Adipose tissue (AT) lipolysis insulin resistance results in excess free fatty acid (FFA) release. We tested the hypothesis that the ability of insulin to suppress AT lipolysis is unrelated to the ability of niacin to suppress lipolysis, because niacin acts through a different proximal signaling pathway. Ten volunteers (5 women and 5 men) with upper-body obesity and/or type 2 diabetes mellitus (T2DM) underwent two study visits with overnight intravenous infusions of niacin (1.4 mg/min) or saline, followed by a hyperinsulinemic-euglycemic clamp. FFA-palmitate Ra was measured using [U-13C] and [2H9]palmitate infusions; abdominal AT biopsies were performed before and during the insulin clamp. The suppression of FFA-palmitate Ra by insulin on the saline control day and by niacin after an overnight infusion were highly correlated (r = -0.93, P < 0.001). Fasting AT Akt (pAktS473/474-to-panAkt ratio, P = 0.01) and perilipin 1 (PLN1) (pPLN1S552-to-panPLN1 ratio, P = 0.02) phosphorylation were less during niacin treatment than in the saline control study. Because the suppression of lipolysis by insulin and niacin are highly correlated within individuals and because niacin and insulin act through different proximal signaling pathways, we propose dysregulated AT lipolysis in obesity/T2DM is due to dysfunction(s) in distal lipolysis proteins rather than isolated "insulin resistance."

Pancreatic β-cells play a central role in type 2 diabetes mellitus (T2DM), yet the interactions between β-cells and stromal components within the islet microenvironment remain poorly defined. We investigated the contribution of pancreatic fibroblasts to β-cell dysfunction and T2DM progression. We used single-cell sequencing technology and in vitro experiments to investigate the mechanisms by which bariatric surgery ameliorates T2DM. We introduce the novel concept of a "metabolic synapse" to describe the interaction between pancreatic fibroblasts and β-cells. Our findings reveal that pancreatic fibroblasts secrete excessive glutamate in the early stages of T2DM. Elevated glutamate concentrations within the islet microenvironment subsequently activate N-methyl-d-aspartic acid receptors (NMDARs), triggering PANoptosis in pancreatic β-cells and accelerating T2DM progression. Consistent with this, significant changes in NMDAR expression were observed in human pancreatic samples from patients with T2DM. These findings uncover a previously unrecognized fibroblast-β-cell communication pathway in the islet niche, provide mechanistic insights into T2DM pathogenesis, and highlight the glutamate-NMDAR axis as a potential therapeutic target for nonsurgical intervention.

Adipokines serve crucial functions in diabetic kidney disease (DKD) pathogenesis. Growth differentiation factor 5 (GDF5) is highly expressed in adipose tissue, but its specific role in DKD is unknown. In this study, we observed elevated GDF5 expression in both patients with DKD and db/db mice, suggesting a potential association between GDF5 and DKD progression. Elevated plasma GDF5 levels are associated with an increased risk of incident chronic kidney disease in patients with type 2 diabetes. In animal studies, adipose-specific overexpression of GDF5 increased circulating GDF5 and exacerbated renal injury in db/db mice, characterized by increased tubulointerstitial injury and inflammation infiltration. Conversely, adipose-specific knockdown reduced circulating GDF5 and alleviated renal injury. In vitro studies demonstrated that GDF5 induces partial epithelial-mesenchymal transition in renal tubular epithelial cells via activation of the SMAD1/5/8 signaling pathway, as evidenced by reduced E-cadherin expression and increased Snail1 levels. Notably, the supernatant from GDF5-treated injured HK-2 cells was found to enhance the secretion of proinflammatory cytokines by macrophages. These findings suggest that adipose-derived GDF5 acts as a novel mediator contributing to tubulointerstitial injury in DKD.

Weight cycling has been demonstrated, in humans and animal models, to increase cardiometabolic disease and disrupt glucose homeostasis. Both obesity itself and weight cycling cause adipose tissue inflammation and metabolic dysfunction. Studies show that even after weight loss, increased numbers of lipid-associated macrophages and memory T cells persist in adipose tissue and become more inflammatory on weight regain. This suggests that the immune system retains an obesogenic memory, which may contribute to the elevated inflammation and metabolic dysfunction associated with weight cycling. We show that blocking the CD70-CD27 axis, critical for the formation of immunologic memory, decreases the number of memory T cells and T-cell clonality within adipose tissue after weight loss and weight cycling. Furthermore, although CD70-/- mice have metabolic responses to stable obesity similar to those of wild-type mice, they are protected from the worsened glucose tolerance associated with weight cycling. Our data are the first to support mitigating the metabolic consequences of weight cycling through an immunomodulatory mechanism. We propose a new avenue of therapeutic intervention targeting memory T cells to minimize the adverse consequences of weight cycling. These findings are timely, given the increasing use of weight-loss drugs, which may lead to more instances of human weight cycling.

