Blood pressure reduction and RAAS inhibition in diabetic kidney disease: therapeutic potentials and limitations

Efficacy of astragalus combined with renin-angiotensin-aldosterone system blockers in the treatment of stage III diabetic nephropathy: a systematic review and meta-analysis

OBJECTIVE

To determine the efficacy and safety of Astragalus combined with renin-angiotensin-aldosterone system (RAAS) blockers in treating stage III diabetic nephropathy (DN) by meta-analysis.

METHODS

PubMed, Embase, Cochrane Library, Wiley, and Web of Science databases were searched for articles published between August 2007 and August 2022. Clinical studies on Astragalus combined with RAAS blockers for the treatment of stage III DN were included. Meta-analysis was performed by RevMan 5.1 and Stata 14.3 software.

RESULTS

A total of 32 papers were included in this meta-analysis, containing 2462 patients from randomized controlled trials, with 1244 receiving the combination treatment and 1218 solely receiving RAAS blockers. Astragalus combined with RAAS blockers yielded a significantly higher total effective rate (TER) (mean difference [MD] 3.63, 95% confidence interval [CI] 2.59-5.09) and significantly reduced urinary protein excretion rate (UPER), serum creatinine (Scr), blood urine nitrogen (BUN) and glycosylated hemoglobin (HbAlc) levels. In subgroup analysis, combining astragalus and angiotensin receptor blocker significantly lowered fasting plasma glucose (FPG) and 24 h urinary protein (24hUTP) levels, compared with the combined astragalus and angiotensin-converting enzyme inhibitor treatment. Meanwhile, the latter significantly decreased the urinary microprotein (β2-MG). Importantly, the sensitivity analysis confirmed the study's stability, and publication bias was not detected for UPER, BUN, HbAlc, FPG, or β2-MG. However, the TER, SCr, and 24hUTP results suggested possible publication bias.

CONCLUSIONS

The astragalus-RAAS blocker combination treatment is safe and improves outcomes; however, rigorous randomized, large-scale, multi-center, double-blind trials are needed to evaluate its efficacy and safety in stage III DN.

Unveiling Selected Influences on Chronic Kidney Disease Development and Progression

Currently, more and more people are suffering from chronic kidney disease (CKD). It is estimated that CKD affects over 10% of the population worldwide. This is a significant issue, as the kidneys largely contribute to maintaining homeostasis by, among other things, regulating blood pressure, the pH of blood, and the water-electrolyte balance and by eliminating unnecessary metabolic waste products from blood. What is more, this disease does not show any specific symptoms at the beginning. The development of CKD is predisposed by certain conditions, such as diabetes mellitus or hypertension. However, these disorders are not the only factors promoting the onset and progression of CKD. The primary purpose of this review is to examine renin-angiotensin-aldosterone system (RAAS) activity, transforming growth factor-β1 (TGF-β1), vascular calcification (VC), uremic toxins, and hypertension in the context of their impact on the occurrence and the course of CKD. We firmly believe that a deeper comprehension of the cellular and molecular mechanisms underlying CKD can lead to an enhanced understanding of the disease. In the future, this may result in the development of medications targeting specific mechanisms involved in the decline of kidney function. Our paper unveils the selected processes responsible for the deterioration of renal filtration abilities.

An increase in albuminuria is associated with a higher incidence of malignancies

Background

A single albuminuria measurement is reported to be an independent predictor of cancer risk. Whether change in albuminuria is also independently associated with cancer is not known.

Methods

We included 64 303 subjects of the Stockholm CREAtinine Measurements (SCREAM) project without a history of cancer and with at least two urine albumin-creatinine ratio (ACR) tests up to 2 years apart. Albuminuria changes were quantified by the fold-change in ACR over 2 years, and stratified into the absence of clinically elevated albuminuria (i.e. never), albuminuria that remained constant, and albuminuria that increased or decreased. The primary outcome was overall cancer incidence. Secondary outcomes were site-specific cancer incidences.

Results

During a median follow-up of 3.7 (interquartile range 3.6-3.7) years, 5126 subjects developed de novo cancer. After multivariable adjustment including baseline estimated glomerular filtration rate and baseline ACR, subjects with increasing ACR over 2 years had a 19% (hazard ratio 1.19; 95% confidence interval 1.08-1.31) higher risk of overall cancer compared with those who never had clinically elevated ACR. No association with cancer risk was seen in the groups with decreasing or constant ACR. Regarding site-specific cancer risks, subjects with increasing ACR or constant ACR had a higher risk of developing urinary tract and lung cancer. No other associations between 2-year ACR changes and site-specific cancers were found.

Conclusions

Increases in albuminuria over a 2-year period are associated with a higher risk of developing overall, urinary tract and lung cancer, independent of baseline kidney function and albuminuria. These data add important weight to the link that exists between albuminuria and cancer incidence.

