Novel Co-Polyamides Containing Pendant Phenyl/Pyridinyl Groups with Potential Application in Water Desalination Processes.

This study explores the development and evaluation of a novel series of aromatic co-polyamides featuring diverse pendant groups, including phenyl and pyridinyl derivatives, designed for water desalination membrane applications. These co-polyamides, synthesized with a combination of hexafluoroisopropyl, oxyether, phenyl, and amide groups, exhibited excellent solubility in polar aprotic solvents, thermal stability exceeding 350 °C, and the ability to form robust, flexible films. Membranes prepared via phase inversion demonstrated variable water permeability and NaCl rejection rates, significantly influenced by the pendant group chemistry.

Luminal flow in the connecting tubule induces afferent arteriole vasodilation.

Background: Renal autoregulatory mechanisms modulate renal blood flow. Connecting tubule glomerular feedback (CNTGF) is a vasodilator mechanism in the connecting tubule (CNT), triggered paracrinally when high sodium levels are detected via the epithelial sodium channel (ENaC). The primary activation factor of CNTGF-whether NaCl concentration, independent luminal flow, or the combined total sodium delivery-is still unclear.

Update on NKCC2 regulation in the thick ascending limb (TAL) by membrane trafficking, phosphorylation, and protein-protein interactions.

Purpose Of Review: The thick ascending limb (TAL) of loop of Henle is essential for NaCl, calcium and magnesium homeostasis, pH balance and for urine concentration. NKCC2 is the main transporter for NaCl reabsorption in the TAL and its regulation is very complex. There have been recent advancements toward understanding how NKCC2 is regulated by protein trafficking, protein-protein interaction, and phosphorylation/dephosphorylation.

The FSGS protein actinin-4 interacts with NKCC2 to regulate thick ascending limb NaCl reabsorption.

In the kidney, the thick ascending limb (TAL) of the loop of Henle plays a vital role in NaCl homeostasis and blood pressure regulation. In human and animal models of salt-sensitive hypertension, NaCl reabsorption via the apical Na/K/2Cl cotransporter (NKCC2) is abnormally increased in the TAL. We showed that NaCl reabsorption is controlled by the presence of NKCC2 at the apical surface of TALs.

KO rat: a new model of metabolic syndrome with spontaneous hypertension.

ALMS1 is a protein initially associated with Alström syndrome. This is a rare human disorder characterized by metabolic dysfunction, hypertension, obesity and hyperinsulinemia. In addition, gene was linked to hypertension status in a multipoint linkage population analysis.

Luminal Flow in the Connecting Tubule induces Afferent Arteriole Vasodilation.

Background: Renal autoregulatory mechanisms modulate renal blood flow. Connecting tubule glomerular feedback (CNTGF) is a vasodilator mechanism in the connecting tubule (CNT), triggered paracrinally when high sodium levels are detected via the epithelial sodium channel (ENaC). The primary activation factor of CNTGF-whether NaCl concentration, independent luminal flow, or the combined total sodium delivery-is still unclear.

Dissociation of Hypertension and Renal Damage After Cessation of High-Salt Diet in Dahl Rats.

Background: Every year, thousands of patients with hypertension reduce salt consumption in an effort to control their blood pressure. However, hypertension has a self-sustaining character in a significant part of the population. We hypothesized that chronic hypertension leads to irreversible renal damage that remains after removing the trigger, causing an elevation of the initial blood pressure.

Ionenes as Potential Phase Change Materials with Self-Healing Behavior.

Ionenes are poly(ionic liquids) (PILs) comprising a polymer backbone with ionic groups along the structure. Ionenes as solid-solid phase change materials are a recent research field, and some studies have demonstrated their potential in thermal dissipation into electronic devices. Eight ionenes obtained through Menshutkin reactions were synthesized and characterized.

Role of Alström syndrome 1 in the regulation of glomerular hemodynamics.

Inactivating mutations in the gene in humans cause Alström syndrome, characterized by the early onset of obesity, insulin resistance, and renal dysfunction. However, the role of ALMS1 in renal function and hemodynamics is unclear. We previously found that ALMS1 is expressed in thick ascending limbs, where it binds and decreases Na-K-2Cl cotransporter activity.

