Proenkephalin Research Articles

Effects of Selenium Yeast on Egg Quality, Plasma Antioxidants, Selenium Deposition and Eggshell Formation in Aged Laying Hens.

Internal egg and eggshell quality are often deteriorated in aging laying hens, which causes huge economic losses in the poultry industry. Selenium yeast (SY), as an organic food additive, is utilized to enhance laying performance and egg quality. To extend the egg production cycle, effects of selenium yeast supplementation on egg quality, plasma antioxidants and selenium deposition in aged laying hens were evaluated. In this study, five hundred and twenty-five 76-week-old Jing Hong laying hens were fed a selenium-deficient (SD) diet for 6 weeks. After Se depletion, the hens were randomly divided into seven treatments, which included an SD diet, and dietary supplementation of SY and sodium selenite (SS) at 0.15, 0.30, and 0.45 mg/kg to investigate the effect on egg quality, plasma antioxidant capacity, and selenium content in reproductive organs. After 12 weeks of feeding, dietary SY supplementation resulted in higher eggshell strength (SY0.45) (p < 0.05) and lower shell translucence. Moreover, organs Se levels and plasma antioxidant capacity (T-AOC, T-SOD, and GSH-Px activity) were significantly higher with Se supplementation (p < 0.05). Transcriptomic analysis identified some key candidate genes including cell migration inducing hyaluronidase 1 (CEMIP), ovalbumin (OVAL), solute carrier family 6 member 17 (SLC6A17), proopiomelanocortin (POMC), and proenkephalin (PENK), and potential molecular processes (eggshell mineralization, ion transport, and eggshell formation) involved in selenium yeast's effects on eggshell formation. In conclusion, SY has beneficial functions for eggshell and we recommend the supplementation of 0.45 mg/kg SY to alleviate the decrease in eggshell quality in aged laying hens.

Up-regulation of BDNF/TrkB signaling by δ opioid receptor agonist SNC80 modulates depressive-like behaviors in chronic restraint-stressed mice

Depressive disorder is a psychiatric disease characterized by its main symptoms of low mood and anhedonia. Due to its complex etiology, current clinical treatments for depressive disorder are limited. In this study, we assessed the role of the δ opioid receptor (δOR) system in the development of chronic-restraint-stressed (CRS)-induced depressive behaviors. We employed a 21-day CRS model and detected the c-fos activation and protein levels' changes in enkephalin (ENK)/δOR. It was found that the hippocampus and amygdala were involved in CRS-induced depression. The expression of pro-enkephalin (PENK), the precursors of the endogenous ligand for δOR, was significantly decreased in the hippocampus and amygdala following CRS. We then treated the mice with SNC80, a specific δOR agonist, to examine its anti-depressant effects in the tail suspension test (TST), forced swimming test (FST), and sucrose preference test (SPT). SNC80 administration significantly reversed depressive-like behaviors, and this antidepressant effect could be blocked by a TrkB inhibitor: ANA-12. Although ANA-12 treatment had no significant effect on the expression of ENK/δOR, it blocked the promoting effects of brain-derived neurotrophic factor (BDNF)/tyrosine kinase B(TrkB) signaling by SNC80 in the hippocampus and amygdala. Therefore, the present study demonstrates that SNC80 exerts anti-depressant effects by up-regulating the BDNF/TrkB signaling pathway in the hippocampus and amygdala in CRS-induced depression and provides evidence that δOR's agonists may be potential anti-depressant therapeutic agents.

Effect of Bladder Injection of OnabotulinumtoxinA on the Central Expression of Genes Associated with the Control of the Lower Urinary Tract: A Study in Normal Rats.

To investigate a possible central mechanism of action of Botulinum toxin A (BoNT/A) following injection in the bladder, complementary to the acknowledged peripheral bladder effect, we studied changes in the expression of neuropeptides and receptors involved in lower urinary tract function in the spinal cord (SC) and dorsal root ganglia (DRG) of normal rats following BoNT/A bladder injection. Thirty-six Sprague-Dawley rats, divided into three groups of n = 12, received bladder injections of 2U or 5U OnabotulinumtoxinA (BOTOX®), or saline. Six animals from each group were sacrificed on days 7 and 14. Expression of Tachykinin 1 (Tac1), capsaicin receptor (TRPV1), neuropeptide Y (NPY), proenkephalin (PENK) and muscarinic receptors M1, M2, M3, was evaluated in the bladder, L6-S1 DRG, and SC segments using real-time PCR and Western blotting. Real-time PCR revealed increased expression of NPY in all tissues except for SC, and increased TRPV1 and PENK expression in DRG and SC, whereas expression of Tac1, M1 and M2 was decreased. Less significant changes were noted in protein levels. These findings suggest that bladder injections of OnabotulinumtoxinA may be followed by changes in the expression of sensory, sympathetic and cholinergic bladder function regulators at the DRG/SC level.

