Expansion of Anticomplement Therapy Indications from Rare Genetic Disorders to Common Kidney Diseases.

Complement constitutes a major part of the innate immune system. The study of complement in human health has historically focused on infection risks associated with complement protein deficiencies; however, recent interest in the field has focused on overactivation of complement as a cause of immune injury and the development of anticomplement therapies to treat human diseases. The kidneys are particularly sensitive to complement injury, and anticomplement therapies for several kidney diseases have been investigated. Overactivation of complement can result from loss-of-function mutations in complement regulators; gain-of-function mutations in key complement proteins such as C3 and factor B; or autoantibody production, infection, or tissue stresses, such as ischemia and reperfusion, that perturb the balance of complement activation and regulation. Here, we provide a high-level review of the status of anticomplement therapies, with an emphasis on the transition from rare diseases to more common kidney diseases.

Stretch-activated ion channel TMEM63B associates with developmental and epileptic encephalopathies and progressive neurodegeneration.

By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human disease is limited. Here, we describe 17 unrelated individuals with severe early-onset developmental and epileptic encephalopathy (DEE), intellectual disability, and severe motor and cortical visual impairment associated with progressive neurodegenerative brain changes carrying ten distinct heterozygous variants of TMEM63B, encoding for a highly conserved stretch-activated ion channel. The variants occurred de novo in 16/17 individuals for whom parental DNA was available and either missense, including the recurrent p.Val44Met in 7/17 individuals, or in-frame, all affecting conserved residues located in transmembrane regions of the protein. In 12 individuals, hematological abnormalities co-occurred, such as macrocytosis and hemolysis, requiring blood transfusions in some. We modeled six variants (p.Val44Met, p.Arg433His, p.Thr481Asn, p.Gly580Ser, p.Arg660Thr, and p.Phe697Leu), each affecting a distinct transmembrane domain of the channel, in transfected Neuro2a cells and demonstrated inward leak cation currents across the mutated channel even in isotonic conditions, while the response to hypo-osmotic challenge was impaired, as were the Ca2+ transients generated under hypo-osmotic stimulation. Ectopic expression of the p.Val44Met and p.Gly580Cys variants in Drosophila resulted in early death. TMEM63B-associated DEE represents a recognizable clinicopathological entity in which altered cation conductivity results in a severe neurological phenotype with progressive brain damage and early-onset epilepsy associated with hematological abnormalities in most individuals.

Comprehensive functional characterization of complement factor I rare variant genotypes identified in the SCOPE geographic atrophy cohort.

Rare variants (RVs) in the gene encoding the regulatory enzyme complement factor I (CFI; FI) that reduce protein function or levels increase age-related macular degeneration risk. A total of 3357 subjects underwent screening in the SCOPE natural history study for geographic atrophy secondary to age-related macular degeneration, including CFI sequencing and serum FI measurement. Eleven CFI RV genotypes that were challenging to categorize as type I (low serum level) or type II (normal serum level, reduced enzymatic function) were characterized in the context of pure FI protein in C3b and C4b fluid phase cleavage assays and a novel bead-based functional assay (BBFA) of C3b cleavage. Four variants predicted or previously characterized as benign were analyzed by BBFA for comparison. In all, three variants (W51S, C67R, and I370T) resulted in low expression. Furthermore, four variants (P64L, R339Q, G527V, and P528T) were identified as being highly deleterious with IC50s for C3b breakdown >1 log increased versus the WT protein, while two variants (K476E and R474Q) were ∼1 log reduced in function. Meanwhile, six variants (P50A, T203I, K441R, E548Q, P553S, and S570T) had IC50s similar to WT. Odds ratios and BBFA IC50s were positively correlated (r = 0.76, p < 0.01), while odds ratios versus combined annotation dependent depletion (CADD) scores were not (r = 0.43, p = 0.16). Overall, 15 CFI RVs were functionally characterized which may aid future patient stratification for complement-targeted therapies. Pure protein in vitro analysis remains the gold standard for determining the functional consequence of CFI RVs.

Analysis of MRI-derived spleen iron in the UK Biobank identifies genetic variation linked to iron homeostasis and hemolysis.

