# Impact of Therapeutic Doses of Prednisolone and Other Glucocorticoids on Insulin Secretion from Human Islets.

Omolara Khadijat Tijani, Maria Moreno Lopez, Isaline Louvet, Ana Acosta Montalvo, Anaïs Coddeville, Valery Gmry, Julien K. Conte, Francois Pattou, Marie-Christine Vantyghem, Chiara Saponaro, et al.

► To cite this version:

Omolara Khadijat Tijani, Maria Moreno Lopez, Isaline Louvet, Ana Acosta Montalvo, Anaïs Coddeville, et al. Impact of Therapeutic Doses of Prednisolone and Other Glucocorticoids on Insulin Secretion from Human Islets. Annales d'Endocrinologie = Annals of Endocrinology, 2024, Annales d'Endocrinologie = Annals of Endocrinology, 86 (2), pp.101676. 10.1016/j.ando.2024.101676. hal-04890191

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Original article

# Impact of therapeutic doses of prednisolone and other glucocorticoids on insulin secretion from human islets

Omolara Khadijat Tijani, Maria Moreno-Lopez, Isaline Louvet, Ana Acosta-Montalvo, Anaïs Coddeville, Valery Gmyr, Julie Kerr-Conte, François Pattou, Marie-Christine Vantyghem, Chiara Saponaro, Caroline Bonner, Stéphanie Espiard*

University of Lille, CHU de Lille, Inserm U1190, EGID, Institut Pasteur de Lille, 59000 Lille, France

## INFO ARTICLE

Keywords :

Glucocorticoids

Hyperglycemia

Diabetes

Human islets

Insulin secretion

## ABSTRACT

**Introduction.** – Glucocorticoid-induced diabetes (GCID) is a prevalent health issue, generally attributed to insulin resistance. High doses of dexamethasone (DEX) are known to inhibit glucose-stimulated insulin secretion (GSIS), but the effects of lower doses, commonly used in chronic therapy, and equipotent doses of other glucocorticoids (GCs) such as hydrocortisone (HC) and prednisone (PRED) remain underexplored. This study aimed to investigate these effects in vitro, and explore variations between patients.

**Materials and methods.** – Dynamic perfusion assays were conducted on human islets to evaluate the impact of different GCs on GSIS. The islets were treated for 24 h with 250 nM PRED and other GCs at equipotent anti-inflammatory doses (HC: 1 µM; DEX: 38 nM).

**Results.** – In 11 human islet donor preparations, 250 nM PRED, corresponding to a clinical oral dose of 5 mg/day, significantly inhibited the first and second phase of GSIS: area under the curve (AUC) decreased by 32.3% (*P* < 0.001), first phase by 41.5% (*P* < 0.001), and second phase by 38.4% (*P* < 0.001). Despite interindividual differences in GSIS response to PRED, no significant differences were observed according to body mass index, gender or age. Comparing the effects of GCs at equipotent anti-inflammatory doses, DEX had a more pronounced inhibitory effect on GSIS than HC or PRED.

**Conclusions.** – In vitro, low-dose PRED treatment significantly impacted GSIS. DEX had a more unfavorable impact on GSIS than HC or PRED, indicating that metabolic effects do not align with anti-inflammatory potency.

© 2024 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

## 1. Abbreviations

GSIS glucose-stimulated insulin secretion

GCs glucocorticoids

GCID glucocorticoid-induced diabetes

PRED prednisolone

DEX dexamethasone

HC hydrocortisone

GR glucocorticoid receptor

## 2. Introduction

Glucocorticoids (GCs) are widely prescribed medications used to treat various conditions: inflammatory disease, autoimmune disorder, cancer and organ transplant rejection. At any given time, 1–3% of the general population is receiving long-term GC therapy [1,2]. While GCs are known for their anti-inflammatory properties, they also significantly affect glucose and lipid homeostasis. Consequently, 2–40% of patients develop GC-induced diabetes (GCID) as a side effect [3–5]. Notably, GCID risk is elevated regardless of the route of GC administration, whether oral, inhaled or topical [4]. This metabolic impact is further seen in Cushing syndrome, a condition characterized by endogenous cortisol excess, where 7–64% of patients develop impaired glucose tolerance or diabetes [6].