Phloretin as an add-on therapy to losartan attenuates diabetes-induced AKI in rats: A potential therapeutic approach targeting TLR4-induced inflammation

AIM

Targeting Toll-like receptor 4 (TLR4) and Angiotensin II type 1 receptor (AT1R) could provide renoprotection during acute kidney injury (AKI) mainly by regulating inflammation, oxidative stress, mitochondrial dysfunction, and apoptosis. Phloretin (TLR4 inhibitor) as an add-on therapy to losartan (AT1R inhibitor) could provide more therapeutic benefits against AKI under diabetic condition. We aimed to study the effect of phloretin as an add-on therapy to losartan against AKI under diabetic condition.

MAIN METHODS

To mimic diabetic AKI condition, bilateral ischemia-reperfusion injury (BIRI) was done in diabetic male Wistar rats, and sodium azide treatment was given to high glucose NRK52E cells to mimic hypoxia-reperfusion injury. In diabetic rats, phloretin (50 mg/kg/per os (p.o.)) and losartan (10 mg/kg/p.o.) treatment was given for 4 days and 1 h prior to surgery while in NRK52E cells, both drugs (phloretin 50 μM and losartan 10 μM) were given 24 h prior to the hypoxia condition. The in vivo and in vitro samples were further used for different experiments.

KEY FINDINGS

Treatment with phloretin and losartan decreased diabetic and AKI biomarkers such as plasma creatinine, blood urea nitrogen (BUN), and kidney injury molecular 1 (KIM1). Moreover, a combination of phloretin and losartan significantly preserved ΔΨm and kidney morphology potentially by inhibiting TLR4-associated inflammation and AT1R-associated mitochondrial dysfunction, thereby oxidative stress.

SIGNIFICANCE

Combination therapy of phloretin and losartan was more effective than monotherapies. Both drugs target TLR4/MyD88/NF-κB pathway and reduce inflammation and mitochondrial dysfunction in AKI under diabetic condition.

Transcriptomic analysis of diabetic kidney disease and neuropathy in mouse models of type 1 and type 2 diabetes

Diabetic kidney disease (DKD) and diabetic peripheral neuropathy (DPN) are common complications of type 1 (T1D) and type 2 (T2D) diabetes. However, the mechanisms underlying pathogenesis of these complications are unclear. In this study, we optimized a streptozotocin-induced db/+ murine model of T1D and compared it to our established db/db T2D mouse model of the same C57BLKS/J background. Glomeruli and sciatic nerve transcriptomic data from T1D and T2D mice were analyzed by self-organizing map and differential gene expression analysis. Consistent with prior literature, pathways related to immune function and inflammation were dysregulated in both complications in T1D and T2D mice. Gene-level analysis identified a high degree of concordance in shared differentially expressed genes (DEGs) in both complications and across diabetes type when using mice from the same cohort and genetic background. As we have previously shown a low concordance of shared DEGs in DPN when using mice from different cohorts and genetic backgrounds, this suggests that genetic background may influence diabetic complications. Collectively, these findings support the role of inflammation and indicate that genetic background is important in complications of both T1D and T2D.

Dietary interventions improve diabetic kidney disease, but not peripheral neuropathy, in a db/db mouse model of type 2 diabetes

Patients with type 2 diabetes often develop the microvascular complications of diabetic kidney disease (DKD) and diabetic peripheral neuropathy (DPN), which decrease quality of life and increase mortality. Unfortunately, treatment options for DKD and DPN are limited. Lifestyle interventions, such as changes to diet, have been proposed as non-pharmacological treatment options for preventing or improving DKD and DPN. However, there are no reported studies simultaneously evaluating the therapeutic efficacy of varying dietary interventions in a type 2 diabetes mouse model of both DKD and DPN. Therefore, we compared the efficacy of a 12-week regimen of three dietary interventions, low carbohydrate, caloric restriction, and alternate day fasting, for preventing complications in a db/db type 2 diabetes mouse model by performing metabolic, DKD, and DPN phenotyping. All three dietary interventions promoted weight loss, ameliorated glycemic status, and improved DKD, but did not impact percent fat mass and DPN. Multiple regression analysis identified a negative correlation between fat mass and motor nerve conduction velocity. Collectively, our data indicate that these three dietary interventions improved weight and glycemic status and alleviated DKD but not DPN. Moreover, diets that decrease fat mass may be a promising non-pharmacological approach to improve DPN in type 2 diabetes given the negative correlation between fat mass and motor nerve conduction velocity.

