Offenberger, J. | Search bioRxiv

bioRxiv2026

Abnormally low expression of tumor necrosis factor stimulated gene 6 (TSG-6) in obese type 2 diabetic mice contributes to altered inflammation and delayed cutaneous wound healing

Type 2 diabetes mellitus (T2DM) is a chronic disorder associated with obesity and hyperglycemia. T2DM is linked to significant clinical complications such as delayed wound healing and diabetic foot ulcers. Tumor necrosis factor-stimulated gene 6 (TSG-6) is a protein with multiple functions including regulation of cytokine binding to glycosaminoglycans in extracellular matrices and on vascular endothelial walls. Loss of TSG-6 in knockout mice increases skin inflammation and delays wound healing. Here, in both a genetic model (db/db mice) and a dietary model that simulates human T2DM (mice treated with a high-fat diet [HFD] and streptozotocin [STZ]), we observed sustained hyperglycemia and a reproducible delay in wound closure. TSG-6 expression was markedly reduced in diabetic skin in these models, both before injury and post wounding. HFD+STZ diabetic mouse wounds showed elevated levels of pro-inflammatory cytokines (IL-6, TNF-, and MIP-1) and lower levels of the anti-inflammatory cytokine IL-10, relative to normoglycemic mice. Re-introduction of TSG-6 protein into the wounds normalized healing rates, corrected abnormal cytokine expression levels, and increased macrophage accumulation in dermal and adipose compartments. Thus, T2DM is associated with reduced levels of TSG-6 in diabetic skin, which contributes to the pro-inflammatory milieu and the delay in wound closure.

physiology↗

bioRxiv2024

Behavioral impairments are linked to neuroinflammation in mice with Cerebral Cavernous Malformation disease

BackgroundCerebral Cavernous Malformations (CCMs) are neurovascular abnormalities in the central nervous system (CNS) caused by loss of function mutations in KRIT1 (CCM1), CCM2, or PDCD10 (CCM3) genes. One of the most common symptoms in CCM patients is associated with motor disability, weakness, seizures, stress, and anxiety, and the extent of the symptom or symptoms may be due to the location of the lesion within the CNS or whether multiple lesions are present. Previous studies have primarily focused on understanding the pathology of CCM using animal models. However, more research has yet to explore the potential impact of CCM lesions on behavioral deficits in animal models, including effects on short-term and long-term memory, motor coordination, and function. MethodsWe used the accelerating RotaRod test to assess motor and coordination deficits. We also used the open field test to assess locomotor activity and pathology-related behavior and Pavlovian fear conditioning to assess short--and long-term memory deficits. Our behavioral studies were complemented by proteomics, histology, immunofluorescence, and imaging techniques. We found that neuroinflammation is crucial in behavioral deficits in male and female mice with neurovascular CCM lesions (Slco1c1-iCreERT2; Pdcd10fl/fl; Pdcd10BECKO). ResultsFunctional behavior tests in male and female Pdcd10BECKO mice revealed that CCM lesions cause sudden motor coordination deficits associated with the manifestation of profound neuroinflammatory lesions. Our findings indicate that maturation of CCM lesions in Pdcd10BECKO mice also experienced a significant change in short- and long-term memory compared to their littermate controls, Pdcd10fl/fl mice. Proteomic experiments reveal that as CCM lesions mature, there is an increase in pathways associated with inflammation, coagulation, and angiogenesis, and a decrease in pathways associated with learning and plasticity. Therefore, our study shows that Pdcd10BECKO mice display a wide range of behavioral deficits due to significant lesion formation in their central nervous system and that signaling pathways associated with neuroinflammation and learning impact behavioral outcomes. ConclusionsOur study found that CCM animal models exhibited behavioral impairments such as decreased motor coordination and amnesia. These impairments were associated with the maturation of CCM lesions that displayed a neuroinflammatory pattern.

animal behavior and cognition↗