Insulin resistance is the primary mechanism underlying GCID [7–10]. Short-term (2–15 days) administration of dexamethasone (DEX, 3–5 mg) or prednisolone (PRED, 30 mg) in healthy volunteers, and chronic high-dose corticosterone exposure in mice, enhanced

<footnote>* Corresponding author.</footnote>

<footnote>** Co-corresponding author.</footnote>

<footnote>Adresses e-mail : caroline.bonner@univ-lille.fr (C. Bonner), stephanie.espiard@univ-lille.fr (S. Espiard).</footnote>
insulin secretion and increased β-cell function and mass. These changes are compensatory responses to GC-induced insulin resistance [9,11–13]. This compensatory nature makes studying the direct effects of GCs on β-cell function in vivo particularly challenging. However, acute GC administration demonstrates distinct effects on insulin secretion. In interventional studies with healthy volunteers, a single oral dose of PRED 15–75 mg or DEX 1 mg directly impaired insulin secretion during glucose infusion, meal tests and oral glucose tolerance tests [9,14,15]. These findings are further supported by in vitro studies using rat or mouse-perfused pancreas and murine or human cell lines treated with DEX, hydrocortisone (HC), or corticosterone. Both acute and chronic GC exposure affects β-cell function, specifically by inhibiting glucose-stimulated insulin secretion (GSIS) in a time- and dose-dependent manner [16–23]. Studies on human islets demonstrated that GSIS remained unimpaired at physiological GC concentrations (20 nM cortisol or 200 nM cortisone) [24], while impairment emerges at supra-pharmacological concentrations, such as 2 µM DEX [18,23].

Translating these experimental findings into clinical practice presents several challenges. Although PRED is the most commonly prescribed GC [2], with low-dose therapy (≤ 7.5 mg/day) recommended for chronic treatment [25], most in vitro studies used DEX at supra-clinical concentrations. Pharmacokinetic data indicate that oral PRED doses of 5–10 mg achieve peak plasma concentrations of 300–700 nM (equivalent to 45.6–106.4 nM DEX) [26]. To bridge the gap between laboratory research and clinical practice, our study had two aims. Firstly, we evaluated the impact of clinically relevant low-dose PRED (250 nM) on GSIS in human islets. Secondly, given that GCs possess distinct pharmacokinetic profiles, we compared the effects of PRED, DEX and HC on GSIS at equipotent anti-inflammatory doses.

# 3. Research design and methods

## 3.1. Human islet isolation

Human islets were isolated from brain-dead donors using a modified Ricordi method, as previously described [27,28]. Following purification and washing, the endocrine fraction was cultured for 18–36 hours prior to experimentation, in complete CMRL media containing 5.5 mM glucose (Gibco, Life Technologies, Paris, France) and supplemented with 0.625% human serum albumin (HSA) and 100 U/mL penicillin-streptomycin (Gibco, Cat #15140122). All experimental procedures complied with French regulations and were approved by the Institutional Review Board of the University and University Hospital of Lille, France. Only islets exhibiting > 90% viability and > 70% purity (endocrine-to-exocrine ratio) were selected for experiments.

## 3.2. GC treatment

Human islets (300 islet equivalents) were washed twice in DPBS 1X (Gibco, Cat #14040141) and cultured in a 5.5 mM glucose media (Gibco, Life Technologies, Paris, France), supplemented with 0.625% human serum albumin (HAS), 100 U/mL penicillin-streptomycin (Gibco, Cat #15140148). The media contained either GCs (PRED, HC, DEX) or 0.001% methanol/ethanol (control). Clinical oral PRED dosing ranges from 5–90 mg/day for acute treatment, while chronic therapy typically targets the lowest possible dose, ≤ 7.5 mg/day, corresponding to plasma peak concentrations of approximately 300–700 nM (Supplementary Table 1) [29–38]. To investigate PRED's impact on GSIS, islets were treated with PRED (Sigma-Aldrich, Cat# P6004) at 250 nM, 500 nM, and 1 µM for 24 h. Based on equipotent anti-inflammatory conversion factors (where

5 mg PRED equals 20 mg HC or 0.76 mg DEX) [25,39], HC was used at 1 µM (Sigma-Aldrich, Cat# H0888) and DEX at 38 nM (Sigma-Aldrich, Cat# D2915).

