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Background The safety of coronavirus disease 2019 (COVID-19) vaccines during pregnancy is a particular concern. Here, we addressed the neonatal outcomes after maternal vaccination of COVID-19 during pregnancy. Methods We systematically searched PubMed, EMBASE, and the WHO COVID-19 Database for studies on neonatal outcomes after maternal COVID-19 vaccination from inception to 3 July 2022. Main neonatal outcomes were related to preterm, small for gestation (SGA), NICU admission, low Apgar score at 5 min ( Results A total of 15 studies were included. We found that maternal vaccination during pregnancy was related to the reduction rates of Preterm, SGA, Low Apgar score at 5 min ( Conclusions COVID-19 vaccination in pregnant women does not raise significant adverse effects on neonatal outcomes and is related to a protective effect on some neonatal outcomes. Impact Present study has addressed the neonatal outcomes after maternal vaccination of COVID-19 during pregnancy. COVID-19 vaccination in pregnant women does not raise significant adverse effects on neonatal outcomes and is related to a protective effect on some neonatal outcomes. The present study could encourage pregnant women to be vaccinated against COVID-19.

Background Preterm birth has been identified as a risk factor for development of long-term chronic kidney disease. Podocyte loss has been reported to contribute to this process in preterm animal models. However, details about podocyte loss in preterm infants and related perinatal risk factors have not been well clarified. Methods Forty full-term infants and 106 preterm infants were enrolled. Urine samples were collected from full-term infants within 4–7 days of birth and preterm infants at 37–40 weeks of corrected age. Levels of urine podocin mRNA, urine protein (UP), and urine microalbumin (UMA) were measured, and the relationship between these markers was evaluated. Clinical information in these infants was collected, and potential correlates that may lead to increased podocyte loss during the perinatal period were identified using linear regression analysis. Results Urine podocyte loss indicated by the urine podocin mRNA to creatinine ratio (UpodCR) was higher in preterm infants than in full-term infants. UpodCR was correlated with the levels of UP and UMA. Multiple linear regression analysis also showed that lower gestational age (GA) at birth and small for gestational age (SGA) were high risk factors for urine podocyte loss. Conclusions Increasing urine podocyte loss was identified in preterm infants. Moreover, perinatal factors were associated with podocyte loss and may be a potential direction for comprehensive research and intervention in this field. Graphical Abstract A higher resolution version of the Graphical abstract is available as Supplementary information

Podocyte abnormalities are common mechanism driving the progression of glomerular diseases, which account for most chronic kidney diseases (CKDs). However, the role of podocyte in the mechanism of high-risk long-term CKD caused by prematurity has not been well clarified. In present study, urine samples of 86 preterm infants and 32 full-term infants were collected, and podocyte-specific podocin mRNA levels in urine pellet were applied to indicate urinary podocyte mRNA excretion. In addition, in a preterm animal rat model, preterm rats were identified by delivery 2 days early. From the age of 3 weeks–12 months, urine samples were collected to examine podocyte mRNA excretion by measuring podocyte-specific podocin mRNA levels. Kidney samples at the age of 3 weeks, 2 months, and 12 months were collected from 8, 5 and 6 preterm rats and 9, 6 and 8 full-term rats, respectively, to examine podocyte density and podocyte area by measuring the podocyte specific nuclear marker WT-1 and the podocyte specific marker synaptopodin. As results, a more than threefold increase of urinary podocyte-specific podocin mRNA excretion rate was found in preterm infants compared with full-term infants. In addition, there was negative correlation between gestational age at birth and urinary podocin mRNA excretion. In preterm rats, a reduction in the total number of differentiated podocytes in glomeruli and an increased podocyte podocin mRNA excretion rate in urine were detected at the end of kidney differentiation. Moreover, long-term follow-up data in preterm rats showed there was an increased the risk of renal disease indicated by persistent podocyte mRNA loss, proteinuria, and enlarged glomeruli. In conclusion, increasing podocyte mRNA excretion in urine and podocyte loss in kidney led by prematurity drive the progression of long-term abnormal kidney function and could potentially explain the high risk of long-term CKD in preterm infants.

