A new animal model of cardiorenal syndrome could be established by inducing heart failure through coronary artery ligation in spontaneously hypertensive rats.

In rats with unilateral nephrectomy and cardiac dysfunction, renal function deteriorates at an accelerated rate, as evidenced by increased proteinuria. Whether myocardial infarct-induced heart failure (HF) exacerbates renal injury in hypertensive rats with mild renal injury has not been reported. Rats underwent either coronary ligation or sham surgery. Thirty spontaneously hypertensive rats (SHRs) aged 8 weeks were randomly divided into two groups. Group 1 was the sham group, in which the rats underwent thoracotomy without ligation of the coronary artery. Group 2 underwent coronary artery ligation. The rats in group 2 underwent coronary artery ligation on week 0. The experiment lasted 12 weeks. Urine was collected in metabolic cages over a 24-h period. Urine was collected from the rats 2 days before the end of the experiment, and the ratio of urinary protein to urinary creatinine was measured in the clinical laboratory. All rats were examined by echocardiogram one day before the end of the experiment. On the last day of the experiment, blood was collected and sent to the laboratory for analysis. Hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) staining were performed on heart and kidney sections. The ejection fraction in group 2 was lower than that in group 1 (P < 0.001). The urinary albumin to creatinine ratio in group 2 was greater than that in group 1 (P < 0.001). The urea and creatinine levels in group 1 were significantly lower than those in group 2 (P < 0.01). The levels of brain natriuretic peptide (BNP), neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C were greater in the second group than in the first group (P < 0.05). The interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) levels in group 2 were significantly greater than those in group 1 (P < 0.001). The malondialdehyde (MDA) levels in Group 2 were greater than those in Group 1 (P < 0.01). The glutathione peroxidase (GSH-Px) levels in Group 2 were lower than those in Group 1 (P < 0.05). The level of angiotensin II (AT-II) in group 1 was lower than that in group 2 (P < 0.001). Cardiac dysfunction secondary to myocardial infarction could induce cardiorenal interactions in SHRs. It could be interpreted by the activation of oxidative stress, changes in inflammation and alteration of renin-angiotensin-aldosterone system.

PHENOTYPING REPAIR AFTER ACUTE KIDNEY INJURY: PRECISION MEDICINE TO CLINICAL TRIALS.

Acute kidney injury (AKI) is common during hospitalization and is associated with long-term risk of readmissions and chronic kidney disease (CKD). Preclinical studies and novel urine biomarkers have demonstrated that subclinical inflammation and repair continue for several months after AKI. We conducted three clinical and translational studies to alleviate long-term sequelae after AKI. First, we assessed repair in deceased donor kidneys which can assist with organ allocation and reduce discard. In an ongoing study, organ procurement organizations are measuring repair biomarkers via lateral flow devices to assess organ quality and adding it to their workflow. Second, we performed research biopsies during AKI to interrogate kidney tissue with novel transcriptomic and proteomic techniques to advance therapeutic development. Third, we initiated pragmatic clinical trials to reduce readmissions after an episode of AKI by providing nurse navigator and pharmacist support to optimize blood pressure, fluid, and medication management.

Adverse effects of metamizole on heart, lung, liver, kidney, and stomach in rats.

BACKGROUND: Metamizole is banned in some countries because of its toxicity, although it is widely used in some European countries. In addition, there is limited information on its safety profile, and it is still debated whether it is toxic to the heart, lungs, liver, kidneys, and stomach. AIMS: Our study investigated the effects of metamizole on the heart, lung, liver, kidney, and stomach tissues of rats. METHODS: Eighteen rats were divided into three groups, wassix healthy (HG), 500 mg/kg metamizole (MT-500), and 1000 mg/kg metamizole (MT-1000). Metamizole was administered orally twice daily for 14 days. Meanwhile, the HG group received pure water orally. Biochemical, histopathologic, and macroscopic examinations were performed on blood samples and tissues. RESULTS: Malondialdehyde (MDA), total glutathione (tGSH), superoxide dismutase (SOD), and catalase (CAT) in the lung and gastric tissues of MT-500 and MT-1000 groups were almost the same as those of the HG (p > 0.05). However, MDA levels in the heart and liver tissues of MT-500 and MT-1000 groups were higher (p < 0.05) compared to the HG, while tGSH levels and SOD, and CAT activities were lower (p < 0.05). MDA levels of MT-500 and MT-1000 groups in the kidney tissue increased the most (p < 0.001), and tGSH levels and SOD and CAT activities decreased the most (p < 0.001) compared to HG. Metamizole did not cause oxidative damage in the lung and gastric tissue. While metamizole did not change troponin levels, it significantly increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine levels compared to HG. Histopathologically, mild damage was detected in heart tissue, moderate damage in liver tissue, and severe damage in renal tissue. However, no histopathologic damage was found in any groups' lung and gastric tissues. CONCLUSION: Metamizole should be used under strict control in patients with cardiac and liver diseases and it would be more appropriate not to use it in patients with renal disease.