In response to the lockdowns and travel bans during the coronavirus disease 2019 pandemic, Peter C. Butler at the University of California, Los Angeles (UCLA), started a virtual islet biology seminar series. After the authors of this article joined him as co-organizers, this initiative became the Islet Research Seminar Series (IRSS). Like islets of Langerhans adapt to their changing environment, the islet biology community quickly embraced this new format. The IRSS evolved into a lasting scientific forum that convenes weekly and is attended by islet biologists from the U.S., Canada, Europe, and Israel. The series covers a range of topics in islet biology, with presentations from scientists representing all career stages. It has proven particularly valuable for trainees and early-stage investigators in exposing them to a variety of topics in islet biology without travel required and facilitating more spontaneous interactions with senior scientists than at in-person meetings. While the online format is not meant to replace live scientific conferences, we believe that the IRSS plays a unique role in keeping the islet biology community connected and abreast of the most recent scientific discoveries in our field. The success of this platform stands as a testament to the scientific community to adapt and thrive through challenges. This article is dedicated to Peter C. Butler, UCLA, who initiated the IRSS.

Pancreatic islet cells differentiate from a common progenitor pool through tightly regulated transcriptional and epigenetic programs. ISL1, a LIM homeodomain transcription factor, is essential for islet development, but its molecular functions remain poorly defined. Here, we demonstrate that ISL1 is critical for maintaining endocrine cell identity and enabling terminal differentiation, particularly of α- and β-cells. Using conditional Isl1 deletion in endocrine precursors, combined with single-cell RNA sequencing and chromatin profiling (H3K27ac and H3K27me3), we reveal disruption of the transcriptional and epigenetic landscape in Isl1-deficient islets. Loss of Isl1 results in the failure to establish α-cell identity, loss of δ- and γ-cell lineages, and the persistence of immature β-cells with impaired functional profiles in Isl1CKO mice. Longitudinal single-cell analysis shows that Isl1CKO endocrine cells exhibit sustained progenitor-like states and defective β-cell maturation. These defects are accompanied by activation of stress and diabetes-associated transcriptional programs, along with sex-specific responses that may influence disease onset and progression. Mechanistically, ISL1 represses intermediate progenitor programs and facilitates chromatin remodeling necessary for endocrine lineage commitment and terminal maturation. Our findings highlight a previously underappreciated role for ISL1 in preserving endocrine cell fate and function and offer insight into how its dysregulation may contribute to diabetes.

Skeletal muscle glucose transporter 4 (GLUT4) translocation to the plasma membrane determines glucose uptake in response to insulin and exercise and is disrupted in insulin resistance, making its experimental measurement critical. Confocal light microscopy is widely used for this purpose because of its ability to provide quantitative, high-resolution spatial information from small tissue amounts. However, conventional immunofluorescence colocalization microscopy lacks sensitivity and specificity in the detection of GLUT4 translocation. We validated the use of exofacial epitope-specific GLUT4 antibodies to quantify sarcolemmal GLUT4 translocation in fixed, nonpermeabilized adult human and rodent muscle fibers. Across human, mouse, and rat muscles, these antibodies sensitively detected stimulus-induced GLUT4 translocation, and labeling was abolished in muscle-specific GLUT4-knockout muscle, confirming specificity. Importantly, this study includes the first unambiguous visualization of endogenous GLUT4 translocation in intact human skeletal muscle fibers after insulin stimulation and exercise. In TBC1D4-knockout rats, insulin-stimulated GLUT4 translocation was absent despite wild-type-level GLUT4 expression, confirming an essential role for TBC1D4 in this process. Thus, exofacial GLUT4 antibodies provide a straightforward, sensitive, and specific approach to quantify endogenous GLUT4 translocation in fixed adult skeletal muscle.

