Estrogen genotoxicity causes preferential development of Fuchs endothelial corneal dystrophy in females

Fuchs endothelial corneal dystrophy (FECD) is a genetically complex, age-related, female-predominant disorder characterized by loss of post-mitotic corneal endothelial cells (CEnCs). Ultraviolet-A (UVA) light has been shown to recapitulate the morphological and molecular changes seen in FECD to a greater extent in females than males, by triggering CYP1B1 upregulation in females. Herein, we investigated the mechanism of greater CEnC susceptibility to UVA in females by studying estrogen metabolism in response to UVA in the cornea. Loss of NAD(P)H quinone oxidoreductase 1 (NQO1) resulted in increased production of estrogen metabolites and mitochondrial-DNA adducts, with a higher CEnC loss in Nqo1-/- female compared to wild-type male and female mice. The CYP1B1 inhibitors, trans-2,3',4,5'-tetramethoxystilbene (TMS) and berberine, rescued CEnC loss. Injection of wild-type male mice with estrogen (E2; 17β-estradiol) increased CEnC loss, followed by increased production of estrogen metabolites and mitochondrial DNA (mtDNA) damage, not seen in E2-treated Cyp1b1-/-male mice. This study demonstrates that the endo-degenerative phenotype is driven by estrogen metabolite-dependent CEnC loss that is exacerbated in the absence of NQO1; thus, explaining the mechanism accounting for the higher incidence of FECD in females. The mitigation of estrogen-adduct production by CYP1B1 inhibitors could serve as a novel therapeutic strategy for FECD.

Foliar application of triacontanol ameliorates heat stress through regulation of the antioxidant defense system and improves yield of eggplant

Abstract Transplanting time and genotype contribute to improving crop yield and quality of eggplant (Solanum melongena L.). A field experiment was conducted to investigate the impact of foliar applied of triacontanol (TRIA) and eggplant genotypes 25919, Nirala, 28389 and Pak-10927,transplanted on 1 March,15 March, and 1 April on exposure to high air temperature conditions. The experiment was performed according to Randomized Complete Block Design and the data was analyzed by using Tuckey,s test . The TRIA was applied at 10µM at flowering stage; distilled water was used as the control. Rate of photosynthesis and transpiration, stomatal conductance, water use efficiency, and effects on antioxidative enzymes (superoxide dismutase, catalase and peroxidase) were evaluated. The 10µM TRIA increased photosynthesis rate and water use efficiency and yield was improved in all genotypes transplanted at the different dates. Foliar application of 10µM TRIA increased antioxidative enzyme activities (SOD, POD & CAT) and improved physiological as well as biochemical attributes of eggplant genotypes exposed to high heat conditions. Highest activity of dismutase enzyme 5.41mg/1g FW was recorded in Nirala genotype in second transplantation. Whereas, lowest was noted in PAK-10927 (2.30mg/g FW). Maximum fruit yield was found in accession 25919 (1.725kg per plant) at 1st transplantation with Triacontanol, whereas accession PAK-10927 gave the lowest yield (0.285 kg per plant) at control treatment on 3rd transplantation. Genotype, transplanting date and application of TRIA improved growth, yield and quality attributes under of heat stress in eggplant.

Dysregulation of DNA repair genes in Fuchs endothelial corneal dystrophy

Fuchs Endothelial Corneal Dystrophy (FECD), a late-onset oxidative stress disorder, is the most common cause of corneal endothelial degeneration and is genetically associated with CTG repeat expansion in TCF4. We previously reported accumulation of nuclear (nDNA) and mitochondrial (mtDNA) damage in FECD. Specifically, mitochondrial DNA damage was a prominent finding in development of disease in the ultraviolet-A (UVA) induced FECD mouse model. We hypothesize that an aberrant DNA repair may contribute to the increased DNA damage seen in FECD. We analyzed differential expression profiles of 84 DNA repair genes by real-time PCR arrays using Human DNA Repair RT-Profiler plates using cDNA extracted from Descemet's membrane-corneal endothelium (DM-CE) obtained from FECD patients with expanded (>40) or non-expanded (<40) intronic CTG repeats in Transcription Factor 4 (TCF4) gene and from age-matched normal donors. Change in mRNA expression of <0.5- or >2.0-fold in FECD relative to normal was set as cutoff for down- or upregulation. Downregulated mitochondrial genes were further validated using the UVA-based mouse model of FECD. FECD specimens exhibited downregulation of 9 genes and upregulation of 8 genes belonging to the four major DNA repair pathways, namely, base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), and double strand break (DSB) repair, compared to normal donors. MMR gene MSH2 and BER gene POLB were preferentially upregulated in expanded FECD. BER genes LIG3 and NEIL2, DSB repair genes PARP3 and TOP3A, NER gene XPC, and unclassified pathway gene TREX1, were downregulated in both expanded and non-expanded FECD. MtDNA repair genes, Lig3, Neil2, and Top3a, were also downregulated in the UVA-based mouse model of FECD. Our findings identify impaired DNA repair pathways that may play an important role in DNA damage due to oxidative stress as well as genetic predisposition noted in FECD.

Two new species of genus Leucoagaricus (Agaricaceae, Agaricales) from Pakistan

The genus of basidiomycetous fungi, Leucoagaricus, occurs worldwide, from subtropical to boreal latitudes. Several collections of Leucoagaricus were made during mycological field trips conducted in different forests of Margalla, Pakistan. An integrative framework combining morphological and phylogenetic data was employed for their study. As a result, the two species La.margallensis and La.glareicolor are here described as new to science. Detailed macro- and micro-morphological descriptions, and a molecular phylogenetic reconstruction based on nrITS and LSU sequence data are provided and used to discriminate the new species from morphologically and phylogenetically close taxa. Whereas, our phylogenetic tree inference gave unequivocal support for the inclusion of these two species within the section Leucoagaricus.

