Proteinaceous Deposits Research Articles

Interaction of alkaline and acid treatment on the removal of proteinaceous mineral-enriched dairy fouling from UHT treatment

CIP processes in milk processing plants are frequently oversized to reliably meet hygienic and safety requirements. Cleaning follows a fixed protocol, but the exact mechanisms and intermediate products are often unknown. This study presents an experimental approach to elucidate the interaction between alkaline and acidic treatment with special regard to the impact of acid on proteinaceous deposits. The protein containing fouling layers become yellowish in colour by acidic treatment; this is attributed to the xantho-proteic reaction and no efficient removal is thereby achieved. In contrast, the removal is efficient if an efficient initial alkaline treatment step is performed. An efficient initial alkaline treatment step was identified as crucial for the further course of cleaning and a short alkaline treatment soaked the entire soil, which enabled an efficient subsequent acidic removal. Lower concentrations of HNO3 demonstrate more efficient cleaning than higher ones, suggesting an optimum acid concentration during CIP.

Congenital pulmonary alveolar proteinosis in a neonate

The male patient was referred to the hospital at 44 days old due to dyspnea after birth and inability to wean off oxygen. His brother died three days after birth due to respiratory failure. The main symptoms observed were respiratory failure, dyspnea, and hypoxemia. A chest CT scan revealed characteristic reduced opacity in both lungs with a "crazy-paving" appearance. The bronchoalveolar lavage fluid (BALF) showed periodic acid-Schiff positive proteinaceous deposits. Genetic testing indicated a compound heterozygous mutation in the ABCA3 gene. The diagnosis for the infant was congenital pulmonary alveolar proteinosis (PAP). Congenital PAP is a significant cause of challenging-to-treat respiratory failure in full-term infants. Therefore, congenital PAP should be considered in infants experiencing persistently difficult-to-treat dyspnea shortly after birth. Early utilization of chest CT scans, BALF pathological examination, and genetic testing may aid in early diagnosis.

Integrated analysis of transcriptomic and proteomic alterations in mouse models of ALS/FTD identify early metabolic adaptions with similarities to mitochondrial dysfunction disorders

Objective Sporadic and familial amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disease that results in loss of motor neurons and, in some patients, associates with frontotemporal dementia (FTD). Apart from the accumulation of proteinaceous deposits, emerging literature indicates that aberrant mitochondrial bioenergetics may contribute to the onset and progression of ALS/FTD. Here we sought to investigate the pathophysiological signatures of mitochondrial dysfunction associated with ALS/FTD. Methods By means of label-free mass spectrometry (MS) and mRNA sequencing (mRNA-seq), we report pre-symptomatic changes in the cortices of TDP-43 and FUS mutant mouse models. Using tissues from transgenic mouse models of mitochondrial diseases as a reference, we performed comparative analyses and extracted unique and common mitochondrial signatures that revealed neuroprotective compensatory mechanisms in response to early damage. Results In this regard, upregulation of both Acyl-CoA Synthetase Long-Chain Family Member 3 (ACSL3) and mitochondrial tyrosyl-tRNA synthetase 2 (YARS2) were the most representative change in pre-symptomatic ALS/FTD tissues, suggesting that fatty acid beta-oxidation and mitochondrial protein translation are mechanisms of adaptation in response to ALS/FTD pathology. Conclusions Together, our unbiased integrative analyses unveil novel molecular components that may influence mitochondrial homeostasis in the earliest phase of ALS.

A Kinetic Model for Describing the Heterogeneity of Susceptibility to Chemical or Physical Change

Molecules in foods and food ingredients exist in a variety of states, each of which has a different susceptibility to chemical and physical change. A model was proposed for the change in behavior over time based on the assumption that the free energy of activation in relation to the rate constant obeyed a Gaussian distribution. This model could well explain the unique behaviors observed in the thermal inactivation of immobilized enzymes, formation of aldehydes from lignin by alkaline nitrobenzene oxidation, autoxidation processes of microencapsulated lipids, flavor release from microcapsules, and desorption of proteinaceous deposits fouled on stainless steel surfaces.

