interleukin-10, C: Interleukin-13, D: interleukin 1-beta, E: Interleukin-4, F: Interleukin-6, G: tumor necrosis factor alpha (TNF alpha), H: KC/GRO. \*: p < 0.05, \*: p < 0.01.</figcaption></figure>

In SPECT/CT imaging, ARD rats displayed a higher cerebral uptake of ⁹⁹mTc-DTPA compared to controls: 6.9e⁻⁴ ± 1.7e⁻⁴%IA/g vs. 1.4e⁻⁴ ± 0.4e⁻⁴%IA/g, n = 12, p < 0.0001 (Fig. 3b), meaning higher BBB permeability, as illustrated in Fig. 3c and d, while no difference was found regarding cerebral perfusion quantified by ⁹⁹mTc-HMPAO SPECT/CT imaging between the two groups: 0.61 ± 0.09 vs. 0.53 ± 0.10%IA/g, n = 11, p = 0.500 (Fig. 3e), as illustrated in Fig. 3f and g.

#### 3.3. Rats fed with ARD displayed impaired memory and depression

ARD rats exhibited visual memory impairment, as evidenced by a decrease in the discrimination index in the Object Location (OL) test compared to the control group (0.03 ± 0.18 vs. 0.42 ± 0.04; p = 0.003) (Fig. 4a). Additionally, ARD rats showed increased sniffing time in the social memory test compared to control rats in Trial 3 (19.4 ± 6.7 vs. 7.6 ± 4.3 s; n = 12; p < 0.001) and again in Trial 4 (21.1 ± 8.1 vs. 7.4 ± 5.4 s; n = 12; p < 0.001), with no significant difference observed in Trial 5 with the new encounter (18.7 ± 6.2 s vs. 14.3 ± 8.6 s; n = 12; p = 0.14) (Fig. 4b), indicating an alteration in social memory with difficulties to recognize novel from familial other rat.

ARD rats also displayed a depressive-like phenotype, as indicated by an increased coat state score (2.8 ± 0.8 vs. 0.6 ± 0.6; p < 0.001) (Fig. 4c), suggesting less grooming in those rats, and increased immobility time in the Forced Swim Test (FST) (123 ± 26 vs. 68 ± 19 s; p < 0.001) (Fig. 4d) indicating more negative mood. No significant differences were observed between ARD and control rats in the Open Field (OF) test in terms of duration (3.7 ± 2.7 vs. 4.1 ± 2.4 s; p = 0.77) or entries (20.8 ± 9.0 vs. 21.1 ± 7.4; p = 0.94) in the center zone (Fig. 4e-f), suggesting no difference in anxiety.

Furthermore, ARD rats showed no significant differences in time spent (14.5 ± 15.8 s vs. 14.5 ± 7.3 s; p = 0.99) or entries (11.5 ± 9.2 vs. 7.8 ± 5.5; p = 0.42) in the open arms of the Elevated Plus Maze (EPM) compared to control rats, also suggesting a lack of anxiety in ARD rats (Fig. 4g-h).
<figure><img src="image_6.png" /><figcaption>**Fig. 2.** Levels of cytokines in cerebro-spinal fluid of rats fed with adenine rich (ard) and control (ctrl) diets. A: Interleukin-10, B: interleukin 1-beta, C: Interleukin-6, D: tumor necrosis factor alpha (TNF alpha), E: KC/GRO.</figcaption></figure>

## 4. Discussion

In this work, we have performed a detailed analysis of neuro-behavioral phenotypes, dosage of cytokines and markers of pericyte dysfunction in serum and CSF, along with precise techniques of brain isotopic imaging in a robust model of CKD.

We confirmed the increased permeability of the BBB in CKD, as we previously reported in rodents and humans [17,18], without alteration of brain perfusion.

