CGG repeat expansion in LRP12 in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the degeneration of motor neurons. Although repeat expansion in C9orf72 is its most common cause, the pathogenesis of ALS isn't fully clear. In this study, we show that repeat expansion in LRP12, a causative variant of oculopharyngodistal myopathy type 1 (OPDM1), is a cause of ALS. We identify CGG repeat expansion in LRP12 in five families and two simplex individuals. These ALS individuals (LRP12-ALS) have 61-100 repeats, which contrasts with most OPDM individuals with repeat expansion in LRP12 (LRP12-OPDM), who have 100-200 repeats. Phosphorylated TDP-43 is present in the cytoplasm of iPS cell-derived motor neurons (iPSMNs) in LRP12-ALS, a finding that reproduces the pathological hallmark of ALS. RNA foci are more prominent in muscle and iPSMNs in LRP12-ALS than in LRP12-OPDM. Muscleblind-like 1 aggregates are observed only in OPDM muscle. In conclusion, CGG repeat expansions in LRP12 cause ALS and OPDM, depending on the length of the repeat. Our findings provide insight into the repeat length-dependent switching of phenotypes.

Design and Synthesis of Novel Squaraine-Based Fluorescent Probe for Far-Red Detection of Chymotrypsin Enzyme.

Chymotrypsin, a crucial enzyme in human digestion, catalyzes the breakdown of milk proteins, underscoring its significance in both health diagnostics and dairy quality assurance. Addressing the critical need for rapid, cost-effective detection methods, we introduce a groundbreaking approach utilizing far-red technology and HOMO-Förster resonance energy transfer (FRET). Our novel probe, SQ-122 PC, features a unique molecular design that includes a squaraine dye (SQ), a peptide linker, and SQ moieties synthesized through solid-phase peptide synthesis. Demonstrating a remarkable quenching efficiency of 93.75% in a tailored H2O:DMSO (7:3) solvent system, our probe exhibits absorption and emission properties within the far-red spectrum, with an unprecedented detection limit of 0.130 nM. Importantly, our method offers unparalleled selectivity towards chymotrypsin, ensuring robust and accurate enzyme detection. This pioneering work underscores the immense potential of far-red-based homo-FRET systems in enabling the sensitive and specific detection of chymotrypsin enzyme activity. By bridging the gap between cutting-edge technology and biomedical diagnostics, our findings herald a new era of enzyme sensing, promising transformative advancements in disease diagnosis and dairy quality control.

In Vitro and In Silico Studies on Angiotensin I-Converting Enzyme Inhibitory Peptides Found in Hydrophobic Domains of Porcine Elastin.

One of the most striking aspects of the primary structure in the hydrophobic domains of the tropoelastin molecule is the occurrence of the VAPGVG repeating sequence. Since the N-terminal tripeptide VAP of VAPGVG showed a potent ACE inhibitory activity, the ACE inhibitory activity of various derivatives of VAP was examined in vitro. The results showed that VAP derivative peptides VLP, VGP, VSP, GAP, LSP, and TRP exhibited potent ACE inhibitory activities, while the non-derivative peptide APG showed only weak activity. In in silico studies, the docking score S value showed that VAP derivative peptides VLP, VGP, VSP, LSP, and TRP had stronger docking interactions than APG. Molecular docking in the ACE active pocket showed that TRP, the most potent ACE inhibitory peptide among the VAP derivatives, had a larger number of interactions with ACE residues in comparison with APG and that the TRP molecule appeared to spread widely in the ACE pocket, while the APG molecule appeared to spread closely. Differences in molecular spread may be a reason why TRP exhibits more potent ACE inhibitory activity than APG. The results suggest that the number and strength of interactions between the peptide and ACE are important for the ACE- inhibitory potency of the peptide.

Immunological abnormalities in patients with early-onset ataxia with ocular motor apraxia and hypoalbuminemia.