Early molecular layer interneuron hyperactivity triggers Purkinje neuron degeneration in SCA1

Toxic proteinaceous deposits and alterations in excitability and activity levels characterize vulnerable neuronal populations in neurodegenerative diseases. Using invivo two-photon imaging in behaving spinocerebellar ataxia type 1 (Sca1) mice, wherein Purkinje neurons (PNs) degenerate, we identify an inhibitory circuit element (molecular layer interneurons [MLINs]) that becomes prematurely hyperexcitable, compromising sensorimotor signals in the cerebellum at early stages. Mutant MLINs express abnormally elevated parvalbumin, harbor high excitatory-to-inhibitory synaptic density, and display more numerous synaptic connections on PNs, indicating an excitation/inhibition imbalance. Chemogenetic inhibition of hyperexcitable MLINs normalizes parvalbumin expression and restores calcium signaling in Sca1 PNs. Chronic inhibition of mutant MLINs delayed PN degeneration, reduced pathology, and ameliorated motor deficits in Sca1 mice. Conserved proteomic signature of Sca1 MLINs, shared with human SCA1 interneurons, involved the higher expression of FRRS1L, implicated in AMPA receptor trafficking. We thus propose that circuit-level deficits upstream of PNs are one of the main disease triggers in SCA1.

Oral manifestations of amyloidosis in a multiple myeloma patient: A case report

Abstract The term amyloidosis refers to a wide range of diseases in which amorphous, extracellular, eosinophilic proteinaceous deposits form at various locations. In this article, we describe a case of amyloidosis with multiple myeloma in which the oral symptoms of the disease served as the main diagnostic clues. A male patient in his early 60s who had multiple tongue swellings presented to our department. Following an incisional biopsy, histological analysis revealed the presence of eosinophilic, amorphous hyaline-like material that was positive for Congo red staining and was indicative of amyloidosis. The presence of abnormal plasma cells in the patient’s bone marrow aspiration after the biopsy was done was suggestive of multiple myeloma. The patient is currently undergoing the CyBorD (Cyclophosphamide, Bortezomib, and Dexamethasone) treatment for multiple myeloma that has just been diagnosed. We offer this instance to demonstrate that, although uncommon, amyloidosis can initially only manifest as numerous swellings on the tongue.

Effect of temperature, wall shear stress, and NaOH concentration on cleaning effectiveness.

The objective of this research was to evaluate the effect of various operational parameters and their interaction on cleaning rate of NaOH. The parameters include wall shear stress, temperatures, and NaOH concentrations of cleaning fluid. The higher cleaning effectiveness for proteinaceous deposits was achieved at higher wall shear stress. The wall shear stress of 2.42Pa removed over 90% of foulant after 10min of operation, which was significantly higher than the removal of lower wall shear stress (0.84 and 0.39Pa). Similarly, the cleaning rate increased with increase in temperature and concentration of cleaning solution. The use of cleaning solution (0.05% NaOH) at 65°C provided significantly higher cleaning rate than 25°C. A cleaning solution concentration of 0.5% NaOH provided significantly higher removal of foulant than 0% or 0.05% concentrations. However, analysis on the interaction between temperature and the wall shear stress suggested that the temperature above 45°C and wall shear stress above 0.65Pa did not provide significant improvement in cleaning efficacy. When a cleaning solution temperature was maintained at 45°C, higher wall shear stress provided more rapid removal of the foulant when the cleaning agent concentration was 0.05% or 0.5%. In water rinse conducted without chemical agents, no much improvements in foulant removal were observed with increase in wall shear stress. The change of activation energy (Ea ) indicates that water rinse was sensitive to temperature change at higher wall shear stress. However, cleaning with cleaning agents was less sensitive to temperature variation compared to the water rinse. PRACTICAL APPLICATION: Considering the intense use of water and chemical compounds during cleaning operation, finding operating condition to ensure acceptable cleanness with minimized input is desired. Temperature, cleaning agent concentration, and wall shear stress are the major components to influence the cleaning efficacy. The result of the study demonstrates the potential for optimization of in-place cleaning by appropriate adjustments of the CIP operating parameters.