Leech Poecilobdella manillensis protein extract ameliorated hyperuricemia by restoring gut microbiota dysregulation and affecting serum metabolites.

BACKGROUND: Hyperuricemia (HUA) is a public health concern that needs to be solved urgently. The lyophilized powder of Poecilobdella manillensis has been shown to significantly alleviate HUA; however, its underlying metabolic regulation remains unclear. AIM: To explore the underlying mechanisms of Poecilobdella manillensis in HUA based on modulation of the gut microbiota and host metabolism. METHODS: A mouse model of rapid HUA was established using a high-purine diet and potassium oxonate injections. The mice received oral drugs or saline. Additionally, 16S rRNA sequencing and ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry-based untargeted metabolomics were performed to identify changes in the microbiome and host metabolome, respectively. The levels of uric acid transporters and epithelial tight junction proteins in the renal and intestinal tissues were analyzed using an enzyme-linked immunosorbent assay. RESULTS: The protein extract of Poecilobdella manillensis lyophilized powder (49 mg/kg) showed an enhanced anti-trioxypurine ability than that of allopurinol (5 mg/kg) (P < 0.05). A total of nine bacterial genera were identified to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder, which included the genera of Prevotella, Delftia, Dialister, Akkermansia, Lactococcus, Escherichia_Shigella, Enterococcus, and Bacteroides. Furthermore, 22 metabolites in the serum were found to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder, which correlated to the Kyoto Encyclopedia of Genes and Genomes pathways of cysteine and methionine metabolism, sphingolipid metabolism, galactose metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis. Correlation analysis found that changes in the gut microbiota were significantly related to these metabolites. CONCLUSION: The proteins in Poecilobdella manillensis powder were effective for HUA. Mechanistically, they are associated with improvements in gut microbiota dysbiosis and the regulation of sphingolipid and galactose metabolism.

Remote liver ischemic preconditioning protects against renal ischemia/reperfusion injury via phosphorylation of extracellular signal-regulated kinases 1 and 2 in mice.

Perioperative acute kidney injury (AKI), which is mainly mediated by renal ischemia‒reperfusion (I/R) injury, is commonly observed in clinical practice. However, effective measures for preventing and treating this perioperative complication are still lacking in the clinic. Thus, we designed this study to examine whether remote liver ischemic preconditioning (RLIPC) has a protective effect on damage caused by renal I/R injury. In a rodent model, 30 mice were divided into five groups to assess the effects of RLIPC and ERK1/2 inhibition on AKI. The groups included the sham-operated (sham), kidney ischemia and reperfusion (CON), remote liver ischemic preconditioning (RLIPC), CON with the ERK1/2 inhibitor U0126 (CON+U0126), and RLIPC with U0126 (RLIPC+U0126). RLIPC consisted of 4 liver ischemia cycles before renal ischemia. Renal function and injury were assessed through biochemical assays, histology, cell apoptosis and protein phosphorylation analysis. RLIPC significantly mitigated renal dysfunction, tissue damage, inflammation, and apoptosis caused by I/R, which was associated with ERK1/2 phosphorylation. Furthermore, ERK1/2 inhibition with U0126 negated the protective effects of RLIPC and exacerbated renal injury. To summarize, we demonstrated that RLIPC has a strong renoprotective effect on kidneys post I/R injury and that this effect may be mediated by phosphorylation of ERK1/2.

Positive Feedback Mechanism in Aristolochic Acid I Exposure-Induced Anemia and DNA Adduct Formation: Implications for Balkan Endemic Nephropathy.