Development of Novel Phase-Change Materials Derived from Methoxy Polyethylene Glycol and Aromatic Acyl Chlorides.

In this research, novel, organic, solid-liquid phase-change materials (PCMs) derived from methoxy polyethylene glycol (MPEG) and aromatic acyl chlorides (ACs) were prepared through a condensation reaction. The MPEGs were used as phase-change functional chains with different molecular weights (350, 550, 750, 2000, and 5000 g/mol). The aromatic ACs, terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC), were employed as bulky linker cores.

Development and Characterization of Films with Propolis to Inhibit Mold Contamination in the Dairy Industry.

Due to the number of polyphenols with multiple biological activities, propolis has high potential to be used as an active agent in food protective films. Therefore, this study aimed to develop and characterize a sodium alginate film with ethanolic extract of propolis (EEP) for its potential use as protective active packaging against filamentous fungi in ripened cheese. Three different concentrations of EEP were analyzed: 0, 5 and 10% /.

A FRET sensor for the real-time detection of long chain acyl-CoAs and synthetic ABHD5 ligands.

Intracellular long-chain acyl-coenzyme As (LC-acyl-CoAs) are thought to be under tight spatial and temporal controls, yet the ability to image LC-acyl-CoAs in live cells is lacking. Here, we developed a fluorescence resonance energy transfer (FRET) sensor for LC-acyl-CoAs based on the allosterically regulated interaction between α/β hydrolase domain-containing 5 (ABHD5) and Perilipin 5. The genetically encoded sensor rapidly detects intracellular LC-acyl-CoAs generated from exogenous and endogenous fatty acids (FAs), as well as synthetic ABHD5 ligands.

Knockout of ACE-N facilitates improved cardiac function after myocardial infarction.

Angiotensin-converting enzyme (ACE) hydrolyzes -acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) into inactive fragments through its N-terminal site (ACE-N). We previously showed that Ac-SDKP mediates ACE inhibitors' cardiac effects. Whether increased bioavailability of endogenous Ac-SDKP caused by knocking out ACE-N also improves cardiac function in myocardial infarction (MI)-induced heart failure (HF) is unknown.

Aldehyde Dehydrogenase 2 Activator Augments the Beneficial Effects of Empagliflozin in Mice with Diabetes-Associated HFpEF.

To ameliorate diabetes mellitus-associated heart failure with preserved ejection fraction (HFpEF), we plan to lower diabetes-mediated oxidative stress-induced 4-hydroxy-2-nonenal (4HNE) accumulation by pharmacological agents that either decrease 4HNE generation or increase its detoxification.A cellular reactive carbonyl species (RCS), 4HNE, was significantly increased in diabetic hearts due to a diabetes-induced decrease in 4HNE detoxification by aldehyde dehydrogenase (ALDH) 2, a cardiac mitochondrial enzyme that metabolizes 4HNE. Therefore, hyperglycemia-induced 4HNE is critical for diabetes-mediated cardiotoxicity and we hypothesize that lowering 4HNE ameliorates diabetes-associated HFpEF.

Biodegradable gelatin-based films with nisin and EDTA that inhibit Escherichia coli.

In this study, we developed gelatin-based films for active packaging with the ability to inhibit E. coli. We created these novel biodegradable gelatin-based films with a nisin-EDTA mix.

Decreased tubuloglomerular feedback response in high-fat diet-induced obesity.

Obesity increases the risk of renal damage, but the mechanisms are not clear. Normally, kidneys autoregulate to keep the glomerular capillary pressure (P), renal blood flow, and glomerular filtration rate in a steady state. However, in obesity, higher P, renal blood flow, and glomerular filtration rate are noted.

Novel Polyelectrolytes Obtained by Direct Alkylation and Ion Replacement of a New Aromatic Polyamide Copolymer Bearing Pyridinyl Pendant Groups.

