Pre-treatment with ß-hydroxybutyrate mitigates cisplatin-induced acute kidney injury.

ß-Hydroxybutyrate (ß-HB), the primary circulating ketone body, plays a dual role as both a metabolic fuel and an endogenous signaling molecule, offering diverse systemic benefits. Recent studies have highlighted the renoprotective effects of exogenous ß-HB therapy in various animal models of kidney disease. In this investigation, our goal was to assess whether pre-treatment with exogenous ß-HB could alleviate kidney damage in a mouse model of cisplatin-induced acute kidney injury (AKI). Prior to cisplatin administration, intraperitoneal administration of ß-HB was carried out, and the groups were classified into four: Sham, ß-HB, cisplatin, and ß-HB + cisplatin. The tubular damage score and serum creatinine levels were significantly lower in the ß-HB + cisplatin group compared to the cisplatin group. Furthermore, the expression of phosphorylated NF-κB, inflammatory cytokines, and the quantity of F4/80-positive macrophages in the ß-HB + cisplatin group were reduced compared to those in the cisplatin group. Additionally, oxidative stress markers for DNA, protein, and lipid in the ß-HB + cisplatin group were markedly diminished compared to those in the cisplatin group. The number of TUNEL-positive and cleaved caspase 3-positive tubular cells in the ß-HB + cisplatin group was lower than in the cisplatin group. Pre-treating with exogenous ß-HB effectively mitigated kidney damage by suppressing inflammation, oxidative stress, and tubular apoptosis in cisplatin-induced AKI. Therefore, exogenous ß-HB as a pre-treatment emerges as a promising and novel strategy for preventing cisplatin-induced AKI.

Akt1 is involved in renal fibrosis and tubular apoptosis in a murine model of acute kidney injury-to-chronic kidney disease transition.

Maladaptive repair after acute kidney injury (AKI) can predispose patients to chronic kidney disease (CKD). However, the molecular mechanism underlying the AKI-to-CKD transition remains unclear. The Akt signaling pathway has been reported to be involved in the pathological processes of both AKI and CKD. In this study, we investigated the role of Akt1 in a murine model of the AKI-to-CKD transition. Wild-type (WT) and Akt1-/- mice were subjected to unilateral ischemia-reperfusion injury (UIRI), with their kidneys harvested after two days and two, four, and six weeks after UIRI. The dynamic changes in tubulointerstitial fibrosis, markers of tubular epithelial-mesenchymal transition (EMT), and tubular apoptosis were investigated. Akt1 of the three Akt isoforms was activated during the AKI-to-CKD transition. After UIRI, tubulointerstitial fibrosis and tubular EMT were significantly increased in WT mice, but were attenuated in Akt1-/- mice. The expression of the transforming growth factor (TGF)-ß1/Smad was increased in both WT and Akt1-/- mice, but was not different between the two groups. The levels of phosphorylated glycogen synthase kinase (GSK)-3ß, Snail, and ß-catenin in the Akt1-/- mice were lower than those in the WT mice. The number of apoptotic tubular cells and the expression of cleaved caspase-3/Bax were both lower in Akt1-/- mice than in WT mice. Genetic deletion of Akt1 was associated with attenuation of tubulointerstitial fibrosis, tubular EMT, and tubular apoptosis during the AKI-to-CKD transition. These findings were associated with TGF-ß1/Akt1/GSK-3ß/(Snail and ß-catenin) signaling independent of TGF-ß1/Smad signaling. Thus, Akt1 signaling could serve as a potential therapeutic target for inhibiting the AKI-to-CKD transition.

Inhibition of pyruvate dehydrogenase kinase 4 ameliorates kidney ischemia-reperfusion injury by reducing succinate accumulation during ischemia and preserving mitochondrial function during reperfusion.

