bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.07.01.662673

Endothelial Kallikrein-Related Peptidase 8 Promotes Diabetic Nephropathy through a LIFR dependent mechanism

Abstract

BackgroundDiabetic nephropathy (DN) is the primary microvascular complication of diabetes mellitus; however, the exact pathways in endothelial cells (ECs) linked to DN progress remain unclear. Tissue kallikrein-related peptidases (KLKs) participate in pathophysiological processes in ECs. We aimed to explore the roles of endothelial KLKs in DN and define the underlying mechanisms. Methods and resultsKLK8 was the most highly upregulated member of KLKs in renal tissues in streptozotocin (STZ)-induced diabetic mice and cultured glomerular ECs (GECs) upon high glucose (HG) treatment. Both global (Klk8-/-) and endothelial Klk8 knockout (Klk8{Delta}EC) mice displayed improved albuminuria, mesangial matrix expansion and glomerulosclerosis caused by STZ compared to Klk8f/f mice. Single-cell RNA seq (scRNA-seq) showed that many pathways associated with DN in ECs, mesangial cells (MCs) and tubule cells were reversed in Klk8{Delta}EC mice. Endothelial-to-mesenchymal transition (EndMT) was extensively improved in Klk8{Delta}EC mice, and by KLK8 siRNA in cultured GECs upon HG. Using proteome and other biochemical approaches, we revealed that KLK8 cleaved syndecan-4(SDC4), which contributed to loss of glycocalyx integrity in GECs in cultured cells and animal diabetic models. Furthermore, scRNA-seq showed that Lifr was one of the key genes linked to the disease progressed in ECs and MCs and regulated by endothelial Klk8. LIFR signaling contributed to HG-induced GEC dysfunction and MC activation, which was associated with endothelial Klk8. Knockdown of Lifr by lentivirus-Lifr shRNA ameliorated hallmark features of DN and improved EndMT and Sdc4 expression glomeruli of diabetic mice. LIFR was upregulated in GECs and MCs in DN patients. Circulatory levels of LIF, KLK8 and soluble SDC4 were increased in patients with DN, and KLK8 level was positively correlated with LIF, soluble SDC4 and creatinine levels. ConclusionEndothelial KLK8 promotes GECs dysfunction and abnormal crosstalk with MCs through a LIFR-dependent signaling in DN, which immediately highlights therapeutic targets for DN. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=171 SRC="FIGDIR/small/662673v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@dae3b1org.highwire.dtl.DTLVardef@9aab24org.highwire.dtl.DTLVardef@59eaa5org.highwire.dtl.DTLVardef@13c138a_HPS_FORMAT_FIGEXP M_FIG C_FIG

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ni, X., Du, J., Li, M., Jiang, Y., Tang, Z., Xu, D.-H., Yin, H., Yuan, J., Zhu, X.-Y.. 2025-07-07. Endothelial Kallikrein-Related Peptidase 8 Promotes Diabetic Nephropathy through a LIFR dependent mechanism. https://doi.org/10.1101/2025.07.01.662673

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Autophagic flux is increased in peripheral blood mononuclear cells in atherosclerotic vascular disease and associates inversely with adverse cardiovascular events

Background: Autophagy is a homeostatic pathway supporting stress adaptation and is dysregulated in atherosclerosis. Its potential as a biomarker or therapeutic target in atherosclerotic vascular disease (ASVD) remains incompletely defined. We measured autophagic flux in peripheral blood mononuclear cells (PBMCs) from patients with peripheral arterial disease (PAD) or carotid stenosis (CS), compared with healthy controls, and explored clinical outcome associations. Methods: Ninety-four patients with PAD or CS and 19 healthy controls were studied. Autophagic flux was quantified from fresh blood using a validated ex vivo chloroquine inhibition ELISA measuring LC3BII accumulation. Major adverse cardiovascular events (MACE) and major adverse limb events (MALE) were ascertained over a median follow up of 828 days. Results: The ASVD cohort comprised claudication (n = 16), chronic limb threatening ischemia (CLTI; n = 49), and CS (n = 29). Autophagic flux was higher in ASVD than controls (mean 281.4 vs. 182.3 ng LC3BII/mg protein/h; p < 0.0001) and remained independently associated after multivariable adjustment. Within CLTI, concurrent infection was associated with lower flux (p = 0.001), approaching control levels (p = 0.327). In CLTI, higher flux quartiles were associated with lower MACE risk, most strongly for quartile 3 (hazard ratio 0.07 vs. quartile 1, 95% CI 0.01 to 0.50; p = 0.009). Conclusion: Autophagic flux is elevated in PBMCs from ASVD patients, independent of age and sex. Attenuated flux in CLTI with concurrent infection may indicate autophagic exhaustion in advanced disease. The association between higher flux and lower MACE in CLTI suggests prognostic utility, warranting evaluation in larger prospective studies.

