Increased Serum VEGF-B Level Is Associated With Renal Function Impairment in Patients With Type 2 Diabetes

Elevated hydrostatic pressure disturbs expression of growth factors in human renal epithelial cells

Obstructive uropathy is a common kidney disease caused by elevated hydrostatic pressure (HP), but relevant molecular and cellular mechanisms have not yet been well understood. In this study, we ex vivo investigated the effects of elevated HP on human renal epithelial cells (HREpCs). Primary HREpCs were subjected to 100 cmH2O HP for 8 or 48 h. Then, the cells were cultured without HP stimulation for another 24 h or 72 h. Cell morphology showed almost no change after 8h HP treatment, but exhibited reversible elongation after 48h HP treatment. HP treatment for 8 h increased the expression of TGFB1 and VEGFA but decreased the expression of CSF2 and TGFB2. On the other hand, HP treatment for 48 h downregulated the expression of CSF2, TGFB2, PDGFB, VEGFA, and VEGFB, while upregulated the expression of TGFB3. Interestingly, all changes induced by 48 h HP treatment were detected more severe compared to 8 h HP treatment. In conclusion, elongated ex vivo HP loading to renal epithelial cells induces reversible changes on cell morphology and disturbs the expression of several growth factors, which provides novel mechanistic insight on elevated HP-caused kidney injury such as obstructive uropathy.

The role of perirenal adipose tissue deposition in chronic kidney disease progression: Mechanisms and therapeutic implications

Chronic kidney disease (CKD) represents a significant and escalating global health challenge, with morbidity and mortality rates rising steadily. Evidence increasingly implicates perirenal adipose tissue (PRAT) deposition as a contributing factor in the pathogenesis of CKD. This review explores how PRAT deposition may exert deleterious effects on renal structure and function. The anatomical proximity of PRAT to the kidneys not only potentially causes mechanical compression but also leads to the dysregulated secretion of adipokines and inflammatory mediators, such as adiponectin, leptin, visfatin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and exosomes. Additionally, PRAT deposition may contribute to renal lipotoxicity through elevated levels of free fatty acids (FFA), triglycerides (TAG), diacylglycerol (DAG), and ceramides (Cer). PRAT deposition is also linked to the hyperactivation of the renin-angiotensin-aldosterone system (RAAS), which further exacerbates CKD progression. Recognizing PRAT deposition as an independent risk factor for CKD underscores the potential of targeting PRAT as a novel strategy for the prevention and management of CKD. This review further discusses interventions that could include measuring PRAT thickness to establish a baseline, managing metabolic risk factors that promote its deposition, and inhibiting key PRAT-induced signaling pathways.

Vascular Endothelial Growth Factor-B Blockade with CSL346 in Diabetic Kidney Disease: A Phase 2A Randomized Controlled Trial

Key Points

Background

Increased vascular endothelial growth factor B (VEGF-B) expression in patients with diabetic kidney disease (DKD) is associated with increased lipid deposition in glomerular podocytes. Reducing VEGF-B activity in animal models of DKD using an anti–VEGF-B antibody improved histological evidence of glomerular injury and reduced albuminuria, effects attributed to prevention of ectopic lipid deposition in the kidney. CSL346 is a novel humanized monoclonal antibody that binds VEGF-B with high affinity. Targeting VEGF-B in patients with type 2 diabetes mellitus may improve DKD progression markers.

Methods

An international, randomized, double-blind, placebo-controlled, phase 2a study (NCT04419467) assessed CSL346 (8 or 16 mg/kg subcutaneously every 4 weeks for 12 weeks) in participants with type 2 diabetes mellitus and a urinary albumin-creatinine ratio (UACR) ≥150 mg/g (17.0 mg/mmol), and eGFR >20 ml/min per 1.73 m2. Efficacy, safety/tolerability, pharmacokinetics, and pharmacodynamics of CSL346 were evaluated. The primary analysis compared the change from baseline in log-transformed UACR between the two CSL346 dose groups combined versus placebo at week 16.

Results

In total, 114 participants were randomized. CSL346 did not significantly reduce UACR compared with placebo at week 16 (combined CSL346 group difference from placebo [95% confidence interval], 4.0% [−14.7 to 26.8]). Furthermore, no effect was seen in participant subgroups (degree of kidney impairment or sodium-glucose cotransporter 2 inhibitor use) or on urinary biomarkers reflecting proximal tubular injury. CSL346 was generally well tolerated; however, diastolic BP was significantly higher with CSL346 16 mg/kg versus placebo from week 2 onward, with differences ranging from +3.8 to +5.3 mm Hg (P = 0.002 at week 16).