Balkan endemic nephropathy (BEN) is a chronic kidney disease that predominantly affects inhabitants of rural farming communities along the Danube River tributaries in the Balkans. Long-standing research has identified dietary exposure to aristolochic acids (AAs) as the principal toxicological cause. This study investigates the pathophysiological role of anemia in BEN, noting its earlier and more severe manifestation in BEN patients compared to those with other chronic kidney diseases. Utilizing a mouse model, our research demonstrates that prolonged exposure to aristolochic acid I (AA-I) (the most prevalent AA variant) leads to significant red blood cell depletion through DNA damage, such as DNA adduct formation in bone marrow, prior to observable kidney function decline. Furthermore, in vitro experiments with kidney cells exposed to lowered oxygen and pH conditions mimicking an anemia environment show enhanced DNA adduct formation, suggesting increased AA-I mutagenicity and carcinogenicity. These findings indicate for the first time a positive feedback mechanism of AA-induced anemia, DNA damage, and kidney impairment in BEN progression. These results not only advance our understanding of the underlying mechanisms of BEN but also highlight anemia as a potential target for early BEN diagnosis and therapy.

The role of protein prenylation inhibition through targeting FPPS by zoledronic acid in the prevention of renal fibrosis in rats.

Renal fibrosis (RF) represents the most widespread pathological condition in chronic kidney disease (CKD). Recently, protein prenylation has been implicated in the fibrosis's progression. The research examined the renoprotective effect of zoledronic acid (ZA) (50 µg/kg/week) in a rat model of carbon tetrachloride (CCl4)-induced RF through targeting protein prenylation. Forty Wistar male rats were split up into the control group, vehicle-treated group, model-RF group, and RF-ZA group. Mean arterial blood pressure (MBP), BUN, serum creatinine, and urine albumin-creatinine ratio (uACR), protein levels of farnesyl pyrophosphate (FPP), tumour necrosis factor-alpha (TNF-α), transforming growth factor-ß (TGF-ß), and malondialdehyde (MDA), and catalase and gene expression of farnesyl pyrophosphate synthase (FPPS) and nuclear factor-kB (NF-κB) were measured. Immunohistochemical staining for renal interleukin-6 (IL-6), α-smooth muscle actin (α-SMA), and caspase-3, as well as histopathological alterations, were assessed. ZA considerably ceased the reduction in MBP, markedly reduced uACR, serum creatinine, BUN, and expression of FPPS, FPP, NF-κB, TGF-ß, TNF-α, and MDA, and significantly increased catalase levels compared to the model-RF rats. ZA ameliorated the CCl4-induced histopathological alterations and suppressed the expression of caspase-3, α-SMA, and IL-6. In conclusion, ZA preserved renal function and prevented renal fibrosis in a rat model. These were achieved through targeting protein prenylation mainly by inhibiting FPPS.

ALTERATIONS IN HISTIDINE METABOLISM IS A FEATURE OF EARLY AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE (ADPKD).

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by epithelial proliferation and progressive cyst enlargement. Using a non-targeted high-resolution metabolomics approach, we analyzed biofluids from 36 ADPKD and 18 healthy controls with estimated glomerular filtration rate (eGFR) > 60 ml/min to identify features specific to ADPKD or that associate with disease severity [eGFR or height-corrected total kidney volume (htTKV)]. Multiple pathways differed between ADPKD subjects and controls, with the histidine pathway being the most highly represented. Plasma histidine, urinary N-methylhistamine, methylimidazole-acetaldehyde, and imidazole-acetaldehyde, as well as 3-methylhistidine and anserine were increased, while plasma N-acetylhistamine and urinary imidazole-acetic acid were decreased in ADPKD compared to controls. In ADPKD, urinary histidine and a histidine derivative, urocanate (a precursor of glutamate), were significantly associated. HtTKV and eGFR were inversely associated with urinary glutamine and plasma 4-imidazolone-5-propionic acid, respectively. Supernatant from cultured human ADPKD renal cystic epithelia demonstrated increased aspartate and glutamate levels at 8 and 24 hours compared to primary tubular epithelia (p < 0.001). Following exposure over 48 hours to α-fluromethylhistidine, an inhibitor of histamine production, primary human PKD1 cyst epithelia proliferation increased significantly from baseline (p < 0.01) and greater than non-cystic epithelia (p < 0.05). The histidine ammonia lyase inhibitor nitromethane reversed α-fluromethylhistidine-induced cyst epithelia proliferation indicating a role for glutamate in cyst growth. In conclusion, histidine metabolism is altered preferentially leading to glutamate production and epithelial proliferation in ADPKD and associates with disease severity.

What makes the kidney so tolerant?