Enteroviruses (EVs) have long been implicated in the development of islet autoimmunity (IA) and type 1 diabetes. However, given the ubiquity of EV infections in children, disease susceptibility is likely driven by host-specific immune responses rather than viral exposure alone. To investigate the host antibody response to EVs, we used virome-wide serological profiling (VirScan) to compare the EV antigen landscapes in IA-positive case children versus IA-negative control children across two independent pediatric cohorts separated by 12 years, using samples collected at the time point of seroconversion. We identified a reproducible and distinct EV-specific antibody signature in IA-positive case samples, with an enriched immunogenic hotspot localized within a highly conserved region in the 3D RNA-dependent RNA polymerase. Additionally, IA-positive male children exhibited significantly heightened antibody responses against a motif in the VP1 capsid protein compared with IA-negative male children (risk ratio 1.24; 95% CI 1.02, 1.52; P = 0.03). Our findings provide paradigm-shifting evidence that differential antiviral humoral responses, rather than the specific types of EV infection, play a central role in IA development, highlighting the need for an updated framework to study host-virus interactions in autoimmune pathogenesis.

Glucagon-like peptide 1 (GLP-1) receptor agonists improve dyslipidemia and reduce cardiovascular risk in type 2 diabetes (T2D), but the role of endogenous GLP-1 in lipid metabolism remains unclear. We evaluated the effect of dipeptidyl peptidase 4 (DPP-4) inhibition on the response of plasma triglycerides (TGs) to intraduodenal lipid and a mixed meal, and the impact of GLP-1 receptor blockade with exendin(9-39) in T2D. Fifteen participants with T2D, managed by diet and/or metformin, were studied on three occasions in a double-blind, randomized, crossover design. Vildagliptin (50 mg) or placebo was administered orally (t = -60 min), followed by intravenous exendin(9-39) from t = -60 to 150 min on one of the two vildagliptin days or 0.9% saline on two other days. A lipid emulsion was infused intraduodenally (2 kcal/min, t = 0-120 min), followed by a mixed meal (t = 120-150 min). Plasma TG levels, quantified by liquid chromatography-tandem mass spectrometry, increased after lipid and meal, with most individual TGs corresponding to those in the lipid emulsion. Vildagliptin reduced TG(54:4) and TG(54:5) concentrations (each P < 0.01), without affecting total TGs. Blocking endogenous GLP-1 during vildagliptin treatment increased plasma total TGs (P < 0.001), associated with elevations of 10 individual TG species (P < 0.05 each). These outcomes suggest that endogenous GLP-1 contributes to the physiological modulation of postprandial TG appearance in T2D.

There is significant interest in antigen-specific approaches to delaying type 1 diabetes in preclinical stages and supporting tolerance after diagnosis. We conducted a phase I trial of a nonintegrating DNA plasmid constructed to secrete the type 1 diabetes antigen preproinsulin (PPI) and the immune modulatory cytokines transforming growth factor-β1 (TGF-β1), interleukin-10 (IL-10), and IL-2. In this placebo-controlled, double-masked study of 47 adults with stage 3 type 1 diabetes, we showed that the drug is safe and well tolerated, with most reported adverse events (AEs) categorized as grade 1 and with no clinically significant difference in AEs among treatment groups. There were no untoward metabolic or immune effects. We found pharmacodynamic evidence of treatment, as demonstrated by a dose-dependent type 1 interferon (IFN) signature. Plasmid DNA, representing a pharmocokinetic measure, was detected in the two highest dosing groups. We did not find global or antigen-specific immune cell changes following treatment with a DNA plasmid expressing PPI, IL-2, IL-10, and TGF-β1, and we did not detect immune changes driven by IL-2, IL-10, or TGF-β1. Our results support further trials of this novel tolerizing antigen construct.

Diabetic corneal neuropathy (DCN) and diabetic retinopathy (DR) are microvascular complications and share common pathophysiological mechanisms. However, the relationship between them remains poorly defined. In this cross-sectional study, we aimed to investigate the association among DCN, DR, and tear mediators in 1,654 eyes from 822 participants, comprising 634 patients with type 2 diabetes and 188 healthy participants. Our data demonstrated that compared with control participants, all patients with diabetes had significantly impaired corneal nerve metrics, increased dendritic cell length and density, and larger corneal microneuromas, even in the absence of DR. Patients with nonproliferative DR (NPDR) and proliferative DR (PDR) showed significantly reduced corneal nerve parameters compared with those with no DR. Furthermore, patients with PDR presented significantly worse ocular surface clinical manifestations than patients with no DR, patients with NPDR, and control participants. Cumulative link mixed models demonstrated that corneal sensitivity and corneal nerve parameters were significantly associated with the severity of DR. Tear substance P concentrations were significantly lower across all stages of DR compared with control participants. Tear MMP-9, substance P, and IGFBP-3 levels were significantly associated with corneal nerve and ocular surface parameters. This study demonstrates that DCN precedes the onset of DR and worsens with the severity of DR. Corneal nerve status could be an early indicator and predictor of DR.