CD206+/MHCII− macrophage accumulation at nerve injury site correlates with attenuation of allodynia in TASTPM mouse model of Alzheimer's disease

Chronic pain is undertreated in people with Alzheimer's disease (AD) and better understanding of the underlying mechanisms of chronic pain in this neurodegenerative disease is essential. Neuropathic pain and AD share a significant involvement of the peripheral immune system. Therefore, we examined the development of nerve injury-induced allodynia in TASTPM (APPsweXPS1.M146V) mice and assessed monocytes/macrophages at injury site. TASTPM developed partial allodynia compared to WT at days 7, 14 and 21 days after injury, and showed complete allodynia only after treatment with naloxone methiodide, a peripheralized opioid receptor antagonist. Since macrophages are one of the sources of endogenous opioids in the periphery, we examined macrophage infiltration at injury site and observed that CD206+/MHCII− cells were more numerous in TASTPM than WT. Accordingly, circulating TASTPM Ly6Chigh (classical) monocytes, which are pro-inflammatory and infiltrate at the site of injury, were less abundant than in WT. In in vitro experiments, TASTPM bone marrow-derived macrophages showed efficient phagocytosis of myelin extracts containing amyloid precursor protein, acquired CD206+/MHCII− phenotype, upregulated mRNA expression of proenkephalin (PENK) and accumulated enkephalins in culture media. These data suggest that in TASTPM nerve-injured mice, infiltrating macrophages which derive from circulating monocytes and may contain amyloid fragments, acquire M2-like phenotype after myelin engulfment, and release enkephalins which are likely to inhibit nociceptive neuron activity via activation of opioid receptors.

Comparative Transcriptomic Analysis of mRNAs, miRNAs and lncRNAs in the Longissimus dorsi Muscles between Fat-Type and Lean-Type Pigs.

In pigs, meat quality and production are two important traits affecting the pig industry and human health. Compared to lean-type pigs, fat-type pigs contain higher intramuscular fat (IMF) contents, better taste and nutritional value. To uncover genetic factors controlling differences related to IMF in pig muscle, we performed RNA-seq analysis on the transcriptomes of the Longissimus dorsi (LD) muscle of Laiwu pigs (LW, fat-type pigs) and commercial Duroc × Landrace × Yorkshire pigs (DLY, lean-type pigs) at 150 d to compare the expression profiles of mRNA, miRNA and lncRNA. A total of 225 mRNAs, 12 miRNAs and 57 lncRNAs were found to be differentially expressed at the criteria of |log2(foldchange)| > 1 and q < 0.05. The mRNA expression of LDHB was significantly higher in the LD muscle of LW compared to DLY pigs with log2(foldchange) being 9.66. Using protein interaction prediction method, we identified more interactions of estrogen-related receptor alpha (ESRRA) associated with upregulated mRNAs, whereas versican (VCAN) and proenkephalin (PENK) were associated with downregulated mRNAs in LW pigs. Integrated analysis on differentially expressed (DE) mRNAs and miRNAs in the LD muscle between LW and DLY pigs revealed two network modules: between five upregulated mRNA genes (GALNT15, FKBP5, PPARGC1A, LOC110258214 and LOC110258215) and six downregulated miRNA genes (ssc-let-7a, ssc-miR190-3p, ssc-miR356-5p, ssc-miR573-5p, ssc-miR204-5p and ssc-miR-10383), and between three downregulated DE mRNA genes (IFRD1, LOC110258600 and LOC102158401) and six upregulated DE miRNA genes (ssc-miR1379-3p, ssc-miR1379-5p, ssc-miR397-5p, ssc-miR1358-5p, ssc-miR299-5p and ssc-miR1156-5p) in LW pigs. Based on the mRNA and ncRNA binding site targeting database, we constructed a regulatory network with miRNA as the center and mRNA and lncRNA as the target genes, including GALNT15/ssc-let-7a/LOC100523888, IFRD1/ssc-miR1379-5p/CD99, etc., forming a ceRNA network in the LD muscles that are differentially expressed between LW and DLY pigs. Collectively, these data may provide resources for further investigation of molecular mechanisms underlying differences in meat traits between lean- and fat-type pigs.