Histopathology unveiling the structural damage in gonads of Catla catla due to freshwater contamination

Potentially harmful materials, e.g., heavy metals, pesticides, dyes, and hydrocarbons, are often released untreated into freshwater bodies. When such pollutants are released in large quantities, there may be large-scale, sudden mortalities of aquatic organisms. This study summarizes experimental evidence about the disruption of gonadal development due to freshwater contamination. Adult fish specimens of Catla catla were collected from the River Chenab downstream of the Chakbandi Main Drain (CMD) entrance into the Chenab River. CMD collects domestic and industrial sewage wastes from Faisalabad city and disposes them into River Chenab, polluting this water body. Water samples were analyzed from each site of fish harvest for water quality parameters. Collected fish specimens were subjected to histopathological evaluation to detect the impact of pollution on the gonads of this fish species. The male Catla catla gonads showed marked histopathological alterations such as testes degeneration, generalized tissue degeneration produced by fragmentation and detachment of basement membrane, necrosis, and fibrosis in the testis. A loss of tubular arrangement, rupturing of the blood vessels, delimiting seminiferous lobules, vascular hypertrophy of the interstitial compartment, and appearance of a clustered organization were observed. The follicular epithelium in vitellogenic oocytes, rupturing and detachment of follicular basement membrane tissue with cytoplasmic vacuolization, immature oocytes with scattered yolk droplets, hypertrophied follicular epithelium, interstitial proteinaceous fluid deposition, and structural deterioration of follicles with early oocytes were observed in the ovary.

Influence of polydopamine functionalization on the rapid protein immobilization by alternating current electrophoretic deposition

Biomolecule immobilization onto implant surfaces is an interesting approach which allows fine-tuning the biological response upon implantation. However, the relatively low adsorption rates seen in current methodologies typically lead to long processing times, which can affect the activity of the biomolecules. Here, we investigate the effect of combining a bioinspired polydopamine (PDA) functionalization strategy with alternating current electrophoretic deposition (AC-EPD) for the immobilization of bovine serum albumin (BSA) on Ti6Al4V. PDA films introduce a high density of functional groups on the metal surface for the permanent attachment, while AC-EPD has the potential to actively concentrate biomolecules at the implant surface within a short time. First, PDA films were optimized in terms of the dopamine (DA) starting concentration. Next, amine-rich PDA-functionalized Ti6Al4V substrates served as electrodes during AC-EPD of BSA. While an improved deposition yield could already be observed for the PDA and AC-EPD strategies individually, significant merit lays in their combination, as was revealed by thicker proteinaceous deposits on the PDA-functionalized Ti6Al4V serving as anode during the high-amplitude half cycle of the AC signal. This provides a proof-of-concept for the synergistic effect of a PDA coupling chemistry in combination with AC electrophoresis as a time-efficient coating methodology for the proteins.

What is your diagnosis? Ovarian mass in a mare.

What is your diagnosis? Ovarian mass in a mare.

Exposure of α-Synuclein Aggregates to Organotypic Slice Cultures Recapitulates Key Molecular Features of Parkinson's Disease.