Ischemia-reperfusion (IR) injury, a leading cause of acute kidney injury (AKI), is still without effective therapies. Succinate accumulation during ischemia followed by its oxidation during reperfusion leads to excessive reactive oxygen species (ROS) and severe kidney damage. Consequently, the targeting of succinate accumulation may represent a rational approach to the prevention of IR-induced kidney injury. Since ROS are generated primarily in mitochondria, which are abundant in the proximal tubule of the kidney, we explored the role of pyruvate dehydrogenase kinase 4 (PDK4), a mitochondrial enzyme, in IR-induced kidney injury using proximal tubule cell-specific Pdk4 knockout (Pdk4ptKO) mice. Knockout or pharmacological inhibition of PDK4 ameliorated IR-induced kidney damage. Succinate accumulation during ischemia, which is responsible for mitochondrial ROS production during reperfusion, was reduced by PDK4 inhibition. PDK4 deficiency established conditions prior to ischemia resulting in less succinate accumulation, possibly because of a reduction in electron flow reversal in complex II, which provides electrons for the reduction of fumarate to succinate by succinate dehydrogenase during ischemia. The administration of dimethyl succinate, a cell-permeable form of succinate, attenuated the beneficial effects of PDK4 deficiency, suggesting that the kidney-protective effect is succinate-dependent. Finally, genetic or pharmacological inhibition of PDK4 prevented IR-induced mitochondrial damage in mice and normalized mitochondrial function in an in vitro model of IR injury. Thus, inhibition of PDK4 represents a novel means of preventing IR-induced kidney injury, and involves the inhibition of ROS-induced kidney toxicity through reduction in succinate accumulation and mitochondrial dysfunction.

ß-hydroxybutyrate ameliorates sepsis-induced acute kidney injury.

BACKGROUND: Sepsis is a major cause of acute kidney injury (AKI). Recent studies have demonstrated that ß-hydroxybutyrate (ß-HB) alleviates renal ischemia-reperfusion injury and cisplatin-induced renal injury in murine models. This study aimed to investigate whether ß-HB ameliorates sepsis-induced AKI (SIAKI) in a lipopolysaccharide (LPS)-induced mouse sepsis model. METHODS AND RESULTS: SIAKI was induced by intraperitoneally injecting LPS to C57BL/6 male mice. ß-HB was administrated intraperitoneally before LPS injection. The mice were divided into sham, ß-HB, LPS, and ß-HB + LPS groups. The histological damage score and serum creatinine level were significantly increased in the LPS group mice, but attenuated in the ß-HB + LPS group mice. The expression of phosphorylated nuclear factor-κB tumor necrosis factor-α/interleukin-6 and the number of F4/80-positive macrophages in the ß-HB + LPS group mice were lower than those in the LPS group mice. The number of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells, cleaved caspase-3 expression, and Bax/Bcl-2 ratio in the ß-HB + LPS group mice were lower than those in the LPS group mice. CONCLUSION: ß-HB pre-treatment ameliorates SIAKI by reducing tubular apoptosis and inflammatory responses. Thus, ß-HB pre-treatment could be a potential prophylactic strategy against SIAKI.

Association between anti-endothelial antigen antibodies and allograft rejection in kidney transplantation.

BACKGROUND: Endothelial cells are vital in the transplant immune system as semiprofessional antigen-presenting cells. Few studies have investigated the importance of anti-endothelin subtype A receptor (ETAR) antibodies in kidney transplantation. Here, we aimed to analyze the association between anti-angiotensin II type I receptor (AT1R) and anti-ETAR antibodies and the association between the presence of anti-endothelial antibodies and the risk of allograft rejection in kidney transplantation. METHODS: In total, 252 patients who underwent kidney transplantation were enrolled in this study. Antibodies for human leukocyte antigens (HLAs) and non-HLAs were analyzed immediately before transplantation. Patients were categorized based on the occurrence of antibody-mediated rejection (AMR) or T-cell-mediated rejection (TCMR) by 2017 Banff classification. All p-values were two-tailed, and statistical significance was set at p < 0.05. RESULTS: Patients with anti-AT1R antibodies had a 3.49-fold higher risk of TCMR than those without anti-AT1R antibodies. Patients with anti-ETAR antibodies had a 5.84-fold higher risk of AMR than those without anti-ETAR antibodies. The hazard ratio of AMR in patients with both HLA DSAs and anti-ETAR antibodies, relative to patients without anti-ETAR antibodies and HLA DSAs, was 32.85 (95% CI = 1.82-592.91). CONCLUSION: Our findings indicated that anti-ETAR antibodies are associated with AMR, and patients with both anti-ETAR antibodies and de novo HLA DSAs were at a high risk of AMR.