Early-onset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH) is a neurodegenerative disorder caused by mutation in the aprataxin (APTX)-coding gene APTX, which is involved in DNA single-strand break repair (SSBR). The neurological abnormalities associated with EAOH are similar to those observed in patients with ataxia-telangiectasia. However, the immunological abnormalities in patients with EAOH have not been described. In this study, we report that EAOH patients have immunological abnormalities, including lymphopenia; decreased levels of CD4+ T-cells, CD8+ T-cells, and B-cells; hypogammaglobulinemia; low T-cell recombination excision circles and kappa-deleting element recombination circles; and oligoclonality of T-cell receptor ß-chain variable repertoire. These immunological abnormalities vary among the EAOH patients. Additionally, mild radiosensitivity in the lymphocytes obtained from the patients with EAOH was demonstrated. These findings suggested that the immunological abnormalities and mild radiosensitivity evident in patients with EAOH could be probably caused by the DNA repair defects.

Hematopoietic stem cell transplantation for progressive combined immunodeficiency and lymphoproliferation in patients with activated phosphatidylinositol-3-OH kinase δ syndrome type 1.

BACKGROUND: Activated phosphatidylinositol-3-OH kinase δ syndrome type 1 (APDS1) is a recently described primary immunodeficiency syndrome characterized by recurrent respiratory tract infections, lymphoid hyperplasia, and Herpesviridae infections caused by germline gain-of-function mutations of PIK3CD. Hematopoietic stem cell transplantation (HSCT) can be considered to ameliorate progressive immunodeficiency and associated malignancy, but appropriate indications, methods, and outcomes of HSCT for APDS1 remain undefined. OBJECTIVE: Our objective was to analyze the clinical manifestations, laboratory findings, prognosis, and treatment of APDS1 and explore appropriate indications and methods of HSCT. METHODS: We reviewed retrospectively the medical records of cohorts undergoing HSCT at collaborating facilities. RESULTS: Thirty-year overall survival was 86.1%, but event-free survival was 39.6%. Life-threatening events, such as severe infections or lymphoproliferation, were frequent in childhood and adolescence and were common indications for HSCT. Nine patients underwent HSCT with fludarabine-based reduced-intensity conditioning. Seven patients survived after frequent adverse complications and engraftment failure. Most symptoms improved after HSCT. CONCLUSION: Patients with APDS1 showed variable clinical manifestations. Life-threatening progressive combined immunodeficiency and massive lymphoproliferation were common indications for HSCT. Fludarabine-based reduced-intensity conditioning-HSCT ameliorated clinical symptoms, but transplantation-related complications were frequent, including graft failure.

Clinical and Immunological Characterization of ICF Syndrome in Japan.

OBJECTIVE: Immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is a rare autosomal recessive primary immunodeficiency. Hypogammaglobulinemia is a major manifestation of ICF syndrome, but immunoglobulin replacement therapy does not seem to be effective for some ICF patients. Therefore, we aimed to reassess the immunological characteristics of this syndrome. METHODS: Eleven Japanese patients with ICF syndrome were enrolled. We performed whole-exome sequencing in four cases and homozygosity mapping using SNP analysis in two. We evaluated their clinical manifestations and immunological status. RESULTS: We newly diagnosed six ICF patients who had tentatively been diagnosed with common variable immunodeficiency. We identified two novel mutations in the DNMT3B gene and one novel mutation in the ZBTB24 gene. All patients showed low serum IgG and/or IgG2 levels and were treated by periodic immunoglobulin replacement therapy. Three of the six patients showed worse results of the mitogen-induced lymphocyte proliferation test. Analyses of lymphocyte subpopulations revealed that CD19+CD27+ memory B cells were low in seven of nine patients, CD3+ T cells were low in three patients, CD4/8 ratio was inverted in five patients, CD31+ recent thymic emigrant cells were low in two patients, and CD19+ B cells were low in four patients compared with those in the normal controls. ICF2 patients showed lower proportions of CD19+ B cells and CD16+56+ NK cells and significantly higher proportions of CD3+ T cells than ICF1 patients. T cell receptor excision circles were undetectable in two patients. Despite being treated by immunoglobulin replacement therapy, three patients died of influenza virus, fatal viral infection with persistent Epstein-Barr virus infection, or JC virus infection. One of three dead patients showed normal intelligence with mild facial anomaly. Two patients presented with autoimmune or inflammatory manifestations. Infectious episodes decreased in three patients who were started on trimethoprim-sulfamethoxazole and/or antifungal drugs in addition to immunoglobulin replacement therapy. These patients might have suffered from T cell immunodeficiency. CONCLUSION: These results indicate that patients with ICF syndrome have a phenotype of combined immunodeficiency. Thus, to achieve a better prognosis, these patients should be treated as having combined immunodeficiency in addition to receiving immunoglobulin replacement therapy.

