Adenoviral Transfer of Human Aquaporin-8 Gene to Mouse Liver Improves Ammonia-Derived Ureagenesis.

We previously reported that, in cultured hepatocytes, mitochondrial aquaporin-8 (AQP8) channels facilitate the conversion of ammonia to urea and that the expression of human AQP8 (hAQP8) enhances ammonia-derived ureagenesis. In this study, we evaluated whether hepatic gene transfer of hAQP8 improves detoxification of ammonia to urea in normal mice as well as in mice with impaired hepatocyte ammonia metabolism. A recombinant adenoviral (Ad) vector encoding hAQP8, AdhAQP8, or a control Ad vector was administered via retrograde infusion into the bile duct of the mice. Hepatocyte mitochondrial expression of hAQP8 was confirmed using confocal immunofluorescence and immunoblotting. The normal hAQP8-transduced mice showed decreased plasma ammonia and increased liver urea. Enhanced ureagenesis was confirmed via the NMR studies assessing the synthesis of 15N-labeled urea from 15N-labeled ammonia. In separate experiments, we made use of the model hepatotoxic agent, thioacetamide, to induce defective hepatic metabolism of ammonia in mice. The adenovirus-mediated mitochondrial expression of hAQP8 was able to restore normal ammonemia and ureagenesis in the liver of the mice. Our data suggest that hAQP8 gene transfer to mouse liver improves detoxification of ammonia to urea. This finding could help better understand and treat disorders with defective hepatic ammonia metabolism.

Enhanced ammonia detoxification to urea in hepatocytes transduced with human aquaporin-8 gene.

Hepatic ammonia detoxification to urea is critical for the prevention of hyperammonemia and neurological damage. Hepatocyte mitochondrial aquaporin-8 (AQP8) channels have been involved in ammonia-derived ureagenesis. Herein, we studied whether the adenoviral gene transfer of human AQP8 (hAQP8) to hepatocyte mitochondria enhances ammonia conversion to urea. Using primary cultured rat hepatocytes, we first confirmed the mitochondrial expression of hAQP8 and then, using unlabeled or 15 N-labeled ammonia, we demonstrated that the urea synthesis was significantly enhanced in hAQP8-transduced hepatocytes. Studies using isolated hAQP8-expressing mitochondria also showed an increased ammonia metabolism. hAQP8 transduction was able to recover the impaired ammonia-derived ureagenesis in hepatotoxin-treated hepatocytes. Our data suggest that mitochondrially-expressed hAQP8 enhances and improves hepatocyte ammonia conversion to urea, a finding with potential therapeutic implications for liver disease with impaired ammonia detoxification.

Preocupaciones del profesorado sobre la inclusión de alumnos con discapacidad en aulas ordinárias / Preocupações do professor sobre a inclusão de alunos com deficiência nas salas de aula de educação regular / Teachers' concerns about the inclusion of students with disabilities in regular education classrooms

Este estudio tiene como objetivo principal conocer las preocupaciones de los profesores de los diferentes niveles educativos, en el caso de que alumnos con discapacidad fueran escolarizados en sus aulas. Se ha contado con la participación de 400 profesores. La información se ha recogido a través de un cuestionario elaborado ad hoc basándonos en la escala "Concern about Inclusive Education Scale" (CIE), ampliándola y adaptándola al contexto español. Los resultados muestran las principales preocupaciones de los profesores de la Comunidad Valenciana y apuntan a la necesidad de profundizar en este tema para poder diseñar una formación específica que ayude a los profesores a hacer frente a las inquietudes con las que se enfrentan en su labor docente.

O objetivo principal deste estudo é o de conhecer as preocupações dos professores em diferentes etapas da educação, no caso de alunos com deficiência serem colocados em suas salas de aula. Participaram deste estudo, 400 professores. A informação foi recolhida através de um questionário ad hoc baseado na escala Concern on Inclusive Education Scale (CIE), estendido e adaptado ao contexto espanhol. Os resultados mostram as principais preocupações dos professores da Comunidade Valenciana e apontam a necessidade de aprofundar este tema, a fim de projetar uma formação específica que ajude os professores a lidar com as preocupações que enfrentam em seu trabalho de ensino

The main objective of this study is to know the concerns of teachers at different levels of education, in the event that students with disabilities were placed in their classrooms. 400 teachers participated. The information was collected through an ad hoc questionnaire based on the "Concern about Inclusive Education Scale" (CIE), extended and adapted to the Spanish context. The results show the main concerns of teachers in the Valencian Community and suggest the need to study this subject in greater depth in order to design specific training that helps teachers to deal with the concerns they face in their work.