Functional Characterization and Molecular Marker Development of the Proenkephalin as Biomarker of Food Addiction in Food Habit Domestication of Mandarin Fish (Siniperca chuatsi)

Proenkephalin (PENK), as the precursor of endogenous opioid enkephalin (ENK), is widely present in the nervous system and plays an important role in animal food addiction and rewarding behavior. In our study, we intend to study the functional characterization and molecular marker development of the penk gene related to food habit domestication of mandarin fish. We found that the penk gene of mandarin fish had three types of endogenous opioid peptide sequences. Compared with other tissues, penk mRNA was highly expressed in the whole brain. Intracerebroventricular (ICV) injection of lysine or methionine significantly increased the expression of penk mRNA. The expression of penk mRNA in the brain of mandarin fish that could be easily domesticated from eating live prey fish to artificial diets was significantly higher than those that could not. After feeding with high-carbohydrate artificial diets, the expression of penk mRNA showed no significant difference between mandarin fish with hypophagia and those that still ate normally. A total of four single nucleotide polymorphisms (SNP) loci related to easy domestication toward eating artificial diets were screened from the mandarin fish population. Additionally, the TT genotype at one of the loci was significantly correlated with the food habit domestication of mandarin fish.

Role of proenkephalin in the diagnosis of severe and subclinical acute kidney injury during the perioperative period of liver transplantation

In recent decades, clinical research on early biomarkers of renal injury has been frequent and intensive, with proenkephalin (PENK) being indicated as a promising filtration biomarker (BM). From a cohort of 57 patients, blood samples were collected preoperatively and 48 h after liver transplantation (LT). The following BMs were analyzed: PENK, cystatin-C (CYS-C), and serum creatinine (Scr). Diagnosis of AKI was based on the KDIGO criteria. Of the 57 patients undergoing LT, 50 (88%) developed acute kidney injury (AKI) and were categorized as follows: no-AKI/mild-AKI - 21 (36.8%) and severe-AKI 36 (63.2%). During the preoperative period, only PENK was significantly higher in patients with severe AKI, with an AUC of 0.69 (CI 0.54–0.83), a cutoff of 55.30 pmol/l, a sensitivity of 0.86, a specificity of 0.52, and an accuracy of 0.75. In addition, subclinical AKI was determined preoperatively in 32 patients. Forty-eight hours after LT, PENK maintained its performance in determining severe AKI, with an AUC of 0.83 (CI 0.72–0.94), a cutoff of 119.05 pmol/l, a sensitivity of 0.81, a specificity of 0.90, and an accuracy of 0.84. PENK detected AKI 48 h earlier than serum creatinine. In a multivariate linear regression analysis, PENK was an independent predictor of severe AKI. This small study suggests that the filtration biomarker PENK shows promise for detecting AKI in patients undergoing LT, revealing greater accuracy and an earlier rise in patients with severe AKI. The combination of kidney functional and filtration BMs may aid in the management and prevention of AKI progression.

Aerobic exercise improves motor function and striatal MSNs-Erk/MAPK signaling in mice with 6-OHDA-induced Parkinson's disease.

In Parkinson’s disease (PD) state, with progressive loss of dopaminergic neurons in the substantia nigra, the striatal dopamine (DA) and glutamate (Glu) levels change, resulting in dysfunction of basal ganglia motor regulation. The PD patient presents motor dysfunction such as resting tremor, bradykinesia, and muscular rigidity. To investigate the mechanism of aerobic exercise to improve PD-related motor dysfunction, in the current study, 6-hydroxydopamine (6-OHDA) was used to induce the PD mice model, and the motor function of PD mice was comprehensively evaluated by open-field test, rotarod test, and gait test. The co-expression of prodynorphin (PDYN) and proenkephalin (PENK) with extracellular signal-regulated kinase (Erk1/2) and phosphorylation Erk1/2 (p-Erk1/2) were detected by double-labeling immunofluorescence. The results showed that a 4-week aerobic exercise intervention could effectively improve the motor dysfunction of PD mice. Moreover, it was found that the expressions of Erk1/2 and p-Erk1/2 in the dorsal striatum (Str) of PD mice were significantly increased, and the number of positive cells co-expressed by Erk1/2, p-Erk1/2, and PENK was significantly higher than PDYN. The above phenomenon was reversed by a 4-week aerobic exercise intervention. Therefore, this study suggests that the mechanism by which aerobic exercise improves PD-related motor dysfunction may be related to that the aerobic exercise intervention alleviates the activity of extracellular signal-regulated kinase/mitogen-activated protein kinases (Erk/MAPK) signaling pathway in striatal medium spiny neurons expressing D2-like receptors (D2-MSNs) of PD mice by regulating the striatal DA and Glu signaling.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00221-022-06360-4.