Alternative splicing is an essential mechanism for generating protein diversity by producing distinct isoforms from a single gene. Dysregulation of splicing that affects pancreatic function and immune tolerance has been linked to both types 1 and 2 diabetes. Next-generation sequencing technologies, with their short read lengths, are limited in their ability to accurately detect splice variants. Long-read sequencing technologies offer the potential to overcome these limitations by providing full-length transcript information; however, their application in single-cell RNA sequencing has been hindered by technical challenges, including insufficient read lengths and higher error rates. Furthermore, cell types that produce high levels of a single transcript, such as islet endocrine cells, can obscure identification of lower-abundance transcripts. In this study, we optimized a protocol for single-cell long-read sequencing in pancreatic islets to improve read length and transcript detection. Our findings demonstrate that 5' library preparation protocols outperform 3' protocols, resulting in better transcript identification. Furthermore, we show that targeted depletion of insulin transcripts enhances the detection of informative reads, highlighting the utility of transcript-depletion strategies. This optimized protocol enables isoform-specific gene expression analysis and reveals differential transcript usage across the various cell types in pancreatic islets. By leveraging this approach, we gain deeper insights into the transcriptomic complexity and cellular heterogeneity within pancreatic islets.

Recent advances in RNA sequencing (RNA-seq) techniques allow the identification of tissue-specific alternative splicing and can thereby provide new insights into molecular mechanisms of energy metabolism. Full-length transcriptomics based on single-molecule real-time sequencing (SMRT-seq) enable precise detection of isoforms with 99% accuracy in an unbiased manner. In this proof-of-concept study, we integrated SMRT-seq, bulk RNA-seq, and comprehensive metabolic phenotyping to investigate reduced mitochondrial function in the skeletal muscle of individuals with type 2 diabetes. Muscle biopsies were taken from nine individuals with type 2 diabetes and nine age- and BMI-matched glucose-tolerant men. Whole-body insulin sensitivity (WBIS) was assessed by hyperinsulinemic-euglycemic clamps, and muscle mitochondrial respiration was assessed by high-resolution respirometry. In muscle samples, SMRT-seq was used to create full-length reads and isoforms, which were mapped to the genome. Short-read sequencing was used to compare isoform expression between the groups. Participants with diabetes exhibited lower WBIS and fatty acid-driven and complex I-linked respiration compared with control participants. SMRT-seq revealed ∼67,000 isoforms originating from ∼14,000 unique genes. Although isoform numbers per gene did not differ, SMRT-seq-based mapping enabled refined data set clustering compared with conventional short-read sequencing and identified four splicing variants of the ATP5F1A gene encoding a subunit for ATP synthase. Among these, two novel transcripts were expressed exclusively in control participants. This study identified splicing variants of ATP synthase that were differentially expressed between participants with type 2 diabetes and those with normal glucose tolerance, which may contribute to the reduced fatty acid oxidation in diabetes.

Chronic overnutrition promotes excessive hepatic triglyceride accumulation, subsequently leading to insulin resistance and systemic metabolic dysfunction. Inorganic pyrophosphatase 1 (PPA1), an enzyme that hydrolyzes inorganic pyrophosphate, plays a key role in driving synthetic biochemical reactions. Here, we identified PPA1 as a novel regulator of systemic energy expenditure that functions by controlling hepatic production of fibroblast growth factor 21 (FGF21). FGF21 is a hormone predominantly secreted by the liver that protects against obesity by enhancing whole-body energy expenditure. Although nutritional states and various transcription factors are known to regulate hepatic FGF21 expression, the underlying mechanisms remain elusive. In this study, we demonstrate that hepatic-specific deletion of PPA1 effectively attenuates high-fat diet-induced obesity, reduces hepatic lipid deposition, and improves systemic insulin sensitivity in vivo. PPA1 ablation in the liver significantly elevates circulating FGF21 levels and increases whole-body energy expenditure by promoting adipose tissue browning and thermogenesis. Knockdown of hepatic FGF21 expression partially counteracts the protective effect conferred by PPA1 deficiency. Mechanistically, hepatic PPA1 deficiency elevates FGF21 through the GCN2/eIF2α/ATF4 pathway, a process that is dependent on the loss of its enzymatic activity. Our findings not only establish PPA1 as a critical regulator of systemic energy metabolism but also identify it as a novel modulator of FGF21, highlighting its potential as a therapeutic target for obesity and related metabolic disorders.