Aquaporin gene transfer for hepatocellular cholestasis.

Bile secretion by hepatocytes is an osmotic process. The output of bile salts and other organic anions (e.g. glutathione), through the bile salt transporter BSEP/ABCB11 and the organic anion transporter MRP2/ABCC2, respectively, are considered to be the major osmotic driving forces for water secretion into bile canaliculi mainly via aquaporin-8 (AQP8) channels. The down-regulated canalicular expression of these key solute transporters and AQP8 would be a primary event in the establishment of hepatocellular cholestasis. Recent studies in animal models of hepatocellular cholestasis show that the hepatic delivery of AdhAQP1, an adenovector encoding for the archetypical water channel human aquaporin-1 (hAQP1), improves bile secretion and restores to normal the elevated serum bile salt levels. AdhAQP1-transduced hepatocytes show that the canalicularly-expressed hAQP1 not only enhances osmotic membrane water permeability but also induces the transport activities of BSEP/ABCB11 and MRP2/ABCC2 by redistribution in canalicular cholesterol-rich microdomains likely through interactions with the cholesterol-binding protein caveolin-1. Thus, the hepatic gene transfer of hAQP1 improves the bile secretory failure in hepatocellular cholestasis by increasing both biliary output and choleretic efficiency of key osmotic solutes, such as, bile salts and glutathione. The study of hepatocyte aquaporins has provided new insights into the mechanisms of bile formation and cholestasis, and may lead to innovative treatments for cholestatic liver diseases.

Further evidence for the involvement of mitochondrial aquaporin-8 in hepatocyte lipid synthesis.

We recently provided evidence suggesting that mitochondrial aquaporin-8 (mtAQP8), a channel protein able to conduct H2O2, is involved in the modulation of hepatocyte cholesterogenesis. To expand that study, we cultured human hepatocyte-derived Huh-7 cells in medium with lipoprotein-deficient serum (LPDS) to induce the de novo synthesis of cholesterol and fatty acids. We found that LPDS induced mtAQP8 expression and that AQP8 gene silencing significantly down-regulated the LPDS-induced synthesis of cholesterol and fatty acids as well as the expression of the corresponding key biosynthetic enzymes, 3-hydroxy-3-methylglutaryl-CoA reductase and fatty acid synthase. Our data further support a regulatory role of mtAQP8 in hepatocyte lipid homeostasis.

Epidemiology of human papillomavirus-related oropharyngeal cancer in a classically low-burden region of southern Europe.

The incidence of human papillomavirus (HPV)-related oropharyngeal cancer is increasing in some regions. Nevertheless, the epidemiology of this disease has not been extensively investigated in southern Europe. We conducted a retrospective cohort study of patients diagnosed with primary oropharyngeal cancer from 1991 to 2016. Cancer tissues underwent histopathological evaluation, DNA quality control, HPV-DNA detection and p16INK4a immunohistochemistry. Data were collected from medical records. Factors associated with HPV positivity and time trends were evaluated with multivariable Bayesian models. The adjusted prevalence of HPV-related cases in 864 patients with a valid HPV-DNA result was 9.7%, with HPV-DNA/p16INK4a double positivity being considered. HPV-related oropharyngeal cancer was likely to occur in non-smokers and non-drinkers, to be located in the tonsil or diagnosed at advanced stages. Time-trend analysis showed an increasing risk of HPV-related oropharyngeal cancer in the most recent periods (5-year period increase of 30%). This increase was highest and with a clear increasing trend only in the most recent years (2012-2016). The prevalence of HPV-related oropharyngeal cancer started to sharply increase in the most recent years in our setting, as occurred two decades ago in areas where most oropharyngeal cancer cases are currently HPV-related. Our results provide a comprehensive assessment of the epidemiological landscape of HPV-related oropharyngeal cancer in a region of southern Europe.

Data of ureagenesis from ammonia, glutamine and alanine, and mitochondrial aquaporin-8 expression in thioacetamide-treated hepatocytes.