Various organ allografts differ in their propensity to be spontaneously accepted without any immunosuppressive treatment. Understanding the mechanisms behind these differences can aid in managing alloimmune responses in general. C57BL/6 mice naturally accept DBA/2J kidney allografts, forming tertiary lymphoid organs containing regulatory T cells (rTLOs), crucial for graft acceptance. In this issue of the JCI, Yokose and colleagues revealed that rTLOs promote conversion of cytotoxic alloreactive CD8+ T cells into exhausted/regulatory ones, through an IFN-γ-mediated mechanism. Their study provides insights into tolerance development that could help promote the acceptance of grafts at higher risk of rejection.

Polyphenol (-)-Epigallocatechin Gallate (EGCG) mitigated kidney injury by regulating metabolic homeostasis and mitochondrial dynamics involvement with Drp1-mediated mitochondrial fission in mice.

The study aimed to examine effects of (-)-epigallocatechin-3-gallate (EGCG) on energy metabolism and mitochondrial dynamics in mouse model of renal injury caused by doxorubicin (DOX). Here, mice were divided into Control group, EGCG-only treated group, DOX group, and three doses of EGCG plus DOX groups. Our results showed that EGCG behaved beneficial effects against kidney injury via attenuation of pathological changes in kidney tissue, which was confirmed by reducing serum creatinine (SCr), blood urea nitrogen (BUN), and apoptosis. Subsequently, changes in reactive oxygen species generation, malondialdehyde content, and activities of antioxidant enzymes were considerably ameliorated in EGCG + DOX groups when compared to DOX group. Furthermore, EGCG-evoked renal protection was associated with increases of mitochondrial membrane potential and decreases of mitochondrial fission protein Dynamin-related protein 1 (Drp1). Moreover, changing glycolysis into mitochondrial oxidative phosphorylation was observed, evidenced by controlling activities of malate dehydrogenase (MDH) and hexokinase (HK) in EGCG + DOX groups when compared to DOX group, indicating that reprogramming energy metabolism was linked to EGCG-induced renal protection in mice. Therefore, EGCG was demonstrated to have a protective effect against kidney injury by reducing oxidative damage, metabolic disorders, and mitochondrial dysfunction, suggesting that EGCG has potential as a feasible strategy to prevent kidney injury.

To target cellular senescence in diabetic kidney disease: the known and the unknown.

Cellular senescence represents a condition of irreversible cell cycle arrest, characterized by heightened senescence-associated beta-galactosidase (SA-ß-Gal) activity, senescence-associated secretory phenotype (SASP), and activation of the DNA damage response (DDR). Diabetic kidney disease (DKD) is a significant contributor to end-stage renal disease (ESRD) globally, with ongoing unmet needs in terms of current treatments. The role of senescence in the pathogenesis of DKD has attracted substantial attention with evidence of premature senescence in this condition. The process of cellular senescence in DKD appears to be associated with mitochondrial redox pathways, autophagy, and endoplasmic reticulum (ER) stress. Increasing accumulation of senescent cells in the diabetic kidney not only leads to an impaired capacity for repair of renal injury, but also the secretion of pro-inflammatory and profibrotic cytokines and growth factors causing inflammation and fibrosis. Current treatments for diabetes exhibit varying degrees of renoprotection, potentially via mitigation of senescence in the diabetic kidney. Targeting senescent cell clearance through pharmaceutical interventions could emerge as a promising strategy for preventing and treating DKD. In this paper, we review the current understanding of senescence in DKD and summarize the possible therapeutic interventions relevant to senescence in this field.

Effects of long-term dehydration and quick rehydration on the camel kidney: pathological changes and modulation of the expression of solute carrier proteins and aquaporins.