We found increased levels of pro-inflammatory cytokines in our model of CKD. These results are consistent with similar experiment in other murine models of CKD [33]. However, the association of CKD with systemic inflammation in humans is well known, with an increase of serum levels of IL-1b, IL-6 and TNFα notably [34]. Our work confirms that systemic inflammation is present in our model of CKD. The observed increase in pro-inflammatory cytokine concentrations in serum, without corresponding elevation in CSF, suggests that the dysregulation of these cytokines does not necessarily imply their direct passage across the BBB, challenging the hypothesis of peripheral cytokine-mediated neuro-inflammation in the central nervous system. These findings indicate that peripheral inflammation may influence CNS function through alternative mechanisms, such as microglial or pericyte signaling pathways, or endothelial dysfunction, rather than by direct diffusion of cytokines into the CSF. Recently, Zimmermann *et al.* described the implication of potassium efflux in the microglia and its activation, the activation of IL-1β/IL-1R pathway in the brain, linked to BBB permeability and cognitive

impairment in CKD [35]. Moreover, the accumulation of IS can lead to increased cerebral inflammation [36]. IL-1β and uremic toxins appear as interesting potential therapeutic targets to treat or prevent cognitive impairment in CKD.

On the other hand, we found an increase in PDGFRβ levels in the CSF of ARD rats. PDGFRβ is expressed by pericytes. Pericytes play a major role in the integrity of the BBB, by regulating the polarization of astrocyte feet, the diameter of brain vessels and angiogenesis [37,38]. PDGFRβ respond to endothelial PDGFRβ produced by brain capillaries and regulates pericyte proliferation, attachment to endothelial cells, and survival. Interestingly, mice with partial PDGFRβ deficiency have reduction in capillary-associated pericytes [39]. Accumulation of PDGFRβ in the CSF suggests pericyte dysfunction, which is a common mechanism in both neurovascular and neurodegenerative diseases [40], notably demonstrated in Alzheimer's disease [41]. Our results suggest that pericyte dysfunction contributes to CKD-induced BBB disruption. Interestingly, stimulation of cerebrovascular endothelial cells with inflammatory cytokines *in vitro* induced release of shedding type endothelial cell-derived extracellular vesicles which, when added to the culture media of cerebrovascular pericytes were incorporated into the cells and modified pericyte transcriptome[42]. Further studies are needed to assess the changes in interactions between endothelial cells and pericytes during cognitive impairment and its link to BBB dysfunction in the context of CKD.

We also further described the neurobehavioural phenotypes associated with BBB disruption during CKD and found alteration of short-term
<figure><img src="image_7.png" /><figcaption>**Fig. 3.** Blood-brain barrier permeability and cerebral perfusion in rats fed with adenine rich (ard) and control (ctrl) diets. pericyte dysfunction: A: levels of PDGFRβ in cerebro-spinal fluid. blood-brain barrier permeability: B: brain content of ⁹⁹mTc-DTPA cerebral scintigraphy in percentage of injected activity per gram of brain (% IA/g) at D30, with SPECT/CT images in axial plane of a control (C) and ARD (D). cerebral perfusion: E: brain content of ⁹⁹mTc-HMPAO cerebral scintigraphy in percentage of injected activity per gram of brain (% IA/g) at D42, with SPECT/CT images in coronal and axial planes of a control (F) and ARD (G) rat. \*: p < 0.05, ****: p < 0.0001.</figcaption></figure>

<figure><img src="image_8.png" /><figcaption>**Fig. 4.** Neurobehavioural tests: cognitive and mood involvement in rats fed with adenine rich (ard) and control (ctrl) diets. visual memory: A: discrimination index of the object location test. social memory: B: sniffing time in social recognition test. depression: C: score of coast test, D: immobility time in forced swim test. anxiety: number of entries (E) and duration (F) in the center of the elevated plus maze, number of entries (G) and duration (G) in the open arms of the elevated plus maze. \*: p < 0.01, **: p < 0.05, ***: p < 0.001.</figcaption></figure>

spatial and social memory, but also depressive features without anxious phenotypes. Depression is indeed highly prevalent during CKD, concerning about one quarter of all CKD patients, which is higher than

observed in the general population [43]. Mechanisms of depression in CKD are numerous and complex, and involve psychological and social aspects linked to the chronic disease, like negative perceptions from the
patients and the general population [44], increased chronic inflamma-
tion and accumulation of tryptophan-derived uremic toxins like kynur-
enines and indoxyl sulphate [7,45]. Also, depression and cognitive
impairment have a bi-directional relationship and both can worsen each
other.