Dual emissive bispyrene peptide probes for highly sensitive measurements of trypsin activity and evaluation of trypsin inhibitors.

Peptide substrates were double labeled with pyrenes to prepare fluorescent probes for highly sensitive detection of protease activity and evaluation of protease inhibitors using pyrene monomer/excimer signals. Two proximate pyrene moieties formed excited state dimers in the probes, and these pyrene excimer formations were dissociated by tryptic digestion. The specificity constant of the optimum bispyrene peptide probe was 2.7 times higher than that of the conventional peptide-4-methylcoumarin amide. Moreover, our probe had high sensitivity with an estimated detection limit for trypsin of 4.11 pM. The half maximal inhibitory concentration and dissociation constant of the Bowman-Birk inhibitor were successfully estimated.

Efficient near infrared fluorescence detection of elastase enzyme using peptide-bound unsymmetrical squaraine dye.

Extended wavelength analyte-responsive fluorescent probes are highly desired for the imaging applications owing to their deep tissue penetration, and minimum interference from autofluorescence by biomolecules. Near infra-red (NIR) sensitive and self-quenching fluorescent probe based on the dye-peptide conjugate (SQ 1 PC) was designed and synthesized by facile and efficient one-pot synthetic route for the detection of Elastase activity. In the phosphate buffer solution, there was an efficient quenching of fluorescence of SQ 1 PC (86%) assisted by pronounced dye-dye interaction due to H-aggregate formation. Efficient and fast recovery of this quenched fluorescence of SQ 1 PC (> 50% in 30s) was observed on hydrolysis of this peptide-dye conjugate by elastase enzyme. Presently designed NIR sensitive self-quenching substrate offers the potential application for the detection of diseases related to proteases by efficient and fast detection of their activities.

Phosphatase and tensin homolog (PTEN) mutation can cause activated phosphatidylinositol 3-kinase δ syndrome-like immunodeficiency.

BACKGROUND: Activated phosphatidylinositol 3-kinase δ syndrome (APDS) is a recently discovered primary immunodeficiency disease (PID). Excess phosphatidylinositol 3-kinase (PI3K) activity linked to mutations in 2 PI3K genes, PIK3CD and PIK3R1, causes APDS through hyperphosphorylation of AKT, mammalian target of rapamycin (mTOR), and S6. OBJECTIVE: This study aimed to identify novel genes responsible for APDS. METHODS: Whole-exome sequencing was performed in Japanese patients with PIDs. Immunophenotype was assessed through flow cytometry. Hyperphosphorylation of AKT, mTOR, and S6 in lymphocytes was examined through immunoblotting, flow cytometry, and multiplex assays. RESULTS: We identified heterozygous mutations of phosphatase and tensin homolog (PTEN) in patients with PIDs. Immunoblotting and quantitative PCR analyses indicated that PTEN expression was decreased in these patients. Patients with PTEN mutations and those with PIK3CD mutations, including a novel E525A mutation, were further analyzed. The clinical symptoms and immunologic defects of patients with PTEN mutations, including lymphocytic AKT, mTOR, and S6 hyperphosphorylation, resemble those of patients with APDS. Because PTEN is known to suppress the PI3K pathway, it is likely that defective PTEN results in activation of the PI3K pathway. CONCLUSION: PTEN loss-of-function mutations can cause APDS-like immunodeficiency because of aberrant PI3K pathway activation in lymphocytes.

Novel fluorescent substrates for detection of trypsin activity and inhibitor screening by self-quenching.

A group of self-quenching-based substrates with two fluorescent peptides for detection of trypsin activity was designed and synthesized. The substrates could be easily synthesized using simple solid-phase peptide synthesis techniques. Two fluorescent peptide substrates for trypsin were conjugated to the amino groups of lysine as a branched unit. The fluorescence of these substrates was self-quenched owing to the highly assembled fluorophores on the substrates. The release of these concentrated fluorophores by proteases allows for fluorescence recovery. Self-quenching reduced the fluorescence of the substrates by 64.1%, and the fluorescence intensity was recovered by the release of the fluorophores from the substrate peptides via tryptic cleavage. The kinetic assay revealed that the kcat/Km values of the substrates were almost comparable to those of the standard fluorescent probe, peptide-MCA. The detection limit for trypsin was 111pM, and the calculation of IC50 and Ki values for the Bowman-Birk inhibitor was achieved using these substrates. These easily synthesizable self-quenching-based substrates have the potential to be useful for the detection of other disease-related protease activities.