## 3.3. Glucose-stimulated insulin secretion (GSIS) assessment using dynamic islet perfusion

For each perfusion experiment, 300 islet equivalents were loaded into individual chambers and perfused at 1 mL/min with continuously gassed KREBS solution containing 1 mg/mL BSA (pH 7.3) [40]. Islets underwent 50 minutes' low glucose (3 mM) preincubation before sample collection. Effluent fractions were then collected at 2-minute intervals for 20 minutes during sequential exposure to low (3 mM) and high (15 mM) glucose concentrations. Flow rate, oxygen level, temperature and pressure were maintained constant throughout the experiment. Following perfusion, islets were recovered from each chamber and transferred to 500 µL acid-ethanol solution (1.5% HCl, 70% EtOH, 28.5% ddH₂O) for insulin extraction [41]. Insulin secretion rates were normalized to total insulin content and expressed as percentage per minute. GSIS was quantified by analyzing the area under the curve (AUC) and evaluating both first- and second-phase insulin secretion (calculated as the average of respectively the first and last 10 minutes of 15 mmol/L glucose stimulation). GSIS was further analyzed by calculating the percentage decrease in total AUC and first and second-phase insulin secretion as:

$$ \frac{(\text{vehicle treated islets} - \text{GC treated islets})}{(\text{vehicle treated islets})} \times 100 $$

## 3.4. Donor characteristics

Clinical and biological characteristics of all donors are summarized in Supplementary Table 2. Donors were categorized according to body mass index (BMI) as follows: lean (BMI < 25 kg/m²), overweight (BMI > 25 kg/m² to < 30 kg/m²), obese (BMI 30–34.9 kg/m²), and morbidly obese (BMI ≥ 35 kg/m²). Glycemic status was classified based on HbA1c level: normal glycemia (HbA1c < 5.7%) and glucose intolerant (HbA1c 5.7–6.4%) [42].

## 3.5. Statistical analysis

Statistical analyses were performed with GraphPad Prism 10.2.0 (GraphPad Software, La Jolla, California, USA). Data are expressed as mean ± SEM. Comparison between control and GC treatment used non-parametric Wilcoxon paired t-tests. Comparison between groups used non-parametric Wilcoxon unpaired t-tests. Comparison between the different doses of PRED and GCs at equipotent dose used one-way ANOVA with Sidak's multiple comparison post-hoc tests, and two-way ANOVA and non-parametric tests with Sidak's post-hoc tests for multiple comparisons, as applicable. Differences were considered significant at *P* < 0.05. Significance was expressed as follows: *P* < 0.05, **P* < 0.01, ***P* < 0.001 and ****P* < 0.0001.

# 4. Results

## 4.1. Low therapeutic dose of prednisolone inhibits biphasic insulin secretion in human islets

In our dose-response study, PRED treatment at 250 nM, 500 nM and 1 µM significantly reduced both first- and second-phase insulin secretion compared to untreated control islets, with comparable inhibition across all doses (Fig. 1A, B). Insulin content remained unchanged (n = 4) (Fig. 1C). Based on these findings, we selected
<figure><img src="image_3.png" /><figcaption>**Fig. 1.** Treatment with a low dose of PRED inhibits the first and second phases of insulin secretion in islets isolated from donors with various metabolic phenotypes. Glucose-stimulated insulin secretion assessed by dynamic perfusion in human islet cultures treated with vehicle (gray), 250 nM (red), 500 nM (blue), or 1 µM (green) PRED for 24 h. (A) Islets were perfused with 3 mmol/L and 15 mmol/L glucose concentrations, and insulin secretion was normalized to percentage insulin content (n = 4). (B) The first and second phases of insulin secretion were calculated as the first and the last 10 minutes of 15 mmol/L glucose stimulation, respectively. Comparison between the control vehicle-treated islets and PRED-treated islets in the first and second phase of insulin secretion used non-parametric Wilcoxon paired t-tests; \*\*\*P = 0.0001, for PRED 250 nM vs. control, \*\*\*P = 0.0003, for PRED 500 nM vs. control, \*\*\*P < 0.0001, for PRED 1 µM vs. control, for the first phase of insulin secretion; \*\*P = 0.0016, for PRED 250 nM vs. control, \*\*P = 0.0019, for PRED 500 nM vs. control, \*\*P = 0.0018, for PRED 1 µM vs. control, for the second phase of insulin secretion. (C) Insulin content of human islets at the end of dynamic perfusion experiments (n = 4). Comparison between controls and PRED-treated islets used non-parametric Wilcoxon paired t-tests. (D) After 24 h treatment with vehicle (gray) or 250 nM PRED (red), islets were perfused with 3 mmol/L and 15 mmol/L glucose concentrations, and insulin secretion was normalized to percentage insulin content (n = 7). (E) The first and second phases of insulin secretion were calculated as the first and the last 10 minutes of 15 mmol/L glucose stimulation, respectively. Comparison between the control islets and PRED treatment in the first and second phases of insulin secretion used non-parametric Wilcoxon paired t-tests; \*P = 0.0156. (F) Insulin content of human islets at the end of dynamic perfusion experiments (n = 7). Comparison between the controls and PRED-treated islets used non-parametric Wilcoxon paired t-tests.</figcaption></figure>