Conclusions

CSL346 did not reduce UACR compared with placebo at 16 weeks in participants with type 2 diabetes mellitus and DKD and was associated with an increase in diastolic BP.

Clinical Trial registry name and registration number:

VEGF-B Blockade with the Monoclonal Antibody CSL346 in Subjects with DKD, NCT04419467.

Diabetic Macular Edema Is Predictive of Renal Failure in Patients With Diabetes Mellitus and Chronic Kidney Disease

CONTEXT

Chronic hyperglycemia in patients with diabetes mellitus (DM) causes retinal damage and leakage, resulting in vision loss. Although diabetic retinopathy (DR) and diabetic kidney disease (DKD) are usually correlated, the relationship between diabetic macular edema (DME) and DKD remains unknown.

OBJECTIVE

To assess whether DME presence can predict renal failure in patients with DM and chronic kidney disease (CKD).

METHODS

This retrospective cohort study used data from 120 healthcare organizations in the TriNetX network. Electronic medical records of approximately 90 million patients were reviewed. The study population was classified into DME and non-DME cohorts. Primary and secondary outcomes were new-onset end-stage renal disease (ESRD) and all-cause mortality, respectively. Covariate factors were incorporated to reduce confounding effects.

RESULTS

Before matching, the DME cohort used more medication and had poorer renal function and blood sugar control than the non-DME cohort. Subsequently, the 2 groups were well-matched in demographics, socioeconomic status, lifestyle, comorbidities, and medication usage. The DME cohort had a significantly higher risk of ESRD, dialysis, and renal transplantation than the non-DME cohort. Subgroup analyses showed consistent results irrespective of follow-up duration, initial estimated glomerular filtration rate, or glycated hemoglobin levels. Additionally, the DME cohort had a lower risk of all-cause mortality than the non-DME cohort.

CONCLUSION

Statistically significant 5-year increased risks of ESRD, dialysis, and renal transplantation were observed in patients with concurrent DME. Therefore, close monitoring and follow-up of the renal function in DM patients with DME are necessary and strongly recommended.

Serum VEGF as a predictive marker of glycemic control and diabetic nephropathy in Chinese older adults with type 2 diabetes mellitus

Objectives

Recent researches have demonstrated good correlation between vascular endothelial growth factor (VEGF) and diabetic nephropathy (DN); however, this relationship seems less clear-cut when VEGF was measured in blood samples. We tended to explore the possible association between serum VEGF and glycemic control and diabetic nephropathy severity in Chinese older adults with type 2 diabetes mellitus (T2DM).

Materials and methods

This study retrospectively enrolled 595 older T2DM adults at random. Participants were clinically grouped across the urine albumin-to-creatinine ratio (UACR) and the HbA1c tertiles by genders. Linear regressions were performed for the correlation of VEGF with HbA1c and UACR and binary logistic regressions for the odds of DN after adjusting for confounders. The receiver operating characteristic (ROC) curves were conducted for the predictive value of VEGF for DN.

Results

Both males and females with DN exhibited higher VEGF levels than non-DN (P < 0.001). Furthermore, a positive correlation of VEGF with UACR and HbA1c was presented regardless of adjusting confounding factors (P < 0.001). Serum VEGF level and fasting plasma glucose (FPG) were independent risk factors of DN in older adults of both genders (P < 0.05), while the risk prediction of DN by HbA1c only reflected in female patients (P < 0.05). The ROC curve of VEGF for DN had the area under curve (AUC) of 0.819 for males and 0.793 for females, indicating the clinical value of serum VEGF as a predictive biomarker.

Conclusions

Serum VEGF was strongly associated with UACR and HbA1c in both genders, and could be regarded as a predictive biomarker for glycemic control and diabetic nephropathy in older adults with T2DM.

Changing landscape of anti-angiogenic therapy: Novel approaches and clinical perspectives

