The therapeutic effect of lipo PGE1 on diabetic neuropathy-changes in endothelin and various angiopathic factors

Annexin A1 Regulates NLRP3 Inflammasome Activation and Modifies Lipid Release Profile in Isolated Peritoneal Macrophages

Annexin A1 (AnxA1) is a potent anti-inflammatory protein that downregulates proinflammatory cytokine release. This study evaluated the role of AnxA1 in the regulation of NLRP3 inflammasome activation and lipid release by starch-elicited murine peritoneal macrophages. C57bl/6 wild-type (WT) and AnxA1-null (AnxA1^-/-) mice received an intraperitoneal injection of 1.5% starch solution for macrophage recruitment. NLRP3 was activated by priming cells with lipopolysaccharide for 3 h, followed by nigericin (1 h) or ATP (30 min) incubation. As expected, nigericin and ATP administration decreased elicited peritoneal macrophage viability and induced IL-1β release, more pronounced in the AnxA1^-/- cells than in the control peritoneal macrophages. In addition, nigericin-activated AnxA1^-/- macrophages showed increased levels of NLRP3, while points of co-localization of the AnxA1 protein and NLRP3 inflammasome were detected in WT cells, as demonstrated by ultrastructural analysis. The lipidomic analysis showed a pronounced release of prostaglandins in nigericin-stimulated WT peritoneal macrophages, while ceramides were detected in AnxA1^-/- cell supernatants. Different eicosanoid profiles were detected for both genotypes, and our results suggest that endogenous AnxA1 regulates the NLRP3-derived IL-1β and lipid mediator release in macrophages.

Lipo-prostaglandin E1 improves renal hypoxia evaluated by BOLD-MRI in patients with diabetic kidney disease

OBJECTIVE

To evaluate the effect of lipo-PGE1 on renal hypoxia in patients with DKD by BOLD-MRI.

MATERIALS AND METHODS

All patients were divided into DKD group and CKD-without-diabetes group. All patients received intravenous 10 μg lipo-PGE1 once daily for 14 days. BOLD-MRI was performed before and after lipo-PGE1 administration to acquire renal CR2* and MR2* values.

RESULTS

Renal MR2* value in DKD group after lipo-PGE1 treatment were significantly decreased compared with the baseline. However, no significant differences in MR2* values were found in the CKD-without-diabetes group.

CONCLUSIONS

Lipo-PGE1 was shown to improve kidney medullary oxygenation in patients with DKD.

Clinical efficacy of different doses of lipo-prostaglandin E1 in the treatment of painful diabetic peripheral neuropathy

OBJECTIVE

To observe the clinical efficacy of different doses of alprostadil (lipo-prostaglandin E1, lipo-PGE1) in the treatment of painful diabetic peripheral neuropathy (DPN).

METHODS

Sixty patients with painful DPN were equally and randomly assigned into three groups. Two groups received different doses of lipo-PGE1 by intravenous drip injection (A group: low-dose lipo-PGE1; B group: high-dose lipo-PGE1) following intravenous bolus injection of mecobalamin (MeCbl, 0.5mg once daily (QD)); the third group received MeCbl alone (C group). All patients received optimized treatment to lower blood glucose, blood pressure, and blood lipids to target levels. The efficacy of lipo-PGE1 in the three groups of patients was observed after 3weeks of treatment.

RESULTS

The overall response rate was 90% in the B group, significantly higher than that in the A and C groups (80% and 55%, respectively; P<0.05). During the observation period, there was no incidence of serious adverse reactions (e.g., acute heart failure, sudden drop in blood pressure, or malignant arrhythmias) in any of the three groups.

CONCLUSIONS

High-dose lipo-PGE1 has better efficacy than low-dose lipo-PGE1 or MeCbl alone in the treatment of painful DPN.