Prodynorphin and Proenkephalin in Cerebrospinal Fluid of Sporadic Creutzfeldt-Jakob Disease.

Proenkephalin (PENK) and prodynorphin (PDYN) are endogenous opioid peptides mainly produced in the striatum and, to a lesser extent, in the cerebral cortex. Dysregulated metabolism and altered cerebrospinal fluid (CSF) levels of PENK and PDYN have been described in several neurodegenerative diseases. However, no study to date investigated these peptides in the CSF of sporadic Creutzfeldt–Jakob disease (sCJD). Using liquid chromatography-multiple reaction monitoring mass spectrometry, we evaluated the CSF PDYN- and PENK-derived peptide levels in 25 controls and 63 patients with sCJD belonging to the most prevalent molecular subtypes (MM(V)1, VV2 and MV2K). One of the PENK-derived peptides was significantly decreased in each sCJD subtype compared to the controls without a difference among subtypes. Conversely, PDYN-derived peptides were selectively decreased in the CSF of sCJD MV2K, a subtype with a more widespread overall pathology compared to the sCJD MM(V)1 and the VV2 subtypes, which we confirmed by semiquantitative analysis of cortical and striatal neuronal loss and astrocytosis. In sCJD CSF PENK and PDYN were associated with CSF biomarkers of neurodegeneration but not with clinical variables and showed a poor diagnostic performance. CSF PDYN and PENK-derived peptides had no significant diagnostic and prognostic values in sCJD; however, the distinct marker levels between molecular subtypes might help to better understand the basis of phenotypic heterogeneity determined by divergent neuronal targeting.

MGE-Like Neural Progenitor Cell Survival and Expression of Parvalbumin and Proenkephalin in a Jaundiced Rat Model of Kernicterus

Kernicterus is a permanent condition caused by brain damage from bilirubin toxicity. Dystonia is one of the most debilitating symptoms of kernicterus and results from damage to the globus pallidus (GP). One potential therapeutic strategy to treat dystonia in kernicterus is to replace lost GP neurons and restore basal ganglia circuits through stem cell transplantation. Toward this end, we differentiated human embryonic stem cells (hESCs) into medial ganglion eminence (MGE; the embryological origin of most of the GP neurons)-like neural precursor cells (NPCs). We determined neurochemical phenotype in cell culture and after transplanting into the GP of jaundiced Gunn rats. We also determined grafted cell survival as well as migration, distribution, and morphology after transplantation. As in the GP, most cultured MGE-like NPCs expressed γ-aminobutyric acid (GABA), with some co-expressing markers for parvalbumin (PV) and others expressing markers for pro-enkephalin (PENK). MGE-like NPCs survived in brains at least 7 weeks after transplantation, with most aggregating near the injection site. Grafted cells expressed GABA and PV or PENK as in the normal GP. Although survival was low and the maturity of grafted cells varied, many cells produced neurite outgrowth. While promising, our results suggest the need to further optimize the differentiation protocol for MGE-like NPC for potential use in treating dystonia in kernicterus.

Plasma Pro-Enkephalin A and Ischemic Stroke Risk: The Reasons for Geographic and Racial Differences in Stroke Cohort