We present data about the synthesis of urea from different substrates, i.e., free ammonia, glutamine and alanine in primary cultured rat hepatocytes treated or untreated with the model hepatotoxic agent thioacetamide (TAA). We also provide data about the expression of mitochondrial aquaporin-8 (mtAQP8), a hepatocyte channel protein which facilitates ammonia diffusion into mitochondria to supply the urea cycle. Ammonia-derived ureagenesis was significantly inhibited by about 30% while that from the both amino acids resulted unaffected in TAA-treated hepatocytes. Protein expression of mtAQP8 was decreased by about 80% after TAA treatment. These data can be useful for the understanding of the mechanisms of drug-induced hepatic dysfunction.

Hepatic glycerol metabolism is early reprogrammed in rat liver cancer development.

Evidence shows that oral glycerol supplementation during the early stages of rat liver cancer reduces the growth of preneoplastic lesions. Besides, human hepatocellular carcinoma (HCC) cells display decreased expression of glycerol channel aquaporin 9 (AQP9) and also diminished glycerol-3-phosphate (G3P) content. According to this, we analyzed glycerol metabolism during the initial stages of rat liver carcinogenesis. Wistar rats were subjected to a 2-phase model of hepatocarcinogenesis (initiated-promoted, IP group) or left untreated (control, C group). Different features of glycerol metabolism were compared between both groups. IP animals showed increased plasma free glycerol levels and liver AQP9 protein expression. Also, IP rats showed increased glycerol kinase (GK) and glycerol-3-phosphate dehydrogenase (GPDH) hepatic activities. Gluconeogenesis from glycerol both in vivo and in isolated perfused liver was higher in rats having liver preneoplasia. Nevertheless, preneoplastic foci notably reduced AQP9 and GK protein expressions, displaying a reduced ability to import glycerol and to convert it into G3P, as a way to preserve preneoplastic hepatocytes from the deleterious effect of G3P. In conclusion, the metabolic shift that takes place in the initial stages of liver cancer development comprises an increased hepatic utilization of glycerol for gluconeogenesis. Enhanced glucose production from glycerol is mostly carried out by the surrounding non-preneoplastic tissue and can be used as an energy source for the early transformed liver cells.

Data of H2O2 release from AQP8-knockdown rat hepatocyte mitochondria.

This article reports experimental data related to the research article entitled "Mitochondrial aquaporin-8 is involved in SREBP-controlled hepatocyte cholesterol biosynthesis" [Danielli et al., 2019]. We present data about hydrogen peroxide (H2O2) release from mitochondria isolated from rat hepatocytes with or without silencing of aquaporin-8 (AQP8) protein expression. The rate of mitochondrial H2O2 release (pmoles/min/mg mitochondrial protein) was found to be decreased by about 50% in AQP8-knockdown mitochondria.

Mitochondrial aquaporin-8 is involved in SREBP-controlled hepatocyte cholesterol biosynthesis.

Cholesterol, via sterol regulatory element-binding protein (SREBP) transcription factors, activates or represses genes involved in its hepatic biosynthetic pathway, and also modulates the expression of hepatocyte mitochondrial aquaporin-8 (mtAQP8), a channel that can function as peroxiporin by facilitating the transmembrane diffusion of H2O2. Here we tested the hypothesis that mtAQP8 is involved in the SREBP-mediated regulation of hepatocyte cholesterol biosynthesis. Using human hepatocyte-derived Huh-7 cells and primary rat hepatocytes, we found that mtAQP8 knockdown significantly downregulated de novo cholesterol synthesis as well as protein expressions of SREBP-2 and its target gene, a rate-limiting enzyme in cholesterol synthesis 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCR). In contrast, adenovirus-mediated human AQP8 mitochondrial expression significantly increased de novo cholesterol synthesis and protein expressions of SREBP-2 and HMGCR. In mtAQP8-overexpressed hepatocytes, mitochondrial H2O2 release was found to be increased; and a mitochondria-targeted antioxidant prevented the upregulation of mitochondrial H2O2 release and that of cholesterol synthesis. Our results suggest that peroxiporin mtAQP8 plays a role in the SREBP-controlled hepatocyte cholesterogenesis, a finding that might be relevant to cholesterol-related metabolic disorders.

Rapid scanning optical delay line based on a diffraction grating pair for a low-coherence reflectometer.

We present a simple low-coherence time-domain interferometric reflectometer with a rapidly scanning optical delay line (RSODL) based on a non-parallel diffraction grating (DG) pair. The novelty of the solution is that the lightwave in the reference channel is focused on a galvo-mirror in a sub-mm static spot, which allows implementation of fast microelectromechanical systems scan optics. It is shown that the DG pair can be operated as a non-dispersive element that provides dynamic group delay of a reference lightwave. The DG pair system is also capable of tuning the RSODL dispersion from negative to positive values. The experimental depth range in air was obtained as large as 2.5 mm for axial resolution of 20 µm.