Meta-analysis of methylcobalamin alone and in combination with prostaglandin E1 in the treatment of diabetic peripheral neuropathy

This study aimed to compare the efficacy and safety of prostaglandin E1 plus methylcobalamin (PGE1-MC) with that of methylcobalamin alone (MC) on diabetic peripheral neuropathy (DPN). We searched published randomized controlled trials (RCTs) of PGE1 combined with MC for DPN up to June 1, 2013. Data were extracted to evaluate methodological quality and describe characteristics of studies in duplicate. A random or a fixed effect model was used to analyze outcomes which were expressed as relative risk (RR) or mean difference with a 95 % confidence interval (CI). All data were analyzed using Review Manager 5.2 software. Twenty-six RCTs involving 2,107 individuals were included. Meta-analysis showed that PGE1-MC combination therapy was significantly better than MC monotherapy (RR = 1.40; 95 % CI 1.33-1.48) on efficacy. The weighted mean differences in nerve conduction velocities (NCVs) were 6.72 (95 % CI: 5.42-8.02) for median motor nerve conduction velocity (MNCV), 5.13 (CI 4.13-6.13) for median sensory nerve conduction velocity (SNCV), 5.74 (CI 4.87-6.61) for peroneal MNCV and 4.62 (CI 3.89-5.34) for peroneal SNCV in favor of the PGE1 + MC combination group. Moreover, there were no serious adverse events in both groups during the treatment period. The results of the meta-analysis show that treatment with PGE1-MC is safe and can gain better outcomes in neuropathic symptoms and NCVs compared with MC alone. However, the conclusion may not be strong because most of the studies included in this meta-analysis have poor methodological quality.

Pathophysiology, diagnosis and treatment of intermittent claudication in patients with lumbar canal stenosis

Spinal nerve roots have a peculiar structure, different from the arrangements in the peripheral nerve. The nerve roots are devoid of lymphatic vessels but are immersed in the cerebrospinal fluid (CSF) within the subarachnoid space. The blood supply of nerve roots depends on the blood flow from both peripheral direction (ascending) and the spinal cord direction (descending). There is no hypovascular region in the nerve root, although there exists a so-called water-shed of the bloodstream in the radicular artery itself. Increased mechanical compression promotes the disturbance of CSF flow, circulatory disturbance starting from the venous congestion and intraradicular edema formation resulting from the breakdown of the blood-nerve barrier. Although this edema may diffuse into CSF when the subarachnoid space is preserved, the endoneurial fluid pressure may increase when the area is closed by increased compression. On the other hand, the nerve root tissue has already degenerated under the compression and the numerous macrophages releasing various chemical mediators, aggravating radicular symptoms that appear in the area of Wallerian degeneration. Prostaglandin E1 (PGE1) is a potent vasodilator as well as an inhibitor of platelet aggregation and has therefore attracted interest as a therapeutic drug for lumbar canal stenosis. However, investigations in the clinical setting have shown that PGE1 is effective in some patients but not in others, although the reason for this is unclear.

Prostaglandin E1 for preventing the progression of diabetic kidney disease

BACKGROUND

Diabetic kidney disease (DKD) is one of the major chronic microvascular complications in diabetes mellitus, and may progress to end-stage kidney disease (ESKD). There are no definitely effective approaches for preventing, delaying or treating DKD. Small studies have shown that Prostaglandin E1 (PGE1) can improve renal blood circulation and decrease proteinuria and albuminuria.

OBJECTIVES

To assess the benefits and harms of PGE1 for preventing the progression of DKD.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Chinese Biomedicine Database (CBM) and reference lists of articles with no language restriction.

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs comparing any PGE1 agent used for preventing the progression of DKD, regardless of dosage, mode of administration, addition of cointerventions or duration of treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. For dichotomous outcomes (all-cause mortality, ESKD), results were expressed as relative risk (RR) with 95% confidence intervals (CI). Continuous outcomes (microalbuminuria, proteinuria, albuminuria, doubling of serum creatinine, serum creatinine) were expressed as mean difference (MD) with 95% CI.

MAIN RESULTS

Six studies (271 patients) were included. Five studies investigated PGE1 with or without fosinopril/losartan versus fosinopril/losartan or no treatment and one compared PGE1 versus Xueshuantong (a Chinese medicinal herb). There was a significant decrease in urinary albumin excretion rate (UAER) in patients treated with PGE1 (MD -48.28 microg/min, 95% CI -75.29 to -21.28), other outcomes also showed a significant decrease in the patients with PGE1 (albuminuria: MD -143.66 mg/24 h, 95% CI -221.48 to -65.84; proteinuria: MD -300 g/24 h, 95% CI -518.34 to -81.66). PGE1 had a positive effect on albuminuria (MD -660 mg/24 h, 95% CI -867.07 to -452.93) in clinical DKD (CDN, III stage of DN) compared with Xueshuantong. No data on incidence of ESKD, all-cause mortality or quality of life were available.