The Relationship between Renin-Angiotensin-Aldosterone System (RAAS) Activity, Osteoporosis and Estrogen Deficiency in Type 2 Diabetes

Type 2 diabetes (T2D) is associated with a plethora of comorbidities, including osteoporosis, which occurs due to an imbalance between bone resorption and formation. Numerous mechanisms have been explored to understand this association, including the renin-angiotensin-aldosterone system (RAAS). An upregulated RAAS has been positively correlated with T2D and estrogen deficiency in comorbidities such as osteoporosis in humans and experimental studies. Therefore, research has focused on these associations in order to find ways to improve glucose handling, osteoporosis and the downstream effects of estrogen deficiency. Upregulation of RAAS may alter the bone microenvironment by altering the bone marrow inflammatory status by shifting the osteoprotegerin (OPG)/nuclear factor kappa-Β ligand (RANKL) ratio. The angiotensin-converting-enzyme/angiotensin II/Angiotensin II type 1 receptor (ACE/Ang II/AT1R) has been evidenced to promote osteoclastogenesis and decrease osteoblast formation and differentiation. ACE/Ang II/AT1R inhibits the wingless-related integration site (Wnt)/β-catenin pathway, which is integral in bone formation. While a lot of literature exists on the effects of RAAS and osteoporosis on T2D, the work is yet to be consolidated. Therefore, this review looks at RAAS activity in relation to osteoporosis and T2D. This review also highlights the relationship between RAAS activity, osteoporosis and estrogen deficiency in T2D.

The prevalence of chronic kidney disease among type 2 diabetes mellitus patients in central South Africa

BACKGROUND

 Type 2 diabetes mellitus (T2DM) is a leading cause of chronic kidney disease (CKD). The prevalence of CKD among T2DM patients in Africa is 22.0%. The cut-off age for dialysing diabetic patients in the resource-limited state sector in South Africa is 50 years. Type 2 diabetes mellitus patients who develop CKD are likely to be excluded from chronic dialysis and rely on control of risk factors, including blood pressure and blood glucose levels, to prevent CKD progression. We aimed to determine the prevalence of CKD among T2DM patients attending the diabetes clinic at Pelonomi Academic Hospital, Bloemfontein.

METHODS

 In this retrospective cross-sectional study, medical records of patients (January 2016 and December 2018) were reviewed to collect demographic and clinical information.

RESULTS

 In total, 244 records were reviewed. Sixty-one (25.0%, 95% confidence interval [CI]: 20% - 30.8%) T2DM patients had CKD. The rate of CKD was slightly higher in males (n = 24/81; 29.6%) compared with females (n = 37/163; 22.7%). Most patients with CKD (n = 58; 95.1%) were 50 years of age. Only 17.8% of patients achieved a glycosylated haemoglobin (HbA1c) of 7.0%. Blood pressure was controlled in 14.3% of hypertensive patients. Renin-angiotensin-aldosterone system inhibitors were used by 78.6% of patients.

CONCLUSION

 A high prevalence of clinically significant CKD among T2DM patients with poor prospects of chronic dialysis in a resource-limited setting was observed. The risk factors for CKD development and progression should be adequately managed in T2DM patients.Contribution: This study emphasises the need for further research and innovation to improve outcomes of T2DM patients with CKD in resource-constrained settings.

Non-Haemodynamic Mechanisms Underlying Hypertension-Associated Damage in Target Kidney Components

Arterial hypertension (AH) is a global challenge that greatly impacts cardiovascular morbidity and mortality worldwide. AH is a major risk factor for the development and progression of kidney disease. Several antihypertensive treatment options are already available to counteract the progression of kidney disease. Despite the implementation of the clinical use of renin-angiotensin aldosterone system (RAAS) inhibitors, gliflozins, endothelin receptor antagonists, and their combination, the kidney damage associated with AH is far from being resolved. Fortunately, recent studies on the molecular mechanisms of AH-induced kidney damage have identified novel potential therapeutic targets. Several pathophysiologic pathways have been shown to play a key role in AH-induced kidney damage, including inappropriate tissue activation of the RAAS and immunity system, leading to oxidative stress and inflammation. Moreover, the intracellular effects of increased uric acid and cell phenotype transition showed their link with changes in kidney structure in the early phase of AH. Emerging therapies targeting novel disease mechanisms could provide powerful approaches for hypertensive nephropathy management in the future. In this review, we would like to focus on the interactions of pathways linking the molecular consequences of AH to kidney damage, suggesting how old and new therapies could aim to protect the kidney.

Niclosamide from an anthelmintic drug to a promising adjuvant therapy for diabetic kidney disease: randomized clinical trial

BACKGROUND

Diabetic kidney disease (DKD) is a serious complication that begins with albuminuria and often leads to a rapid progressive decline in renal function. Niclosamide is a potent inhibitor of the Wnt/β-catenin pathway, which controls the expression of multiple genes of the renin-angiotensin-aldosterone system (RAAS), which in turn is influences the progression of DKD. This study was conducted to evaluate the effect of niclosamide as adjuvant therapy on DKD.

