Effects of Sustained-Release Beraprost in Patients With Primary Glomerular Disease or Nephrosclerosis: CASSIOPEIR Study Results

Effects of Beraprost on Intestinal Microcirculation and Barrier Function in a Mouse Model of Renal Failure

OBJECTIVE

Endothelial dysfunction plays an important role in the pathogenesis of chronic kidney disease. Prostacyclin (PGI2), an endothelial cell-produced endogenous prostaglandin, plays a crucial role in maintaining endothelial function. However, its effects on intestinal microcirculation and barrier function are not fully understood. We hypothesized that PGI2 improves intestinal microcirculation and barrier function via endothelial protective effects.

METHODS

ICR and ICGN (a spontaneous nephrotic model) mice were used in this study. Intestinal microcirculation was visualized in vivo to investigate PGI2 effects. Beraprost served as PGI2. PGI2 administration spanned 4 weeks, following which we assessed its influence on intestinal endothelial, intestinal barrier, and renal functions.

RESULTS

We visualized intestinal microcirculation and endothelial glycocalyx in the intestinal blood vessels. Beraprost administration induced a 1.2-fold dilatation of the vascular diameter of the small intestine. Intestinal blood flow in ICGN mice was significantly reduced compared that in ICR mice but improved with beraprost administration. ICGN mice exhibited reduced serum albumin levels, decreased ambulation, an imbalance in intestinal reactive oxygen species (ROS)/nitric oxide (NO), and impaired tight junctions; all were ameliorated by beraprost administration.

CONCLUSIONS

Beraprost improves intestinal microcirculation and barrier function by ameliorating ROS/NO imbalances, thereby reducing physical inactivity during renal failure.

Intervention control of aerobic exercise in maintaining quality of life and pulmonary hypertension in hemodialysis patients

BACKGROUND

Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients, which seriously affects the quality of life of patients and threatens their life safety. Prevention, treatment and improvement of pulmonary hypertension are of great significance to improve the quality of life of patients.

AIM

To investigate the intervention and control of pedal-powered bicycle in maintaining quality of life and pulmonary hypertension in hemodialysis patients.

METHODS

73 patients with maintenance hemadialysis combined with pulmonary arterial hypertension at a hemodialysis center in a certain hospital from May 2021 to May 2022 are selected. Patients are divided into two groups, 37 cases in the control group (group C) and 36 cases in the intervention group (group I). Patients are divided into two groups, group C is treated with oral administration of betaglandin sodium combined with routine nursing care. Based on group C, group I conducts power cycling exercises.

RESULTS

After treatment, group I patients had higher muscle strength, 36-Item Short Form Health Survey scores, and Kidney Disease Targets Areas scores; The 6-minute walk distance test index level was higher and the Borg score was lower; The group I had lower systolic blood pressure, greater vital capacity, higher positive emotion, lower systolic pulmonary artery pressure index level, higher arterial partial oxygen pressure level, lower pulmonary vascular resistance index level, and higher blood oxygen saturation level [158.91 ± 11.89 vs 152.56 ± 12.81, 1795.01 ± 603.18 vs 1907.20 ± 574.15, 24.00 (22.00, 29.00) vs 24.00 (22.00, 28.00), P < 0.001].

CONCLUSION

Aerobic exercise combined with Western medicine treatment can effectively improve patients' pulmonary hypertension, alleviate their negative emotions, and enable them to achieve a higher level of quality of life.

Prostacyclin Mitigates Renal Fibrosis by Activating Fibroblast Prostaglandin I 2 Receptor

SIGNIFICANCE STATEMENT

Renal fibrosis is a common pathologic process of progressive CKD. We have provided strong evidence that PGI 2 is an important component in the kidney injury/repairing process by reducing fibrosis and protecting renal function from declining. In our study, administration of a PGI 2 analog or selective PTGIR agonist after the acute injury ameliorated renal fibrosis. Our findings provide new insights into the role of PGI 2 in kidney biology and suggest that targeting PGI 2 /PTGIR may be a potential therapeutic strategy for CKD.

BACKGROUND

Prostanoids have been demonstrated to be important modulators to maintain tissue homeostasis in response to physiologic or pathophysiologic stress. Prostacyclin (PGI 2 ) is a member of prostanoids. While limited studies have shown that PGI 2 is involved in the tissue injury/repairing process, its role in renal fibrosis and CKD progression requires further investigation.

METHODS

Prostacyclin synthase ( Ptgis )-deficient mice, prostaglandin I 2 receptor ( Ptgir )-deficient mice, and an oral PGI 2 analog and selective PTGIR agonist were used to examine the role of PGI 2 in renal fibrosis in mouse models. We also analyzed the single-cell RNA-Seq data to examine the PTGIR -expressing cells in the kidneys of patients with CKD.