The following work shows, for the first time, the synthesis and characterization of a new family of polyelectrolytes, along with their preliminary assessments in terms of desalin water treatment. These materials fall into the category of aromatic co-polyamides, which are obtained by the direct condensation of monomers 4,4'-oxydianiline (ODA), isophthaloyl chloride, and 3,5-diamino--(pyridin-4-ylmethyl)benzamide (PyMDA). Thereby, the charged nature exhibited by these materials was achieved through the quaternization of PyMDA moieties using linear iodoalkanes of different lengths (CI with = 1, 2, 4, and 6).

High SARS-CoV-2 Viral Load in Urine Sediment Correlates with Acute Kidney Injury and Poor COVID-19 Outcome.

Background: AKI is a complication of coronavirus disease 2019 (COVID-19) that is associated with high mortality. Despite documented kidney tropism of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there are no consistent reports of viral detection in urine or correlation with AKI or COVID-19 severity. Here, we hypothesize that quantification of the viral load of SARS-CoV-2 in urine sediment from patients with COVID-19 correlates with occurrence of AKI and mortality.

The deleterious role of the prostaglandin E EP receptor in angiotensin II hypertension.

Angiotensin II (ANG II) plays a key role in regulating blood pressure and inflammation. Prostaglandin E (PGE) signals through four different G protein-coupled receptors, eliciting a variety of effects. We reported that activation of the EP receptor reduces cardiac contractility.

Molecular regulation of NKCC2 in blood pressure control and hypertension.

Purpose Of Review: The apical Na/K/2Cl cotransporter (NKCC2) mediates NaCl reabsorption by the thick ascending limb, contributing to maintenance of blood pressure (BP). Despite effective NKCC2 inhibition by loop diuretics, these agents are not viable for long-term management of BP due to side effects. Novel molecular mechanisms that control NKCC2 activity reveal an increasingly complex picture with interacting layers of NKCC2 regulation.

Superoxide increases surface NKCC2 in the rat thick ascending limbs via PKC.

The apical Na-K-2Cl cotransporter (NKCC2) mediates NaCl reabsorption by the thick ascending limb (TAL). The free radical superoxide ( ) stimulates TAL NaCl absorption by enhancing NKCC2 activity. In contrast, nitric oxide (NO) scavenges and inhibits NKCC2.

Fructose acutely stimulates NKCC2 activity in rat thick ascending limbs by increasing surface NKCC2 expression.

The thick ascending limb (TAL) reabsorbs 25% of the filtered NaCl through the Na-K-2Cl cotransporter (NKCC2). NKCC2 activity is directly related to surface NKCC2 expression and phosphorylation. Higher NaCl reabsorption by TALs is linked to salt-sensitive hypertension, which is linked to consumption of fructose in the diet.

Role of Alström syndrome 1 in the regulation of blood pressure and renal function.

Elevated blood pressure (BP) and renal dysfunction are complex traits representing major global health problems. Single nucleotide polymorphisms identified by genome-wide association studies have identified the Alström syndrome 1 (ALMS1) gene locus to render susceptibility for renal dysfunction, hypertension, and chronic kidney disease (CKD). Mutations in the ALMS1 gene in humans causes Alström syndrome, characterized by progressive metabolic alterations including hypertension and CKD.

Urinary concentrating defect in mice lacking Epac1 or Epac2.

cAMP is a universal second messenger regulating a plethora of processes in the kidney. Two downstream effectors of cAMP are PKA and exchange protein directly activated by cAMP (Epac), which, unlike PKA, is often linked to elevation of [Ca]. While both Epac isoforms (Epac1 and Epac2) are expressed along the nephron, their relevance in the kidney remains obscure.

Single-molecule labeling for studying trafficking of renal transporters.

The ability to detect and track single molecules presents the advantage of visualizing the complex behavior of transmembrane proteins with a time and space resolution that would otherwise be lost with traditional labeling and biochemical techniques. Development of new imaging probes has provided a robust method to study their trafficking and surface dynamics. This mini-review focuses on the current technology available for single-molecule labeling of transmembrane proteins, their advantages, and limitations.