METHODS

Out of 127 patients screened for eligibility, 60 patients completed the study. After randomization, 30 patients in the niclosamide arm received ramipril plus niclosamide, and 30 patients in the control arm received ramipril only for 6 months. The primary outcomes were the changes in urinary albumin to creatinine ratio (UACR), serum creatinine, and estimated glomerular filtration rate (eGFR). The secondary outcomes were measurements of urinary matrix metalloproteinase-7 (MMP-7), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and podocalyxin (PCX). Comparisons between the two arms were done using student t-test. Correlation analysis was done using Pearson correlation.

RESULTS

Niclosamide decreased UACR by 24% (95% CI - 30 to - 18.3%) while there was a rise in UACR in the control arm by 11% (95% CI 4 to 18.2%) after 6 months (P < 0.001). Moreover, a significant reduction in MMP-7 and PCX was noticed in the niclosamide arm. Regression analysis revealed a strong association between MMP-7, which is a noninvasive biomarker predicting the activity of the Wnt/β-catenin signaling, and UACR. A 1 mg/dL decline in MMP-7 level was associated with a 25 mg/g lowering in UACR (B = 24.95, P < 0.001).

CONCLUSION

The addition of niclosamide to patients with diabetic kidney disease receiving an angiotensin-converting enzyme inhibitor significantly reduces albumin excretion. Further larger-scale trials are needed to confirm our results.

TRIAL REGISTRATION

The study was prospectively registered on clinicaltrial.gov on March 23, 2020, with identification code NCT04317430.

The therapeutic potential of arctigenin against multiple human diseases: A mechanistic review

BACKGROUND

Arctigenin (ATG), a dibenzyl butyrolactone lignan compound, is one of the major bioactive components from the medicinal plant Arctium lappa. ATG possesses remarkable therapeutic potential against a wide range of human diseases, such as cancers, immune disorders and chronical diseases. The molecular mechanisms behind the biological effects of ATG have been intensively studied.

PURPOSE

This review aims to systematically summarize the updated knowledge of the proteins and signaling pathways behind the curative property of ATG, and further analyze the potential connections between them.

METHOD

SciFinder, Pubmed, Web of Science and Cochrane Library databases were queried for publications reporting the therapeutic properties of ATG. "Arctigenin", "disease", "cancer", "inflammation", "organ damage", "infection", "toxicity" and "pharmacokinetics" were used as the searching titles.

RESULT

625 publications were identified and 95 met the inclusion criteria and exclusion criteria. 42 studies described the molecular mechanisms implicated in ATG treatments. Several proteins including phosphodiesterase subtype 4D (PDE4D), estrogen receptor (ER) β, protein phosphatase 2A (PP2A), phosphoinositide 3-kinase (PI3K) and transmembrane protein 16A (TMEM16A) are targeted by ATG in different settings. The frequently described signaling pathways are TLR4/NF-κB, PI3K/AKT/mTOR, AMP-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor 2 (Nrf-2) signalings.

CONCLUSION

Inhibition of PI3K/AKT pathway and activation of AMPK signaling play the pivotal roles in the therapeutic effects of ATG. PI3K/AKT and AMPK signaling widely link to other signaling pathways, modulating various biological processes such as anti-inflammation, anti-oxidative stress, anti-fibrosis, anti-ER stress, anti-steatosis and pro-apoptosis, which constitute the curative mechanisms of ATG against multiple human diseases.

Promising novel therapeutic targets for kidney disease: Emphasis on kidney-specific proteins

Worldwide, around 850 million people are diagnosed with kidney disease but the available treatment options are still limited. Preclinical studies propose a plethora of druggable targets that can attenuate kidney disease and could qualify as novel therapeutic strategies, although most of these targets still await clinical testing. Here, we review some promising candidate targets for chronic kidney disease: intermedin, periostin, sirtuin, the cannabinoid receptor, Klotho, and uromodulin. For acute kidney injury, we discuss Apelin, Elabela, growth differentiation factor-15, Fyn kinase, and Klotho. Target selection for further clinical development should consider redundancies with the standard of care, potential synergistic effects with existing treatments, as well as the potential of additional effects on the cardiovascular system as a common comorbidity in patients with kidney disease.

microRNA-29b-3p attenuates diabetic nephropathy in mice by modifying EZH2

OBJECTIVE

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease around the world. This study investigated the role of microRNA (miR)-29b-3p in DN and the mechanism of the miR-29b-3p/EZH2 axis in DN.