RESULTS

Increased PTGIS expression has been observed in fibrotic kidneys in both humans and mice. Deletion of the PTGIS gene aggravated renal fibrosis and decline of renal function in murine models. A PGI 2 analog or PTGIR agonist that was administered after the acute injury ameliorated renal fibrosis. PTGIR, the PGI 2 receptor, deficiency blunted the protective effect of the PGI 2 analog. Fibroblasts and myofibroblasts were the major cell types expressing PTGIR in the kidneys of patients with CKD. Deletion of PTGIR in collagen-producing fibroblastic cells aggravated renal fibrosis. The protective effect of PGI 2 was associated with the inhibition of fibroblast activation through PTGIR-mediated signaling.

CONCLUSIONS

PGI 2 is an important component in the kidney injury/repairing process by preventing the overactivation of fibroblasts during the repairing process and protecting the kidney from fibrosis and decline of renal function. Our findings suggest that PGI 2 /PTGIR is a potential therapeutic target for CKD.

Obstructive nephropathy and molecular pathophysiology of renal interstitial fibrosis

The kidneys play a key role in maintaining total body homeostasis. The complexity of this task is reflected in the unique architecture of the organ. Ureteral obstruction greatly affects renal physiology by altering hemodynamics, changing glomerular filtration and renal metabolism, and inducing architectural malformations of the kidney parenchyma, most importantly renal fibrosis. Persisting pathological changes lead to chronic kidney disease, which currently affects ∼10% of the global population and is one of the major causes of death worldwide. Studies on the consequences of ureteral obstruction date back to the 1800s. Even today, experimental unilateral ureteral obstruction (UUO) remains the standard model for tubulointerstitial fibrosis. However, the model has certain limitations when it comes to studying tubular injury and repair, as well as a limited potential for human translation. Nevertheless, ureteral obstruction has provided the scientific community with a wealth of knowledge on renal (patho)physiology. With the introduction of advanced omics techniques, the classical UUO model has remained relevant to this day and has been instrumental in understanding renal fibrosis at the molecular, genomic, and cellular levels. This review details key concepts and recent advances in the understanding of obstructive nephropathy, highlighting the pathophysiological hallmarks responsible for the functional and architectural changes induced by ureteral obstruction, with a special emphasis on renal fibrosis.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Treatments for Chronic Kidney Disease: A Systematic Literature Review of Randomized Controlled Trials

Delaying disease progression and reducing the risk of mortality are key goals in the treatment of chronic kidney disease (CKD). New drug classes to augment renin-angiotensin-aldosterone system (RAAS) inhibitors as the standard of care have scarcely met their primary endpoints until recently. This systematic literature review explored treatments evaluated in patients with CKD since 1990 to understand what contemporary data add to the treatment landscape. Eighty-nine clinical trials were identified that had enrolled patients with estimated glomerular filtration rate 13.9-102.8 mL/min/1.73 m2 and urinary albumin-to-creatinine ratio (UACR) 29.9-2911.0 mg/g, with (75.5%) and without (20.6%) type 2 diabetes (T2D). Clinically objective outcomes of kidney failure and all-cause mortality (ACM) were reported in 32 and 64 trials, respectively. Significant reductions (P < 0.05) in the risk of kidney failure were observed in seven trials: five small trials published before 2008 had evaluated the RAAS inhibitors losartan, benazepril, or ramipril in patients with (n = 751) or without (n = 84-436) T2D; two larger trials (n = 2152-2202) published onwards of 2019 had evaluated the sodium-glucose co-transporter 2 (SGLT2) inhibitors canagliflozin (in patients with T2D and UACR > 300-5000 mg/g) and dapagliflozin (in patients with or without T2D and UACR 200-5000 mg/g) added to a background of RAAS inhibition. Significant reductions in ACM were observed with dapagliflozin in the DAPA-CKD trial. Contemporary data therefore suggest that augmenting RAAS inhibitors with new drug classes has the potential to improve clinical outcomes in a broad range of patients with CKD.

Comparison of Pharmacokinetic Profiles of Beraprost Sustained Release in Japanese, Chinese, and Korean Healthy Adult Males

BACKGROUND AND OBJECTIVES

Beraprost sodium (BPS), an orally administrable prostaglandin I₂ derivative, is used for the treatment of chronic arterial occlusion and pulmonary arterial hypertension and has potential efficacy in nephropathy. Beraprost sustained release (beraprost SR) is an oral sustained-release formulation of BPS. To confirm the dose rationale reported in a multi-regional study of nephropathy patients in Asia, this open-label study evaluated ethnic differences in the pharmacokinetic profiles of BPS and its active diastereomer (BPS-314d) after beraprost SR administration among healthy Japanese, Chinese, and Korean adult males.