Junk food consumption in relation to menstrual abnormalities among adolescent girls: A comparative cross sectional study

Objectives: The study was aimed at evaluating the association between junk food consumption and BMI of adolescent girls along with the menstrual abnormalities and to compare it with controls. Methods: A cross-sectional study was conducted among 200 girls between 13 – 19 years of age at Bahria International Hospital, Lahore based on self-administered questionnaire from July 2021 to September 2021. The total subjects were divided in two groups Viz; Group-A which comprised of 100 girls with menstrual abnormalities and Group-B included 100 girls without menstrual problem (control group). The data recorded on the questionnaire about the demographic profile, anthropometric measurements, menstrual cycle characteristics, and dietary habits was subjected to statistical analysis using SPSS version 20 and Chi-Square was used to test quantitative significance between the two groups. Results: The mean age of participants was 17.02±1.76 years. It was observed that 40% girls had irregular menstrual cycle, 56% girls were suffering from dysmenorrhea and almost all girls of Group-I were suffering from premenstrual dysfunctions. The current study found a non-significant difference between two groups with regard to body mass index (P≥0.05). Significant difference was observed between two groups (P ≤ 0.05) as junk food consumption was high in Group-A as compared to Group-B. However, no significant difference was found between Group-A and B in relation to the consumption of salty snacks and frozen meat items (P≥0.05). Conclusion: The results suggested that junk food consumption affects menstrual cycle negatively however more studies are needed to confirm the association of BMI, consumption of salty snacks and frozen meat items with menstrual abnormalities. doi: https://doi.org/10.12669/pjms.38.8.6177 How to cite this:Latif S, Naz S, Ashraf S, Jafri SA. Junk food consumption in relation to menstrual abnormalities among adolescent girls: A comparative cross sectional study. Pak J Med Sci. 2022;38(8):---------. doi: https://doi.org/10.12669/pjms.38.8.6177 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Acetylcholinesterase inhibitory potential of scorpion venom in Aedes aegypti (Diptera: Culicidae)

Scorpion venom contains a variety of neurotoxins which interact with ion channels and affect their activities. The present study was designed to evaluate the potential of scorpion venom as acetylcholinesterase (AChE) inhibitor by using Aedes aegypti as model organism. Venoms of two species, Hottentota tamulus (Fabricus, 1798) and Androctonus finitimus (Pocock, 1897) were selected for this study. Two peptides (36 kDa from H. tamulus and 54 kDa from A. finitimus) were separated from scorpion venom by using HPLC. Selected peptides caused significantly higher mortality in larvae and adults of Aedes aegypti than control (no mortalities were observed in control groups). Significant acetylcholinesterase (AChE) inhibitory potential of both peptides was recorded by spectrophotometer. The peptide of A. finitimus caused significantly higher mortality (95±1.53% in larvae and 100% in adults) than the peptide of H. tamulus (84.33±2.33% in larvae and 95.37±1.45% in adults). While H. tamulus peptide was more efficient in reducing AChE activity (0.029±0.012 in larvae and 0.03±0.003 in adults) than the peptide of A. finitimus (0.049±0.005 in larvae and 0.047±0.001 in adults). It was concluded that H. tamulus venom peptide was more efficiently reducing AChE activity, thus it could be a potential bio-insecticide which can be synthesized at industrial scale for the control of harmful insects.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Colchicine anti-inflammatory therapy for non-intensive care unit hospitalized COVID-19 patients: results from a pilot open-label, randomized controlled clinical trial

Systemic inflammation is a hallmark of severe coronavirus disease-19 (COVID-19). Anti-inflammatory therapy is considered crucial to modulate the hyperinflammatory response (cytokine storm) in hospitalized COVID-19 patients. There is currently no specific, conclusively proven, cost-efficient, and worldwide available anti-inflammatory therapy available to treat COVID-19 patients with cytokine storm. The present study aimed to investigate the treatment benefit of oral colchicine for hospitalized COVID-19 patients with suspected cytokine storm. Colchicine is an approved drug and possesses multiple anti-inflammatory mechanisms. This was a pilot, open-label randomized controlled clinical trial comparing standard of care (SOC) plus oral colchicine (colchicine arm) vs. SOC alone (control arm) in non-ICU hospitalized COVID-19 patients with suspected cytokine storm. Colchicine treatment was initiated within first 48 hours of admission delivered at 1.5 mg loading dose, followed by 0.5 mg b.i.d. for next 6 days and 0.5 mg q.d. for the second week. A total of 96 patients were randomly allocated to the colchicine (n=48) and control groups (n=48). Both colchicine and control group patients experienced similar clinical outcomes by day 14 of hospitalization. Treatment outcome by day 14 in colchicine vs control arm: recovered and discharged alive: 36 (75.0%) vs. 37 (77.1%), remain admitted after 14-days: 4 (8.3%) vs. 5 (10.4%), ICU transferred: 4 (8.3%) vs. 3 (6.3%), and mortality: 4 (8.3%) vs. 3 (6.3%). The speed of improvement of COVID-19 acute symptoms including shortness of breath, fever, cough, the need of supplementary oxygen, and oxygen saturation level, was almost identical in the two groups. Length of hospitalization was on average 1.5 day shorter in the colchicine group. There was no evidence for a difference between the two groups in the follow-up serum levels of inflammatory biomarkers including C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), ferritin, interleukin-6 (IL-6), high-sensitivity troponin T (hs-TnT) and N-terminal pro b-type natriuretic peptide (NT pro-BNP). According to the results of our study, oral colchicine does not appear to show clinical benefits in non-ICU hospitalized COVID-19 patients with suspected cytokine storm. It is possible that the anti-inflammatory pathways of colchicine are not crucially involved in the pathogenesis of COVID-19.

Efficacy of Flaxseed and Fish Oils on Adults with Rheumatoid Arthritis

OBJECTIVE

To assess the relative efficacy of flaxseed and fish oils in the management of rheumatoid arthritis.

METHODS

The comparative study was conducted in the outpatient department of Rheumatology at Fatima Memorial Hospital, Shadman, Lahore, Pakistan, from July to December 2017, and comprised rheumatoid arthritis patients who were divided into group A receiving 3g/day of flaxseed oil and group B receiving 3g/day of fish oil for 90 days. Blood samples were taken at baseline and post-intervention to note the difference on biochemical parameters. Data was analysed using SPSS 21.

RESULTS

Of the 60 patients, there were 30(50%) in each of the two groups. Overall, there were 8(13.3%) males and 52(86.7%) females. Both groups showed significant change in all biochemical parameters compared to baseline values (p<0.05). Intergroup comparison showed that flaxseed oil treatment was significantly more effective than fish oil treatment (p<0.05).

CONCLUSIONS

While both forms of intervention were found to be effective, flaxseed oil was significantly more effective.