METHODS

Peripheral blood samples of DN patients were collected and miR-29b-3p and EZH2 expression levels were evaluated using RT-qPCR. DN mouse models were successfully established, and then treated with miR-29b-3p overexpression or EZH2 silence. IL-1β, IL-6, and TNF-α levels were assessed by ELISA. Blood glucose, serum creatinine (Scr), 24-h urine volume, 24-h urine protein, and blood urea nitrogen (BUN) levels were examined by automatic biochemical analyzer detection. HE staining was performed to observe the renal histopathology, and TUNEL staining was implemented to test apoptosis in renal tissues. The binding relationship between miR-29b-3p and EZH2 was validated by using a bioinformatics website and dual luciferase reporter gene assay.

RESULTS

miR-29b-3p was lowly expressed, and EZH2 was highly expressed in patients with DN. Overexpressing miR-29b-3p or silencing EZH2 attenuated renal dysfunction, suppressed inflammation and apoptosis, and relieved renal injuries in mice with DN. miR-29b-3p inhibited EZH2, and miR-29b-3p overexpression mitigated renal injuries in DN mice by repressing EZH2.

CONCLUSION

miR-29b-3p suppresses EZH2 expression thereby inhibiting the progression of DN in mice.

The effects of Ophiocordyceps sinensis combined with ACEI/ARB on diabetic kidney disease: A systematic review and meta-analysis

BACKGROUND

Ophiocordyceps sinensis (OS), a medicinal fungus, has been made into OS preparations, which are frequently used as adjunctive therapy for patients with Diabetic Kidney Disease (DKD) in China. It is necessary to assess the efficacy and safety of OS preparations in the adjunctive treatment of DKD by conducting a systematic review and meta-analysis.

OBJECTIVE

Ophiocordyceps sinensis preparations were evaluated for their efficacy and safety as adjunctive therapy to conventional drugs (angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs)) for DKD.

METHODS

We searched seven electronic literature databases for randomized controlled trials (RCTs) comparing ACEI/ARB and OS combined with ACEI/ARB from inception up to March 2022. Two reviewers extracted data and assessed the risk of bias independently. Evidence certainty was rated using the GRADE system. Standardized mean difference (SMD) or mean difference (MD) was pooled with random effects models and was reported with corresponding 95% confidence intervals (CIs). Meta-analysis, sensitivity analysis and Egger's test were performed using R software (version 14.2) (PROSPERO registration no. CRD42021248634).

RESULTS

Thirty eight RCTs involving 3167 patients met the inclusion criteria. No trials were reported with outcomes about kidney disease progression and cardiovascular events. In meta-analysis, compared with the control group of ACEI/ARB alone, OS combined with ACEI/ARB can achieve better effects in the treatment of DKD on reducing serum creatinine (Scr) [MD_Scr =-11.48 95% CI [-15.78, -7.18], p < 0.01], blood urea nitrogen (BUN) [MD_BUN= -1.00, 95% CI [-1.44, -0.55], p < 0.01], β2-microglobulin (β2-MG) [SMD_β2-MG= -1.32, 95% CI [-2.27, -0.37], p < 0.01], cystatin C (CysC) [MD_CysC=-0.64, 95% CI [-0.83, -0.45], p < 0.01], 24-h urine proteinuria (24hUP) [SMD_24hUP= -1.99, 95% CI [-2.68; -1.31], p < 0.01], urine microalbumin (UALB) [MD_UALB= -37.41, 95% CI [-44.76, -30.06], p < 0.01] and decreasing urinary albumin excretion rate (UAER) [MD_UAER= -24.11, 95% CI [-30.54, -17.68], p < 0.01] and albumin creatinine ratio (ACR) [SMD_ACR = 1.01, 95% CI [-1.73, -0.29], p < 0.01]. The OS adjuvant treatment also improved outcomes of blood pressure, blood glucose, blood lipid, inflammation and oxidative stress. No significant change in fasting blood glucose (FPG), glycated hemoglobin (HbA1c), malondialdehyde (MDA), and transforming growth factor beta 1 (TGF-β1) was detected. Yet, no significant difference was found about the adverse events between the two groups.

CONCLUSIONS

Ophiocordyceps sinensis preparation combined with ACEI/ARB has beneficial influence on renal function, decrease proteinuria, dyslipidemia, and even oxidative stress and inflammation in DKD patients. However, there is no trial that evaluated outcomes of kidney disease progression and cardiovascular events. Future study should move beyond surrogate endpoints to actual cardiovascular or renal outcome benefits with an aim to explore effects of OS preparation in the long-term.