The spleen plays a key role in iron homeostasis. It is the largest filter of the blood and performs iron reuptake from old or damaged erythrocytes. Despite this role, spleen iron concentration has not been measured in a large, population-based cohort. In this study, we quantify spleen iron in 41,764 participants of the UK Biobank by using magnetic resonance imaging and provide a reference range for spleen iron in an unselected population. Through genome-wide association study, we identify associations between spleen iron and regulatory variation at two hereditary spherocytosis genes, ANK1 and SPTA1. Spherocytosis-causing coding mutations in these genes are associated with lower reticulocyte volume and increased reticulocyte percentage, while these common alleles are associated with increased expression of ANK1 and SPTA1 in blood and with larger reticulocyte volume and reduced reticulocyte percentage. As genetic modifiers, these common alleles may explain mild spherocytosis phenotypes that have been observed clinically. Our genetic study also identifies a signal that co-localizes with a splicing quantitative trait locus for MS4A7, and we show this gene is abundantly expressed in the spleen and in macrophages. The combination of deep learning and efficient image processing enables non-invasive measurement of spleen iron and, in turn, characterization of genetic factors related to the lytic phase of the erythrocyte life cycle and iron reuptake in the spleen.

High Rate of Passenger Lymphocyte Syndrome after ABO Minor Incompatible Lung Transplantation.

Rationale: Passenger lymphocyte syndrome (PLS) may complicate minor ABO mismatched lung transplantation (LuTX) via donor-derived red cell antibody-induced hemolysis.Objectives: To ascertain the incidence and specificity of PLS-relevant antibodies among the study population as well as the dynamics of hemolysis parameters and the transfusion requirement of patients with or without PLS.Methods: In this cohort study, 1,011 patients who received LuTX between January 2010 and June 2019 were studied retrospectively. Prospectively, 87 LuTX (July 2019 to June 2021) were analyzed. Postoperative ABO antibody and hemolytic marker determinations, transfusion requirement, and duration of postoperative hospital care were analyzed. Retrospectively, blood group A recipients of O grafts with PLS were compared with those without.Measurements and Main Results: PLS affected 18.18% (retrospective) and 30.77% (prospective) of A recipients receiving O grafts, 5.13% of B recipients of O grafts, and 20% of AB patients receiving O transplants. Anti-A and anti-A1 were the predominant PLS-inducing antibodies, followed by anti-B and anti-A,B. Significantly lower hemoglobin values (median, 7.4 vs. 8.3 g/dl; P = 0.0063) and an approximately twice as high percentage of patients requiring blood transfusions were seen in PLS. No significant differences in other laboratory markers, duration of hospital stay, or other complications after LuTX were registered.Conclusions: Minor ABO incompatible LuTX recipients are at considerable risk of developing clinically significant PLS. Post-transplant monitoring combining red cell serology and hemolysis marker determination appears advisable so as not to overlook hemolytic episodes that necessitate antigen-negative transfusion therapy.

The amino acid sensor GCN2 controls red blood cell clearance and iron metabolism through regulation of liver macrophages.

GCN2 (general control nonderepressible 2) is a serine/threonine-protein kinase that controls messenger RNA translation in response to amino acid availability and ribosome stalling. Here, we show that GCN2 controls erythrocyte clearance and iron recycling during stress. Our data highlight the importance of liver macrophages as the primary cell type mediating these effects. During different stress conditions, such as hemolysis, amino acid deficiency or hypoxia, GCN2 knockout (GCN2-/-) mice displayed resistance to anemia compared with wild-type (GCN2+/+) mice. GCN2-/- liver macrophages exhibited defective erythrophagocytosis and lysosome maturation. Molecular analysis of GCN2-/- cells demonstrated that the ATF4-NRF2 pathway is a critical downstream mediator of GCN2 in regulating red blood cell clearance and iron recycling.

Circulating immune complexes and G6PD deficiency predict readmissions for blackwater fever and severe anemia in children with severe malaria in Eastern Uganda.