BACKGROUND: Recurrent dehydration causes chronic kidney disease in humans and animal models. The dromedary camel kidney has remarkable capacity to preserve water and solute during long-term dehydration. In this study, we investigated the effects of dehydration and subsequent rehydration in the camel's kidney histology/ultrastructure and changes in aquaporin/solute carrier proteins along with gene expression. RESULTS: In light microscopy, dehydration induced few degenerative and necrotic changes in cells of the cortical tubules with unapparent or little effect on medullary cells. The ultrastructural changes encountered in the cortex were infrequent during dehydration and included nuclear chromatin condensation, cytoplasmic vacuolization, mitochondrial swelling, endoplasmic reticulum/ lysosomal degeneration and sometimes cell death. Some mRNA gene expressions involved in cell stability were upregulated by dehydration. Lesions in endothelial capillaries, glomerular membranes and podocyte tertiary processes in dehydrated camels indicated disruption of glomerular filtration barrier which were mostly corrected by rehydration. The changes in proximal tubules brush borders after dehydration, were accompanied by down regulation of ATP1A1 mRNA involved in Na + /K + pump that were corrected by rehydration. The increased serum Na, osmolality and vasopressin were paralleled by modulation in expression level for corresponding SLC genes with net Na retention in cortex which were corrected by rehydration. Medullary collecting ducts and interstitial connective tissue were mostly unaffected during dehydration. CKD, a chronic nephropathy induced by recurrent dehydration in human and animal models and characterized by interstitial fibrosis and glomerular sclerosis, were not observed in the dehydrated/rehydrated camel kidneys. The initiating factors, endogenous fructose, AVP/AVPR2 and uric acid levels were not much affected. TGF-ß1 protein and TGF-ß1gene expression showed no changes by dehydration in cortex/medulla to mediate fibrosis. KCNN4 gene expression level was hardly detected in the dehydrated camel's kidney; to encode for Ca + + -gated KCa3.1 channel for Ca + + influx to instigate TGF-ß1. Modulation of AQP 1, 2, 3, 4, 9 and SLC protein and/or mRNAs expression levels during dehydration/rehydration was reported. CONCLUSIONS: Long-term dehydration induces reversible or irreversible ultrastructural changes in kidney cortex with minor effects in medulla. Modulation of AQP channels, SLC and their mRNAs expression levels during dehydration/rehydration have a role in water conservation. Cortex and medulla respond differently to dehydration/rehydration.

Sodium butyrate improves renal injury in diabetic nephropathy through AMPK/SIRT1/PGC-1α signaling pathway.

Diabetic nephropathy (DN) is a prototypical chronic energy metabolism imbalance disease. The AMPK/Sirt1/PGC-1α signaling pathway plays a pivotal role in regulating energy metabolism throughout the body. Gut microbiota ferment indigestible carbohydrates to produce a variety of metabolites, particularly short-chain fatty acids (SCFAs), which exert positive effects on energy metabolism. However, the potential for SCFAs to ameliorate DN-associated renal injury via the AMPK/Sirt1/PGC-1α pathway remains a matter of debate. In this study, we investigated the effects of sodium butyrate (NaB), a SCFA, on energy metabolism in mice with spontaneous DN at two different doses. Body weight, blood glucose and lipid levels, urinary protein excretion, liver and kidney function, interleukin-6 (IL-6) levels, and the expressions of AMPK, phosphorylated AMPK (p-AMPK), mitofusin 2 (MFN2), optic atrophy 1 (OPA1), and glucagon-like peptide-1 receptor (GLP-1R) were monitored in mice. Additionally, butyrate levels, gut microbiota composition, and diversity in colonic stool were also assessed. Our findings demonstrate that exogenous NaB supplementation can improve hyperglycemia and albuminuria, reduce renal tissue inflammation, inhibit extracellular matrix accumulation and glomerular hypertrophy, and could alter the gut microbiota composition in DN. Furthermore, NaB was found to upregulate the expressions of MFN2, OPA1, p-AMPK, and GLP-1R in DN renal tissue. These results suggest that NaB could improve the composition of gut microbiota in DN, activate the AMPK/Sirt1/PGC-1α signaling pathway, and enhance mitochondrial function to regulate energy metabolism throughout the body. Collectively, our findings indicate that NaB may be a novel therapeutic agent for the treatment of DN.

Protective role of melatonin against diclofenac-induced acute kidney injury.

Diclofenac (DF), a non-steroidal anti-inflammatory drug, is commonly used to relieve pain and inflammation. High doses of DF might induce acute kidney injury (AKI), particularly in elderly, a known vulnerable population. AIM: We aimed to assess the protective role of melatonin (Mel) on DF-induced AKI in aged rats and to highlight the underpinning mechanisms include, oxidative stress and inflammation focusing on microRNA-34a (miR-34a), nuclear factor erythroid-2-related factor-2/hemeoxygenase-1 (Nrf2/HO-1) and NLR family-pyrin domain containing-3 (NLRP3) inflammasome pathways, and to elucidate the possibility of epithelial sodium channel (ENaC) involvement. MATERIALS AND METHODS: Thirty old male Wistar rats were allocated randomly into 3 groups: Control, DF and Mel-DF groups. KEY FINDINGS: Melatonin provided nephroprotective effects against DF-induced AKI via attenuating the expression of renal miR-34a and subsequently promoting the signaling of Nrf2/HO-1 with elevation of the antioxidant defense capacity and suppressing NLRP3 inflammasomes. Melatonin alleviated DF-induced hypernatremia via decreasing the ENaC expression. Renal histopathological examination revealed significant reduction in vascular congestion, mononuclear infiltration, glomerulo-tubular damage, fibrosis and TNF-α optical density. SIGNIFICANCE: It can be assumed that melatonin is a promising safe therapeutic agent in controlling DF-induced AKI in elderly.