The accumulation of proteinaceous deposits comprised largely of the α-synuclein protein is one of the main hallmarks of Parkinson's disease (PD) and related synucleinopathies. Their progressive development coincides with site-specific phosphorylation, oxidative stress and eventually, compromised neuronal function. However, modeling protein aggregate formation in animal or in vitro models has proven notably difficult. Here, we took advantage of a preclinical organotypic brain slice culture model to study α-synuclein aggregate formation ex vivo. We monitored the progressive and gradual changes induced by α-synuclein such as cellular toxicity, autophagy activation, mitochondrial dysfunction, cellular death as well as α-synuclein modification including site-specific phosphorylation. Our results demonstrate that organotypic brain slice cultures can be cultured for long periods of time and when cultured in the presence of aggregated α-synuclein, the molecular features of PD are recapitulated. Taken together, this ex vivo model allows for detailed modeling of the molecular features of PD, thus enabling studies on the cumulative effects of α-synuclein in a complex environment. This provides a platform to screen potential disease-modifying therapeutic candidates aimed at impeding α-synuclein aggregation and/or cellular transmission. Moreover, this model provides a robust replacement for in vivo studies that do not include behavioral experiments, thus providing a way to reduce the number of animals used in an accelerated timescale.

β-Synuclein: An Enigmatic Protein with Diverse Functionality.

α-Synuclein (αS) is a small, unstructured, presynaptic protein expressed in the brain. Its aggregated form is a major component of Lewy bodies, the large proteinaceous deposits in Parkinson’s disease. The closely related protein, β-Synuclein (βS), is co-expressed with αS. In vitro, βS acts as a molecular chaperone to inhibit αS aggregation. As a result of this assignation, βS has been largely understudied in comparison to αS. However, recent reports suggest that βS promotes neurotoxicity, implying that βS is involved in other cellular pathways with functions independent of αS. Here, we review the current literature pertaining to human βS in order to understand better the role of βS in homeostasis and pathology. Firstly, the structure of βS is discussed. Secondly, the ability of βS to (i) act as a molecular chaperone; (ii) regulate synaptic function, lipid binding, and the nigrostriatal dopaminergic system; (iii) mediate apoptosis; (iv) participate in protein degradation pathways; (v) modulate intracellular metal levels; and (vi) promote cellular toxicity and protein aggregation is explored. Thirdly, the P123H and V70M mutations of βS, which are associated with dementia with Lewy bodies, are discussed. Finally, the importance of post-translational modifications on the structure and function of βS is reviewed. Overall, it is concluded that βS has both synergistic and antagonistic interactions with αS, but it may also possess important cellular functions independent of αS.

Picomolar-sensitive β-amyloid fibril fluorophores by tailoring the hydrophobicity of biannulated π-elongated dioxaborine-dyes

The pathological origin of Alzheimer's disease (AD) is still shrouded in mystery, despite intensive worldwide research efforts. The selective visualization of β-amyloid (Aβ), the most abundant proteinaceous deposit in AD, is pivotal to reveal AD pathology. To date, several small-molecule fluorophores for Aβ species have been developed, with increasing binding affinities. In the current work, two organic small-molecule dioxaborine-derived fluorophores were rationally designed through tailoring the hydrophobicity with the aim to enhance the binding affinity for Aβ1-42 fibrils —while concurrently preventing poor aqueous solubility—via biannulate donor motifs in D-π-A dyes. An unprecedented sub-nanomolar affinity was found (Kd = 0.62 ± 0.33 nM) and applied to super-sensitive and red-emissive fluorescent staining of amyloid plaques in cortical brain tissue ex vivo. These fluorophores expand the dioxaborine-curcumin-based family of Aβ-sensitive fluorophores with a promising new imaging agent.

UV Resonance Raman explores protein structural modification upon fibrillation and ligand interaction