Studies on parasitic prevalence in pet birds from Punjab, Pakistan

During this one year study, blood and fecal samples of doves (Zenaida asiatica), ducks (Anas platyrhynchos), pigeons (Columba livia), partridges (Alectoris chukar), turkeys (Meleagris gallopavo) and goose (Chen caerulescens) were collected to assess the parasitic prevalence in these birds. The birds were kept at Avian Conservation and Research Center, Department of Wildlife and Ecology, University of Veterinary and Animal Sciences, Lahore. All these avian species were kept in separate cages and their entire body was inspected on regularly basis to record external parasites. For internal parasites, 100 blood and 100 fecal samples for each species were analyzed. During present study, two species of ectoparasites i.e. fowl ticks (Args persicus) and mite (Dermanyssus gallinae) while 17 species of endoparasites; three from blood and 14 from fecal samples were identified. Prevalence of blood parasites was Plasmodium juxtanucleare 29.3%, Aegyptinella pullorum 15% and Leucoctoyzoon simond 13%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Syngamus trachea with parasitic prevalence of 50%, Capillaria anatis 40%, Capillaria annulata 37.5%, Heterakis gallinarum 28.3%, Ascardia galli 24% and Allodpa suctoria 2%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 12.1% and Prosthogonimus macrorchis 9.1% were also recorded from fecal samples of the birds. Single cestode species Raillietina echinobothrida having parasitic prevalence of 27% and 3 protozoan species i.e. Eimeria maxima having prevalence 20.1%, Histomonas meleagridis 8% and Giardia lamblia 5.3% were recorded. In our recommendation, proper medication and sanitation of the bird's houses and cages is recommended to avoid parasites.

Postoperative complications of colorectal cancer

Colorectal cancer is the third most common cancer, and surgery is the most common treatment. Several surgical options are available, but each is associated with a range of potential complications. The timely and efficient identification of these complications is vital for effective clinical management of these patients in order to minimise their morbidity and mortality. This review aims to describe the range of commonly performed surgical treatments for colorectal surgery. In addition, frequent post-surgical complications are explored with investigative options explained and illustrated.

Implication of Prophetic Variables and their Impulsive Interplay in CA Prostate Patients Experiencing Osteo-Metastasis

AIMS

To identify variables having a critical role in prostate cancer patients experiencing osteometastasis.

BACKGROUND

Prostatic carcinoma is a multifactorial complex disorder that exhibits an increased propensity to develop bone metastasis. An interplay of inflammatory and bone remodeling parameters promotes the formation of pre-metastatic niches in bones of patients, which could render them more vulnerable to skeletal disabilities.

OBJECTIVE

To evaluate the multi-dynamic inter-relationship of circulating variables in prostate cancer patients experiencing osteo-metastasis.

MATERIALS AND METHODS

Fifty-seven (n=57) men with clinically confirmed prostate cancer, fifty-nine (n=59) with skeletal metastases, and one hundred (n=100) healthy subjects i.e., men aging from 53-84 years with no clinical evidence of prostate were recruited from the Jinnah Hospital Lahore, Pakistan. Informed consent was obtained, and a venous blood sample was drawn and stored at -70oC until assayed. Levels of variables were evaluated using appropriate methods. Levels of Matrix Metalloproteinases (MMPs), Osteopontin (OPN), TGH- β, and sRANKL were estimated by the ELISA method. Each sample was suspended and the given protocol was employed. ELISA readings were obtained for the estimation of all variables.

RESULTS

Highly significant (P˂0.05) differential expression of oxidative stress, inflammatory cytokines, and bone remodeling variables were observed in localized and osteo-metastatic CA prostate patients. A strong positive correlation was revealed among OPN, sRANKL, MMP-7, MMP-9, PSA, and TGF-β (OPN vs. MMP-7, r=0.698* and OPN vs. MMP-9, r=0.765**, OPN vs. RANKL, =0.856*, sRANKL vs. MMP-9, r=0.825**, TGF- β vs. RANKL, r=0.868* and PSA vs. TGF- β, r=0.752*); lower levels of OPG were estimated in metastasized patients, showing that both osteolytic and osteoblastic phases of bone remodeling occur simultaneously.

CONCLUSION

The altered oxidative and inflammatory responses endorse Matrix Metalloproteinases (MMPs) increased activity, RANKL/OPG imbalance, and enhanced bone matrix proteins turnover, which can foster the process of osteo-metastasis. The perturbed RANKL/OPG drift and enhanced PSA levels are associated with increased TGF-β activity to aggravate Epithelial Mesenchymal transition (EM) and osteo-tropism of prostate cancer. Thus, designing novel targets of these major variables can minimize the incidence of prostate cancer patients.

Interspecific variations in external and internal egg quality among various captive avian species from Punjab, Pakistan

Present study was planned to determine variations in external and internal quality egg parameters of different avian species including ostrich Struthio camelus, ducks Anas platyrhynchos, chicken Gallus gallus, turkeys Meleagris gallopavo and grey francolin Francolinus pondicerinus. All the birds were kept under similar rearing conditions. A total of 150 eggs were collected for each species to record external features of these eggs. Statistically significant (p<0.05) variations were recorded in egg weight, egg length and egg width between ostrich, ducks, chicken, turkey and quail eggs. Significantly (p<0.05) higher egg weight, egg length and egg width was observed for ostrich eggs while the same was lowest for grey francolin eggs. Similarly, significantly (p<0.05) greater shape index and egg volume values were observed for ostrich eggs while lowest shape index values were recorded for turkey eggs and egg volume was lowest for grey francolin. Significantly, higher (p<0.05) values of egg density were noted for eggs of the quail and the same were lowest for ostrich eggs. Non-significant variations in egg density values were observed between eggs of the ducks, chicken, turkey and grey francolin. It has been concluded that the positive correlations between the internal and external egg quality traits indicated that the traits can be improved through selection.

937 Is the Dog Still Man's Best Friend?

Introduction

It is colloquially known that dogs are man’s best friend. However, animal attacks cause a large number of injuries and deaths worldwide, with 70% of injuries being caused by pets. This study highlights the impact of dog related injuries.

Method

Data was collected retrospectively over 1 year in a small district general hospital. The search term “dog” was used to find patients who had attended A&E or fracture clinic. This data was analysed for patient demographics, injury type and severity, management, and cost to the NHS.