Recent single-cell RNA sequencing (scRNA-seq) analyses have offered much insight into the gene expression profiles in early-stage kidney development. However, comprehensive gene expression profiles from mid- and late-stage kidney development are lacking. In the present study, by using the scRNA-seq technique, we analyzed 54,704 rat kidney cells from just after birth to adulthood (six time points: postnatal days 0, 2, 5, 10, 20, and 56) including the mid and late stages of kidney development. Twenty-five original clusters and 13 different cell types were identified during these stages. Gene expression in these 13 cell types was mapped, and single cell atlas of the rat kidney from birth to maturity (http://youngbearlab.com) was built to enable users to search for a gene of interest and to evaluate its expression in different cells. The variation trend of six major types of kidney cells—intercalated cells of the collecting duct (CD-ICs), principal cells of the collecting duct (CD-PCs), cells of the distal convoluted tubules (DCTs), cells of the loop of Henle (LOH), podocytes (PDs), and cells of the proximal tubules (PTs)—during six postnatal time points was demonstrated. The trajectory of rat kidney development and the order of induction of the six major types of kidney cells from just after birth to maturity were determined. In addition, features of the dynamically changing genes as well as transcription factors during postnatal rat kidney development were identified. The present study provides a resource for achieving a deep understanding of the molecular basis of and regulatory events in the mid and late stages of kidney development.

Background Alport syndrome is a rare hereditary kidney disease manifested with progressive renal failure. Considerable variation exists in terms of disease progression among patients with Alport syndrome. Identification of patients at high risk of rapid progression remains an unmet need. Urinary epidermal growth factor (uEGF) has been shown to be independently associated with risk of progression to adverse kidney outcome in multiple independent adult chronic kidney disease (CKD) cohorts. In this study, we aim to assess if uEGF is associated with kidney impairment and its prognostic value for children with Alport syndrome. Methods One hundred and seventeen pediatric patients with Alport syndrome and 146 healthy children (3–18 years old) were included in this study. uEGF was measured in duplicates in baseline urine samples using ELISA (R&D) and concentration was normalized by urine creatinine (uEGF/Cr). In patients with longitudinal follow-up data (n = 38), progression was defined as deteriorated kidney function (CKD stage increase) during follow-up period (follow-up length is about 31 months in average). The association of baseline uEGF/Cr level with estimated glomerular filtration rate (eGFR) slope and Alport syndrome patients’ progression to a more advanced CKD stage during the follow-up period was used to evaluate the prognostic value of the marker. Results We found that uEGF/creatinine (uEGF/Cr) decreases with age in pediatric patients with Alport syndrome with a significantly faster rate than in healthy children of the same age group. uEGF/Cr is significantly correlated with eGFR (r = 0.75, p

The aim of this study was to elucidate whether genetic screening test results of pediatric patients with steroid-resistant nephrotic syndrome (SRNS) vary with ethnicity.Using high-throughput DNA sequencing, 28 nephrotic syndrome-related genes were analyzed in 110 chil-dren affected by SRNS and 10 children with isolated proteinuria enrolled by 5 centers in China (67 boys, 53 girls). Their age at disease onset ranged from 1 day to 208 months (median, 48.8 months). Patients were excluded if their age at onset of disease was over 18 years or if they were diagnosed as having Alport syndrome.A genetic etiology was identified in 28.3% of our cohort and the likelihood of establishing a genetic diagnosis decreased as the age at onset of nephrotic syndrome increased. The most common mutated genes were ADCK4 (6.67%), NPHS1 (5.83%), WT1 (5.83%), and NPHS2 (3.33%), and the difference in the frequencies of ADCK4 and NPHS2 mutations between this study and a study on monogenic causes of SRNS in the largest international cohort of 1,783 different families was significant. A case of congenital nephrotic syndrome was attributed to a homozygous missense mutation in ADCK4, and a de novo missense mutation in TRPC6 was detected in a case of infantile nephrotic syndrome.Our results showed that, in the first and the largest multicenter cohort of Chinese pediatric SRNS reported to date, ADCK4 is the most common causative gene, whereas there is a low prevalence of NPHS2 mutations. Our data indicated that the genetic testing results for pediatric SRNS patients vary with different ethnicities, and this information will help to improve management of the disease in clinical practice.