Non-albuminuric Diabetic Kidney Disease Phenotype: Beyond Albuminuria

Diabetic kidney disease (DKD) is the leading cause of chronic and end-stage kidney disease worldwide. Its pathogenic mechanism is complex, and it can affect the entire structures of the kidneys such as the glomerulus, tubules and interstitium. Currently, the urinary albumin excretion rate and the estimated glomerular filtration rate are widely accepted as diagnostic criteria. However, some studies have reported a different or non-classical clinical course of DKD, with some patients showing declined kidney function with normal levels of albuminuria, known as the 'non-albuminuric DKD' phenotype. The pathogenesis of this phenotype remains unclear, but some clinical and pathological features have been postulated. This review explores the evidence regarding this topic.

Recent findings on the cellular and molecular mechanisms of action of novel food-derived antihypertensive peptides

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Hypertension has remained a silent-killer.

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Novel peptides recently isolated from food proteins.

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Molecular mechanism of blood pressure-lowering: renin and ACE-inhibition, and beyond.

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Proposed molecular mechanisms for future research.

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Novel peptides are excellent candidates for nutraceutical development.

Hypertension impacts negatively on the quality of life of sufferers, and complications associated with uncontrolled hypertension are life-threatening. Hence, many research efforts are exploring the antihypertensive properties of bioactive peptides derived from food proteins using in vitro ACE-inhibitory assay, experimentally-induced and spontaneous hypertensive rats, normotensive and hypertensive human models. In this study, the cellular and molecular mechanisms of blood pressure-lowering properties of novel peptides reported in recent studies (2015-July 30, 2021) were discussed. In addition to common mechanisms such as the inhibition of angiotensin I-converting enzyme (ACE) and renin activities, recently recognized mechanisms through which bioactive peptides exert their antihypertensive properties including the induction of vasodilation via upregulation of cyclo-oxygenase (COX) and prostaglandin receptor and endothelial nitric oxide synthase expression and L-type Ca²⁺ channel blockade were presented. Similarly, emerging mechanisms of blood pressure-lowering by bioactive peptides such as modulation of inflammation (TNF-α, and other cytokines signaling), oxidative stress (Keap-1/Nrf2/ARE/HO-1 and related signaling pathways), PPAR-γ/caspase3/MAPK signaling pathways and inhibition of lipid accumulation were discussed. The review also highlighted factors that influence the antihypertensive properties of peptides such as method of hydrolysis (type and number of enzymes, and chemical used for hydrolysis, and microbial fermentation), and amino acid sequence and chain length of peptides.

SGLT2 Inhibition in Type 1 Diabetes with Diabetic Kidney Disease: Potential Cardiorenal Benefits Can Outweigh Preventable Risk of Diabetic Ketoacidosis

PURPOSE OF REVIEW

The aim of this review is to summarize existing research investigating the use of sodium glucose cotransporter-2 (SGLT2) inhibitors in patients with type 1 diabetes mellitus (T1DM) while highlighting potential strategies to mitigate the risk of diabetic ketoacidosis (DKA).

RECENT FINDINGS

SGLT2 inhibitors have been studied in patients with T1DM in phase 3 clinical trials such as the inTandem, DEPICT, and EASE trials, which demonstrated consistent reductions in HbA1c. Secondary analyses of these trials have also reported potential kidney protective effects that are independent of improved glycemic control. However, trials in patients with type 2 diabetes mellitus (T2DM) have found an increased risk of DKA with SGLT2 inhibitors, a serious concern in patients with T1DM. SGLT2 inhibitors provide cardiovascular benefits and kidney protection in patients with T2DM and are a promising therapeutic option for patients with T1DM due to overlapping pathophysiological mechanisms. However, SGLT2 inhibitors increase the risk of DKA, and there is currently a lack of research investigating the beneficial effects of SGLT2 inhibitors in patients with T1DM. Preventative measure for DKA would have to be implemented and the risks would need to be carefully balanced with the benefits offered by SGLT2 inhibitors. Additional research will also be required to determine the kidney protective effects of SGLT2 inhibitors in patients with T1DM and diabetic kidney disease and to quantify the risk of DKA after the implementation of preventative measures, proper patient education, and ketone monitoring.

Can SGLT2 inhibitors answer unmet therapeutic needs in chronic kidney disease?

Chronic kidney disease (CKD) is a global health problem, affecting more than 850 million people worldwide. The number of patients receiving renal replacement therapy (dialysis or renal transplantation) has increased over the years, and it has been estimated that the number of people receiving renal replacement therapy will more than double from 2.618 million in 2010 to 5.439 million in 2030, with wide differences among countries. The main focus of CKD treatment has now become preserving renal function rather than replacing it. This is possible, at least to some extent, through the optimal use of multifactorial therapy aimed at preventing end-stage kidney disease and cardiovascular events. Sodium/glucose cotransporter 2 inhibitors (SGLT2i) reduce glomerular hypertension and albuminuria with beneficial effects on progression of renal damage in both diabetic and non-diabetic CKD. SGLT2 inhibitors also show great benefits in cardiovascular protection, irrespective of diabetes. Therefore, the use of these drugs will likely be extended to the whole CKD population as a new standard of care.