Pancreatic islet α-cells are increasingly recognized as amino acid sensors for the organism. Building on our prior work in β-cells, we sought to determine whether the mitochondrial phosphoenolpyruvate (PEP) cycle is involved in α-cell amino acid sensing. Three different methods were used to probe the PEP cycle, including pyruvate kinase activators (TEPP-46), and mice with α-cell-specific deletion (KO) of pyruvate kinase M (PKM1/2-αKO) or mitochondrial PEP carboxykinase (PCK2-αKO). The mitochondrial fuel leucine, in the presence of glutamine, antagonized alanine/arginine-stimulated Ca2+ influx and glucagon secretion under hypoglycemic conditions. Both PKM1/2 and PCK2 deletion prevented leucine from closing α-cell KATP channels. The Ca2+ response to amino acids was suppressed by pyruvate kinase activation with TEPP-46 and enhanced by α-cell deletion of PKM1/2 or PCK2-all without changing glucagon secretion. Using diazoxide/KCl to probe the pathways downstream of membrane depolarization, we identified a further role of the PEP cycle in homeostatically regulating Ca2+ levels. In sum, α-cell pyruvate kinase and the mitochondrial PEP cycle senses leucine and inhibits KATP channels similarly to β-cells, while restricting amino acid-stimulated membrane depolarization and Ca2+ influx. However, none of the amino acids tested, including alanine/arginine, regulate glucagon secretion by modulating membrane depolarization or Ca2+ influx.

GLP-1 receptor agonists have emerged as key pharmacological tools in the treatment of type 2 diabetes and obesity. While their anorexigenic effects are well characterized, the mechanisms by which GLP-1 modulates pancreatic β-cell function remain only partially understood. In this article, we argue that GLP-1 receptor agonists should be viewed as integrative regulators of β-cell function and explore the multifaceted actions of GLP-1 analogs on β-cell signaling. GLP-1 influences key secretagogues and intracellular mediators (calcium, glutamate, γ-aminobutyric acid, serotonin, and urocortin-3), with complex roles in insulin exocytosis. Additionally, we discuss the interplay between calcium and cAMP, and how GLP-1 modulates both pathways to coordinate insulin secretion. Emerging evidence suggests that GLP-1 analogs affect mitochondrial morphology and redox homeostasis. Considering the relatively low expression of classical antioxidant enzymes in β-cells, and their reliance on both glycolytic and mitochondrial metabolism to sustain insulin secretion, the influence of GLP-1 on mitochondrial dynamics and reactive oxygen species may play a central role in sustaining cell function and viability. Despite recent advances, critical gaps persist in the literature, particularly regarding organelle cross talk, intracellular calcium stores, and the modulation of vesicular content. Drawing on current evidence, we propose that three mechanistic dimensions (intracellular neurotransmitters, mitochondrial remodeling, and redox control) represent key areas where clarifying GLP-1 actions could most effectively advance the field. Further investigation into these mechanisms is essential for a comprehensive understanding of GLP-1 actions in β-cells. This knowledge may help refine current incretin-based therapies and identify novel molecular targets for the treatment of metabolic disorders.

Insulin autoantibodies (IAAs) are commonly measured by radiobinding assays (RBAs), which detect both high- and low-affinity binding. Improved assays that preferentially detect high-affinity IAA are likely to provide greater specificity and thereby increase the diagnostic accuracy of IAA for early-stage type 1 diabetes (T1D). This study aimed to develop and validate a novel bridging ELISA for IAA detection. The bridging ELISA detects IAAs by their bivalent cross-linking of two proinsulin moieties in fluid phase. Validation was performed by using samples from 227 patients with newly diagnosed stage 3 T1D and 1,021 control participants. Additionally, 202 children positive for IAA by RBA from general population screening were tested by the bridging ELISA and electrochemiluminescence (ECL) assay. At 99.5% specificity, ELISA detected IAA in 65.2% of patients with stage 3 T1D vs. 60.8% by RBA. Among children identified as having RBA-positive IAA in general population screening, 80.3% of those with multiple islet autoantibodies and 48.1% of those with a single IAA had ELISA-IAA positive findings (P < 0.0001). For children with a single IAA by RBA, ELISA detected 78.9% of those with ECL-IAA-positive findings vs. 27.9% of those with ECL-IAA negative findings (P < 0.0001). Samples that were IAA negative by ELISA showed lower antibody affinity. The ELISA-IAA assay demonstrates high sensitivity and specificity and could become a practical tool for T1D population screening and clinical diagnosis across laboratories.