Maintenance of the critical care system during the pandemic in non-COVID-19 patients requiring continuous renal replacement therapy: a single center experience.

BACKGROUND: During the COVID-19 pandemic, maintenance of essential healthcare systems became very challenging. We describe the triage system of our institute, and assess the quality of care provided to critically ill non-COVID-19 patients requiring continuous renal replacement therapy (CRRT) during the pandemic. METHODS: We introduced an emergency triage pathway early in the pandemic. We retrospectively reviewed the medical records of patients who received CRRT in our hospital from January 2016 to March 2021. We excluded end-stage kidney disease patients on maintenance dialysis. Patients were stratified as medical and surgical patients. The time from hospital arrival to intensive care unit (ICU) admission, the time from hospital arrival to intervention/operation, and the in-hospital mortality rate were compared before (January 2016 to December 2019) and during (January 2021 to March 2021) the pandemic. RESULTS: The mean number of critically ill patients who received CRRT annually in the surgical department significantly decreased during the pandemic in (2016-2019: 76.5 ± 3.1; 2020: 56; p < 0.010). Age, sex, and the severity of disease at admission did not change, whereas the proportions of medical patients with diabetes (before: 44.4%; after: 56.5; p < 0.005) and cancer (before: 19.4%; after: 32.3%; p < 0.001) increased during the pandemic. The time from hospital arrival to ICU admission and the time from hospital arrival to intervention/operation did not change. During the pandemic, 59.6% of surgical patients received interventions/operations within 6 hours of hospital arrival. In Cox's proportional hazard modeling, the hazard ratio associated with the pandemic was 1.002 (0.778-1.292) for medical patients and 1.178 (0.783-1.772) for surgical patients. CONCLUSION: Our triage system maintained the care required by critically ill non-COVID-19 patients undergoing CRRT at our institution.

Balanced Free Essential Amino Acids and Resistance Exercise Training Synergistically Improve Dexamethasone-Induced Impairments in Muscle Strength, Endurance, and Insulin Sensitivity in Mice.

Our previous study shows that an essential amino acid (EAA)-enriched diet attenuates dexamethasone (DEX)-induced declines in muscle mass and strength, as well as insulin sensitivity, but does not affect endurance. In the present study, we hypothesized that the beneficial effects will be synergized by adding resistance exercise training (RET) to EAA, and diet-free EAA would improve endurance. To test hypotheses, mice were randomized into the following four groups: control, EAA, RET, and EAA+RET. All mice except the control were subjected to DEX treatment. We evaluated the cumulative rate of myofibrillar protein synthesis (MPS) using 2H2O labeling and mass spectrometry. Neuromuscular junction (NMJ) stability, mitochondrial contents, and molecular signaling were demonstrated in skeletal muscle. Insulin sensitivity and glucose metabolism using 13C6-glucose tracing during oral glucose tolerance tests were analyzed. We found that EAA and RET synergistically improve muscle mass and/or strength, and endurance capacity, as well as insulin sensitivity, and glucose metabolism in DEX-treated muscle. These improvements are accomplished, in part, through improvements in myofibrillar protein synthesis, NMJ, fiber type preservation, and/or mitochondrial biogenesis. In conclusion, free EAA supplementation, particularly when combined with RET, can serve as an effective means that counteracts the adverse effects on muscle of DEX that are found frequently in clinical settings.

Metabolic Evaluation of the Dietary Guidelines' Ounce Equivalents of Protein Food Sources in Young Adults: A Randomized Controlled Trial.