Cardiovascular autonomic neuropathy and incident diabetic kidney disease in patients with type 2 diabetes

AIMS

We investigated the association between cardiovascular autonomic neuropathy (CAN) and incident diabetic kidney disease (DKD).

METHODS

This retrospective longitudinal study included 2,033 patients with type 2 diabetes (mean age 57.2 years, 57.4% male, and median diabetes duration 8.0 years), free of renal dysfunction or cardiovascular disease at initiation. Cardiovascular autonomic reflex tests were performed once at baseline, and CAN was defined as ≥ 2 abnormal parasympathetic test results. Urine ACR and eGFR were concurrently measured at baseline and every 3-6 months thereafter. Incident DKD was defined as the development of ACR ≥ 30 mg/g at two or more follow-up examinations or eGFR < 60 ml/min/1.73 m² with ≥ 25% decrease from baseline.

RESULTS

During a median follow-up of 2.9 years (1.1 - 4.8), 290 (14.3%) patients developed DKD, comprising 79.7% (N = 231) cases of new-onset albuminuria alone, 14.5% (N = 42) cases of eGFR decline alone, and 5.8% (N = 17) cases of both. Compared to those without CAN, patients with CAN had a significantly higher risk of incident DKD in a multivariable Cox regression model (HR 1.56, 95% CI 1.15 - 2.12; P = 0.005).

CONCLUSION

CAN is may be a useful marker for long-term complications including DKD in patients with type 2 diabetes. Monitoring of CAN helps to identify high risk patients of future renal impairment.

Renal Protection with SGLT2 Inhibitors: Effects in Acute and Chronic Kidney Disease

PURPOSE OF REVIEW

This review offers a critical narrative evaluation of emerging evidence that sodium-glucose co-transporter-2 (SGLT2) inhibitors exert nephroprotective effects in people with type 2 diabetes.

RECENT FINDINGS

The SGLT2 inhibitor class of glucose-lowering agents has recently shown beneficial effects to reduce the onset and progression of renal complications in people with and without diabetes. Randomised clinical trials and 'real world' observational studies, mostly involving type 2 diabetes patients, have noted that use of an SGLT2 inhibitor can slow the decline in glomerular filtration rate (GFR), reduce the onset of microalbuminuria and slow or reverse the progression of proteinuria. The nephroprotective effects of SGLT2 inhibitors are class effects observed with each of the approved agents in people with a normal or impaired GFR. These effects are also observed in non-diabetic, lean and normotensive individuals suggesting that the mechanisms extend beyond the glucose-lowering, weight-lowering and blood pressure-lowering effects that accompany their glucosuric action in diabetes patients. A key mechanism is tubuloglomerular feedback in which SGLT2 inhibitors cause more sodium to pass along the nephron: the sodium is sensed by macula cells which act via adenosine to constrict afferent glomerular arterioles, thereby protecting glomeruli by reducing intraglomerular pressure. Other effects of SGLT2 inhibitors improve tubular oxygenation and metabolism and reduce renal inflammation and fibrosis. SGLT2 inhibitors have not increased the risk of urinary tract infections or the risk of acute kidney injury. However, introduction of an SGLT2 inhibitor in patients with a very low GFR is not encouraged due to an initial dip in GFR, and it is prudent to discontinue therapy if there is an acute renal event, hypovolaemia or hypotension.

KCa3.1 in diabetic kidney disease

PURPOSE OF REVIEW

Diabetic kidney disease (DKD) is a significant health concern. Innovative strategies to prevent or limit the progression of DKD are urgently needed due to the limitation of existing treatments. KCa3.1, a potassium channel, is involved in a range of biological processes from cell survival to cell death. This review summarizes the current knowledge on the pathophysiological functions of the KCa3.1 channel, specifically its involvement in maintaining mitochondrial function. More specifically, the therapeutic potential of targeting KCa3.1 in DKD is systematically discussed in the review.

RECENT FINDINGS

Mitochondrial dysfunction contributes to the development and progression of DKD. Accumulating evidence indicates that KCa3.1 dysregulation plays a crucial role in mitochondrial dysfunction, in addition to driving cellular activation, proliferation and inflammation. Recent studies demonstrate that KCa3.1 deficiency improves diabetes-induced mitochondrial dysfunction in DKD, which is attributed to modulation of mitochondrial quality control through mitigating the altered mitochondrial dynamics and restoring abnormal BNIP3-mediated mitophagy.

