Inflammatory cytokines, particularly IL-1β, TNF-α, and interferon-gamma (IFN-γ), secreted by infiltrating immune cells, not only exert cytotoxic effects on β-cells but also disrupt endothelial cell function within the microvasculature (20). These cytokines impair the structural integrity of islet capillaries by promoting endothelial apoptosis and increasing vascular permeability. The islet endothelium, crucial for maintaining optimal oxygen and nutrient exchange, becomes compromised under inflammatory stress. This leads to increased vascular permeability, reduced nitric oxide bioavailability, and endothelial cell apoptosis. As the vasculature deteriorates, the effective delivery of oxygen and nutrients to β-cells diminishes, contributing to the onset of hypoxia (21). Additionally, chronic inflammation leads to the deposition of extracellular matrix proteins and fibrosis, which physically obstructs oxygen diffusion within the islets (22). This fibrotic remodeling occurs in parallel with increased leukocyte adhesion and transmigration, facilitated by the upregulation of adhesion molecules such as ICAM-1 and VCAM-1 on endothelial surfaces, further perpetuating local inflammation and vascular dysfunction (23). Beyond the islets, systemic vascular dysfunction is frequently observed in individuals with T1D, even in the early stages of the disease. This includes impaired flow-mediated dilation, increased arterial stiffness, and microvascular rarefaction. Such changes are not only markers of early cardiovascular risk but may also reflect persistent low-grade inflammation, endothelial activation, and impaired repair mechanisms. Importantly, alterations in vascular health may precede overt hyperglycemia and serve as early indicators of disease development in at-risk individuals.

Sustained hyperglycemia, a hallmark of T1D, exacerbates hypoxia through several mechanisms. High glucose levels induce oxidative stress in endothelial cells, reducing their ability to respond to angiogenic signals and repair damaged vasculature (24, 25). Furthermore, hyperglycemia increases the metabolic demand of β-cells, forcing them to consume more oxygen for insulin production and secretion (26, 27). This hypermetabolic state creates an oxygen imbalance, where demand surpasses supply, further deepening the hypoxic state. Hyperglycemia also induces advanced glycation end products (AGEs), which contribute to endothelial dysfunction and impair microvascular function (28).

The autoimmune nature of T1D results in the infiltration of immune cells, including T cells, B cells, and macrophages, into the pancreatic islets (29, 30). These cells are metabolically active and consume large amounts of oxygen to sustain their pro-inflammatory activity. For example, activated macrophages rely on aerobic glycolysis, a process driven by high oxygen consumption, to produce inflammatory mediators (31–33). Similarly, autoreactive T cells utilize oxygen to proliferate and release cytokines, further straining the already limited oxygen availability within the islets (34). This increased oxygen demand by immune cells compounds the hypoxic burden on β-cells, creating a vicious cycle of oxygen deprivation and immune activation (35, 36).

As β-cells are destroyed by autoimmune attack, the remaining β-cells are forced to compensate by increasing their insulin production. This overactivation leads to higher metabolic activity and oxygen consumption. Simultaneously, the stress imposed by hyperglycemia and inflammatory cytokines amplifies oxidative phosphorylation within β-cells, leading to excessive mitochondrial oxygen utilization and the generation of reactive oxygen species (ROS). The combination of high oxygen consumption and ROS-induced mitochondrial dysfunction further exacerbates hypoxia and β-cell vulnerability (37). Unlike other tissues, β cells have relatively low antioxidant capacity, making them particularly susceptible to oxidative stress (38). This environment promotes endoplasmic reticulum stress, unfolded protein response (UPR) activation, and mitochondrial dysfunction, processes that can trigger pro-apoptotic signaling cascades and compromise β-cell viability.

In T1D, the capillary network within the islets becomes increasingly dysfunctional due to pericyte loss, basement membrane thickening, and impaired angiogenesis. This dysfunction reduces the ability of the capillaries to adequately supply oxygen and nutrients to β-cells. Studies have shown that islet endothelial cells are particularly sensitive to inflammatory and hyperglycemic stress, which accelerates their deterioration and diminishes capillary density over time (39–41).

β-cells exhibit increased sensitivity to mitochondrial dysfunction, particularly when subjected to the simultaneous stressors of hypoxia and hyperglycemia (55, 56). Chronic hypoxia compromises the efficiency of oxidative phosphorylation by limiting oxygen availability, which is a critical substrate for the electron transport chain (57). This results in reduced ATP production and altering cellular energy homeostasis (58). Concurrently, hyperglycemia exacerbates the metabolic burden on mitochondria by driving an excessive flux of glucose-derived substrates through the tricarboxylic acid (TCA) cycle (59). This overloading of mitochondrial metabolism leads to an increased generation of ROS, creating a state of oxidative stress (60). The accumulation of ROS initiates widespread oxidative damage to lipids, proteins, and mitochondrial DNA, impairing the integrity and function of the mitochondria. This oxidative stress also disrupts the delicate balance of intracellular signaling pathways critical for β-cells survival, such as those regulating insulin secretion (56, 61). Additionally, the sustained oxidative environment activates apoptotic pathways, including mitochondrial outer membrane permeabilization and cytochrome c release, which accelerate β-cell death (62).