BACKGROUND: The Dietary Guidelines for Americans (DGAs) published an "ounce equivalents" recommendation to help consumers meet protein requirements with a variety of protein food sources. However, the metabolic equivalency of these varied protein food sources has not been established. OBJECTIVE: We have investigated the hypothesis that the anabolic responses to consumption of ounce equivalents of protein food sources would be directly related to the essential amino acid (EAA) content of the protein food source. METHODS: Following 3 d of dietary control, a total of 56 healthy young adults underwent an 8.5-h metabolic study using stable isotope tracer methodology. The changes from baseline following consumption of 1 of 7 different protein food sources were compared with the baseline value for that individual (n = 8 per group). RESULTS: Consumption of ounce equivalents of animal-based protein food sources (beef sirloin, pork loin, eggs) resulted in a greater gain in whole-body net protein balance above baseline than the ounce equivalents of plant-based protein food sources (tofu, kidney beans, peanut butter, mixed nuts; P < 0.01). The improvement in whole-body net protein balance was due to an increase in protein synthesis (P < 0.05) with all the animal protein sources, whereas the egg and pork groups also suppressed protein breakdown compared with the plant protein sources (P < 0.01). The magnitude of the whole-body net balance (anabolic) response was correlated with the EAA content of the protein food source (P < 0.001). CONCLUSION: The "ounce equivalents" of protein food sources as expressed in the DGAs are not metabolically equivalent in young healthy individuals. The magnitude of anabolic response to dietary proteins should be considered as the DGAs develop approaches to establish healthy eating patterns.

The impact of Hayward green kiwifruit on dietary protein digestion and protein metabolism.

PURPOSE: The purpose of the study was to determine if an actinidin protease aids gastric digestion and the protein anabolic response to dietary protein. METHODS: Hayward green kiwifruit (containing an actinidin protease) and Hort 16A gold kiwifruit (devoid of actinidin protease) were given in conjunction with a beef meal to healthy older subjects. Twelve healthy older males (N = 6) and females (N = 6) were studied with a randomized, double-blinded, crossover design to assess muscle and whole-body protein metabolism before and after ingestion of kiwifruit and 100 g of ground beef. Subjects consumed 2 of each variety of kiwifruit daily for 14 d prior to each metabolic study, and again during each study with beef intake. RESULTS: Hayward green kiwifruit consumption with beef resulted in a more rapid increase in peripheral plasma essential amino acid concentrations. There were significant time by kiwifruit intake interactions for plasma concentrations of EAAs, branched chain amino acids (BCAAs), and leucine (P < 0.01). However, there was no difference in the total amount of EAAs absorbed. As a result, there were no differences between kiwifruit in any of the measured parameters of protein kinetics. CONCLUSION: Consumption of Hayward green kiwifruit, with a beef meal facilitates protein digestion and absorption of the constituent amino acids as compared to Hort 16A gold kiwifruit. CLINICAL TRIAL: NCT04356573, April 21, 2020 "retrospectively registered".

Akt1 is involved in tubular apoptosis and inflammatory response during renal ischemia-reperfusion injury.

Renal ischemia-reperfusion injury (IRI) is one of the major causes of acute kidney injury (AKI). Although Akt is involved in renal IRI, it is unclear as to which Akt isoform plays an important role in renal IRI. In this study, we investigated the role of Akt1 in renal IRI. We subjected the C57BL/6 male mice to unilateral IRI with contralateral nephrectomy. Two days after IRI, IRI-kidneys were harvested. The mice were divided into four groups: wild type (WT) IRI, Akt1-/- IRI, WT sham, and Akt1-/- sham. We found that Akt1, not Akt2 or Akt3, was markedly activated in WT IRI than in WT sham mice. The histologic damage score and serum creatinine level significantly increased in WT IRI mice, the increase being the highest in Akt1-/- IRI mice. The number of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells and expression of cleaved caspase-3/Bax were higher in Akt1-/- IRI mice than in WT IRI mice. The expression of Bcl-2 was lower in Akt1-/- IRI mice than in WT IRI mice. The expression of tumor necrosis factor-α/interleukin-6/interleukin-1ß and number of F4/80-positive macrophages were markedly higher in Akt1-/- IRI than in WT IRI mice. The expression of phosphorylated nuclear factor-κB p65 was also higher in Akt1-/- IRI mice than in WT IRI mice. Our results show that Akt1 deletion exacerbates kidney damage as it increases tubular apoptosis and inflammatory response during renal IRI. Akt1 could be a potential therapeutic target for developing treatments against IRI-induced AKI.