Podocyte depletion is a common mechanism driving progression in glomerular diseases. Alport Syndrome glomerulopathy, caused by defective α3α4α5 (IV) collagen heterotrimer production by podocytes, is associated with an increased rate of podocyte detachment detectable in urine and reduced glomerular podocyte number suggesting that defective podocyte adherence to the glomerular basement membrane might play a role in driving progression. Here a genetically phenotyped Alport Syndrome cohort of 95 individuals [urine study] and 41 archived biopsies [biopsy study] were used to test this hypothesis. Podocyte detachment rate (measured by podocin mRNA in urine pellets expressed either per creatinine or 24-hour excretion) was significantly increased 11-fold above control, and prior to a detectably increased proteinuria or microalbuminuria. In parallel, Alport Syndrome glomeruli lose an average 26 podocytes per year versus control glomeruli that lose 2.3 podocytes per year, an 11-fold difference corresponding to the increased urine podocyte detachment rate. Podocyte number per glomerulus in Alport Syndrome biopsies is projected to be normal at birth (558/glomerulus) but accelerated podocyte loss was projected to cause end-stage kidney disease by about 22 years. Biopsy data from two independent cohorts showed a similar estimated glomerular podocyte loss rate comparable to the measured 11-fold increase in podocyte detachment rate. Reduction in podocyte number and density in biopsies correlated with proteinuria, glomerulosclerosis, and reduced renal function. Thus, the podocyte detachment rate appears to be increased from birth in Alport Syndrome, drives the progression process, and could potentially help predict time to end-stage kidney disease and response to treatment.

Objective: Survivin is a member of the inhibitor of apoptosis protein family, which uniquely promotes mitosis and regulates apoptosis in cancer cells. Recent studies have demonstrated that survivin also expresses in several normal adult cells. In the present study, we aimed to investigate the function of survivin in the terminally differentiated epithelial cells, podocytes. Methods: Survivin expression and location were detected by Quantitative Real-Time PCR, western blot and fluorescence confocal microscopy methods in normal and injured mouse podocytes. Cyto-protection function of survivin was also studied in cultured podocyte injured by puromycin aminonucleoside (PAN), transfected with survivin siRNA to down-regulate survivin expression, or with survivin plasmid to transiently over-express survivin. Results: In podocytes, PAN stimulated expressions of survivin and the apoptosis related molecule caspase 3. Knockdown of survivin expression by siRNA increased the activation of caspase 3, induced podocyte apoptosis and remarkable rearrangement of actin cytoskeleton. Moreover, over-expression of survivin inhibited PAN-induced podocyte apoptosis and cytoskeleton rearrangement. Conclusion: Our data provides the evidence that survivin plays an important role in protecting podocytes from apoptosis induced by PAN. The mechanism of survivin related anti-apoptosis may, at least partially, be through the activation of caspase 3.

Microsomal prostaglandin E2 synthase-1 (mPGES-1), an inducible enzyme that converts prostaglandin H2 (PGH2) to prostaglandin E2 (PGE2), plays an important role in a variety of diseases. So far, the role of mPGES-1 in idiopathic pulmonary fibrosis (IPF) remained unknown. The current study aimed to investigate the role of mPGES-1 in pulmonary fibrosis induced by bleomycin in mice. We found that mPGES-1 deficient (mPGES-1−/−) mice exhibited more severe fibrotic lesions with a decrease in PGE2 content in lungs after bleomycin treatment when compared with wild type (mPGES-1+/+) mice. The mPGES-1 expression levels and PGE2 content were also decreased in bleomycin-treated mPGES-1+/+ mice compared to saline-treated mPGES-1+/+ mice. Moreover, in both mPGES-1−/− and mPGES-1+/+ mice, bleomycin treatment reduced the expression levels of E prostanoid receptor 2 (EP2) and EP4 receptor in lungs, whereas had little effect on EP1 and EP3. In cultured human lung fibroblast cells (MRC-5), siRNA-mediated knockdown of mPGES-1 augmented transforming growth factor-β1 (TGF-β1)-induced α-smooth muscle actin (α-SMA) protein expression, and the increase was reversed by treatment of PGE2, selective EP2 agonist and focal adhesion kinase (FAK) inhibitor. In conclusion, these findings revealed mPGES-1 exerts an essential effect against pulmonary fibrogenesis via EP2-mediated signaling transduction, and activation of mPGES-1-PGE2-EP2-FAK signaling pathway may represent a new therapeutic strategy for treatment of IPF patients.