While mitochondrial dysfunction is well documented in type 2 diabetes, similar mechanisms may contribute to β-cell loss in T1D. However, the direct connection with T1D remains unclear, highlighting the need for future investigations to elucidate the role of mitochondrial impairment in T1D pathogenesis. Emerging evidence suggests that in T1D, immune mediated inflammation driven by cytokines such as IL-1β, TNF-α, and IFN-γ, along with local hypoxia, impairs mitochondrial respiration and elevates ROS production in pancreatic β-cells (63). This oxidative stress disrupts ATP synthesis, damages mitochondrial structures, and activates apoptotic pathways (64–66). Hypoxia further exacerbates mitochondrial dysfunction by stabilizing HIF-1α, which promotes a shift to glycolysis and impairs insulin secretion (4, 67, 68). Additionally, chronic inflammation impairs mitophagy, leading to the accumulation of dysfunctional mitochondria (69–71). These synergistic stressors accelerate β-cell dysfunction and death, highlighting potential therapeutic targets in oxidative stress regulation and immune modulation.

In addition to impairing mitochondrial bioenergetics, hypoxia and hyperglycemia synergistically activate endoplasmic reticulum stress pathways, thereby disrupting insulin biosynthesis and triggering apoptotic signaling cascades. Endoplasmic reticulum (ER) stress occurs when the protein-folding capacity of the ER is overwhelmed, leading to an accumulation of misfolded or unfolded proteins within its lumen. This disruption activates a highly conserved cellular mechanism known as the unfolded protein response (UPR). The UPR is designed to mitigate ER stress by halting general protein translation, increasing the production of molecular chaperones to aid in proper protein folding, and enhancing ER-associated degradation (ERAD) to clear misfolded proteins. However, when ER stress is prolonged or severe, the adaptive mechanisms of the UPR become maladaptive, triggering pathways that promote cell dysfunction and death, primarily through apoptosis (72–74).

In the context of hyperglycemia, elevated glucose levels intensify ER stress. The β-cells are highly sensitive to ER stress due to their essential role in insulin biosynthesis, a process that places a significant burden on the ER. Hyperglycemia increases the demand for insulin production, leading to excessive protein synthesis. This heightened demand exacerbates the likelihood of protein misfolding and impairs the ER’s ability to manage the cellular workload. Consequently, persistent hyperglycemia and ER stress contribute to β-cell dysfunction and eventual apoptosis, undermining insulin production and promoting hyperglycemia in a vicious cycle. Moreover, in hypoxic conditions, often observed in inflamed or poorly vascularized tissues, ER stress is further intensified due to impaired oxygen availability, which disrupts protein folding processes that rely on oxidative environments. Proper formation of disulfide bonds in the ER requires oxygen-dependent enzymes such as ERO1 and protein disulfide isomerase (PDI) (75–78). Hypoxia inhibits these redox reactions, leading to the accumulation of misfolded proinsulin, sustained activation of the unfolded protein response (UPR), and subsequent apoptotic signaling (79, 80). Combined with the effects of hyperglycemia, this dual stressor amplifies UPR activation, leading to chronic inflammation through the release of pro-inflammatory cytokines. This inflammatory state exacerbates systemic metabolic disturbances and cellular damage, contributing to the pathogenesis of T1D (81–84).

Hypoxia disrupts cellular homeostasis by impairing various metabolic and repair processes, including autophagy (85). Autophagy is a highly conserved cellular mechanism responsible for degrading and recycling damaged organelles, misfolded proteins, and other cytoplasmic debris (86, 87). In pancreatic β-cells, autophagy plays a critical role in maintaining cellular health, especially given their high metabolic activity and demand for protein synthesis to support insulin production. Under normal conditions, autophagy supports β-cell survival by mitigating oxidative stress, removing damaged mitochondria, and preserving mitochondrial quality, which is essential for ATP production and glucose-stimulated insulin secretion (43, 88, 89). During hypoxia, the ability of β-cells to sustain efficient autophagic activity is compromised. Hypoxia directly inhibits autophagic flux by interfering with key steps in the autophagy pathway. Specifically, the low oxygen levels can disrupt the activity of hypoxia-sensitive proteins and signaling pathways, such as AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin (mTOR) (90). AMPK typically promotes autophagy by activating the ULK1 complex, while mTOR acts as a negative regulator of autophagy (91, 92). In hypoxic conditions, dysregulation of these pathways reduces the induction and progression of autophagy, leading to the accumulation of damaged organelles, such as dysfunctional mitochondria. This exacerbates oxidative stress, as impaired mitochondria produce ROS, creating a self-reinforcing cycle of cellular damage (93–95).