ObjectivesThe opioid neuropeptide pro-enkephalin A (PENK-A) may be a circulating marker of cardiovascular risk, with prior findings relevant to heart failure, kidney disease, and vascular dementia. Despite these findings, the association of PENK-A with ischemic stroke is unknown, so we examined this association in a prospective cohort study and analyzed differences by race and sex. Materials and MethodsThe REasons for Geographic and Racial Differences in Stroke study (REGARDS) is a prospective cohort study of 30,239 Black and White adults. Plasma PENK-A was measured in 473 participants that developed first-time ischemic stroke over 5.9 years and 899 randomly selected participants. Cox models adjusted for demographics and stroke risk factors were used to calculate hazard ratios (HRs) of stroke by baseline PENK-A. ResultsPENK-A was higher with increasing age, female sex, White race, lower body mass index, and antihypertensive medication use. Each SD higher increment of PENK-A was associated with an adjusted HR of 1.20 (95% CI 1.01-1.42) for stroke, with minimal confounding by stroke risk factors. Spline plots suggested a U-shaped relationship, particularly in White men, with an adjusted HR 3.88 (95% CI 1.94-7.77) for the 95th versus 50th percentile of PENK-A in White men. ConclusionsHigher baseline plasma PENK-A was independently associated with future stroke risk in REGARDS. This association was most apparent among White men. There was little confounding by established stroke risk factors, suggesting a possible causal role in stroke etiology. Further research is needed to understand the role of endogenous opioids in stroke pathogenesis.

The opposing action of stromal cell proenkephalin and stem cell transcription factors in prostate cancer differentiation

BackgroundLoss of prostate cancer differentiation or de-differentiation leads to an untreatable disease. Patient survival would benefit if this can be prevented or reversed. Cancer de-differentiation transforms luminal-like (differentiated) adenocarcinoma into less luminal-like and more stem-like (undifferentiated) small cell carcinoma through a sequential activation of stem cell transcription factors (scTF) POU5F1, LIN28A, SOX2 and NANOG. Like stem cells, prostate small cell carcinoma express this quartet of scTF as well as a 10-fold lower level of β2-microglobulin (B2M) than that of differentiated cell types. In organ development, prostate stromal mesenchyme cells mediate epithelial differentiation in part by secreted factors.MethodsThe identified prostate stromal-specific factor proenkephalin (PENK) was cloned, and transfected into scTF+B2Mlo stem-like small cell carcinoma LuCaP 145.1, reprogrammed luminal-like scTF−B2Mhi LNCaP, and luminal-like scTF−B2Mhi adenocarcinoma LuCaP 70CR. The expression of scTF, B2M and anterior gradient 2 (AGR2) was analyzed in the transfected cells.ResultsPENK caused down-regulation of scTF and up-regulation of B2M to indicate differentiation. When transfected into reprogrammed LNCaP, PENK reversed the reprogramming by down-regulation of scTF with attendant changes in cell appearance and colony morphology. When transfected into LuCaP 70CR, PENK up-regulated the expression of adenocarcinoma antigen AGR2, a marker associated with cancer cell differentiation.ConclusionsProstate cancer cells appear to retain their responsiveness to stromal PENK signaling. PENK can induce differentiation to counter de-differentiation caused by scTF activation. The many mutations and aneuploidy characteristic of cancer cells appear not to hinder these two processes. Loss of prostate cancer differentiation is like reprogramming from luminal-like to stem-like.

Proenkephalin and the risk of new-onset heart failure: data from prevention of renal and vascular end-stage disease.

BackgroundEnkephalins of the opioid system exert several cardiorenal effects. Proenkephalin (PENK), a stable surrogate, is associated with heart failure (HF) development after myocardial infarction and worse cardiorenal function and prognosis in patients with HF. The association between plasma PENK concentrations and new‐onset HF in the general population remains to be established.HypothesisWe hypothesized that plasma PENK concentrations are associated with new‐onset HF in the general population.MethodsWe included 6677 participants from the prevention of renal and vascular end‐stage disease study and investigated determinants of PENK concentrations and their association with new‐onset HF (both reduced [HFrEF] and preserved ejection fraction [HFpEF]).ResultsMedian PENK concentrations were 52.7 (45.1–61.9) pmol/L. Higher PENK concentrations were associated with poorer renal function and higher NT‐proBNP concentrations. The main determinants of higher PENK concentrations were lower estimated glomerular filtration rate (eGFR), lower urinary creatinine excretion, and lower body mass index (all p < .001). After a median 8.3 (7.8–8.8) years follow‐up, 221 participants developed HF; 127 HFrEF and 94 HFpEF. PENK concentrations were higher in subjects who developed HF compared with those who did not, 56.2 (45.2–67.6) versus 52.7 (45.1–61.6) pmol/L, respectively (p = .003). In competing‐risk analyses, higher PENK concentrations were associated with higher risk of new‐onset HF (hazard ratio [HR] = 2.09[1.47–2.97], p < .001), including both HFrEF (HR = 2.31[1.48–3.61], p < .001) and HFpEF (HR = 1.74[1.02–2.96], p = .042). These associations were, however, lost after adjustment for eGFR.ConclusionsIn the general population, higher PENK concentrations were associated with lower eGFR and higher NT‐proBNP concentrations. Higher PENK concentrations were not independently associated with new‐onset HFrEF and HFpEF and mainly confounded by eGFR.