Our findings are coherent with previous studies in mice. Mazumder
*et al*. found depressive features, evaluated by forced swim test in CKD
mice fed with ARD, associated with impaired short-term and visual
memory and associated with increased brain inflammation and oxida-
tive stress [9]. Several other studies found alteration in short-term
memory in CKD mice after 5/6 nephrectomy [10,46], which were
associated with hippocampic pyknosis and oxidative stress. Performing
our model of CKD in rats allows more precise behavioural evaluation.
These neurological alterations may however vary depending on the
animal model used. For example, Karbowska *et al*. also found more
anxious and apathic behaviours, with lower motor activity, associated
with increased IS concentrations and decreased neurotransmitters, in
the brain stem of rats after administration of IS in the drinking water
[16].

Our study has some limitations. First, the dosage was not available for all cytokines in the CSF. The longer-term effects of CKD on cognition and the potential reversibility of BBB disruption during experimental models of CKD or acute kidney injury are yet to be discovered. The impact of anti-inflammatory drugs on both BBB permeability and cognitive impairment in the context of CKD should be tested in the future.

Yet this study contributes to our understanding of brain damage in CKD patients, a major and disabling complication, and opens up new perspectives, drawing attention about cognitive impairment and depressive features which are highly prevalent in CKD patients, seem associated with increased BBB permeability [18], and which complexify their care. CKD is associated with chronic inflammation, notably under the influence of chronic dysbiosis leading to uremic toxin accumulation [7]. Attention about cognitive and depressive symptoms should be raised specifically in patients displaying increased markers of inflammation like C-reactive protein on a chronic basis.

5. Conclusion

CKD induces systemic inflammation and BBB permeability associ-
ated with pericyte dysfunction and alteration of memory and depressive
features in rats. BBB disruption seems to be a crucial mechanism
involved in cognitive and mood impairment during CKD.

CRediT authorship contribution statement

**Benjamin Guillet:** Writing – review & editing, Validation, Super-
vision, Conceptualization. **Guillaume Hache:** Writing – review & edit-
ing, Visualization, Supervision, Methodology, Conceptualization.
**Vincent Nail:** Investigation, Software, Writing – review & editing.
**Bobot Mickael:** Writing – original draft, Visualization, Validation,
Methodology, Investigation, Funding acquisition, Formal analysis, Data
curation, Conceptualization. **Amandine Bruyat:** Writing – review &
editing, Visualization, Investigation. **Laurent Thomas:** Writing – review
& editing, Investigation, Formal analysis, Data curation. **Samantha
Fernandez:** Writing – review & editing, Resources, Investigation.
**Alexandre Brodovitch:** Writing – review & editing, Investigation. **José
Boucraut:** Writing – review & editing, Investigation. **Stéphane Burtey:**
Writing – review & editing, Conceptualization.

Declaration of Competing Interest

The authors declare that they have no conflict of interest.

Acknowledgments

This research was funded by the grant 'End-stage renal disease and dialysis' of the Société Francophone de Néphrologie, Dialyse et Transplantation (French Speaking Society of Nephrology) in 2018 and supported by the French Government as part of the France 2030 investment plan, as part of the Aix-Marseille University - A*MIDEX Excellence Initiative (AMX-19-IET-002) - Institut Marseille Imaging. We thank the Plateforme de Biochimie, UMR 1149 INSERM, Université Paris Diderot, Equipe de Recherche Labellisée Centre Nationale pour la Recherche Scientifique 8252, Faculté de Médecine Site Bichat, Paris for performing the biochemical tests.

Data availability

Data will be made available on request.

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