AUTHORS' CONCLUSIONS

PGE1 may have positive effects on DKD by reducing UAER, decreasing albuminuria and lessening proteinuria, with no obvious serious adverse events. However, limited by the poor methodological quality of the included studies and the small number of participants, there is currently insufficient evidence for determining if PGE1 could be used for preventing the progression of DKD. Large, properly randomised, placebo-controlled, double-blind studies are urgently needed.

Development of animal model for vasculatic neuropathy: Induction by ischemic-reperfusion in the rat femoral artery

Ischemic-reperfusion (I/R) is common in various pathological conditions like diabetic complication, complex regional pain syndrome type II (CRPS II), necrotizing vascular occlusive disease and trauma. We have developed an animal model of ischemic-reperfusion injury induced nociceptive sensory neuropathy in rats. The model was validated after 2, 4 and 6h of ischemia followed by prolonged reperfusion. The sensory behavioral assessment revealed thermal and mechanical hyperalgesia in paw and in tail which expressed the peripheral and central neuropathic pain respectively. We observed a decrease in the serum IL-10 and nerve conduction velocity and increase in the serum nitrate, malondialdehyde (MDA) and TNF-alpha levels in the 4 and 6h I/R groups in biochemical and electrophysiological evaluations. Histopathological study had revealed the decrease in nerve fiber density in the moderate and severe I/R groups. We selected the moderate (4h) ischemic-reperfusion injury as beneficial model because of the good correlation with clinical status for the development of neuropathy in human associated with severe pain disorders. This model can be used to explore pathophysiological mechanisms implied in the genesis of neuropathic pain and also to evaluate the new analgesic agents, peripheral neuro-vasoactive substances and neuroprotective drugs.

Blood flow analysis of compressed nerve root after intravenous injection of lipo-prostaglandin E1

Prostaglandin E(1) (PGE(1)) is a potent vasodilator as well as an inhibitor of platelet aggregation and has therefore attracted interest as a therapeutic drug for lumbar canal stenosis. However, investigations in the clinical setting have shown that PGE(1) is effective in some patients but not in others, although the reason for this is unclear. The aim of the present study was to measure changes in intraradicular blood flow after intravenous injection of lipo-PGE(1) (0.15 microg/kg) using a laser Doppler flow meter in control model and nerve root compression model. Then, the nerve root in which blood flow was measured was removed and examined histologically. Intravenous injection of lipo-PGE(1) also resulted in marked increase of blood flow in the uncompressed nerve roots of the control group, but caused minimal enhancement of blood flow at the sites of nerve root compression exhibiting Wallerian degeneration. It is concluded that lipo-PGE(1) has less effect on markedly degenerated nerve roots than it does on those that are normal.

Response of cochlear blood flow to prostaglandin E1 applied topically to the round window

CONCLUSIONS

The increase in cochlear blood flow (CBF) after administration of prostaglandin E1 (PGE1) to the round window depends on increased blood flow through the anterior inferior cerebellar artery (AICA).

OBJECTIVES

To evaluate the response of CBF to PGE1 applied topically to the round window, and to investigate the origin of blood flow changes after this topical application.

MATERIAL AND METHODS

The response of CBF to topically applied PGE1 was measured by placing the tip of a laser Doppler probe on the bony wall of the basal turn of the cochlea after the middle ear mucosa over the cochlea had been removed in guinea pigs and rats. In rats, the CBF response to PGE1 administration was investigated after occlusion of the AICA or stapedial artery.

RESULTS

CBF increased following PGE1 administration in both guinea pigs and rats. In rats, CBF increased from 100% to 132%+/-10% (mean+/-SD) after the topical application of 0.5 microl of a 0.014% PGE1 solution. CBF decreased after occlusion of the AICA or stapedial artery but did not increase after PGE1 administration during occlusion of the AICA. The CBF response to PGE1 administration was similar before and after occlusion of the stapedial artery.