BACKGROUND: Recently, there has been an unexplained increase in the incidence of blackwater fever (BWF) in Eastern Uganda. In this study, we evaluate the association between immune complexes, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and the occurrence and recurrence of BWF in children with severe malaria (SM). METHODS: Between 2014 and 2017, children aged six months to <4 years hospitalized with SM and community children (CC) were recruited at two hospitals in Central and Eastern Uganda. We measured serum circulating immune complexes (cIC) and their relationship to SM complications and post-discharge outcomes and evaluated effect mediation through G6PD deficiency. RESULTS: 557 children with SM and 101 CC were enrolled. The mean age of children was 2.1 years. Children with SM had higher cIC levels than CC, p<0.001. After controlling for age, sex, and site, cIC were associated with severe anemia, jaundice, and BWF (adjusted odds ratio, 95% confidence interval: 7.33 (3.45, 15.58), p<0.0001; 4.31 (1.68, 11.08), p=0.002; and 5.21 (2.06, 13.18), p<0.0001), respectively. cIC predicted readmissions for SM, severe anemia, and BWF (adjusted incidence rate ratios (95% confidence interval): 2.11 (1.33, 3.34), p=0.001; 8.62 (2.80, 26.59), p<0.0001; and 7.66 (2.62, 22.45), p<0.0001), respectively. The relationship was most evident in males where the frequency of the G6PD African allele (A-) was 16.8%. G6PD deficiency was associated with increases in cIC in males (p=0.01) and mediation analysis suggested G6PD deficiency contributes to recurrent severe anemia and BWF via increased cIC. CONCLUSIONS: Immune complexes are associated with hemolytic complications and predict recurrences in SM survivors.

Diacylglycerol kinase-ε is S-palmitoylated on cysteine in the cytoplasmic end of its N-terminal transmembrane fragment.

Diacylglycerol kinase-ε (DGKε) catalyzes phosphorylation of diacylglycerol to phosphatidic acid with a unique specificity toward 1-stearoyl-2-arachidonoyl-sn-glycerol, which is a backbone of phosphatidylinositol (PI). Owing to this specificity, DGKε is involved in the PI cycle maintaining the cellular level of phosphorylated PI derivatives of signaling activity and was also found crucial for lipid metabolism. DGKε dysfunction is linked with the development of atypical hemolytic uremic syndrome (aHUS) and possibly other human diseases. Despite the DGKε significance, data on its regulation by cotranslational and/or post-translational modifications are scarce. Here, we report that DGKε is S-palmitoylated at Cys38/40 (mouse/human DGKε) located in the cytoplasmic end of its N-terminal putative transmembrane fragment. The S-palmitoylation of DGKε was revealed by metabolic labeling of cells with a palmitic acid analogue followed by click chemistry and with acyl-biotin and acyl-polyethylene glycol exchange assays. The S-acyltransferases zDHHC7 (zinc finger DHHC domain containing) and zDHHC17 and the zDHHC6/16 tandem were found to catalyze DGKε S-palmitoylation, which also increased the DGKε abundance. Mouse DGKε-Myc ectopically expressed in human embryonic kidney 293 cells localized to the endoplasmic reticulum where zDHHC6/16 reside and in small amounts also to the Golgi apparatus where zDHHC7 and zDHHC17 are present. The Cys38Ala substitution upregulated, whereas hyperpalmitoylation of wild-type DGKε reduced the kinase activity, indicating an inhibitory effect of the Cys38 S-palmitoylation. In addition, the substitution of neighboring Pro31 with Ala also diminished the activity of DGKε. Taken together, our data indicate that S-palmitoylation can fine-tune DGKε activity in distinct cellular compartments, possibly by affecting the distance between the kinase and its substrate in a membrane.

Shiga Toxin‒Producing Escherichia coli Diagnoses from Health Practitioners, Queensland, Australia.

In Queensland, Australia, 31 of 96 Shiga toxin‒producing Escherichia coli cases during 2020-2022 were reported by a specialty pathology laboratory servicing alternative health practitioners. Those new cases were more likely to be asymptomatic or paucisymptomatic, prompting a review of the standard public health response.

An expert discussion on the atypical hemolytic uremic syndrome nomenclature-identifying a road map to precision: a report of a National Kidney Foundation Working Group.

The term atypical hemolytic uremic syndrome has been in use since the mid-1970s. It was initially used to describe the familial or sporadic form of hemolytic uremic syndrome as opposed to the epidemic, typical form of the disease. Over time, the atypical hemolytic uremic syndrome term has evolved into being used to refer to anything that is not Shiga toxin-associated hemolytic uremic syndrome. The term describes a heterogeneous group of diseases of disparate causes, a circumstance that makes defining disease-specific natural history and/or targeted treatment approaches challenging. A working group of specialty-specific experts in the thrombotic microangiopathies was convened to review the validity of this broad term in an era of swiftly advancing science and targeted therapeutics. A Delphi approach was used to define and interrogate some of the key issues related to the atypical hemolytic uremic syndrome nomenclature.

A case-based narrative review of pregnancy-associated atypical hemolytic uremic syndrome/complement-mediated thrombotic microangiopathy.