Attenuation of liver cancer development by oral glycerol supplementation in the rat.

PURPOSE: Glycerol usage is increasing in food industry for human and animal nutrition. This study analyzed the impact of glycerol metabolism when orally supplemented during the early stage of rat liver carcinogenesis. METHODS: Wistar rats were subjected to a 2-phase model of hepatocarcinogenesis (initiated-promoted, IP group). IP animals also received glycerol by gavage (200 mg/kg body weight, IPGly group). RESULTS: Glycerol treatment reduced the volume of preneoplastic lesions by decreasing the proliferative status of liver foci, increasing the expression of p53 and p21 proteins and reducing the expression of cyclin D1 and cyclin-dependent kinase 1. Besides, apoptosis was enhanced in IPGly animals, given by an increment of Bax/Bcl-2 ratio, Bad and PUMA mitochondrial expression, a concomitant increase in cytochrome c release and caspase-3 activation. Furthermore, hepatic levels of glycerol phosphate and markers of oxidative stress were increased in IPGly rats. Oxidative stress intermediates act as intracellular messengers, inducing p53 activation and changes in JNK and Erk signaling pathways, with JNK activation and Erk inhibition. CONCLUSION: The present work provides novel data concerning the preventive actions of glycerol during the development of liver cancer and represents an economically feasible intervention to treat high-risk individuals.

Cholesterol can modulate mitochondrial aquaporin-8 expression in human hepatic cells.

Hepatocyte mitochondrial aquaporin-8 (mtAQP8) works as a multifunctional membrane channel protein that facilitates the uptake of ammonia for its detoxification to urea as well as the mitochondrial release of hydrogen peroxide. Since early oligonucleotide microarray studies in liver of cholesterol-fed mice showed an AQP8 downregulation, we tested whether alterations of cholesterol content per se modulate mtAQP8 expression in human hepatocyte-derived Huh-7 cells. Cholesterol loading with methyl-ß-cyclodextrin (mßCD):cholesterol complexes downregulated the proteolytic activation of cholesterol-responsive sterol regulatory element-binding protein (SREBP) transcriptions factors 1 and 2, and the expression of the target gene 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR). Under such conditions, mtAQP8 mRNA and protein expressions were significantly reduced. In contrast, cholesterol depletion using mßCD alone increased SREBP-1 and 2 activation and upregulated HMGCR and mtAQP8 mRNA and protein expressions. The results suggest that cholesterol can regulate transcriptionally human hepatocyte mtAQP8 expression likely via SREBPs. The functional implications of our findings are discussed. © 2017 IUBMB Life, 69(5):341-346, 2017.

Cooperative Electronic and Structural Regulation in a Bioinspired Allosteric Photoredox Catalyst.

Herein, we report the first allosteric photoredox catalyst regulated via constructively coupled structural and electronic control. While often synergistically exploited in nature, these two types of control mechanisms have only been applied independently in the vast majority of allosteric enzyme mimics and receptors in the literature. By embedding a model of photosystem II in a supramolecular coordination complex that responds to chloride as an allosteric effector, we show that distance and electronic control of light harvesting can be married to maximize allosteric regulation of catalytic activity. This biomimetic system is composed of a Bodipy photoantenna, which is capable of transferring excited-state energy to a photoredox pair, wherein the excitation energy is used to generate a catalytically active charge-separated state. The structural aspect of allosteric regulation is achieved by toggling the coordination chemistry of an antenna-functionalized hemilabile ligand via partial displacement from a Rh(I) structual node using chloride. In doing so, the distance between the antenna and the central photoredox catalyst is increased, lowering the inherent efficiency of through-space energy transfer. At the same time, coordination of chloride lowers both the charge of the Rh(I) node and the reduction potential of the Rh(II/I) couple, to the extent that electronic quenching of the antenna excited state is possible via photoinduced electron transfer from the metal center. Compared to a previously developed system that operates solely via electronic regulation, the present system demonstrates that coupling electronic and structural approaches to allosteric regulation gives rise to improved switching ratios between catalytically active and inactive states. Contributions from both structural and electronic control mechanisms are probed via nuclear magnetic resonance, X-ray diffraction, electrochemical, spectroelectrochemical, and transient absorption studies. Overall, this work establishes that intertwined electronic and structural regulatory mechanisms can be borrowed from nature to build stimuli-responsive inorganic materials with potential applications in sensing, catalysis, and photonic devices.