The microtubule network in β-cells attenuates insulin secretion by pulling insulin secretory granules away from the plasma membrane. Thus, high-glucose-induced microtubule remodeling is required for robust glucose-stimulated insulin secretion. We now demonstrate that hormones secreted by α-cells regulate microtubule dynamics in β-cells through receptors for glucagon (GcgR) and glucagon-like peptide 1 (GLP-1R). Activation of GcgR or GLP-1R destabilizes microtubules in β-cells, accompanied by increased insulin secretion. In contrast, inhibiting these receptors attenuates high-glucose-induced microtubule destabilization and decreases secretion. Supporting the physiological significance of this regulation, β-cells in islets with a higher α-cell-to-β-cell ratio exhibit more dynamic microtubules than those with a lower ratio, and a high-fat diet challenge in mice, which can compromise β-cell secretion, attenuates this effect in their islets. Within individual islets, β-cells located near α-cells show faster microtubule remodeling upon glucose stimulation than those more distant from α-cells. Consequently, islets with a higher α-cell-to-β-cell ratio secrete more insulin in response to glucose stimulation and plasma membrane depolarization, results recapitulated by exogenous glucagon stimulation or chemically induced microtubule destabilization in islets with lower α-cell-to-β-cell ratios. These combined results suggest that α-cells use glucagon-mediated and/or GLP-1-mediated paracrine signaling to fine-tune β-cell secretion via microtubule remodeling.

Type 2 diabetes increases cardiovascular risk, with endothelial dysfunction playing a key role. Prolonged disease duration exacerbates cardiovascular risk, but the underlying mechanisms remain unclear. We previously demonstrated that red blood cells (RBCs) from individuals with type 2 diabetes impair endothelial function via reduced miRNA (miR)-210-3p. We investigated whether disease duration influences RBC-induced endothelial dysfunction and its link to miR-210-3p. RBCs were isolated from diabetic db/db mice of various ages and from humans with newly diagnosed (<1 year) or long-lasting type 2 diabetes (>7 years). Endothelial-dependent relaxation (EDR), miR-210-3p levels, its target protein glycerol-3-phosphate dehydrogenase 2 (GPD2), and oxidative stress marker 4-hydroxynonenal (4-HNE) were assessed. RBCs from 14- and 22-week-old, but not 7-week-old, db/db mice impaired EDR. These RBCs showed similarly reduced miR-210-3p levels and increased vascular GPD2 and 4-HNE expression. RBCs from individuals with long-lasting type 2 diabetes, but not from the newly diagnosed group, impaired EDR. After ≥7 years, RBCs from initially newly diagnosed individuals impaired EDR, which was rescued by miR-210-3p mimic transfection. In contrast, RBCs from healthy subjects did not impair EDR after follow-up. These findings underscore the pivotal role of disease duration for RBC-mediated vascular dysfunction, linked to miR-210-3p downregulation. RBC miR-210-3p may serve as a biomarker for diabetes-related vascular disease.

Angiotensin II (AngII) activation, a key driver of diabetes pathogenesis and associated complications, induces kidney injury by promoting oxidative stress and inflammation. Ferroptosis is an iron-dependent regulated cell death, playing a crucial role in kidney injury. This study aimed to explore the contribution of ferroptosis to AngII-induced kidney injury and its regulatory mechanisms. Our findings reveal that chronic AngII stimulation leads to renal dysfunction, characterized by elevated serum creatinine levels, increased urinary protein-to-creatinine ratio, and tubular injury. These changes are associated with ferroptosis in renal tubular epithelial cells (TECs) and a marked upregulation of dipeptidase 1 (DPEP1) expression. Notably, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively reversed ferroptosis in TECs, restored tubular integrity, and improved renal function. DPEP1 gene silencing and the DPEP1 inhibitor cilastatin significantly inhibited AngII-induced ferroptosis in TECs. Mechanistically, AngII upregulated DPEP1 expression via the transcription factor SP1. Elevated DPEP1 enhanced ubiquitination of SLC3A2, a key cystine/glutathione transporter. Furthermore, inhibiting DPEP1 with cilastatin in a mouse model effectively reversed ferroptosis and alleviated kidney injury. These findings highlight ferroptosis' key role in AngII-induced kidney injury and suggest DPEP1 targeting as a therapeutic strategy against AngII-driven renal damage.