Results

The majority (77%) of patients were female and elderly, with the modal age group being 70-79. Of the 38% of patients requiring admission, average length of stay was 6.7 days. Fractures made up the majority of injuries (56%) and 17% of patients required operative management. A further 2% suffered from post-operative complications. The average cost to the NHS was £1,695 per patient.

Conclusions

Dog related injuries disproportionately affected women and the elderly, with a large portion requiring operative management. Some patients developed further complications. As well as health burden there was also a financial burden associated with these injuries. These health and financial detriments are not often considered when deciding on pet ownership.

958 Pre-operative Pregnancy Testing in Paediatric Patients

Introduction

NICE emphasises the importance of pregnancy testing before surgical procedures as a patient safety precaution, especially in 13-16-year-olds. This is because, in the UK, a third of females will have been sexually active by the age of 16, meanwhile, in England there are 67,000 operations involving females aged 12-15 annually.

Method

Guidance from NICE and RCPCH was used to create standards to compare against current practice. Surgical admissions involving females aged 13-16 were retrospectively analysed over a one-year period and compared to these standards. Changes, including creation of a protocol, revision of the clerking proforma and staff education, were implemented to improve compliance and patient data was re-audited following this.

Results

Initially, 27% of patients did not have pregnancy testing before their procedure and consent for pregnancy testing was not documented. However, when pregnancy tests were performed, the result was documented 100% of the time. After implementing changes, 100% of patients had pregnancy testing before their procedure and documentation of consent had improved.

Conclusions

Initial practice showed poor compliance with NICE and RCPCH standards. Changes implemented have shown increased compliance to NICE and RCPCH standards and these changes could be used as a model to improve clinical compliance in further areas.

28 Shifting to Virtual MDT in the COVID-19 Era and Beyond

Aim

The COVID19 pandemic has accelerated the need for staff to work remotely. Our aim was to demonstrate how a next-generation digital platform could be used to create a virtual MDT ecosystem in order to manipulate holographic 2D and 3D images in real-time.

Method

This study involved setting up a mock virtual MDT using de-identified DICOM files from a patient who had been treated for colorectal cancer and then subsequently found to have a liver metastasis. The image file was segmented and converted into a 2D and 3D format for visualisation within Microsoft HoloLens 2 ® (smart glasses) using Holocare Solutions ® (Mixed Reality software).

Results

A seamless cross-border pipeline was developed that involved "clinician" training, DICOM segmentation and virtual connection. We successfully performed a virtual MDT with participants able to visualise and manipulate a virtual 3D organ in real-time. The digital network remotely connected sites in England and Norway. The streaming quality was stable and HIPAA compliant. Each participant could observe others as "avatars" interacting with images within the virtual ecosystem allowing image characteristics to be highlighted.

Conclusions

We successfully conducted a virtual MDT using novel hardware and software. Our intention is to conduct a large-scale study to assess the platform's effectiveness in “Real World" MDTs.

Evaluation of serum analytes in pregnant and non-pregnant dairy cows as indicators of pregnancy

This study was conducted to reveal the dynamics of haematological indicators in pregnant and non-pregnant dairy cows. Sixty multiparous healthy dairy cows were divided into four groups based on the length of time they had been pregnant, namely first, second and third trimesters, and non-pregnant (n=15 each). Blood was collected from each animal, and serum was harvested and stored at -20 °C for biochemical profiling. Concentrations of serum total oxidants (TOC), ceruloplasmin oxidase (CpO) and triiodothyronine (T3) were higher (P <0.05) during the third trimester compared with non-pregnant cows. Serum arylesterase (Ary) concentration was lower (P <0.05) during the second and the third trimesters compared with the non-pregnant cows. The concentration of serum total homocysteine (tHcy) was higher (P <0.05) the third trimester compared with the first and the second trimesters. The concentrations of serum total antioxidants (TAC), paraoxonase 1 (PON1), thyroxine (T4), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were not different in the pregnant and the non-pregnant cows. Thus, TOC, Ary, CpO, tHcy and T3 could be taken as biological markers to assess the progression of pregnancy and to develop management tools to improve health status during late gestation in dairy cows Keywords: ceruloplasmin, hepatic enzymes, late gestation, triiodothyronine

Effect of maternal yeast feeding on dam performance and serum health biomarkers of Beetal goat kids

Supplementation with dietary yeast has improved digestibility and productive performance in ruminants. In this research the primary objective was to appraise the effects of dietary yeast supplementation of female goats during the transition period on milk composition and yield and on production and serum health biomarkers of their kids. Twenty-four Beetal goats (4 ± 1.2 years) were randomly assigned to three groups, which received 0, 5, and 10 grams/animal/day of live dried yeast Saccharomyces cerevisiae for 60 days (30 days pre- and post-partum). All goats were fed 500 grams of concentrate with water and green fodder ad libitum. Milk samples were collected at 7, 14, 21, and 28 days post kidding. Kids were weighed on days 0, 7, 15, 22, and 30, and blood samples were collected on days 15 and 30 for serum metabolites (glucose, urea, cholesterol, non-esterified fatty acids (NEFA), serum total proteins, albumin, globulin, albumin to globulin ratio, serum oxidant and antioxidant activity (malondialdehyde) (MDA) and catalase), and liver enzymes aspartate aminotransferase (AST) and alanine transaminase (ALT) assessment. Milk yield was significantly (P =0.02) higher during the post-partum period in yeast-fed goats. Yeast-fed goats also produced milk containing more fat (P <0.001) and protein (P <0.001) compared with control goats. Birth weight, average daily gain, and serum health biomarkers of the kids were not influenced by the treatments. In conclusion, dietary yeast supplementation resulted in increased production performance of the dams without significant impact on their offspring.Keywords: average daily gain, catalase activity, hepatic enzymes, milk production, Saccharomyces cerevisiae, transition period

Genetic variants in the LAMA5 gene in pediatric nephrotic syndrome

BACKGROUND

Nephrotic syndrome (NS), a chronic kidney disease, is characterized by significant loss of protein in the urine causing hypoalbuminemia and edema. In general, ∼15% of childhood-onset cases do not respond to steroid therapy and are classified as steroid-resistant NS (SRNS). In ∼30% of cases with SRNS, a causative mutation can be detected in one of 44 monogenic SRNS genes. The gene LAMA5 encodes laminin-α5, an essential component of the glomerular basement membrane. Mice with a hypomorphic mutation in the orthologous gene Lama5 develop proteinuria and hematuria.