Allosteric supramolecular coordination constructs.

Coordination chemistry is regularly used to generate supramolecular constructs with unique environments around embedded components to affect their intrinsic properties. In certain cases, it can also be used to effect changes in supramolecular structure reminiscent of those that occur within stimuli-responsive biological structures, such as allosteric enzymes. Indeed, among a handful of general strategies for synthesizing such supramolecular systems, the weak-link approach (WLA) uniquely allows one to toggle the frameworks' structural state post-assembly via simple reactions involving hemilabile ligands and transition metal centers. This synthetic strategy, when combined with dynamic ligand sorting processes, represents one of the few sets of general reactions in inorganic chemistry that allow one to synthesize spatially defined, stimuli-responsive, and multi-component frameworks in high to quantitative yields and with remarkable functional group tolerance. The WLA has thus yielded a variety of functional systems that operate similarly to allosteric enzymes, toggling activity via changes in the frameworks' steric confinement or electronic state upon the recognition of small molecule inputs. In this Perspective we present the first full description of the fundamental inorganic reactions that provide the foundation for synthesizing WLA complexes. In addition, we discuss the application of regulatory strategies in biology to the design of allosteric supramolecular constructs for the regulation of various catalytic properties, electron-transfer processes, and molecular receptors, as well as for the development of sensing and signal amplification systems.

An allosteric photoredox catalyst inspired by photosynthetic machinery.

Biological photosynthetic machinery allosterically regulate light harvesting via conformational and electronic changes at the antenna protein complexes as a response to specific chemical inputs. Fundamental limitations in current approaches to regulating inorganic light-harvesting mimics prevent their use in catalysis. Here we show that a light-harvesting antenna/reaction centre mimic can be regulated by utilizing a coordination framework incorporating antenna hemilabile ligands and assembled via a high-yielding, modular approach. As in nature, allosteric regulation is afforded by coupling the conformational changes to the disruptions in the electrochemical landscape of the framework upon recognition of specific coordinating analytes. The hemilabile ligands enable switching using remarkably mild and redox-inactive inputs, allowing one to regulate the photoredox catalytic activity of the photosynthetic mimic reversibly and in situ. Thus, we demonstrate that bioinspired regulatory mechanisms can be applied to inorganic light-harvesting arrays displaying switchable catalytic properties and with potential uses in solar energy conversion and photonic devices.

Allosteric regulation of supramolecular oligomerization and catalytic activity via coordination-based control of competitive hydrogen-bonding events.

Herein, we demonstrate that the activity of a hydrogen-bond-donating (HBD) catalyst embedded within a coordination framework can be allosterically regulated in situ by controlling oligomerization via simple changes in coordination chemistry at distal Pt(II) nodes. Using the halide-induced ligand rearrangement reaction (HILR), a heteroligated Pt(II) triple-decker complex, which contains a catalytically active diphenylene squaramide moiety and two hydrogen-bond-accepting (HBA) ester moieties, was synthesized. The HBD and HBA moieties were functionalized with hemilabile ligands of differing chelating strengths, allowing one to assemble them around Pt(II) nodes in a heteroligated fashion. Due to the hemilabile nature of the ligands, the resulting complex can be interconverted between a flexible, semiopen state and a rigid, fully closed state in situ and reversibly. FT-IR spectroscopy, (1)H DOSY, and (1)H NMR spectroscopy titration studies were used to demonstrate that, in the semiopen state, intermolecular hydrogen-bonding between the HBD and HBA moieties drives oligomerization of the complex and prevents substrate recognition by the catalyst. In the rigid, fully closed state, these interactions are prevented by steric and geometric constraints. Thus, the diphenylene squaramide moiety is able to catalyze a Friedel-Crafts reaction in the fully closed state, while the semiopen state shows no reactivity. This work demonstrates that controlling catalytic activity by regulating aggregation through supramolecular conformational changes, a common approach in Nature, can be applied to man-made catalytic frameworks that are relevant to materials synthesis, as well as the detection and amplification of small molecules.

Large contribution of human papillomavirus in vaginal neoplastic lesions: a worldwide study in 597 samples.