METHODS

Twelve healthy subjects in each ethnic group were enrolled. Subjects received a single oral dose of 120 μg beraprost SR under fasting conditions.

RESULTS

The geometric mean ratio (90% confidence interval) of the maximum plasma concentration (C_max) and area under the plasma concentration-time curve from time 0 to time of the last quantifiable concentration (AUC_last) of BPS was 1.12 (0.85-1.48) and 1.40 (1.05-1.86) in Chinese, and 1.18 (0.90-1.55) and 1.18 (0.89-1.58) in Korean compared to Japanese subjects. These differences were not clinically relevant. Similarly, differences in the C_max and AUC_last of BPS-314d were also small among the ethnic groups. Urinary excretion of BPS and BPS-314d was limited in all ethnic groups. Together, these findings indicate that the pharmacokinetics of beraprost SR are not affected by ethnic background.

CONCLUSIONS

There were no clinically meaningful ethnic differences in the pharmacokinetics of BPS and BPS-314d following beraprost SR administration among Japanese, Chinese and Korean populations.

Prostacyclin analog beraprost sodium efficacy in primary glomerular disease or nephrosclerosis: Analysis of the Japanese subgroup in CASSIOPEIR study

We conducted a multicenter, randomized, double‐blind, placebo‐controlled, phase IIb/III study (CASSIOPEIR) using a renal composite endpoint (i.e., doubling of SCr or end‐stage renal disease) in seven Asian countries/region. CASSIOPEIR compared TRK‐100STP (120 μg and 240 μg) with placebo in patients with non‐diabetic CKD patients with primary glomerular disease or nephrosclerosis (n = 892). However, the superiority of TRK‐100STP over placebo was not observed. A prior phase II study on which the Phase IIb/III study design was based included only Japanese patients. We therefore evaluated TRK‐100STP efficacy and safety in a subgroup of Japanese patients using the CASSIOPEIR dataset. As the timing of treatment initiation is important in CKD, we conducted additional subgroup analyses based on the baseline serum creatinine (SCr) and eGFR. ITT analysis was performed in a Japanese subgroup (n = 339) in which the primary endpoint was the first occurrence of renal composite endpoint. Significant differences were observed for TRK‐100STP 240 μg vs. placebo (P = 0.0493; HR 0.69 [95% CI: 0.47, 1.00]), but no significant difference was observed between TRK‐100 120 μg and placebo (P = 0.3523; HR 0.85). More prominent improvement was observed with TRK‐100STP 240 μg vs. placebo for baseline SCr  < 3.0 mg/dL (P = 0.0031; HR 0.43); SCr < 3.5 mg/dL (P = 0.0237, HR 0.59); and eGFR ≥ 10 mL/min/1.73 m² (P = 0.0339, HR0.67), respectively. No significant changes in urinary albumin/creatinine ratio and blood pressure were observed. TRK‐100STP was generally well tolerated and most adverse drug reactions were mild or moderate in severity. In conclusion, in the Japanese subgroup of CASSIOPEIR, TRK‐100STP 240 μg/day significantly improved the renal composite endpoint compared with placebo, with greater efficacy in subjects with SCr < 3.5 or eGFR ≥ 10 mL/min/1.73 m².

PGI2 Analog Attenuates Salt-Induced Renal Injury through the Inhibition of Inflammation and Rac1-MR Activation

Renal inflammation is known to be involved in salt-induced renal damage, leading to end-stage renal disease. This study aims to evaluate the role of inflammation in anti-inflammatory and renoprotective effects of beraprost sodium (BPS), a prostaglandin I₂ (PGI₂) analog, in Dahl salt-sensitive (DS) rats. Five-week-old male DS rats were fed a normal-salt diet (0.5% NaCl), a high-salt diet (8% NaCl), or a high-salt diet plus BPS treatment for 3 weeks. BPS treatment could inhibit marked proteinuria and renal injury in salt-loaded DS rats with elevated blood pressure, accompanied by renal inflammation suppression. Notably, high salt increased renal expression of active Rac1, followed by increased Sgk1 expressions, a downstream molecule of mineralocorticoid receptor (MR) signal, indicating salt-induced activation of Rac1-MR pathway. However, BPS administration inhibited salt-induced Rac1-MR activation as well as renal inflammation and damage, suggesting that Rac1-MR pathway is involved in anti-inflammatory and renoprotective effects of PGI₂. Based upon Rac1 activated by inflammation, moreover, BPS inhibited salt-induced activation of Rac1-MR pathway by renal inflammation suppression, resulting in the attenuation of renal damage in salt-loaded DS rats. Thus, BPS is efficacious for the treatment of salt-induced renal injury.