Prevalence, Antibiotic-Resistance, and Virulence Characteristics of Vibrio parahaemolyticus in Restaurant Fish Tanks in Seoul, South Korea.

Vibrio parahaemolyticus is a marine bacterium that causes foodborne diarrhea. Many seafood restaurants keep live fish and shellfish in fish tanks for use in raw seafood dishes; thus, the present study aimed to investigate the prevalence, antibiotic-resistance, and virulence characteristics exhibited by V. parahaemolyticus detected in restaurant fish-tank water samples collected in Seoul, South Korea. Fish-tank water samples were collected from 69 restaurants in Seoul, and screened for the presence of V. parahaemolyticus via both a commercial detection kit, and a real-time polymerase chain reaction (RT-PCR) to detect the toxR gene. Antibiotic susceptibility and virulence determinants of V. parahaemolyticus isolates were evaluated and identified using standard disk-diffusion and RT-PCR methods, respectively. Thirty-five (50.7%) of the 69 analyzed water samples were found to be contaminated with V. parahaemolyticus. Those isolates were most often resistant to ampicillin (51.4% of isolates), followed by amikacin and tetracycline (11.4%), and ceftazidime (8.6%). Thirty (85.7%) out of the 35 isolates carried all four cytotoxicity-inducing type III secretion system 1 (T3SS1) genes [specifically, 34 (97.1%), 33 (94.3%), 35 (100%), and 32 (91.4%) isolates carried genes encoding the VP1670, VP1686, VP1689, and VP1694 T3SS1 proteins, respectively]. The type VI secretion systems (T6SS1 and T6SS2) genes were also detected in 11 (31.4%) and 27 (77.1%) isolates, respectively. However, virulence determinants such as the hemolysin (tdh and trh), urease (ureC), T3SS2α, or T3SS2ß genes that are known to be associated with enterotoxicity were not detected in all isolates. Although some known major virulence genes were not detected in the V. parahaemolyticus isolates, the results of this study indicate that restaurant fish tanks are a potential source of antibiotic-resistant V. parahaemolyticus. The presented data support the need for strict guidelines to regulate the maintenance of restaurant fish tanks to prevent antibiotic-resistant foodborne vibriosis.

Quantifying the contribution of dietary protein to whole body protein kinetics: examination of the intrinsically labeled proteins method.

Intrinsically labeled dietary proteins have been used to trace various aspects of digestion and absorption, including quantifying the contribution of dietary protein to observed postprandial amino acid and protein kinetics in human subjects. Quantification of the rate of appearance in peripheral blood of an unlabeled (tracee) amino acid originating from an intrinsically labeled protein (exogenous Ra) requires the assumption that there is no dilution of the isotope enrichment of the protein-bound amino acid in the gastrointestinal tract or across the splanchnic bed. It must also be assumed that the effective volume of distribution into which the tracer and tracee appear can be reasonably estimated by a single value and that any recycling of the tracer is minimal and thus does not affect calculated rates. We have assessed these assumptions quantitatively using values from published studies. We conclude that the use of intrinsically labeled proteins as currently described to quantify exogenous Ra systematically underestimates the true value. When used with the tracer-determined rates of amino acid kinetics, underestimation of exogenous Ra from the intrinsically labeled protein method likely translates to incorrect conclusions regarding protein breakdown, including the effect of a protein meal and the anabolic impact of the speed of digestion and absorption of amino acids. Estimation of exogenous Ra from the bioavailability of ingested protein has some advantages as compared with the intrinsically labeled protein method. We therefore conclude that the bioavailability method for estimating exogenous Ra is preferable to the intrinsically labeled protein method.

Severe negative energy balance during 21 d at high altitude decreases fat-free mass regardless of dietary protein intake: a randomized controlled trial.