RAG1 deficiency may present clinically as selective IgA deficiency.

BACKGROUND: Recombination-activating gene (RAG) 1 and 2 deficiency is seen in patients with severe combined immunodeficiency (SCID) and Omenn syndrome. However, the spectrum of the disease has recently expanded to include a milder phenotype. OBJECTIVE: We analyzed a 4-year-old boy who was initially given the diagnosis of selective immunoglobulin A deficiency (SIgAD) based on immunoglobulin serum levels without any opportunistic infections, rashes, hepatosplenomegaly, autoimmunity or granulomas. The patient was found to be infected with varicella zoster; however, the clinical course was not serious. He produced antiviral antibodies. METHODS: We performed lymphocyte phenotyping, quantification of T cell receptor excision circles (TRECs) and kappa deleting recombination excision circles (KRECs), an analysis of target sequences of RAG1 and 2, a whole-genome SNP array, an in vitro V(D)J recombination assay, a spectratype analysis of the CDR3 region and a flow cytometric analysis of the bone marrow. RESULTS: Lymphocyte phenotyping demonstrated that the ratio of CD4+ to CD8+ T cells was inverted and the majority of CD4+T cells expressed CD45RO antigens in addition to the almost complete lack of B cells. Furthermore, both TRECs and KRECs were absent. Targeted DNA sequencing and SNP array revealed that the patient carried a deletion of RAG1 and RAG2 genes on the paternally-derived chromosome 11, and two maternally-derived novel RAG1 missense mutations (E455K, R764H). In vitro analysis of recombination activity showed that both RAG1 mutant proteins had low, but residual function. CONCLUSIONS: The current case further expands the phenotypic spectrum of mild presentations of RAG deficiency, and suggests that TRECs and KRECs are useful markers for detecting hidden severe, as well as mild, cases.

Late-Onset Combined Immunodeficiency with a Novel IL2RG Mutation and Probable Revertant Somatic Mosaicism.

Primary immunodeficiency disease (PID) is caused by mutations of more than two hundred immunity-related genes. In addition to the heterogeneity of the diseases, the atypical presentation of each disease caused by hypomorphic mutations or somatic mosaicism makes genetic diagnosis challenging. Next-generation sequencing tests all genes simultaneously and has proven its innovative efficacy in genomics. We describe a male PID patient without any family history of immunodeficiency. This patient suffered from recurrent infections from 1 year of age. Laboratory analysis showed hypogammaglobulinemia. T, B, and NK cells were present, but the T cell proliferative response decreased. Whole-exome sequencing analysis identified an IL2RG p.P58T missense mutation. CD8(+) and CD56(+) cells showed revertant somatic mosaicism to the wild-type allele. A late-onset and atypical presentation of the X-linked severe combined immunodeficiency (X-SCID) phenotype might be associated with revertant somatic mosaicism in T and NK cells. This patient is the seventh reported case of X-SCID with revertant somatic mosaicism. His classical clinical management did not result in a molecular diagnosis because of the atypical presentation. The coverage that is provided by whole-exome sequencing of most PID genes effectively excluded differential diagnoses other than X-SCID. As next-generation sequencing becomes available in clinical practice, it will enhance our knowledge of PID and rescue currently undiagnosed patients.

An efficient synthesis of SK-658 and its analogs as potent histone deacetylase inhibitors.

SK-658 is a potent histone deacetylase (HDAC) inhibitor that showed higher activity than SAHA due to the presence of extended hydrophobic group. We designed and synthesized thioester and SS-hybrid bearing SK-658 analogs as HDAC inhibitors. All the compounds were active in nano molar range and showed higher inhibitory activity than SAHA and SK-658. Among these, disulfide compounds showed the highest activity.

A convenient preparation of N (ε)-methyl-L-lysine derivatives and its application to the synthesis of histone tail peptides.