Interplay between adipose tissue secreted proteins, eating behavior and obesity

PurposeAdipokines may play an important role in the complex etiology of human obesity and its metabolic complications. Here, we analyzed the relationship between 15 adipokines, eating behavior and body-mass index (BMI).MethodsThe study included 557 participants of the Sorbs (62.1% women, 37.9% men) and 3101 participants of the population-based LIFE-Adult cohorts (53.4% women, 46.4% men) who completed the German version of the Three-Factor-Eating Questionnaire to assess the eating behavior types cognitive restraint, disinhibition and hunger. Serum levels of 15 adipokines, including adiponectin, adipocyte fatty acid-binding protein (AFABP), angiopoietin-related growth factor (AGF), chemerin, fibroblast growth factor (FGF)-19, FGF-21, FGF-23, insulin-like growth factor (IGF)-1, interleukin (IL) 10, irisin, progranulin, vaspin, pro-neurotensin (pro-NT), pro-enkephalin (PENK) and leptin were measured. Based on significant correlations between several adipokines with different eating behavior items and BMI, we conducted mediation analyses, considering the eating behavior items as potential mediation variable towards BMI.ResultsHere, we found that the positive association between chemerin, AFABP or leptin and BMI in Sorbian women was mediated by higher restraint or disinhibited eating, respectively. Additionally, in Sorbian women, the negative relation between IGF-1 and BMI was mediated by higher disinhibition and the positive link between AGF and BMI by lower disinhibition. In Sorbian men, the negative relationship between PENK and BMI was mediated by lower disinhibition and hunger, whereas the negative relation between IGF-1 and BMI was mediated by higher hunger. In the LIFE-Adult women´s cohort, associations between chemerin and BMI were mediated by decreased hunger or disinhibition, respectively, whereas relations between PENK and BMI were fully mediated by decreased disinhibition.ConclusionOur study suggests that adipokines such as PENK, IGF-1, chemerin, AGF, AFABP and leptin might affect the development of obesity by directly modifying individual eating behavior. Given the observational nature of the study, future experimental or mechanistic work is warranted.

Pro-Enkephalin and its association with renal function in Middle Eastern immigrants and native Swedes

Iraqi-born immigrants residing in Sweden exhibit lower blood pressure as well as better renal function despite an overall worse metabolic risk profile in comparison with native Swedes. This may indicate the presence of cardiorenal protective mechanisms in the Middle Eastern population. Hence, the aim of this study was to investigate whether the association between renal function and Pro-Enkephalin (PENK), a biomarker predictive of both acute and chronic kidney dysfunction, differs across ethnicities. The MEDIM population-based study including a cohort of women and men, born in Iraq or Sweden, aged 30–75 years was conducted in Malmö, Sweden, from 2010 to 2012. The study included fasting blood samples, physical examinations and self-administrated questionnaires. Despite significantly better renal function assessed by creatinine-based eGFR in the Iraqi group, levels of PENK did not differ between the groups, (70.0 pmol/L, born in Iraq (n = 1263) vs 71.1, born in Sweden (n = 689), p = .4). However, the association between PENK and renal function was relatively weaker in the Iraqi born group, as supported by a significant interaction between PENK and country of birth (P Interaction= Country of birth x PENK = 0,010). This observational study suggests that the association between renal function and PENK was weaker in Middle Eastern immigrants. This is of interest as PENK may exhibit a direct effect on renal function, however further research is needed including studies on causality.