METHODS

To identify additional monogenic causes of NS, we performed whole exome sequencing in 300 families with pediatric NS. In consanguineous families we applied homozygosity mapping to identify genomic candidate loci for the underlying recessive mutation.

RESULTS

In three families, in whom mutations in known NS genes were excluded, but in whom a recessive, monogenic cause of NS was strongly suspected based on pedigree information, we identified homozygous variants of unknown significance (VUS) in the gene LAMA5. While all affected individuals had nonsyndromic NS with an early onset of disease, their clinical outcome and response to immunosuppressive therapy differed notably.

CONCLUSION

We here identify recessive VUS in the gene LAMA5 in patients with partially treatment-responsive NS. More data will be needed to determine the impact of these VUS in disease management. However, familial occurrence of disease, data from genetic mapping and a mouse model that recapitulates the NS phenotypes suggest that these genetic variants may be inherited factors that contribute to the development of NS in pediatric patients.

Panel sequencing distinguishes monogenic forms of nephritis from nephrosis in children

BACKGROUND

Alport syndrome (AS) and atypical hemolytic-uremic syndrome (aHUS) are rare forms of chronic kidney disease (CKD) that can lead to a severe decline of renal function. Steroid-resistant nephrotic syndrome (SRNS) is more common than AS and aHUS and causes 10% of childhood-onset CKD. In recent years, multiple monogenic causes of AS, aHUS and SRNS have been identified, but their relative prevalence has yet to be studied together in a typical pediatric cohort of children with proteinuria and hematuria. We hypothesized that identification of causative mutations by whole exome sequencing (WES) in known monogenic nephritis and nephrosis genes would allow distinguishing nephritis from nephrosis in a typical pediatric group of patients with both proteinuria and hematuria at any level.

METHODS

We therefore conducted an exon sequencing (WES) analysis for 11 AS, aHUS and thrombotic thrombocytopenic purpura-causing genes in an international cohort of 371 patients from 362 families presenting with both proteinuria and hematuria before age 25 years. In parallel, we conducted either WES or high-throughput exon sequencing for 23 SRNS-causing genes in all patients.

RESULTS

We detected pathogenic mutations in 18 of the 34 genes analyzed, leading to a molecular diagnosis in 14.1% of families (51 of 362). Disease-causing mutations were detected in 3 AS-causing genes (4.7%), 3 aHUS-causing genes (1.4%) and 12 NS-causing genes (8.0%). We observed a much higher mutation detection rate for monogenic forms of CKD in consanguineous families (35.7% versus 10.1%).

CONCLUSIONS

We present the first estimate of relative frequency of inherited AS, aHUS and NS in a typical pediatric cohort with proteinuria and hematuria. Important therapeutic and preventative measures may result from mutational analysis in individuals with proteinuria and hematuria.

Congenital Nephrotic Syndrome in India in the Current Era: A Multicenter Case Series

BACKGROUND

There is a paucity of information on epidemiology, diagnosis, and treatment outcomes of congenital nephrotic syndrome (CNS) in developing countries.

METHODS

Retrospective (2012-2017) review of case records undertaken across 12 Indian pediatric nephrology centers.

RESULTS

Sixty-five children (58% male, median birth weight 2.4 kg [interquartile range (IQR) 2.1-2.86]) were identified with CNS. Nearly half (45%) were preterm with previous history of fetal loss/sibling death in 22% and history of consanguinity in a third. No infective etiology was confirmed. Genetic reports available for 15 (23%) children identified causal mutations in 10 (8 in NPHS1 [1 novel variant], 1 in WT 1 [novel variant], and 1 in PLCE-1 gene). In addition, 1 child was clinically diagnosed as Galloway Mowat syndrome. Next-generation sequencing showed 80% yield and Sanger sequencing 20%. Albumin infusion and angiotensin-converting enzyme inhibitors were used initially in around two-third of cohort, while only 12% of children received indomethacin. Totally, 22 (34%) children were lost to follow-up after initial visit, and among the rest median follow-up was 69 days (IQR 20-180) with 18 (42%) deaths. Eight children showed partial response (including 2 with NPHS1 compound mutation), 1 complete response, and all of them were alive at last follow-up in contrast to 53% mortality among nonresponders, p = 0.004.

CONCLUSION

This largest reported series on CNS from India revealed suboptimal management with poor outcome as well as low number of CNS being subjected to genetic evaluation.

RHEB gene therapy maintains the chondrogenic characteristics and protects cartilage tissue from degenerative damage during experimental murine osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is characterized by cartilage degeneration resulting from hypertrophic changes in chondrocytes caused by altered gene expression. The involvement of Ras homolog enriched in brain (RHEB) in OA regulation is unclear.

METHODS

Human knee articular cartilage samples - were analyzed for structural and biological changes by histology, immunohistochemistry, real time PCR and western blotting. OA-mouse model developed by surgical destabilization of the medial meniscus (DMM) were treated with adenovirus harboring Rheb gene to analyze onset and progression of OA. Histological scoring, immunohistochemistry, and TUNEL assay was performed to assess cartilage damage across the entire joint.

RESULTS

Human and mouse OA cartilage is degenerated and has markedly reduced levels of RHEB. Human OA-degenerated chondrocytes (DC) exhibited a fibroblastic phenotype and 80 % of degenerative cartilage were senescent, with higher levels of reactive oxygen species (ROS). Gene expression analysis of DC revealed almost no COL2A1 expression and reduced SOX9 and RHEB expression. Transient transfection of RHEB rescued the DC phenotype and reduced senescence and ROS levels markedly. RHEB overexpression also increased COL2A1 and SOX9 expression. In an OA-mouse model, the Rheb protein level decreased as the severity of OA increased. Ectopic expression of Rheb using adenovirus in mouse-OA cartilage suppressed surgically-induced OA pathogenesis accompanied by modulation of Adamts5, Mmp 13, Col 10, and Col2a1 expression. Rheb induction significantly reduced apoptosis in OA-cartilage.

CONCLUSION

RHEB plays an important role in maintaining the chondrogenic characteristics of chondrocytes, and has potential in preventing progression of OA in the destabilize the medial meniscus (DMM) mouse model of OA.