A convenient route is established for the preparation of N (α)-Fmoc-N (ε)-(Boc, methyl)-L-lysine and N (α)-Fmoc-N (ε)-dimethyl-L-lysine as building blocks to be used for the synthesis of methylated peptides. This methodology is based on the use of malonate derivatives and dibromobutane to produce key intermediates, L-2-amino-6-bromohexanoic acid derivatives, which could be modified to the required group at the ε-position. Fmoc-protection is accessible, so these compounds can be used in solution as well as in solid-phase peptide synthesis. Also the peptides containing these methylated lysines have been proved to resist the action of trypsin and lysyl endopeptidase. Thus, this new method could be considered as an improvement of the synthesis of N (ε)-methyl-L-lysine derivatives.

Design and synthesis of mono and bicyclic tetrapeptides thioester as potent inhibitor of histone deacetylases.

Inhibitors of histone deacetylases (HDACs) are a promising class of anticancer agents that have an effect on gene regulation. The naturally occurring cyclic depsipeptide FK228 containing disulfide and Largazole possessing thioester functionalities act as pro-drugs and share the same HDAC inhibition mechanism in cell. Inspired from these facts, we have reported bicyclic tetrapeptide disulfide HDAC inhibitors resembling FK228 with potent activity and enhanced selectivity. In the present study, we report the design and synthesis of several mono and bicyclic tetrapeptide thioester HDAC inhibitors that share the inhibition mechanism similar to Largazole. Most of the compounds showed HDAC1 and HDAC4 inhibition and p21 promoting activity in nanomolar ranges. Among these the monocyclic peptides 1, 2 and bicyclic peptide, 4 are notable demanding more advanced research to be promising anticancer drug candidates.

Bicyclic tetrapeptides as potent HDAC inhibitors: effect of aliphatic loop position and hydrophobicity on inhibitory activity.

Several histone deacetylase (HDAC) inhibiting bicyclic tetrapeptides have been designed and synthesized through intramolecular ring-closing metathesis (RCM) reaction and peptide cyclization. We designed bicyclic tetrapeptides based on CHAP31, trapoxin B and HC-toxin I. The HDAC inhibitory and p21 promoter assay results showed that the aliphatic loop position as well as the hydrophobicity plays an important role toward the activity of the bicyclic tetrapeptide HDAC inhibitors.

Design and synthesis of CHAP31, trapoxin B and HC-toxin based bicyclic tetrapeptides disulfide as potent histone deacetylase inhibitors.

The naturally occurring cyclic depsipeptide, FK228 inhibits histone deacetylase (HDAC) enzymes after reductive cleavage of intra-molecular disulfide bond. One of the sulfhydryl groups produced in the reduction interacts with zinc atom that involved in the catalytic mechanism of type 1 and 2 HDACs such as HDAC1, HDAC4, and HDAC6. In the present study, we describe the development of CHAP31, trapoxin B and HC-toxin based cyclic tetrapeptides with intra-molecular disulfide bond as HDAC inhibitors. The bicyclic tetrapeptides disulfide showed potent HDAC1 and HDAC4 inhibition and p21 promoting activity.

Design and synthesis of peptide-MCA substrates for a novel assay of histone methyltransferases and their inhibitors.

Histone methyltransferases (HMTs) play an important role in controlling gene expression through site-specific methylation of lysines in core and linker histones within chromatin. As the typical HMTs, G9a and Set7/9 have been intensively studied that G9a is specific to the methylation at H3K9 and H3K27 and represses transcription, while Set7/9 methylates at H3K4. In this report we prepared various peptide-MCAs (4-methylcoumaryl-7-amides) related to histone tail and protein-substrates such as p53 and estrogen receptor-α. The fluorogenic substrates are applied for the assay of HMTs and an inhibitor, for example. The most sensitive and specific MCA-substrates to G9a and Set7/9 are discovered. The peptide-MCAs corresponding to the methylation sequences are promising for screening of HMT inhibitors.

Bicyclic tetrapeptide histone deacetylase inhibitors with methoxymethyl ketone and boronic acid zinc-binding groups.

Histone deacetylase (HDAC) inhibitors are a class of potential therapeutics for the treatment of cancer. Bicyclic tetrapeptides equipped with methoxymethyl ketone and boronic acid as zinc-binding group were designed and synthesized. The inhibitory activities of these compounds were evaluated against HDAC enzymes. The cell-free and cell-based assay data showed that both potency and selectivity changed with the change in zinc-binding group. Boronic acid-based compound showed poor activity whereas methoxymethyl ketone-based compound displayed impressive activity in both cell-free and cell-based conditions.