In this 2-phase randomized controlled study, we examined whether consuming a higher-protein (HP) diet would attenuate fat-free mass (FFM) loss during energy deficit (ED) at high altitude (HA) in 17 healthy males (mean ± sd: 23 ± 6 yr; 82 ± 14 kg). During phase 1 at sea level (SL, 55 m), participants consumed a eucaloric diet providing standard protein (SP; 1.0 g protein/kg,) for 21 d. During phase 2, participants resided at HA (4300 m) for 22 d and were randomly assigned to either an SP or HP (2.0 g protein/kg) diet designed to elicit a 40% ED. Body composition, substrate oxidation, and postabsorptive whole-body protein kinetics were measured. Participants were weight stable during SL and lost 7.9 ± 1.9 kg ( P < 0.01) during HA, regardless of dietary protein intake. Decrements in whole-body FFM (3.6 ± 2.4 kg) and fat mass (3.6 ± 1.3 kg) were not different between SP and HP. HP oxidized 0.95 ± 0.32 g protein/kg per day more than SP and whole-body net protein balance was more negative for HP than for SP ( P < 0.01). Based on changes in body energy stores, the overall ED was 70% (-1849 ± 511 kcal/d, no group differences). Consuming an HP diet did not protect FFM during severe ED at HA.-Berryman, C. E., Young, A. J., Karl, J. P., Kenefick, R. W., Margolis, L. M., Cole, R. E., Carbone, J. W., Lieberman, H. R., Kim, I.-Y., Ferrando, A. A., Pasiakos, S. M. Severe negative energy balance during 21 d at high altitude decreases fat-free mass regardless of dietary protein intake: a randomized controlled trial.

Plasma neutrophil gelatinase-associated lipocalin is associated with iron status in anemic patients with pre-dialysis chronic kidney disease.

BACKGROUND: Iron deficiency anemia is common in patients with chronic kidney disease (CKD). Neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of acute kidney injury, is known to be associated with iron metabolism. We investigated whether plasma NGAL level is associated with iron status in pre-dialysis CKD patients with anemia. METHODS: This study included 419 patients who had anemia. The subjects were into categorized into a pre-dialysis group (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m2, n = 288) and a non-CKD group (eGFR >60 ml/min/1.73 m2, n = 131). The associations between plasma NGAL and iron status (serum ferritin and transferrin saturation [TSAT]), eGFR, albumin, uric acid, total cholesterol, calcium, phosphate, and C-reactive protein (CRP) were assessed. RESULTS: In non-CKD group, plasma NGAL was not associated with any baseline variables including iron indices (TSAT and serum ferritin). In pre-dialysis group, univariate analysis showed plasma NGAL correlated with eGFR, CRP, TSAT, and serum ferritin. In multivariate analysis, plasma NGAL was independently associated with TSAT. However, serum ferritin lost its association with plasma NGAL. In ROC analysis for identifying iron deficiency, the plasma NGAL (best cut-off value ≤394 ng/ml) was superior to the serum ferritin (suggested cut-off value ≤500 ng/ml) in both sensitivity and specificity. CONCLUSIONS: Plasma NGAL is associated with iron status in anemic patients with pre-dialysis CKD. Further studies are needed to demonstrate the role of plasma NGAL in assessing the iron deficiency and in guiding the iron therapy for pre-dialysis CKD patients.

Long-term outcomes in acute kidney injury patients who underwent continuous renal replacement therapy: a single-center experience.

INTRODUCTION: Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) is the most severe form of AKI associated with poor short- and long-term patient outcomes. The aim of this study was to evaluate the variables associated with long-term patient survival in our clinic. METHODS: This was a single-center retrospective study with AKI survivors who received CRRT from March 2011 to February 2015. During the study period, all consecutive AKI survivors who underwent CRRT were included. Patients on maintenance dialysis prior to CRRT were excluded. Data were collected by reviewing the patients' medical charts. Long-term follow-up data were gathered through February 2018. RESULTS: A total of 430 patients were included, and 62.8% of the patients were male. The mean age of the patients was 63.4 ± 14.6 years. The mean serum creatinine level at the time of CRRT initiation was 3.5 ± 2.5 mg/dL. At the time of discharge, the mean eGFR and serum creatinine levels were 58.4 ± 46.7 and 1.7 ± 1.6 mg/dL, respectively. After 3 years, 44.9% of the patients had survived. When we investigated the factors associated with long-term patient mortality, a longer stay in the ICU [OR 1.034 (1.016-1.053), p < 0.001], a history of cancer [OR 3.830 (1.037-3.308), p = 0.037], a prolonged prothrombin time [OR 1.852 (1.037-3.308), p = 0.037] and a lower eGFR at the time of discharge [OR 0.988 (0.982-0.995), p = 0.001] were independently associated with long-term patient mortality. CONCLUSION: Our study demonstrates that long-term mortality after CRRT is associated with longer ICU stays and lower eGFRs at the time of hospital discharge. Our data imply the importance of renal recovery for long-term survival of AKI patients treated with CRRT.