Podocytes are critical for maintaining the glomerular filtration barrier and are injured in many renal diseases, especially proteinuric kidney diseases. Recently, reports suggested that podocytes are among the renal cells that synthesize complement components that mediate glomerular diseases. Nevertheless, the profile and extent of complement component expression in podocytes remain unclear. This study examined the expression profile of complement in podocytes under physiological conditions and in abnormal podocytes induced by multiple stimuli. In total, 23/32 complement component components were detected in podocyte by conventional RT-PCR. Both primary cultured podocytes and immortalized podocytes expressed the complement factors C1q, C1r, C2, C3, C7, MASP, CFI, DAF, CD59, C4bp, CD46, Protein S, CR2, C1qR, C3aR, C5aR, and Crry (17/32), whereas C4, CFB, CFD, C5, C6, C8, C9, MBL1, and MBL2 (9/32) complement factors were not expressed. C3, Crry, and C1q-binding protein were detected by tandem mass spectrometry. Podocyte complement gene expression was affected by several factors (puromycin aminonucleoside (PAN), angiotensin II (Ang II), interleukin-6 (IL-6), and transforming growth factor-β (TGF-β)). Representative complement components were detected using fluorescence confocal microscopy. In conclusion, primary podocytes express various complement components at the mRNA and protein levels. The complement gene expressions were affected by several podocyte injury factors.

Transient receptor potential cation channel 6 (TRPC6) is a nonselective cation channel, and abnormal expression and gain of function of TRPC6 are involved in the pathogenesis of hereditary and nonhereditary forms of renal disease. Although the molecular mechanisms underlying these diseases remain poorly understood, recent investigations revealed that many signaling pathways are involved in regulating TRPC6. We aimed to examine the effect of the mammalian target of rapamycin (mTOR) complex (mTOR complex 1 [mTORC1] or mTOR complex 2 [mTORC2]) signaling pathways on TRPC6 in podocytes, which are highly terminally differentiated renal epithelial cells that are critically required for the maintenance of the glomerular filtration barrier. We applied both pharmacological inhibitors of mTOR and specific siRNAs against mTOR components to explore which mTOR signaling pathway is involved in the regulation of TRPC6 in podocytes. The podocytes were exposed to rapamycin, an inhibitor of mTORC1, and ku0063794, a dual inhibitor of mTORC1 and mTORC2. In addition, specific siRNA-mediated knockdown of the mTORC1 component raptor and the mTORC2 component rictor was employed. The TRPC6 mRNA and protein expression levels were examined via real-time quantitative PCR and Western blot, respectively. Additionally, fluorescence calcium imaging was performed to evaluate the function of TRPC6 in podocytes. Rapamycin displayed no effect on the TRPC6 mRNA or protein expression levels or TRPC6-dependent calcium influx in podocytes. However, ku0063794 down-regulated the TRPC6 mRNA and protein levels and suppressed TRPC6-dependent calcium influx in podocytes. Furthermore, knockdown of raptor did not affect TRPC6 expression or function, whereas rictor knockdown suppressed TRPC6 protein expression and TRPC6-dependent calcium influx in podocytes. These findings indicate that the mTORC2 signaling pathway regulates TRPC6 in podocytes but that the mTORC1 signaling pathway does not appear to exert an effect on TRPC6.