Hyperglycemia compounds the autophagic impairment induced by hypoxia. Chronic high glucose levels generate excessive amounts of toxic metabolites, including AGEs and ROS (96). These metabolites further stress cellular systems and increase the demand for autophagic clearance (97–99). However, when autophagic capacity is already compromised due to hypoxia, β-cells are unable to efficiently clear these harmful byproducts. This leads to cellular dysfunction and damage, contributing to β-cell apoptosis and exacerbating the loss of insulin production. Furthermore, hyperglycemia-driven activation of the hexosamine biosynthetic pathway and protein kinase C (PKC) signaling disrupts autophagy by altering post-translational modifications of key autophagy-related proteins (100–102). These modifications reduce the efficiency of autophagosome formation and lysosomal degradation. Additionally, excess glucose exposure causes ER stress, which interacts with and inhibits autophagic pathways, further compounding the inability of β-cells to manage intracellular damage (103).

The combined effects of hypoxia and hyperglycemia create a cellular environment where repair and quality control mechanisms are overwhelmed. The progressive accumulation of damaged organelles, misfolded proteins, and oxidative stress amplifies β-cell dysfunction, contributing to the pathogenesis and progression of diabetes. These findings highlight the critical importance of maintaining autophagic activity for β-cell health and suggest potential therapeutic avenues aimed at restoring autophagic flux in hypoxic and hyperglycemic conditions. Given the multifaceted role of hypoxia in amplifying both immune dysregulation and β-cell intrinsic stress, therapeutic strategies that target hypoxia-adaptive pathways represent a novel and potentially transformative approach for disease modification in T1D.

Advancing our understanding of the molecular mechanisms linking hyperglycemia, hypoxia, and immune dysregulation in T1D is critical for developing targeted therapeutic strategies. Despite significant progress in characterizing the individual contributions of these factors, the precise cellular and molecular pathways through which they interact remain poorly defined. Future research should aim to dissect how hyperglycemia-induced metabolic stress and hypoxia collectively drive immune activation and β-cell dysfunction.

Organoid platforms that recapitulate the 3D architecture and cellular complexity of human islets are emerging as powerful tools for modeling these interactions under controlled conditions (110). By incorporating endothelial and immune components into islet organoids, researchers can more accurately simulate the hypoxic and inflammatory microenvironment characteristic of early T1D, allowing for longitudinal and mechanistic studies of disease initiation and progression.

Single-cell RNA sequencing (scRNA-seq) can play a pivotal role in elucidating the heterogeneity of cellular responses within the hypoxic islet microenvironment (111, 112). This approach enables the high-resolution mapping of transcriptomic changes in β-cells, endothelial cells, and infiltrating immune cells, revealing dynamic interactions that exacerbate hypoxia and inflammation. Spatial transcriptomics can complement scRNA-seq by providing spatial context to molecular changes, capturing the precise localization of hypoxia-related genes in relation to islet architecture and immune cell infiltration (35, 113, 114). Utilizing these techniques will provide novel insights regarding the role of hypoxia in the pathophysiology of T1D.

While advanced in vitro and omics-based platforms are critical for decoding the molecular underpinnings of hypoxia in T1D, translating these insights into viable therapies requires parallel innovation in delivery strategies capable of targeting the islet microenvironment with precision. The development of innovative therapeutic delivery platforms offers significant promise in targeting hypoxia and immune dysregulation in T1D. Traditional systemic treatments are often limited by off-target effects and insufficient delivery to the pancreatic islet microenvironment. Encapsulation technologies for β-cell transplants, for instance, could provide localized protection from immune attack while supporting oxygenation and nutrient delivery. These encapsulated transplants can be engineered to enhance survival and function in the hypoxic and inflamed microenvironment characteristic of T1D (115, 116).

Localized drug delivery systems also hold potential for improving therapeutic precision. Nanoparticle-based carriers, for example, can be designed to deliver antioxidants, hypoxia modulators, or anti-inflammatory agents directly to the islet microenvironment, reducing systemic side effects while maximizing efficacy. Hydrogel-based systems that release therapeutic agents in response to specific triggers, such as low oxygen levels or high reactive oxygen species, could offer another level of control. Further exploration of these delivery systems is needed to refine their effectiveness and scalability, as well as to evaluate their long-term safety and durability in clinical trials (117, 118).