Atypical hemolytic uremic syndrome is a complement-mediated thrombotic microangiopathy caused by uncontrolled activation of the alternative complement pathway in the setting of autoantibodies to or rare pathogenic genetic variants in complement proteins. Pregnancy may serve as a trigger and unmask atypical hemolytic uremic syndrome/complement-mediated thrombotic microangiopathy (aHUS/CM-TMA), which has severe, life-threatening consequences. It can be difficult to diagnose aHUS/CM-TMA in pregnancy due to overlapping clinical features with other thrombotic microangiopathy syndromes including hypertensive disorders of pregnancy. However, the distinction among thrombotic microangiopathy etiologies in pregnancy is important because each syndrome has specific disease management and treatment. In this narrative review, we discuss 2 cases to illustrate the diagnostic challenges and evolving approach in the management of pregnancy-associated aHUS/CM-TMA. The first case involves a 30-year-old woman presenting in the first trimester who was diagnosed with aHUS/CM-TMA and treated with eculizumab from 19 weeks' gestation. Genetic testing revealed a likely pathogenic variant in CFI. She successfully delivered a healthy infant at 30 weeks' gestation. In the second case, a 22-year-old woman developed severe postpartum HELLP syndrome, requiring hemodialysis. Her condition improved with supportive management, yet investigations assessing for aHUS/CM-TMA remained abnormal 6 months postpartum consistent with persistent complement activation but negative genetic testing. Through detailed case discussion describing tests assessing for placental health, fetal anatomy, complement activation, autoantibodies to complement regulatory proteins, and genetic testing for aHUS/CM-TMA, we describe how these results aided in the clinical diagnosis of pregnancy-associated aHUS/CM-TMA and assisted in guiding patient management, including the use of anticomplement therapy.

Major reduction in occurrence of anti-c and anti-E in pregnancy after more than 10 years of preventive matched transfusion with most benefit for c-matching.

Extension with cE-matching of the transfusion policy for women under 45 years to prevent alloimmunization and hemolytic disease of the foetus and newborn (HDFN) was evaluated. After implementation of cEK-matching, anti-c occurrence decreased from 46.8 to 30.4 per 100 000 pregnancies (RR 0.65, 95% CI 0.54-0.79), while anti-E occurrence decreased from 122.1 to 89.9 per 100 000 pregnancies (RR 0.74, 95% CI 0.66-0.84). The c-negative women showed a higher anti-E occurrence before cEK-matching and a more pronounced decline with the new policy. This indicates that cEK-matched transfusion effectively reduces alloimmunization, and that a cK-matched approach could prevent most transfusion-related alloimmunization and HDFN.

Transfusions in autoimmune hemolytic anemias: Frequency and clinical significance of alloimmunization.

BACKGROUND: Autoimmune hemolytic anemia (AIHA) may be associated with transfusion reactions and risk of alloimmunization. OBJECTIVES: To evaluate the transfusion policy and rate of alloimmunization and its clinical significance in AIHA. METHODS: Data from 305 AIHA patients followed at a reference hematologic Center in Milan, Italy from 1997 to 2022 were retrospectively/prospectively collected (NCT05931718). RESULTS: Overall, 33% patients required transfusions with a response rate of 83% and eight transfusion reactions (7%), none hemolytic. Alloantibodies were detected in 19% of patients, being associated with higher transfusion burden (p = 0.01), lower Hb increase post-transfusion (p = 0.05), and transfusion reactions (p = 0.04). Along decades, the rate of RBC transfusions decreased from 53% to 20% and that of alloimmunization dropped from 30% to 6% likely due to the adoption of prestorage leukoreduction, the use of more restrictive Hb thresholds, and the implementation of molecular typing. CONCLUSIONS: Severe symptomatic AIHA may be safely transfused provided appropriate matching of patients and donors.

PKLR mutations in pyruvate kinase deficient Polish patients: Functional characteristics of c.101-1G > A and c.1058delAAG variants.

Pyruvate kinase (PK) deficiency is a rare autosomal recessive disorder characterized by chronic hemolytic anemia of variable severity. Nine Polish patients with severe hemolytic anemia but normal PK activity were found to carry mutations in the PKLR gene encoding PK, five already known ones and one novel (c.178C > T). We characterized two of the known variants by molecular modeling (c.1058delAAG) and minigene splicing analysis (c.101-1G > A). The former gives a partially destabilized PK tetramer, likely of suboptimal activity, and the c.101-1G > A variant gives alternatively spliced mRNA carrying a premature stop codon, encoding a severely truncated PK and likely undergoing nonsense-mediated decay.