the lowest dose (250 nM) for subsequent experiments. In a follow-up study using 7 additional islet preparations for a total 11 donors, 24-hour treatment with 250 nM PRED consistently decreased both phases of insulin secretion compared to controls (Fig. 1D, E), while maintaining comparable insulin content between groups (Fig. 1F).

## 4.2. Prednisolone-induced inhibition of glucose-stimulated insulin secretion is consistent across donor demographics

The magnitude of PRED-mediated GSIS inhibition varied considerably between donors (Supplementary Fig. 1), with reductions in insulin secretion ranging from 11.2% to 67.6% for total AUC, 17.3% to 79.9% for first-phase insulin secretion, and 5.2% to 52.9% for second-phase secretion (Supplementary Table 2). Despite this variability, PRED's inhibitory effect showed no statistically significant differences when stratified by BMI (lean (n = 5) vs. overweight (n = 4); Fig. 2A–C), gender (male (n = 7) vs. female (n = 4); Fig. 2D–F), age (<50 years [n = 4] vs. > 50 years [n = 7]; Fig. 2G–I), or glycated hemoglobin (HbA1c: < 5.7 [n = 6] vs. ≥ 5.7 [n = 5]; Fig. 2J–L). However, islets from overweight and male donors showed a trend toward greater PRED-mediated inhibition (Fig. 2A–F).

## 4.3. Comparative effects of equipotent anti-inflammatory doses of GCs on biphasic insulin secretion in human islets

In clinical practice, low therapeutic oral GC doses are defined as ≤ 7.5 mg/day PRED equivalent, corresponding to ≤ 30 mg/day HC and ≤ 1.2 mg/day DEX [25]. We compared these equipotent doses using islet preparations from 5 donors. DEX demonstrated significantly greater inhibition of insulin secretion compared to PRED and HC (Fig. 3A), with more pronounced impairment of both first- and second-phase insulin secretion (Fig. 3B). Islet insulin content remained comparable across all treatment groups (Fig. 3C). Analysis of percentage inhibition revealed greater DEX-mediated reduction in total insulin secretion (AUC) compared to HC and PRED (Fig. 3D, F). While inhibition of first-phase secretion was comparable across all GCs, DEX induced significantly greater suppression of second-phase secretion compared to HC and PRED (Fig. 3E).

# 5. Discussion

The present study demonstrated that low-dose GC treatment significantly impaired insulin secretion in vitro, with DEX exhi-
<figure><img src="image_4.png" /><figcaption>**Fig. 2.** Inhibition of glucose-stimulated insulin secretion at low therapeutic dose of PRED in donor islets is consistent across BMI, age and gender subgroups. Percentage decrease in area under the curve (AUC) and the first and second phase of glucose-stimulated insulin secretion in human islets treated with vehicle or 250 nM PRED for 24 h. (A - C) Human donors stratified by BMI as lean (< 25 kg/m², light red bars, *n* = 5) and overweight (>25 kg/m² to < 30 kg/m², dark red bars, *n* = 4). (D - F) Human donors stratified by gender as males (light red bars, *n* = 7) and females (dark red bars, *n* = 4). (G - I) Human donors stratified by age as younger (< 50 years, light red bars, *n* = 4) and older (>50 years, dark red bars, *n* = 7). (J - L) Human donors stratified by HbA1c as normoglycemic (<5.7, light red bars, *n* = 6) and glucose intolerant (≥5.7, dark red bars, *n* = 6). All data are expressed as mean ± SEM. Statistical analysis used non-parametric Wilcoxon paired t-tests.</figcaption></figure>

biting stronger inhibitory effects than PRED or HC at clinically relevant concentrations [26,43]. Notably, there was substantial individual variability in GC-mediated effects on GSIS.