MO423PROENKEPHALIN AS A BIOMARKER OF KIDNEY FILTRATION IN ACUTE KIDNEY INJURY

Abstract Background and Aims In the last decades, clinical research biomarker (BM) to improve assessment of kidney function have been intensive, and proenkephalin (PENK) has been identified as a new BM of filtration. We hypothesized whether PENK would have a better accuracy for the diagnosis of severe AKI than serum cystatin (CYS) and the serum creatinine (Scr). We evaluate patient in the peri op of liver transplant (LT). Method Blood samples were collected during the pre and post (until 48 hours) operative (op.) period of LT in 57 eligible patients. Where was analyzed PENK (Sphingotest®), CYS (Milipex) and Scr (Quimioluminence). AKI diagnosis was based on the Kidney Disease International Global Outcomes (KDIGO) criteria using Scr. KDIGO 1 was subclassified according to the International Club of Ascites (ICA). Results Of the 57 patients undergoing LT, 50 (88%) developed AKI according to the KDIGO criteria in the first week after LT. Twenty-one patients without AKI and with KDIGO 1-A (37%) were summarized as the no AKI/mild AKI group, whereas 36 patients with KDIGO 1-B, 2 and 3 (63%) were summarized as the severe AKI group. Before the intra - operative insult only PENK was significantly higher in patients that developed severe AKI, median 55 [P25-75(44,25 – 94,55)] in no AKI/mild AKI versus 90,16 [P25-75(64,70 – 135,76)] pmol/l in severe AKI p 0,021, an AUC 0,685 (CI 0,536 – 0,833), with a cutoff 55 pmol/l, sensibility of 0,86 and specificity 0,52, accuracy 0,75 to severe AKI. Scr levels in pre-op. were non- significantly higher in severe AKI; p=0,088. The CYS in the pre-op was similar within the groups. Pos-operative 48 hours after LT, PENK was significantly higher in severe AKI, median 81 [P25-75(61,25 – 101,50)] versus 161,45 [P25-75(122,85 – 294,03)] in severe AKI - p &amp;lt;0,0001 an AUC 0,83 (CI 0,72 - 0,94) with a cutoff 119,05 pmol/l, sensibility of 0,80 and specificity 0,90, accuracy 0,84 to severe AKI. Scr levels in post-op achieve an AUC 0,77 (CI 0,63 - 0,92) with a cutoff 1,49mg/dl, sensibility of 0,94, specificity 0,67 and accuracy 0,82. In a multivariate linear regression analysis adjusted for age, anestesia time, urine output and fluid balance, the PENK only was independently associated of severe AKI in pre-op. with OR 4,40 (CI 1,40 – 13,88) – p0,001 and the post-op. with OR 44,64 (CI 5,40 – 368,5) – p&amp;lt;0,0001. Conclusion PENK is a promisor filtration biomarker and showed a better acuracy to severe AKI in pre-operative than standard AKI diagnostic by Scr. Prediction of severe AKI in pre-operative period by PENK can help the management of these patients in the future.

Prostate Cancer Differentiation - Stromal Cell PENK and Stem Cell Transcription Factors

Prostate cancer cells from luminal-like (differentiated) adenocarcinoma to less luminal-like and more stem-like (undifferentiated) small cell carcinoma retain responsiveness to signaling by stromal cell factor proenkephalin (PENK). Stem-like cancer cells, like stem cells, express stem cell transcription factor (scTF) LIN28A, NANOG, POU5F1, SOX2 as well as a 10-fold lower level of β2-microglobulin (B2M). Forced expression of this scTF quartet can reprogram adenocarcinoma cells, as represented by LuCaP xenograft lines, to stem-, small cell carcinoma-like derivatives with the phenotypic change from scTF−B2Mhi to scTF+B2Mlo. Prostate stromal mesenchyme cells control organ development through secreted hormone factors and heterotypic cell contact. The highly expressed prostate stromal-specific PENK, when transfected into scTF+B2Mlo small cell carcinoma LuCaP 145.1, caused down-regulation of scTF and up-regulation of B2M to indicate differentiation. When transfected into scTF-reprogrammed adenocarcinoma-like LNCaP cells, PENK reversed the reprogramming through down-regulation of scTF with attendant changes in cell appearance and colony morphology. When transfected into adenocarcinoma LuCaP 70CR, PENK up-regulated the expression of anterior gradient 2 (AGR2), a marker associated with prostate cancer differentiation and better patient survival. Thus, PENK can induce differentiation to counter cancer de-differentiation due to activation of scTF. Loss of cancer differentiation leads to an untreatable disease. Patient survival would benefit if this can be reversed or prevented. Prostate cancer de-differentiation is likened to reprogramming. Cancer cells containing multiple mutations and being aneuploid can, like normal cells, still undergo differentiation.

Differences in Gene Expression of Endogenous Opioid Peptide Precursor, Cannabinoid 1 and 2 Receptors and Interleukin Beta in Peripheral Blood Mononuclear Cells of Patients With Refractory Failed Back Surgery Syndrome Treated With Spinal Cord Stimulation: Markers of Therapeutic Outcomes?