Targeting angiogenesis has remained one of the important aspects in disease biology in general and cancer in particular. Currently (June 2023), over 593 clinical trials have been registered at ClinicalTrials.gov having inference of term 'angiogenesis'. A panel of 14 anti-angiogenic drugs have been approved by FDA for the treatment of variety of cancers and other human ailments. Although the anti-angiogenic therapy (AAT) has gained significant clinical attention as a promising approach in the treatment of various diseases, particularly cancer, however, sizable literature has accumulated in the recent past describing the aggressive nature of tumours after the drug holidays, evolving drug resistance and off-target toxicities. Nevertheless, the emergence of inscrutable compensatory or alternative angiogenic mechanisms is limiting the efficacy of anti-angiogenic drugs and focussing the therapeutic regime as a puzzle of 'Lernaean hydra'. This review offers an overview of recent updates on the efficacy of antiangiogenic therapy and the current clinical performance of aaRTK inhibitors. Additionally, it also explores the changing application landscape of AAT, focusing on its role in diabetic nephropathy, age-related macular degeneration and other neovascular ocular disorders. Combination therapy with antiangiogenic drugs and immune check point inhibitors (ICIs) has emerged as a potential strategy to enhance the therapeutic index of cancer immunotherapy. While clinical studies have demonstrated the clinical efficacy of this approach, they also highlight the complex and sometimes unpredictable adverse events associated with it. Normalizing tumour vasculature has been identified as a key factor in unlocking the full potential of ICIs, thereby providing hope for improved treatment outcomes. The future prospects and challenges of AAT have been described with special reference to integration of technological advances for enhancing its efficacy and applications beyond its discovery.

The link between diabetic retinal and renal microvasculopathy is associated with dyslipidemia and upregulated circulating level of cytokines

Purpose

To investigate the mechanisms underlying the correlations between diabetic retinopathy (DR) and diabetic nephropathy (DKD) and examine whether circulating cytokines and dyslipidemia contribute to both DR and DKD in patients with 2 diabetes mellitus (T2DM).

Methods

A total of 122 patients with T2DM were enrolled and categorized into the DM group (without no DR and DKD), DR group [non-proliferative DR (NPDR), and proliferative DR (PDR)] with no DKD), DR complicated with DKD groups (DR+DKD group). The biochemical profile, including fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and lipid profile were estimated, and plasma inflammatory and angiogenic cytokines [monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF)-A, C, D, and placental growth factor (PlGF)] were analyzed by protein microarrays. The atherogenic plasma index (API) was defined as low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein-cholesterol (HDL-C); atherogenic index (AI) was calculated as [(total cholesterol (TC) -HDL-C)/HDL-C], and atherogenic index of plasma (AIP) was defined as log (TG/HDL-C).

Results

By multivariable disordered regression analysis, after controlling for duration of DM and hypertension, LDL-C (p = 0.019) and VEGF-D (p = 0.029) resulted as independent risk factors for DR. Albumin-to-creatinine ratio (uACR) (p = 0.003) was an independent risk factor for DR with DKD. In DR, NPDR, and PDR groups, grades of A1, A2, and A3 of albuminuria increased with the severity of DR. In A1, A2, and A3 grade groups, the severity of DR (DM, NPDR, and PDR) increased with higher albuminuria grades. Kendall's tau-b correlation coefficient analysis revealed that FBG (p = 0.019), circulating level of PlGF (p = 0.002), and VEGF-D (p = 0.008) were significantly positively correlated with the grades of uACR (p < 0.001), and uACR grades were significantly correlated with DR severity (p < 0.001).

Conclusions

The occurrence and severity of DR are closely correlated with kidney dysfunction. Among the three kidney functional parameters, uACR resulted as the better indicator of DR severity and progression than glomerular filtration (eGFR) and serum creatinine (Scr). Impaired FBG was associated with microalbuminuria, emphasizing that well-controlled FBG is important for both DR and DKD. The link between diabetic retinal and renal microvasculopathy was associated with dyslipidemia and upregulated circulating level of angiogenic cytokines.

The Growth Factors: Potential Biomarkers and Therapeutic Targets in Kidney Diseases

BACKGROUND

Kidney diseases are a prevalent health problem worldwide. Although substantial progress has been made in understanding the pathophysiology of kidney disease, currently there is no satisfactory clinical treatment available to prevent or treat kidney disease. Therefore, strategies to establish early diagnosis, identify the key molecules, and develop novel therapeutic interventions to slow the progression of kidney diseases and reduce their complications are encouraged.

SUMMARY

The growth factors play a crucial role in the development of kidney diseases. The altered levels of growth factors are usually detected in circulation and urine in the disease course. A growing body of studies has suggested that growth factors, receptors, and related regulators are promising biomarkers for the diagnosis and/or prognosis and potential therapeutic targets for the treatment of kidney diseases. In this review, we summarize recent advances in the potential applications of growth factors for diagnostic biomarkers and therapeutic targets in kidney diseases and highlight their performances in clinical trials.

KEY MESSAGES

Most diagnostic and therapeutic strategies targeting growth factors are still far from clinical implementation. The better understanding of growth factor-regulated pathophysiology and the progress of new intervention approaches are expected to facilitate the clinical translation of growth factor-based diagnosis and therapy of kidney diseases.