AIM: This work describes the human papillomavirus (HPV) prevalence and the HPV type distribution in a large series of vaginal intraepithelial neoplasia (VAIN) grades 2/3 and vaginal cancer worldwide. METHODS: We analysed 189 VAIN 2/3 and 408 invasive vaginal cancer cases collected from 31 countries from 1986 to 2011. After histopathological evaluation of sectioned formalin-fixed paraffin-embedded samples, HPV DNA detection and typing was performed using the SPF-10/DNA enzyme immunoassay (DEIA)/LiPA25 system (version 1). A subset of 146 vaginal cancers was tested for p16(INK4a) expression, a cellular surrogate marker for HPV transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance. RESULTS: HPV DNA was detected in 74% (95% confidence interval (CI): 70-78%) of invasive cancers and in 96% (95% CI: 92-98%) of VAIN 2/3. Among cancers, the highest detection rates were observed in warty-basaloid subtype of squamous cell carcinomas, and in younger ages. Concerning the type-specific distribution, HPV16 was the most frequently type detected in both precancerous and cancerous lesions (59%). p16(INK4a) overexpression was found in 87% of HPV DNA positive vaginal cancer cases. CONCLUSIONS: HPV was identified in a large proportion of invasive vaginal cancers and in almost all VAIN 2/3. HPV16 was the most common type detected. A large impact in the reduction of the burden of vaginal neoplastic lesions is expected among vaccinated cohorts.

A multi-state, allosterically-regulated molecular receptor with switchable selectivity.

A biomimetic, ion-regulated molecular receptor was synthesized via the Weak-Link Approach (WLA). This structure features both a calix[4]arene moiety which serves as a molecular recognition unit and an activity regulator composed of hemilabile phosphine alkyl thioether ligands (P,S) chelated to a Pt(II) center. The host-guest properties of the ion-regulated receptor were found to be highly dependent upon the coordination of the Pt(II) center, which is controlled through the reversible coordination of small molecule effectors. The environment at the regulatory site dictates the charge and the structural conformation of the entire assembly resulting in three accessible binding configurations: one closed, inactive state and two open, active states. One of the active states, the semiopen state, recognizes a neutral guest molecule, while the other, the fully open state, recognizes a cationic guest molecule. Job plots and (1)H NMR spectroscopy titrations were used to study the formation of these inclusion complexes, the receptor binding modes, and the receptor binding affinities (Ka) in solution. Single crystal X-ray diffraction studies provided insight into the solid-state structures of the receptor when complexed with each guest molecule. The dipole moments and electrostatic potential maps of the structures were generated via DFT calculations at the B97D/LANL2DZ level of theory. Finally, we describe the reversible capture and release of guests by switching the receptor between the closed and semiopen configurations via elemental anion and small molecule effectors.

Modulation of electronics and thermal stabilities of photochromic phosphino-aminoazobenzene derivatives in weak-link approach coordination complexes.

A series of d(8) transition-metal (Pt(II) and Pd(II)) coordination complexes incorporating phosphine-functionalized aminoazobenzene derivatives as hemilabile phosphino-amine (P,N) ligands were synthesized and studied as model weak-link approach (WLA) photoresponsive constructs. The optical and photochemical properties of these complexes were found to be highly influenced by various tunable parameters in WLA systems, which include type of metal, coordination mode, type of ancillary ligand, solvent, and outer-sphere counteranions. In dichloromethane, reversible chelation and partial displacement of the P,N coordinating moieties allow for toggling between aminoazobenzene- or pseudostilbene- and azobenzene-type derivatives. The reversible switching between electronic states of azobenzene can be controlled through either addition or extraction of chloride counterions and is readily visualized in the separation between π-π* and n-π* bands in the complexes' electronic spectra. In acetonitrile solution, the WLA variables inherent to semiopen complexes have a significant impact on the half-lives of the corresponding cis isomers, allowing one to tune their half-lives from 20 to 21000 s, while maintaining photoisomerization behaviors with visible light. Therefore, one can significantly increase the thermal stability of a cis-aminoazobenzene derivative to the extent that single crystals for X-ray diffraction analysis can be grown for the first time, uncovering an unprecedented edge-to-face arrangement of the phenyl rings in the cis isomer. Overall, the azobenzene-functionalized model complexes shed light on the design parameters relevant for photocontrolled WLA molecular switches, as well as offer new ways of tuning the properties of azobenzene-based, photoresponsive materials.