As delivery technologies evolve to address site-specific therapeutic challenges, data-driven approaches offer a complementary framework to optimize intervention timing, predict therapeutic responses, and uncover non-obvious molecular targets within the hypoxia–autoimmunity axis. The integration of data-driven methodologies, particularly machine learning and computational modeling, has the potential to revolutionize the understanding and treatment of hypoxia-related mechanisms in T1D (119, 120). By leveraging machine learning techniques, researchers can extract meaningful insights from complex, large-scale datasets generated from multi-omics analyses, such as transcriptomics, proteomics, and metabolomics, as well as from clinical trials and patient registries. These algorithms can uncover intricate patterns, correlations, and predictive markers that might otherwise remain undetected (121–123). For instance, specific molecular drivers or pathways linking hypoxia to immune dysregulation, oxidative stress, and β-cell dysfunction can be identified, which are critical in the pathogenesis of T1D (124).

In parallel, computational modeling provides a powerful tool to simulate the dynamic and multifaceted islet microenvironment under various physiological and pathological conditions, including hypoxia, hyperglycemia, and inflammatory stress (125). These models enable researchers to explore how β-cells interact with immune cells and their surrounding microenvironment, allowing for the in silico testing of hypotheses about disease progression and potential interventions. By incorporating data from experimental studies and clinical observations, computational simulations can predict how changes in oxygen availability, nutrient levels, and inflammatory mediators influence β-cell viability and function (126).

Building on the foundation of experimental and computational advances, therapeutic efforts now focus on mitigating hypoxia-driven β-cell dysfunction through molecular and tissue-level interventions. Hypoxia in T1D plays a pivotal role in the dysfunction and death of pancreatic β-cells, amplifying the progression of the disease. Therefore, targeting hypoxia will pave the way to develop novel therapeutic modalities for T1D ( Supplementary Table 2 ). Restoring oxygen levels in the pancreatic microenvironment could alleviate hypoxic stress and improve β-cell survival (127–129). Oxygenation-based approaches, such as hyperbaric oxygen therapy or oxygen-releasing nanoparticles, have been proposed as potential strategies to counteract hypoxia. By addressing the oxygen supply to β-cells, these strategies may mitigate cellular damage and improve metabolic outcomes. Modulation of HIFs is another promising approach for addressing hypoxia-related β-cell dysfunction. Dysregulated HIF-1α signaling during hypoxia contributes to inflammation, impaired autophagy, and β-cell apoptosis (130). Stabilizing HIF-2α or targeting maladaptive HIF-1α activity could enhance angiogenesis, improve islet vascularization, and support β-cell survival. These strategies highlight the therapeutic potential of manipulating hypoxia signaling pathways to mitigate cellular stress and maintain β-cell health (131, 132).

Islet vascularization is critically impaired in T1D, exacerbating hypoxic conditions and β-cell loss. Promoting angiogenesis through VEGF-based therapies or cell-based approaches, such as mesenchymal stem cells (MSCs), could enhance islet perfusion and oxygen delivery (133, 134). These interventions may also address inflammation-induced vascular damage, improving overall islet resilience and functionality in the context of T1D (135).

Hypoxia-induced autophagy impairment is another significant contributor to β-cell dysfunction in T1D. Autophagy plays a crucial role in removing damaged organelles and maintaining cellular health. Hypoxia disrupts this process, leading to the accumulation of damaged mitochondria, increased oxidative stress, and β-cell death (136, 137). Strategies to restore autophagic flux, such as mTOR inhibition or AMPK activation, could counteract hypoxia-induced cellular damage by reactivating autophagy and enhancing cellular stress resilience (138–140). However, systemic administration of these modulators raises concerns due to their broad physiological effects, including metabolic dysregulation, immune suppression, or unintended impacts on proliferative signaling in non-target tissues (141, 142). To circumvent these risks, localized delivery approaches are being developed to restrict therapeutic activity to the pancreatic microenvironment. These include engineered nanoparticles that exploit local tissue markers or microenvironmental cues (such as pH or hypoxia) for targeted release, oxygen-sensitive or hypoxia-responsive hydrogels that release payloads in response to local oxygen tension and encapsulated islet or beta-cell devices incorporating drug reservoirs or responsive release systems (143–148). Such strategies aim to minimize off-target exposure while ensuring sufficient local concentration to modulate autophagy-regulatory pathways within the islet graft or endogenous pancreas. In islet transplantation, hypoxia remains a major barrier to long-term graft survival and function. Transplanted islets often experience hypoxic conditions due to insufficient vascularization, leading to graft failure. Approaches to mitigate hypoxia, such as preconditioning islets with hypoxia-mimicking agents or incorporating oxygen-releasing materials into encapsulation technologies, have the potential to improve transplant outcomes. Additionally, strategies that reduce hypoxia-induced inflammation and oxidative stress could further enhance graft viability (149).