Clonal hematopoiesis and acquired genetic abnormalities of the red cell: An historical review.

Several syndromes affecting the red cell that mimic those induced by germline mutations may result from a somatic mutation that accompanies a myeloid malignancy. These syndromes are most notable in cases of myelodysplastic syndrome, but they are not limited to any one category of myeloid neoplasm. Their occurrence in males exceed the male predominance that is evident in myeloid neoplasms. The syndromes include disorders of globin chain synthesis (α- and ß-thalassemia), heme synthesis (erythropoietic porphyria and erythropoietic uroporphyria), red cell membrane structure (elliptocytosis and spherocytosis), red cell enzyme activity (pyruvate kinase deficiency, glucose-6-phosphate dehydrogenase deficiency) and lowered expression of red cell ABO blood group antigens. This historical review describes the path to uncovering these acquired syndromes and their causal somatic mutations, where known. These syndromes often go unrecognized because of the dominant concern of the primary neoplasm. They may add to the healthcare needs of the patient.

Red blood cell-derived arginase release in hemolytic uremic syndrome.

BACKGROUND: Hemolysis is a cardinal feature of hemolytic uremic syndrome (HUS) and during hemolysis excess arginase 1 is released from red blood cells. Increased arginase activity leads to reduced L-arginine, as it is converted to urea and L-ornithine, and thereby reduced nitric oxide bioavailability, with secondary vascular injury. The objective of this study was to investigate arginase release in HUS patients and laboratory models and correlate arginase levels to hemolysis and kidney injury. METHODS: Two separate cohorts of patients (n = 47 in total) with HUS associated with Shiga toxin-producing enterohemorrhagic E. coli (EHEC) and pediatric controls (n = 35) were investigated. Two mouse models were used, in which mice were either challenged intragastrically with E. coli O157:H7 or injected intraperitoneally with Shiga toxin 2. An in vitro model of thrombotic microangiopathy was developed in which Shiga toxin 2- and E. coli O157 lipopolysaccharide-stimulated human blood cells combined with ADAMTS13-deficient plasma were perfused over glomerular endothelial cells. Two group statistical comparisons were performed using the Mann-Whitney test, multiple groups were compared using the Kruskal-Wallis test followed by Dunn's procedure, the Wilcoxon signed rank test was used for paired data, or linear regression for continuous variables. RESULTS: HUS patients had excessively high plasma arginase 1 levels and activity (conversion of L-arginine to urea and L-ornithine) during the acute phase, compared to remission and controls. Arginase 1 levels correlated with lactate dehydrogenase activity, indicating hemolysis, as well as the need for dialysis treatment. Patients also exhibited high levels of plasma alpha-1-microglobulin, a heme scavenger. Both mouse models exhibited significantly elevated plasma arginase 1 levels and activity. Plasma arginase 1 levels correlated with lactate dehydrogenase activity, alpha-1-microglobulin and urea levels, the latter indicative of kidney dysfunction. In the in vitro model of thrombotic microangiopathy, bioactive arginase 1 was released and levels correlated to the degree of hemolysis. CONCLUSIONS: Elevated red blood cell-derived arginase was demonstrated in HUS patients and in relevant in vivo and in vitro models. The excessively high arginase levels correlated to the degree of hemolysis and kidney dysfunction. Thus, arginase inhibition should be investigated in HUS.

Unveiling biological activities of biosynthesized starch/silver-selenium nanocomposite using Cladosporium cladosporioides CBS 174.62.

BACKGROUND AND OBJECTIVES: Microbial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed. METHODOLOGY: The St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined. RESULTS: The St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively. CONCLUSION: The biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities.

Antimicrobial potential of carvacrol against Edwardsiella piscicida in vitro.