While daily and cumulative GC dose are established risk factors for GCID [25,44-47], the reported relationship between treatment duration and GCID risk is inconsistent [45-47]. Previous in vitro studies showed dose-dependent GSIS inhibition by DEX [20,21]. However, these pharmacological findings have limited clinical relevance, as long-term therapy typically targets daily doses of ≤ 7.5 mg/day PRED equivalent [48]. Earlier studies examining human islets used 2 µM DEX [18,23], equivalent to approximately 13 µM PRED, a concentration achievable with 400 mg oral PRED [25,39]. Our findings extend this knowledge by demonstrating that

even low doses (250 nM PRED, 1 µM HC, and 38 nM DEX) significantly inhibited GSIS.

The anti-inflammatory equipotency ratios relative to HC are 4:1 for PRED and 25:1 for DEX [25]. At equipotent concentrations equivalent to <5 mg oral PRED, DEX showed markedly stronger inhibition of biphasic insulin secretion than PRED or HC, which exhibited similar effects. This observation aligns with previous reports of dissociation between anti-inflammatory and hyperglycemic effects in different GCs [49]. This finding further supports the notion that anti-inflammatory efficacy and metabolic potency do not always correlate. A recent retrospective study corroborated these observations, showing that DEX treatment resulted in higher capillary glucose levels than HC and PRED, which demonstrated
<figure><img src="image_5.png" /><figcaption>**Fig. 3.** Treatment with low therapeutic equipotent anti-inflammatory doses of PRED, HC and DEX inhibits the first and second phases of insulin secretion in islets isolated from donors with various metabolic phenotypes. Glucose-stimulated insulin secretion assessed by dynamic perfusion in human islet cultures treated with vehicle (gray), 250 nM PRED (red), 1 µM HC (blue) or 38 nM DEX (green) for 24 h. Human islets were isolated from *n* = 3 normoglycemic donors, and *n* = 2 donors with overweight and glucose intolerance. (A) Islets were perfused with 3 mmol/L and 15 mmol/L glucose, and insulin secretion was normalized to percentage insulin content (*n* = 5). (B) The first and second phases of insulin secretion were calculated as the first and the last 10 minutes of 15 mmol/L glucose stimulation, respectively. Comparison between the control vehicle-treated islets and GC-treated islets in the first and second phase of insulin secretion used two-way ANOVA with Sidak's multiple comparison post-hoc tests; first phase: **P**=0.0012, for PRED, ***P**=0.0007, for HC, ****P<0.0001, for DEX; second phase: \*P=0.0164, for PRED, \*\*P=0.0019, for HC, \*\*\*P=0.0002, for DEX, relative to control vehicle-treated islets. (C) Insulin content of human islets at the end of dynamic perfusion experiments (*n* = 5). Comparison between the controls and GC-treated islets used one-way ANOVA and non-parametric tests with Sidak's post-hoc test for multiple comparisons. (D-F) Percentage decrease in area under the curve (AUC) and first and second phase of glucose-stimulated insulin secretion on human islets treated with vehicle (gray), 250 nM PRED (red), 1 µM HC (blue) or 38 nM DEX (green) for 24 h. All data are expressed as mean ± SEM. Comparison between controls and GC-treated islets used one-way ANOVA and non-parametric tests with Sidak's post-hoc test for multiple comparisons. AUC: \*P=0.00117, for PRED vs. DEX. Second phase: \*P=0.0230, for PRED vs. HC, \*P=0.0363, for HC vs. DEX, \*\*P=0.0013, for PRED vs. DEX.</figcaption></figure>

similar effects [50]. These differences likely stem from distinct pharmacological properties between GCs: receptor binding affinity, half-life and duration of action, all of which influence their genomic effects [25].

Age consistently emerges as the primary risk factor for GCID [45-47], while associations with ethnicity, BMI, and familial diabetes history show less consistency across studies [45-47]. Kidney disease and reduced glomerular filtration rate also contribute to GCID risk [45,51]. While our study found no significant differences in PRED's effects on GSIS when stratified by BMI, gender, age or HbA1c, these findings warrant cautious interpretation due to the small number of donors and potential stress effects induced by islet isolation. Moreover, our analysis lacked data on ethnicity and baseline kidney function. Recent research identified a type-2 diabetes (T2D)-associated polygenic score that correlates with GCID susceptibility [45]. Studies of polygenic scores highlighted the crucial role of genetic variants affecting β-cell function and insulin secretion in the pathogenesis of diabetes [52]. The marked variability in GC-mediated inhibition of insulin secretion between donors

suggests that genetic factors modulating β-cell response to GCs likely represent a critical determinant of GCID risk.