SUMMARY

Based on its role in fibrosis, inflammation and mitochondrial dysfunction, pharmacological inhibition of KCa3.1 may offer a promising alternative for the treatment of DKD. Due to its safety profile in humans, the repurposing of senicapoc has the potential to expedite an urgently needed new drug in DKD.

Diabetic Complications: An Update on Pathobiology and Therapeutic Strategies

Despite the advent of novel therapies which manage and control diabetes well, the increased risk of morbidity and mortality in diabetic subjects is associated with the devastating secondary complications it produces. Long-standing diabetes majorly drives cellular and molecular alterations, which eventually damage both small and large blood vessels. The complications are prevalent both in type I and type II diabetic subjects. The microvascular complications include diabetic neuropathy, diabetic nephropathy, diabetic retinopathy, while the macrovascular complications include diabetic heart disease and stroke. The current therapeutic strategy alleviates the complications to some extent but does not cure or prevent them. Also, the recent clinical trial outcomes in this field are disappointing. Success in the drug discovery of diabetic complications may be achieved by a better understanding of the underlying pathophysiology and by recognising the crucial factors contributing to the development and progression of the disease. In this review, we discuss the well-studied cellular mechanisms leading to the development and progression of diabetic complications. In addition, we also highlight the various therapeutic paradigms currently in clinical practice.

Gene expression profiles of diabetic kidney disease and neuropathy in eNOS knockout mice: Predictors of pathology and RAS blockade effects

Diabetic kidney disease (DKD) and diabetic peripheral neuropathy (DPN) are two common diabetic complications. However, their pathogenesis remains elusive and current therapies are only modestly effective. We evaluated genome-wide expression to identify pathways involved in DKD and DPN progression in db/db eNOS-/- mice receiving renin-angiotensin-aldosterone system (RAS)-blocking drugs to mimic the current standard of care for DKD patients. Diabetes and eNOS deletion worsened DKD, which improved with RAS treatment. Diabetes also induced DPN, which was not affected by eNOS deletion or RAS blockade. Given the multiple factors affecting DKD and the graded differences in disease severity across mouse groups, an automatic data analysis method, SOM, or self-organizing map was used to elucidate glomerular transcriptional changes associated with DKD, whereas pairwise bioinformatic analysis was used for DPN. These analyses revealed that enhanced gene expression in several pro-inflammatory networks and reduced expression of development genes correlated with worsening DKD. Although RAS treatment ameliorated the nephropathy phenotype, it did not alter the more abnormal gene expression changes in kidney. Moreover, RAS exacerbated expression of genes related to inflammation and oxidant generation in peripheral nerves. The graded increase in inflammatory gene expression and decrease in development gene expression with DKD progression underline the potentially important role of these pathways in DKD pathogenesis. Since RAS blockers worsened this gene expression pattern in both DKD and DPN, it may partly explain the inadequate therapeutic efficacy of such blockers.

A Network Pharmacology-Based Approach for Exploring Key Active Compounds and Pharmacological Mechanisms of Tangshen Formula for Treatment of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the common and severe microvascular complications of diabetes mellitus (DM). The occurrence and development of DN are related to multiple factors in the human body, which makes DN a complex disease, and the pathogeneses of DN have not yet been fully illustrated. Furthermore, DN lacks effective drugs for treatment nowadays. Chinese herbal medicine (CHM) often shows the feature of multicomponents, multitargets, multipathways, and synergistic effects and shows a promising source of new therapeutic drugs for DN. As a CHM, Tangshen Formula (TSF) was used to treat DN patients in China. However, its bioactive compounds and holistic pharmacological mechanisms on DN are both unclear. A network pharmacology approach was firstly applied to explore multiple active compounds and multiple key pharmacological mechanisms for TSF treating DN by drug-targeted interaction databases, herb-compound-target network, protein-protein interaction network, compound-target-pathway network, and analysis methods. And the results showed that TSF have the characteristic of multicomponents, multitargets, multipathways, and synergistic effects for treating DN. The quercetin, naringenin, kaempferol, and isorhamnetin as key active compounds and the PI3K-Akt signaling pathway, TNF signaling pathway, nonalcoholic fatty liver disease (NAFLD), focal adhesion, rap1 signaling pathway, T cell receptor signaling pathway, MAPK signaling pathway, and insulin resistance as the key molecular mechanisms play important roles in TSF treating DN. Moreover, quercetin, naringenin, kaempferol, and isorhamnetin were successfully detected in TSF by the UHPLC-MS/MS analysis method. And their concentrations were 0.224, 8.295, 0.0564, and 0.0879 mg·kg-1, respectively. The present findings not only provide new insights for a deeper understanding of the constituent basis and pharmacology of TSF but also provide guidance for further pharmacological studies on TSF.