Identification of a novel alternatively spliced isoform of antithrombin containing an additional RCL-like loop

Antithrombin (AT3) is one of the most important inhibitors of blood coagulation proteases that belong to the serpin family of protease inhibitors. In this study, a novel alternatively spliced isoform of AT3 was identified, both at transcript and protein level. This novel transcript contains an additional region in the continuation of exon 3b that was included in the transcript due to use of an alternate 5' splice site. The existence of the novel transcript was confirmed in human brain and liver through RT-PCR. An analysis of the complete transcript indicated that the native reactive centre loop (RCL) of AT3 is maintained; however the novel amino acid sequence projects out as an additional loop as evident from MD simulation studies. A unique amino acid sequence present in the novel isoform was used for the development of polyclonal antibody. The expression of novel isoform was confirmed in human brain and liver tissue using Western blot analysis. Interestingly an alignment of RCL like domain with other inhibitory serpins showed significant similarity with the neuroserpin RCL. To the best of our knowledge, this is the first evidence of alternatively spliced AT3 sequence containing an additional loop and could have physiological relevance.

Disruption of MAGI2-RapGEF2-Rap1 signaling contributes to podocyte dysfunction in congenital nephrotic syndrome caused by mutations in MAGI2

The essential role of membrane associated guanylate kinase 2 (MAGI2) in podocytes is indicated by the phenotypes of severe glomerulosclerosis of both MAGI2 knockout mice and in patients with congenital nephrotic syndrome (CNS) caused by mutations in MAGI2. Here, we show that MAGI2 forms a complex with the Rap1 guanine nucleotide exchange factor, RapGEF2, and that this complex is lost when expressing MAGI2 CNS variants. Co-expression of RapGEF2 with wild-type MAGI2, but not MAGI2 CNS variants, enhanced activation of the small GTPase Rap1, a central signaling node in podocytes. In mice, podocyte-specific RapGEF2 deletion resulted in spontaneous glomerulosclerosis, with qualitative glomerular features comparable to MAGI2 knockout mice. Knockdown of RapGEF2 or MAGI2 in human podocytes caused similar reductions in levels of Rap1 activation and Rap1-mediated downstream signaling. Furthermore, human podocytes expressing MAGI2 CNS variants show severe abnormalities of cellular morphology and dramatic loss of actin cytoskeletal organization, features completely rescued by pharmacological activation of Rap1 via a non-MAGI2 dependent upstream pathway. Finally, immunostaining of kidney sections from patients with congenital nephrotic syndrome and MAGI2 mutations showed reduced podocyte Rap1-mediated signaling. Thus, MAGI2-RapGEF2-Rap1 signaling is essential for normal podocyte function. Hence, disruption of this pathway is an important cause of the renal phenotype induced by MAGI2 CNS mutations.

Corticosteroid treatment exacerbates nephrotic syndrome in a zebrafish model of magi2a knockout

Recently, recessive mutations of MAGI2 were identified as a cause of steroid-resistant nephrotic syndrome (SRNS) in humans and mice. To further delineate the pathogenesis of MAGI2 loss of function, we generated stable knockout lines for the two zebrafish orthologues magi2a and magi2b by CRISPR/Cas9. We also developed a novel assay for the direct detection of proteinuria in zebrafish independent of transgenic background. Whereas knockout of magi2b did not yield a nephrotic syndrome phenotype, magi2a^-/- larvae developed ascites, periorbital edema, and proteinuria, as indicated by increased excretion of low molecular weight protein. Electron microscopy demonstrated extensive podocyte foot process effacement. As in human SRNS, we observed genotype/phenotype correlation, with edema onset occurring earlier in zebrafish with truncating alleles (5-6 days post fertilization) versus hypomorphic alleles (19-20 days post fertilization). Paradoxically, corticosteroid treatment exacerbated the phenotype, with earlier onset of edema. In contrast, treatment with cyclosporine A or tacrolimus had no significant effect. Although RhoA signaling has been implicated as a downstream mediator of MAGI2 activity, targeting of the RhoA pathway did not modify the nephrotic syndrome phenotype. In the first CRISPR/Cas9 zebrafish knockout model of SRNS, we found that corticosteroids may have a paradoxical effect in the setting of specific genetic mutations.

Whole-Exome Sequencing Enables a Precision Medicine Approach for Kidney Transplant Recipients

BACKGROUND

Whole-exome sequencing (WES) finds a CKD-related mutation in approximately 20% of patients presenting with CKD before 25 years of age. Although provision of a molecular diagnosis could have important implications for clinical management, evidence is lacking on the diagnostic yield and clinical utility of WES for pediatric renal transplant recipients.

METHODS

To determine the diagnostic yield of WES in pediatric kidney transplant recipients, we recruited 104 patients who had received a transplant at Boston Children's Hospital from 2007 through 2017, performed WES, and analyzed results for likely deleterious variants in approximately 400 genes known to cause CKD.

RESULTS

By WES, we identified a genetic cause of CKD in 34 out of 104 (32.7%) transplant recipients. The likelihood of detecting a molecular genetic diagnosis was highest for patients with urinary stone disease (three out of three individuals), followed by renal cystic ciliopathies (seven out of nine individuals), steroid-resistant nephrotic syndrome (nine out of 21 individuals), congenital anomalies of the kidney and urinary tract (ten out of 55 individuals), and chronic glomerulonephritis (one out of seven individuals). WES also yielded a molecular diagnosis for four out of nine individuals with ESRD of unknown etiology. The WES-related molecular genetic diagnosis had implications for clinical care for five patients.

CONCLUSIONS

Nearly one third of pediatric renal transplant recipients had a genetic cause of their kidney disease identified by WES. Knowledge of this genetic information can help guide management of both transplant patients and potential living related donors.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Effects of carrageenan induced synovitis on joint damage and pain in a rat model of knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) is associated with ongoing pain and joint damage that can be punctuated by acute flares of pain and inflammation. Synovitis in normal knees might resolve without long-term detriment to joint function. We hypothesised that osteoarthritis is associated with impaired resilience to inflammatory flares.

DESIGN

We induced synovitis by injecting carrageenan into rat knees with or without meniscal transection (MNX)-induced OA, and measured synovitis, weightbearing asymmetry (pain behaviour), and joint damage up to 35 days after OA induction (23 days after carrageenan-injection).