The two isoforms of matrix metalloproteinase- 2 have distinct renal spatial and temporal distributions in murine models of types 1 and 2 diabetes mellitus.

BACKGROUND: We recently reported on the enhanced tubular expression of two discrete isoforms of the MMP-2 (full length and N-terminal truncated, FL-MMP-2, NTT-MMP-2) in a murine model and human diabetic kidneys. In the present study, we examined in more detail the temporal and spatial distributions of MMP-2 isoform expression in murine models of Type 1 and Type 2 diabetes mellitus. METHODS: Diabetic models were streptozotocin (STZ)-induced diabetes (Type 1 diabetes mellitus) and db/db mice (Type 2 diabetes mellitus). We quantified the abundance of two isoforms of MMP-2 transcripts by qPCR. A spatial distribution of two isoforms of MMP-2 was analyzed semi-quantitatively according to time after injection of STZ and with increasing age of db/db mice. Furthermore, immunohistochemistry for nitrotyrosine was performed to examine a potential association between oxidative stress and MMP-2 isoform expression. RESULTS: Both isoforms of MMP-2 were upregulated in whole kidneys from STZ and db/db mice. In the case of FL-MMP-2, mRNA levels significantly increased at 12 and 24 weeks in STZ mice, while the isoform expression was significantly increased only at 16 weeks, in the db/db mice. FL-MMP-2 protein levels increased in the cortices and outer medullae of both STZ and db/db mice as a function of the duration of diabetes. For NTT-MMP-2, mRNA levels increased earlier at 4 weeks in STZ mice and at 10 weeks of age in db/db mice. The expression of NTT-MMP-2 also increased, primarily in the cortices of STZ and db/db mice, as a function of the duration of diabetes. Quantitatively, these findings were consistent with the qPCR results in the case of NTT-MMP-2, respectively (STZ 24 weeks, 3.24 ± 3.70 fold; 16 weeks db/db, 4.49 ± 0.55 fold). In addition, nitrotyrosine was expressed primarily in cortex as compared to medulla as a function of the duration of diabetes similar to NTT-MMP-2 expression. CONCLUSIONS: Two isoforms of MMP-2 are highly inducible in two diabetic murine models and become more abundant as a function of time. As the expression patterns were not the same in the two isoforms of MMP-2, it is possible that each isoform has a discrete role in the development of diabetic renal injury.

The role of the specialized team in the operation of continuous renal replacement therapy: a single-center experience.

BACKGROUND: The requirement of continuous renal replacement therapy (CRRT) is increasing with the growing incidence of acute kidney injury (AKI). The decision to initiate CRRT is not difficult if an adequate medical history is obtained. However, the handling and maintenance of CRRT constitute a labor-intensive intervention that requires specialized skills. For these reasons, our center organized a specialized CRRT team in March 2013. The aim of this study is to report on the role of a specialized CRRT team and to evaluate the team's outcome. METHODS: This retrospective single-center study evaluated AKI patients who underwent CRRT in the intensive care unit (ICU) from March 2011 to February 2015. Patients were divided into two groups based on whether they received specialized CRRT team intervention. We collected information on demographic characteristics, laboratory parameters, SOFA score, CRRT initiation time, actual delivered dose and CRRT down-time. In-hospital mortality was defined by medical chart review. Binary logistic regression analysis was used to define factors associated with in-hospital mortality. RESULTS: A total of 1104 patients were included in this study. The mean patient age was 63.85 ± 14.39 years old, and 62.8% of the patients were male. After the specialized CRRT team intervention, there was a significant reduction in CRRT initiation time (5.30 ± 13.86 vs. 3.60 ± 11.59 days, p = 0.027) and CRRT down-time (1.78 ± 2.23 vs. 1.38 ± 2.08 h/day, p = 0.002). The rate of in-hospital mortality decreased after the specialized CRRT team intervention (57.5 vs. 49.2%, p = 0.007). When the multivariable analysis was adjusted, delayed CRRT initiation (HR 1.054(1.036-1.072), p < 0.001) was a significant factor in predicting in-hospital mortality, along with an increased SOFA score, lower serum albumin and prolonged prothrombin time. CONCLUSIONS: Our study shows that specialized CRRT team intervention reduced CRRT initiation time, down-time and in-hospital mortality. This study could serve as a logical basis for implementing specialized CRRT teams hospital-wide.