The precise mechanisms underlying GCID and GC-induced β-cell dysfunction are not fully understood. Studies in mice showed that GC receptor (GR) overexpression significantly reduced acute insulin response to glucose, suggesting direct GR-mediated inhibition of insulin release [53]. Insulin secretion exhibits a characteristic biphasic pattern: an initial phase within 5 minutes of glucose exposure, followed by a sustained second phase lasting 2-4 hours under persistent glucose elevation. Our perfusion analysis enabled examination of both phases. Among five previous studies using dynamic perfusion to investigate GC effects on GSIS [20-22,54,55], one study, using rats islets and high doses of DEX (6.3 µM), reported effects on both phases [55]. Impaired first-phase insulin secretion typically represents an early T2D marker and plays a crucial role in suppressing endogenous glucose production, while the second phase mediates peripheral glucose uptake [56]. Our findings demonstrate that GCs affect both phases of insulin secretion, consistent with the critical role of intracellular Ca2+ signaling in
both acute and sustained insulin release and the observation that reduced Ca2+ efficiency contributes to secretion defects secondary to GC treatment [16–23]. In vivo studies showed that short-term DEX treatment in insulin-sensitive individuals induced compensatory increases in insulin secretion in response to global insulin resistance [12]. However, this compensatory response diminished with prolonged treatment in obese and streptozocin-induced diabetic rats, leading to sustained insulin resistance [7,57], potentially contributing to the development of GCID.

A key strength of our study lies in using human islets, as most previous research relied on rodent models or immortalized cell lines [58]. This distinction is crucial, given that GR affinity differs between mice and humans, limiting the clinical relevance of earlier findings [59]. However, several limitations merit consideration. Firstly, limited islet availability prevented molecular analyses of pathways such as p38 MAPK/TXNI [60–62], insulin biosynthesis and signaling cascades [18–20,23,63]. Secondly, while considered chronic for in vitro analysis, our 24-hour treatment duration was relatively short, and longer exposure might reveal β-cell dedifferentiation into exocrine cells [64]. Thirdly, although we confirmed islet viability visually before each experiment, we did not specifically assess viability and apoptosis, despite GCs' known potential to induce β-cell apoptosis [58].

## 6. Conclusion

The present study demonstrated that low-dose PRED treatment inhibited GSIS in vitro. However, the extent to which this direct inhibitory effect counterbalances insulin resistance-induced hyperinsulinemia in vivo requires further investigation. Our findings support previous studies suggesting that interindividual β-cell susceptibility to GCs may predispose certain individuals to GCID. Furthermore, DEX has a more detrimental effect on GSIS, underscoring that anti-inflammatory equipotency does not equate to metabolic potency. Therefore, our findings confirm that PRED should remain the GC of choice in most clinical settings, while emphasizing the importance of bearing in mind potential metabolic effects even at low doses.

## Disclosure of interest

The authors declare that they have no competing interest.

## Author contributions

CB and SE conceived and supervised the study. OT, MCV, CS, CB, and SE designed the experiments and wrote the manuscript. OT conducted the majority of the experiments. CS, CB, and SE supervised data analysis. MML, IL, AA, and AC performed specific experiments. VG and JKC supervised islet isolation and quality control. JKC and FP provided human islets and contributed to the detailed analysis of donor phenotypes. All authors approved the final version of the manuscript.

## Funding

This study was funded by the Société Française de Diabétologie and SANTELYS for SE, the European Consortium for Islet Transplantation funded by the Juvenile Diabetes Research Foundation for JKC and FP, and the European Genomic Institute for Diabetes (E.G.I.D) ANR-10-LABX-0046 for FP. OT received a PhD stipend from the University of Lille, Lille, France.

## Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

## Acknowledgments

We thank the islet isolation team of Inserm U1190, Translational Research for Diabetes, University of Lille, for their technical support.

## Appendix A. Supplementary data

Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.ando.2024.101676.

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