RESULTS

Carrageenan injection induced weightbearing asymmetry for 1 week, transient increase in knee diameter for 2 days, and a sustained increase in synovial macrophages, endothelial cell proliferation and vascular density compared with naive vehicle-injected controls. MNX surgery induced weightbearing asymmetry and histological evidence of OA. Carrageenan-injection in MNX-operated knees was followed for 2 days by increased weightbearing asymmetry compared either to MNX+vehicle or to sham+carrageenan groups. OA structural damage and synovitis at day 35 were greater in MNX+carrageenan compared to MNX+vehicle and sham+carrageenan groups. Carrageenan injection did not induce OA in Sham-operated knees.

CONCLUSION

Intra-articular injection of the pro-inflammatory compound carrageenan in OA and sham-operated control knees induced a short term increase in joint pain. Even though pain flares resolved in both groups and damage was not induced in sham-operated knees, carrageen injection exacerbated long-term joint damage in OA knees. OA knees display less resilience to inflammatory episodes. Preventing inflammatory flares may be particularly important in preventing symptoms and long term joint damage in OA.

Mutations in multiple components of the nuclear pore complex cause nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) almost invariably progresses to end-stage renal disease. Although more than 50 monogenic causes of SRNS have been described, a large proportion of SRNS remains unexplained. Recently, it was discovered that mutations of NUP93 and NUP205, encoding 2 proteins of the inner ring subunit of the nuclear pore complex (NPC), cause SRNS. Here, we describe mutations in genes encoding 4 components of the outer rings of the NPC, namely NUP107, NUP85, NUP133, and NUP160, in 13 families with SRNS. Using coimmunoprecipitation experiments, we showed that certain pathogenic alleles weakened the interaction between neighboring NPC subunits. We demonstrated that morpholino knockdown of nup107, nup85, or nup133 in Xenopus disrupted glomerulogenesis. Re-expression of WT mRNA, but not of mRNA reflecting mutations from SRNS patients, mitigated this phenotype. We furthermore found that CRISPR/Cas9 knockout of NUP107, NUP85, or NUP133 in podocytes activated Cdc42, an important effector of SRNS pathogenesis. CRISPR/Cas9 knockout of nup107 or nup85 in zebrafish caused developmental anomalies and early lethality. In contrast, an in-frame mutation of nup107 did not affect survival, thus mimicking the allelic effects seen in humans. In conclusion, we discovered here that mutations in 4 genes encoding components of the outer ring subunits of the NPC cause SRNS and thereby provide further evidence that specific hypomorphic mutations in these essential genes cause a distinct, organ-specific phenotype.

Whole-Exome Sequencing Identifies Causative Mutations in Families with Congenital Anomalies of the Kidney and Urinary Tract

BACKGROUND

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most prevalent cause of kidney disease in the first three decades of life. Previous gene panel studies showed monogenic causation in up to 12% of patients with CAKUT.

METHODS

We applied whole-exome sequencing to analyze the genotypes of individuals from 232 families with CAKUT, evaluating for mutations in single genes known to cause human CAKUT and genes known to cause CAKUT in mice. In consanguineous or multiplex families, we additionally performed a search for novel monogenic causes of CAKUT.

RESULTS

In 29 families (13%), we detected a causative mutation in a known gene for isolated or syndromic CAKUT that sufficiently explained the patient's CAKUT phenotype. In three families (1%), we detected a mutation in a gene reported to cause a phenocopy of CAKUT. In 15 of 155 families with isolated CAKUT, we detected deleterious mutations in syndromic CAKUT genes. Our additional search for novel monogenic causes of CAKUT in consanguineous and multiplex families revealed a potential single, novel monogenic CAKUT gene in 19 of 232 families (8%).

CONCLUSIONS

We identified monogenic mutations in a known human CAKUT gene or CAKUT phenocopy gene as the cause of disease in 14% of the CAKUT families in this study. Whole-exome sequencing provides an etiologic diagnosis in a high fraction of patients with CAKUT and will provide a new basis for the mechanistic understanding of CAKUT.

Mutations in WDR4 as a new cause of Galloway-Mowat syndrome

Galloway-Mowat syndrome (GAMOS) is a phenotypically heterogeneous disorder characterized by neurodevelopmental defects combined with renal-glomerular disease, manifesting with proteinuria. To identify additional monogenic disease causes, we here performed whole exome sequencing (WES), linkage analysis, and homozygosity mapping in three affected siblings of an Indian family with GAMOS. Applying established criteria for variant filtering, we identify a novel homozygous splice site mutation in the gene WDR4 as the likely disease-causing mutation in this family. In line with previous reports, we observe growth deficiency, microcephaly, developmental delay, and intellectual disability as phenotypic features resulting from WDR4 mutations. However, the newly identified allele additionally gives rise to proteinuria and nephrotic syndrome, a phenotype that was never reported in patients with WDR4 mutations. Our data thus expand the phenotypic spectrum of WDR4 mutations by demonstrating that, depending on the specific mutated allele, a renal phenotype may be present. This finding suggests that GAMOS may occupy a phenotypic spectrum with other microcephalic diseases. Furthermore, WDR4 is an additional example of a gene that encodes a tRNA modifying enzyme and gives rise to GAMOS, if mutated. Our findings thereby support the recent observation that, like neurons, podocytes of the renal glomerulus are particularly vulnerable to cellular defects resulting from altered tRNA modifications.

GAPVD1 and ANKFY1 Mutations Implicate RAB5 Regulation in Nephrotic Syndrome

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of CKD. The discovery of monogenic causes of SRNS has revealed specific pathogenetic pathways, but these monogenic causes do not explain all cases of SRNS.

METHODS

To identify novel monogenic causes of SRNS, we screened 665 patients by whole-exome sequencing. We then evaluated the in vitro functional significance of two genes and the mutations therein that we discovered through this sequencing and conducted complementary studies in podocyte-like Drosophila nephrocytes.