Amyloids are proteinaceous deposits considered an underlying pathological hallmark of several degenerative diseases. The mechanism of amyloid formation and its inhibition still represent challenging issues, especially when protein structure cannot be investigated by classical biophysical techniques as for the intrinsically disordered proteins (IDPs). In this view, the need to find an alternative way for providing molecular and structural information regarding IDPs prompted us to set a novel, to our knowledge, approach focused on UV Resonance Raman (UVRR) spectroscopy. To test its applicability, we study the fibrillation of hen-egg white lysozyme (HEWL) and insulin as well as their interaction with resveratrol, employing also intrinsic fluorescence spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The increasing of the β-sheet structure content at the end of protein fibrillation probed by FTIR occurs simultaneously with a major solvent exposure of tryptophan (Trp) and tyrosine (Tyr) residues of HEWL and insulin, respectively, as revealed by UVRR and intrinsic fluorescence spectroscopy. However, because the latter technique is successfully used when proteins naturally contain Trp residues, it shows poor performances in the case of insulin, and the information regarding its tertiary structure is exclusively provided by UVRR spectroscopy. The presence of an increased concentration of resveratrol induces mild changes in the secondary structure of both protein fibrils while remodeling HEWL fibril length and promoting the formation of amorphous aggregates in the case of insulin. Although the intrinsic fluorescence spectra of proteins are hidden by resveratrol signal, UVRR Trp and Tyr bands are resonantly enhanced, showing a good sensitivity to the presence of resveratrol and marking a modification in the noncovalent interactions in which they are involved. Our findings demonstrate that UVRR is successfully employed in the study of aggregation-prone proteins and of their interaction with ligands, especially in the case of Trp-lacking proteins.

Interactions between Apolipoprotein E Metabolism and Retinal Inflammation in Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a multifactorial retinal disorder that is a major global cause of severe visual impairment. The development of an effective therapy to treat geographic atrophy, the predominant form of AMD, remains elusive due to the incomplete understanding of its pathogenesis. Central to AMD diagnosis and pathology are the hallmark lipid and proteinaceous deposits, drusen and reticular pseudodrusen, that accumulate in the subretinal pigment epithelium and subretinal spaces, respectively. Age-related changes and environmental stressors, such as smoking and a high-fat diet, are believed to interact with the many genetic risk variants that have been identified in several major biochemical pathways, including lipoprotein metabolism and the complement system. The APOE gene, encoding apolipoprotein E (APOE), is a major genetic risk factor for AMD, with the APOE2 allele conferring increased risk and APOE4 conferring reduced risk, in comparison to the wildtype APOE3. Paradoxically, APOE4 is the main genetic risk factor in Alzheimer’s disease, a disease with features of neuroinflammation and amyloid-beta deposition in common with AMD. The potential interactions of APOE with the complement system and amyloid-beta are discussed here to shed light on their roles in AMD pathogenesis, including in drusen biogenesis, immune cell activation and recruitment, and retinal inflammation.

Impact of morphological alterations on thermal aging of proteinaceous deposits

ABSTRACT Due to external thermal and mechanical stress on proteinaceous fouling layer, a progressive material change, the so-called aging, occurs, which influences both the thermal and mechanical properties. This paper presents a systematic classification of morphological, thermal, and mechanical aging phenomena. The thermal aging of proteinaceous deposits is discussed based on the thermal characterization of fouling experiments. Therefore, differently aged food-based fouling layers from whey protein concentrate solutions are generated in a heated, laminar-operating flow channel. Both, a time dependency and a temperature dependency of the aging process become apparent. The impact of morphological aging and possible temperature-dependent reactions is discussed.

Multichromatic fluorescence towards aberrant proteinaceous aggregates utilizing benzimidazole-based ICT fluorophores

The pathological origin of Alzheimer’s disease (AD) remains uncharted terrain, despite intensive investigation. Discriminating aberrant proteinaceous deposits, such as β-amyloid (Aβ) and (hyperphosphorylated) tau protein by imaging methods, is a vital tool to support investigations towards the network of interacting features that results in AD pathology. In this context, multispectral fluorescence imaging (MSFI) has drawn much attention enabling the distinction of several analytes with merely a single fluorophore emitting a multichromatic fluorescent signal. Herein, we developed three kinds of benzimidazole-derived fluorescent dyes, BZ1–BZ3. The photophysical properties and intramolecular charge transfer (ICT) characteristics of the probes were evaluated in various solvents. Furthermore, a benzimidazole-associated polar-sensitivity displayed multichromatic behavior and enabled the visualization of minute differences in microenvironmental polarity between Aβ and tau aggregates, resulting in different maximal fluorescent emission wavelengths. Indeed, BZ2 demonstrated an approximately 30 nm bathochromic shift in maximal fluorescent emission. All these observations offer a potential for the development of a future generation of benzimidazole-derived ICT-based fluorescent probes.