Mitochondrial copper overload promotes renal fibrosis via inhibiting pyruvate dehydrogenase activity.

Copper is a trace element essential for numerous biological activities, whereas the mitochondria serve as both major sites of intracellular copper utilization and copper reservoir. Here, we investigated the impact of mitochondrial copper overload on the tricarboxylic acid cycle, renal senescence and fibrosis. We found that copper ion levels are significantly elevated in the mitochondria in fibrotic kidney tissues, which are accompanied by reduced pyruvate dehydrogenase (PDH) activity, mitochondrial dysfunction, cellular senescence and renal fibrosis. Conversely, lowering mitochondrial copper levels effectively restore PDH enzyme activity, improve mitochondrial function, mitigate cellular senescence and renal fibrosis. Mechanically, we found that mitochondrial copper could bind directly to lipoylated dihydrolipoamide acetyltransferase (DLAT), the E2 component of the PDH complex, thereby changing the interaction between the subunits of lipoylated DLAT, inducing lipoylated DLAT protein dimerization, and ultimately inhibiting PDH enzyme activity. Collectively, our study indicates that mitochondrial copper overload could inhibit PDH activity, subsequently leading to mitochondrial dysfunction, cellular senescence and renal fibrosis. Reducing mitochondrial copper overload might therefore serve as a strategy to rescue renal fibrosis.

Quantitative Comparison of Deparaffinization, Rehydration, and Extraction Methods for FFPE Tissue Proteomics and Phosphoproteomics.

Formalin-fixed paraffin-embedded (FFPE) tissues are suitable for proteomic and phosphoproteomic biomarker studies by data-independent acquisition mass spectrometry. The choice of the sample preparation method influences the number, intensity, and reproducibility of identifications. By comparing four deparaffinization and rehydration methods, including heptane, histolene, SubX, and xylene, we found that heptane and methanol produced the lowest coefficients of variation (CVs). Using this, five extraction methods from the literature were modified and evaluated for their performance using kidney, leg muscle, lung, and testicular rat organs. All methods performed well, except for SP3 due to insufficient tissue lysis. Heat n' Beat was the fastest and most reproducible method with the highest digestion efficiency and lowest CVs. S-Trap produced the highest peptide yield, while TFE produced the best phosphopeptide enrichment efficiency. The quantitation of FFPE-derived peptides remains an ongoing challenge with bias in UV and fluorescence assays across methods, most notably in SPEED. Functional enrichment analysis demonstrated that each method favored extracting some gene ontology cellular components over others including chromosome, cytoplasmic, cytoskeleton, endoplasmic reticulum, membrane, mitochondrion, and nucleoplasm protein groups. The outcome is a set of recommendations for choosing the most appropriate method for different settings.

Cadmium in Market Pork Kidneys: A Study on Cadmium Bioavailability and the Health Effects Based on Mouse Models.

Edible offal of farmed animals can accumulate cadmium (Cd). However, no studies have investigated Cd bioavailability and its health effects. Here, based on mouse models, market pork kidney samples exhibited high Cd relative bioavailability of 74.5 ± 11.2% (n = 26), close to 83.8 ± 7.80% in Cd-rice (n = 5). This was mainly due to high vitamin D3 content in pork kidney, causing 1.7-2.3-fold up-regulated expression of duodenal Ca transporter genes in mice fed pork kidney compared to mice fed Cd-rice, favoring Cd intestinal absorption via Ca transporters. However, although pork kidney was high in Cd bioavailability, subchronic low-dose (5% in diet) consumption of two pork kidney samples having 0.48 and 0.97 µg Cd g-1 dw over 35 d did not lead to significant Cd accumulation in the tissue of mice fed Cd-free rice but instead remarkably decreased Cd accumulation in the tissue of mice fed Cd-rice (0.48 µg Cd g-1) by ∼50% and increased abundance of gut probiotics (Faecalibaculum and Lactobacillus). Overall, this study contributed to our understanding of the bioavailability and health effects associated with Cd in edible offal, providing mechanistic insights into pork kidney consumption safety based on Cd bioavailability.