RESULTS

We identified conserved, homozygous missense mutations of GAPVD1 in two families with early-onset NS and a homozygous missense mutation of ANKFY1 in two siblings with SRNS. GAPVD1 and ANKFY1 interact with the endosomal regulator RAB5. Coimmunoprecipitation assays indicated interaction between GAPVD1 and ANKFY1 proteins, which also colocalized when expressed in HEK293T cells. Silencing either protein diminished the podocyte migration rate. Compared with wild-type GAPVD1 and ANKFY1, the mutated proteins produced upon ectopic expression of GAPVD1 or ANKFY1 bearing the patient-derived mutations exhibited altered binding affinity for active RAB5 and reduced ability to rescue the knockout-induced defect in podocyte migration. Coimmunoprecipitation assays further demonstrated a physical interaction between nephrin and GAPVD1, and immunofluorescence revealed partial colocalization of these proteins in rat glomeruli. The patient-derived GAPVD1 mutations reduced nephrin-GAPVD1 binding affinity. In Drosophila, silencing Gapvd1 impaired endocytosis and caused mistrafficking of the nephrin ortholog.

CONCLUSIONS

Mutations in GAPVD1 and probably in ANKFY1 are novel monogenic causes of NS. The discovery of these genes implicates RAB5 regulation in the pathogenesis of human NS.

Analysis of 24 genes reveals a monogenic cause in 11.1% of cases with steroid-resistant nephrotic syndrome at a single center

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS) is the second most frequent cause of end-stage renal disease (ESRD) among patients manifesting at under 25 years of age. We performed mutation analysis using a high-throughput PCR-based microfluidic technology in 24 single-gene causes of SRNS in a cohort of 72 families, who presented with SRNS before the age of 25 years.

METHODS

Within an 18-month interval, we obtained DNA samples, pedigree information, and clinical information from 77 consecutive children with SRNS from 72 different families seen at Boston Children's Hospital (BCH). Mutation analysis was completed by combining high-throughput multiplex PCR with next-generation sequencing. We analyzed the sequences of 18 recessive and 6 dominant genes of SRNS in all 72 families for disease-causing variants.

RESULTS

We identified the disease-causing mutation in 8 out of 72 (11.1%) families. Mutations were detected in the six genes: NPHS1 (2 out of 72), WT1 (2 out of 72), NPHS2, MYO1E, TRPC6, and INF2. Median age at onset was 4.1 years in patients without a mutation (range 0.5-18.8), and 3.2 years in those in whom the causative mutation was detected (range 0.1-14.3). Mutations in dominant genes presented with a median onset of 4.5 years (range 3.2-14.3). Mutations in recessive genes presented with a median onset of 0.5 years (range 0.1-3.2).

CONCLUSION

Our molecular genetic diagnostic study identified underlying monogenic causes of steroid-resistant nephrotic syndrome in ~11% of patients with SRNS using a cost-effective technique. We delineated some of the therapeutic, diagnostic, and prognostic implications. Our study confirms that genetic testing is indicated in pediatric patients with SRNS.

Whole Exome Sequencing of Patients with Steroid-Resistant Nephrotic Syndrome

BACKGROUND AND OBJECTIVES

Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes.

RESULTS

In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome.

CONCLUSIONS

Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome.

Mutations in COQ8B (ADCK4) found in patients with steroid-resistant nephrotic syndrome alter COQ8B function

Mutations in COQ8B cause steroid-resistant nephrotic syndrome with variable neurological involvement. In yeast, COQ8 encodes a protein required for coenzyme Q (CoQ) biosynthesis, whose precise role is not clear. Humans harbor two paralog genes: COQ8A and COQ8B (previously termed ADCK3 and ADCK4). We have found that COQ8B is a mitochondrial matrix protein peripherally associated with the inner membrane. COQ8B can complement a ΔCOQ8 yeast strain when its mitochondrial targeting sequence (MTS) is replaced by a yeast MTS. This model was employed to validate COQ8B mutations, and to establish genotype-phenotype correlations. All mutations affected respiratory growth, but there was no correlation between mutation type and the severity of the phenotype. In fact, contrary to the case of COQ2, where residual CoQ biosynthesis correlates with clinical severity, patients harboring hypomorphic COQ8B alleles did not display a different phenotype compared with those with null mutations. These data also suggest that the system is redundant, and that other proteins (probably COQ8A) may partially compensate for the absence of COQ8B. Finally, a COQ8B polymorphism, present in 50% of the European population (NM_024876.3:c.521A > G, p.His174Arg), affects stability of the protein and could represent a risk factor for secondary CoQ deficiencies or for other complex traits.

Advillin acts upstream of phospholipase C ϵ1 in steroid-resistant nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of chronic kidney disease. Here, we identified recessive mutations in the gene encoding the actin-binding protein advillin (AVIL) in 3 unrelated families with SRNS. While all AVIL mutations resulted in a marked loss of its actin-bundling ability, truncation of AVIL also disrupted colocalization with F-actin, thereby leading to impaired actin binding and severing. Additionally, AVIL colocalized and interacted with the phospholipase enzyme PLCE1 and with the ARP2/3 actin-modulating complex. Knockdown of AVIL in human podocytes reduced actin stress fibers at the cell periphery, prevented recruitment of PLCE1 to the ARP3-rich lamellipodia, blocked EGF-induced generation of diacylglycerol (DAG) by PLCE1, and attenuated the podocyte migration rate (PMR). These effects were reversed by overexpression of WT AVIL but not by overexpression of any of the 3 patient-derived AVIL mutants. The PMR was increased by overexpression of WT Avil or PLCE1, or by EGF stimulation; however, this increased PMR was ameliorated by inhibition of the ARP2/3 complex, indicating that ARP-dependent lamellipodia formation occurs downstream of AVIL and PLCE1 function. Together, these results delineate a comprehensive pathogenic axis of SRNS that integrates loss of AVIL function with alterations in the action of PLCE1, an established SRNS protein.

Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

Spontaneous imbibition in parallel layers of packed beads

The imbibition of a wetting fluid in a homogeneous porous medium follows the diffusion-like behavior described by Washburn. The impregnation of a two-layered porous medium by a wetting fluid due to capillary action has been previously described to have two fronts, one saturating the medium and the other, leading front, which propagates in finer pores. Here, we report that the leading front is governed by the porous structure and is not always in the finer pores. Based on the experiments in a layered porous medium of permeability varying perpendicular to the direction of flow, we show that the permeability of the adjacent layers plays a significant role in determining the leading front amongst the layers. We have also developed an analytical model which describes the flow dynamics in the layered porous medium. The model predicts the condition for which the leading front in the larger pores is followed by the front in the finer pores. This condition is also verified experimentally.