Prolonged sitting negatively affects the postprandial plasma triglyceride-lowering effect of acute exercise.

The interaction of prolonged sitting with physical exercise for maintaining health is unclear. We tested the hypothesis that prolonged siting would have a deleterious effect on postprandial plasma lipemia (PPL, postprandial plasma triglycerides) and reduce the ability of an acute exercise bout to attenuate PPL. Seven healthy young men performed three, 5-day interventions [days 1-5 (D1-D5)] in a randomized crossover design with >1 wk between interventions: 1) sitting > 14 h/day with hypercaloric energy balance (SH), 2) sitting >14 h/day with net energy balance (SB), and 3) active walking/standing with net energy balance (WB) and sitting 8.4 h/day. The first high-fat tolerance test (HFTT1) was performed on D3 following 2 days of respective interventions. On the evening of D4 subjects ran on a treadmill for 1 h at ~67% V̇o2max, followed by the second HFTT (HFTT2) on D5. Two days of prolonged sitting increased TG AUCI (i.e., incremental area under the curve for TG), irrespective of energy balance, compared with WB (27% in SH, P = 0.003 and 26% in SB, P = 0.046). Surprisingly, after 4 days of prolonged sitting (i.e.; SH and SB), the acute exercise on D4 failed to attenuate TG AUCI or increase relative fat oxidation in HFTT2, compared with HFTT1, regardless of energy balance. In conclusion, prolonged sitting over 2-4 days was sufficient to amplify PPL, which was not attenuated by acute exercise, regardless of energy balance. This underscores the importance of limiting sitting time even in people who have exercised.

The anabolic response to a meal containing different amounts of protein is not limited by the maximal stimulation of protein synthesis in healthy young adults.

We have determined whole body protein kinetics, i.e., protein synthesis (PS), breakdown (PB), and net balance (NB) in human subjects in the fasted state and following ingestion of ~40 g [moderate protein (MP)], which has been reported to maximize the protein synthetic response or ~70 g [higher protein (HP)] protein, more representative of the amount of protein in the dinner of an average American diet. Twenty-three healthy young adults who had performed prior resistance exercise (X-MP or X-HP) or time-matched resting (R-MP or R-HP) were studied during a primed continuous infusion of l-[(2)H5]phenylalanine and l-[(2)H2]tyrosine. Subjects were randomly assigned into an exercise (X, n = 12) or resting (R, n = 11) group, and each group was studied at the two levels of dietary protein intake in random order. PS, PB, and NB were expressed as increases above the basal, fasting values (mg·kg lean body mass(-1)·min(-1)). Exercise did not significantly affect protein kinetics and blood chemistry. Feeding resulted in positive NB at both levels of protein intake: NB was greater in response to the meal containing HP vs. MP (P < 0.00001). The greater NB with HP was achieved primarily through a greater reduction in PB and to a lesser extent stimulation of protein synthesis (for all, P < 0.0001). HP resulted in greater plasma essential amino acid responses (P < 0.01) vs. MP, with no differences in insulin and glucose responses. In conclusion, whole body net protein balance improves with greater protein intake above that previously suggested to maximally stimulating muscle protein synthesis because of a simultaneous reduction in protein breakdown.