With the alarming rise of antibiotic-resistant bacteria, novel antibacterial substances are urgently needed for controlling and treating multidrug-resistant bacterial infections. Edwardsiella piscicida is an important zoonotic enteric pathogen, that can cause systemic hemorrhagic septicemia in fish. Carvacrol, a major terpene of oregano essential oil, has a wide range of antibacterial activities. This study aimed to analyze the effect of carvacrol on the growth and virulence of E. piscicida in vitro. The minimum inhibitory concentration (MIC) of carvacrol against E. piscicida was 125 µg/mL. The sub-inhibitory concentrations of carvacrol significantly decreased the biofilm formation of E. piscicida in a dose dependent manner, whereas increased the hemolytic activity with a negative correlation. The quantitative real-time PCR results showed that carvacrol at sub-MICs downregulated the expression of related virulence genes, including flagellum (fimA, fliC, flgN), hemolysins (ethA, ethB), quorum sensing systems (luxR, qseB), T3SS (esrB, esrC) and T6SS (evpB, evpC). Moreover, carvacrol (≤1/8 MIC) reduced the cytotoxicity, adherence and internalization activities of E. piscicida to the EPC cells. In vivo trial, the diet mixed with carvacrol increased the survival of zebrafish infected with E. piscicida. Overall, these findings suggested that carvacrol might be a promising therapeutic agent against E. piscicida infection in aquaculture.

Progression of renal damage and tubular regeneration in pregnant and non-pregnant adult female rats inoculated with a sublethal dose of Shiga toxin 2.

BACKGROUND: Shiga toxin-producing Escherichia coli is the main cause of post-diarrheal hemolytic uremic syndrome (HUS) which produces acute kidney injury mainly in children, although it can also affect adults. The kidneys are the organs most affected by Shiga toxin type 2 (Stx2) in patients with HUS. However, previous studies in pregnant rats showed that a sublethal dose of Stx2 causes severe damage in the uteroplacental unit and induces abortion, whereas produces mild to moderate renal damage. The aim of the present work was to study the progression of renal injury caused by a sublethal dose of Stx2, as well as renal recovery, in pregnant and non-pregnant rats, and to investigate whether pregnancy physiology may affect renal damage progression mediated by Stx2. METHODS: Renal function and histopathology was evaluated in pregnant rats intraperitoneally injected with a sublethal dose of Stx2 (0.5 ng/g bwt) at the early stage of gestation (day 8 of gestation), and results in these rats were compared over time with those observed in non-pregnant female rats injected with the same Stx2 dose. Hence, progression of cell proliferation and dedifferentiation in renal tubular epithelia was also investigated. RESULTS: The sublethal dose of Stx2 induced abortion in pregnant rats as well as a significant more extended functional and histological renal injury in non-pregnant rats than in pregnant rats. Stx2 also caused decreased ability to concentrate urine in non-pregnant rats compared to their controls. However, renal water handling in pregnant rats was not altered by Stx2, and was significantly different than in non-pregnant rats. The greatest renal injury in both pregnant and non-pregnant rats was observed at 4 days post-Stx2 injection, and coincided with a significant increase in tubular epithelial proliferation. Expression of mesenchymal marker vimentin in tubular epithelia was consistent with the level of tubular damage, being higher in non-pregnant rats than in pregnant rats. Recovery from Stx2-induced kidney injury was faster in pregnant rats than in non-pregnant rats. CONCLUSIONS: Adaptive mechanisms developed during pregnancy such as changes in water handle and renal hemodynamic may contribute to lessen the Stx2-induced renal injury, perhaps at the expense of fetal loss.

HemoDL: Hemolytic peptides prediction by double ensemble engines from Rich sequence-derived and transformer-enhanced information.

Hemolytic peptides can trigger hemolysis by rupturing red blood cells' membranes and triggering cell disruption. Due to the labor-intensive and time-consuming in-lab identification process, accurate, high-throughput hemolytic peptide prediction is crucial for the growth of peptide sequence data in proteomics and peptidomics. In this study, we offer the HemoDL ensemble learning model, which learns the distinct distribution of sequence characteristics for predicting the hemolytic activity of peptides using a double LightGBM framework. To determine the most informative encoding features, we compare 17 widely used features across four benchmark datasets. Our investigation reveals that CTD, BPF, Charge, AAC, GDPC, ATC, QSO, and transformer-based features exhibit more positive contributions to detecting the hemolytic activity of peptides. Comparison with eight state-of-the-art methods demonstrates that HemoDL outperforms other models, attaining higher Matthews Correlation Coefficient values on four test datasets, ranging from 6.30% to 16.04%, 6.63%-11.26%, 4.76%-9.92%, and 7.41%-15.03%, respectively. Additionally, we provide the HemoDL with a user-friendly graphical interface available at https://github.com/abcair/HemoDL. In summary, the HemoDL model, leveraging CTD, BPF, Charge, AAC, GDPC, ATC, QSO and transformer-based encoding features within a double LightGBM learning framework, achieves high accuracy in predicting the hemolytic activity of peptides.