pathology↗

Quantitative Model of the Ocular Immune Response during Seasonal Allergic Conjunctivitis

Allergic conjunctivitis is an inflammation of the conjunctiva caused by allergen; it is common disorder affecting up to 40% of the population. In this work, we study seasonal allergic conjunctivitis (SAC), also called "hay fever eyes", which is caused by exposure to airborne pollens. We develop a mathematical model quantifying the ocular immune system response to the allergens. First, we present a simplified qualitative description of the immunopathogenesis of SAC. Then, we express each chosen immunopathological mechanism mathematically to construct a system of thirty-one ordinary differential equations. We compare summary statistics of the predicted observable immune signals to experimental measurements and find our model captures key qualitative features of SAC progression. We then compare our predicted time series of histamine concentration to symptom scores and find a strong correlation suggesting the model predicts relevant clinically trends. Next, we calibrate the model through multi-step process. We find the most influential parameters are the production and depletion rates of IL-4, and the production rates of IL-5 and IL-8. These cytokines are targeted in treatments for asthma, atopic dermatitis, and severe eosinophilic associated disorder and suggest potential therapeutic targets for SAC. Our calibrated model mimics most of the summary statistics of the experimentally observable immune signals with discrepancies for IL-5 and IL-13 indicating that additional immunopathological mechanisms could be important.

pathology↗

Dysregulated Platelet GPIb alpha - VWF Signalling in Abdominal Aortic Aneurysm formation and Progression

Background: Platelets are critical drivers of thrombo-inflammatory responses in different cardiovascular diseases. Abdominal aortic aneurysm (AAA) is a progressive, life-threatening vascular disorder mainly characterised by chronic inflammation, extracellular matrix degradation, and the formation of a platelet-rich intraluminal thrombus (ILT). Experimental and clinical evidence identified platelets as main players in AAA pathology as evidenced by elevated platelet activation and procoagulant activity that critically contribute to AAA progression. Methods: The present study investigated the contribution of glycoprotein (GP)Ib alpha, the von Willebrand factor (VWF)-binding subunit of the platelet GPIb-IX-V complex, to AAA initiation and progression in experimental AAA using the ePPE mouse model and in patients. Results: Genetic ablation of platelet GPIb alpha significantly attenuated early aneurysm expansion in experimental AAA, indicating a critical role for GPIb alpha during the initial stages of aneurysm development. This initial effect was compensated at later time points showing no differences in aneurysm progression between groups. Notably, genetic deletion of GPIb alpha induced a constitutively hyperactive platelet phenotype already in naive mice that was further amplified during experimental AAA. This elevated platelet hyperactivity was mainly due to increased GPVI activation of platelets 28 days post-surgery. To assess the clinical relevance, spatial profiles of human ILT specimens from patients with AAA were analysed. In the ILT, we detected a highly compartmentalised distribution of GPIb alpha and VWF with pronounced enrichment within the luminal layer. In parallel, circulating VWF activity as well as platelet surface expression of GPIb alpha were significantly increased in patients with AAA. Conclusion: Collectively, these findings identify a dysregulated GPIb alpha-VWF axis in human AAA pathology, mainly characterised by enhanced platelet GPIb alpha surface expression and increased activity of circulating VWF.

pathology↗