The use of spinal cord stimulation for patients with failed back surgery syndrome (FBSS) is very common. In order to better understand the mechanisms of action of spinal cord stimulation (SCS), our aim was to determine potential changes in relative gene and protein expression in the peripheral blood mononuclear cells (PBMCs) of patients as potential biomarkers of disease outcomes and potential new targets for therapy. Twenty-four patients with diagnosis of FBSS refractory to conservative therapy for at least six months were included in the study. Clinical evaluation in this study included validated questionnaires. Blood samples (10 mL) were collected five times from baseline until two months after implant of the leads. Proenkephalin (PENK), cannabinoid receptors CB1 and CB2, and interleukin 1β (IL 1β) were analyzed. Each patient served as his/her own control by comparing the samples collected at different time points against the baseline sample collected at T0. A total of 16 patients met all relevant criteria during the whole study and were assessed. Only PENK showed significant changes over time (Friedman p = 0.000). A positive correlation was observed between changes in visual analog scale (VAS) scores and PENK and a negative correlation between changes in PENK and Short Form-12 (SF-12) mental component score (MCS) scores, as well as between changes in IL 1β and Pain Detect Questionnaire (PD-Q) scores. As PENK changes increased, so did pain (VAS). As changes in PENK increased, SF-12 MCS health worsened. As changes in IL 1β increased, PD-Q values decreased. No severe adverse events occurred. Previously unknown effects of SCS on levels of PBMCs biomarkers are demonstrated. The findings of our research suggest a potential for useful integration of genome analysis and lymphocyte expression in the daily practice of neurostimulation for pain management and represent a novel road map in the light of the important questions that remain unanswered.

Proenkephalin Decreases in Cerebrospinal Fluid with Symptom Progression of Huntington's Disease.

ABSTRACTObjectiveIdentifying molecular changes that contribute to the onset and progression of Huntington's disease (HD) is of importance for the development and evaluation of potential therapies.MethodsWe conducted an unbiased mass‐spectrometry proteomic analysis on the cerebrospinal fluid of 12 manifest HD patients (ManHD), 13 pre‐manifest (preHD), and 38 controls. A biologically plausible and significant possible biomarker was validated in samples from a separate cohort of patients and controls consisting of 23 ManHD patients and 23 controls.ResultsIn ManHD compared to preHD, 10 proteins were downregulated and 43 upregulated. Decreased levels of proenkephalin (PENK) and transthyretin were closely linked to HD symptom severity, whereas levels of 15 upregulated proteins were associated with symptom severity. The decreased PENK levels were replicated in the separate cohort where absolute quantitation was performed.ConclusionsWe hypothesize that declining PENK levels reflect the degeneration of medium spiny neurons (MSNs) that produce PENK and that assays for PENK may serve as a surrogate marker for the state of MSNs in HD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Proenkephalin Predicts Organ Failure, Renal Replacement Therapy, and Mortality in Patients With Sepsis.

BackgroundKidney failure occurs frequently and is associated with high mortality during sepsis. Proenkephalin (PENK) is an emerging biomarker of kidney function. We explored whether PENK levels could predict severity, organ failure, and mortality in septic patients.MethodsWe measured the PENK level in the plasma of 215 septic patients using the sphingotest penKid assay (Sphingotec GmbH, Hennigsdorf, Germany). This was analyzed in terms of sepsis severity, vasopressor use, 30-day mortality, sequential organ failure assessment (SOFA) renal subscore, the Chronic Kidney Disease Epidemiology Collaboration estimated glomerular filtration rate (CKD-EPI eGFR) categories, and renal replacement therapy (RRT) requirement.ResultsThe PENK levels were significantly higher in patients with septic shock, vasopressor use, and non-survivors than in patients with solitary sepsis, no vasopressor use, and survivors, respectively (P=0.02, P=0.007, P<0.001, respectively). The PENK levels were significantly associated with SOFA renal subscore and CKD-EPI eGFR categories (both P<0.001). The distribution of lower eGFR (<60 mL/min/1.73 m2), RRT requirement, SOFA renal subscore, and the number of organ failures differed significantly according to the PENK quartile (P for trend<0.001 or 0.017). The 30-day mortality rate also differed significantly according to the PENK quartile (P for trend<0.001).ConclusionsPENK could be an objective and reliable marker to predict severity, organ failure, and 30-day mortality in septic patients.