FotoFinder Dermoscopy Analysis and Histopathological Correlation in Primary Localized Cutaneous Amyloidosis.

Primary localized cutaneous amyloidosis (PLCA) causes extracellular proteinaceous deposits in skin. It is clinically divided into macular amyloidosis, lichen amyloidosis and nodular amyloidosis. Atypical presentations of PLCA make the diagnosis challenging, requiring biopsy to confirm amyloid deposition in the upper papillary dermis. This study used FotoFinder dermoscopy to characterize lichen and macular amyloidosis and correlated the dermoscopic features with histopathological findings. This cross-sectional study enrolled patients with a clinical and histopathological diagnosis of PLCA. Dermoscopic examination was performed using the FotoFinder dermoscope, which provides a range of magnification from 20× to 140×. A total of 30 patients were included in the study. Common dermoscopic patterns of MA were white or brown central hubs, and common patterns of LA were white structureless, scar-like areas and central hubs. New dermoscopic findings were a day lily appearance in MA and white rosettes in LA. Dermoscopy plays a pivotal role in demonstrating characteristic findings of PLCA. These findings were well corelated with histopathology, thus avoiding unnecessary biopsy for arriving at an accurate diagnosis of PLCA.

Identification of Two Novel Peptides That Inhibit α-Synuclein Toxicity and Aggregation.

Aggregation of α-synuclein (αSyn) into proteinaceous deposits is a pathological hallmark of a range of neurodegenerative diseases including Parkinson’s disease (PD). Numerous lines of evidence indicate that the accumulation of toxic oligomeric and prefibrillar αSyn species may underpin the cellular toxicity and spread of pathology between cells. Therefore, aggregation of αSyn is considered a priority target for drug development, as aggregation inhibitors are expected to reduce αSyn toxicity and serve as therapeutic agents. Here, we used the budding yeast S. cerevisiae as a platform for the identification of short peptides that inhibit αSyn aggregation and toxicity. A library consisting of approximately one million peptide variants was utilized in two high-throughput screening approaches for isolation of library representatives that reduce αSyn-associated toxicity and aggregation. Seven peptides were isolated that were able to suppress specifically αSyn toxicity and aggregation in living cells. Expression of the peptides in yeast reduced the accumulation of αSyn-induced reactive oxygen species and increased cell viability. Next, the peptides were chemically synthesized and probed for their ability to modulate αSyn aggregation in vitro. Two synthetic peptides, K84s and K102s, of 25 and 19 amino acids, respectively, significantly inhibited αSyn oligomerization and aggregation at sub-stoichiometric molar ratios. Importantly, K84s reduced αSyn aggregation in human cells. These peptides represent promising αSyn aggregation antagonists for the development of future therapeutic interventions.

Molecular Imaging of Tau Protein: New Insights and Future Directions

Tau is a microtubule-associated protein (MAPT) that is highly expressed in neurons and implicated in several cellular processes. Tau misfolding and self-aggregation give rise to proteinaceous deposits known as neuro-fibrillary tangles. Tau tangles play a key role in the genesis of a group of diseases commonly referred to as tauopathies; notably, these aggregates start to form decades before any clinical symptoms manifest. Advanced imaging methodologies have clarified important structural and functional aspects of tau and could have a role as diagnostic tools in clinical research. In the present review, recent progresses in tau imaging will be discussed. We will focus mainly on super-resolution imaging methods and the development of near-infrared fluorescent probes.