Some Secrets of Fluorescent Proteins: Distinct Bleaching in Various Mounting Fluids and Photoactivation of cyan fluorescent proteins at YFP-Excitation

Background
The use of spectrally distinct variants of green fluorescent protein (GFP) such as cyan or yellow mutants (CFP and YFP, respectively) is very common in all different fields of life sciences, e.g. for marking specific proteins or cells or to determine protein interactions. In the latter case, the quantum physical phenomenon of fluorescence resonance energy transfer (FRET) is exploited by specific microscopy techniques to visualize proximity of proteins.

Methodology/Principal Findings
When we applied a commonly used FRET microscopy technique - the increase in donor (CFP)-fluorescence after bleaching of acceptor fluorophores (YFP), we obtained good signals in live cells, but very weak signals for the same samples after fixation and mounting in commercial microscopy mounting fluids. This observation could be traced back to much faster bleaching of CFP in these mounting media. Strikingly, the opposite effect of the mounting fluid was observed for YFP and also for other proteins such as Cerulean, TFP or Venus. The changes in photostability of CFP and YFP were not caused by the fixation but directly dependent on the mounting fluid. Furthermore we made the interesting observation that the CFP-fluorescence intensity increases by about 10 - 15% after illumination at the YFP-excitation wavelength – a phenomenon, which was also observed for Cerulean. This photoactivation of cyan fluorescent proteins at the YFP-excitation can cause false-positive signals in the FRET-microscopy technique that is based on bleaching of a yellow FRET acceptor.

Conclusions/Significance
Our results show that photostability of fluorescent proteins differs significantly for various media and that CFP bleaches significantly faster in commercial mounting fluids, while the opposite is observed for YFP and some other proteins. Moreover, we show that the FRET microscopy technique that is based on bleaching of the YFP is prone to artifacts due to photoactivation of cyan fluorescent proteins under these conditions

Systemic Diseases and Risk of Developing Gastrointestinal Cancer.

Importance: Gastrointestinal (GI) cancers are the second leading cause of cancer-related deaths worldwide. Observations: The global challenges GI cancers pose are high, especially in middle- and low-income countries. Patients with these cancers present with symptoms of poor appetite, weight loss, heartburn, abdominal pain, fatigue, and anaemia. Several risk factors contribute to GI cancers, including age, gender, obesity, pathogenic infections, smoking cigarettes, alcohol consumption, and dietary habits. Most of these cancers are sporadic. However, some patients are at high risk because of a family history of GI cancers. Systemic diseases affect multiple organs, and their chronic occurrence elicits inflammatory responses at various sites. These diseases also contribute to GI cancers. Conclusion and Relevance: In this review, we discuss that untreated systemic diseases, including diabetes, hepatitis, AIDS, ulcers, and hypertension, can potentially lead to GI cancers if they remain untreated for a longer period. Systemic diseases initiate oxidative stress, inflammatory pathways, and genetic manipulations, which altogether confer risks to GI cancers. Here, we describe the association between systemic diseases and their underlying mechanisms leading to GI cancers

Trends in Cancer Prevalence in Punjab, Pakistan: A Systematic Study from 2010 to 2016

Cancer is the second leading cause of death globally. However, in Pakistan, in the absence of a national cancer registry, it is difficult to predict the current status of cancer incidence. Therefore, a need was felt to design a study that can give a depiction of the prevalence of common cancer types and their relevance to the local population in the absence of a proper cancer registry system. In view of this, data was collected from 2010 to 2016 for breast, prostate, head and neck, cervical and colorectal cancer from the cancer hospitals and centres located all over Punjab, Pakistan. All the data were analysed to calculate prevalence percentage, gender-based incidence rate, crude rate, and Age-specific rate (ASR) for each cancer type. The results showed that breast cancer was the most common type and its prevalence showed a linear increase through the study period (P \u3c 0.001). Breast cancer (6561) was followed by prostate (1183), head and neck (833), cervical (697) and colorectal cancer (531) in terms of prevalence. Gender-specific cancers like breast, prostate, and cervical were found to be more common as compared to others. In the case of head and neck and colorectal cancers, males were more susceptible as compared to females. There is a radical increase in cancer cases in the study area and the same could be extrapolated to the whole country. Therefore, for the appropriate and focused efforts to combat this increasing trend of prevalence, it should be constantly monitored, which leads to the recommendation of an effective cancer registry system in the country

Association of Interleukin 17F with Arthritis in Punjabi Families of Pakistan

Arthritis is a chronic inflammatory disease that causes severe joint pain. Interleukin 17F (IL17F) is considered as a candidate gene functionally; it mediates pro-inflammatory responses, depending on the type and site of inflammation. The present study examined the polymorphism of IL17F (rs763780 and rs2397084) among the families affected by arthritis. Demographic data and blood samples were collected from the families with at least one affected offspring with arthritis. Analysis of the IL17F gene polymorphism was performed by the digestion of DNA with NlaIII and AvaII. The results showed that IL17F rs763780 (AA, AG and GG genotypes) and rs2397084 (AA, AG and GG genotypes) were associated with arthritis (OA & RA). It was evaluated that about 65 and 21 percent of the individuals mutated with homozygous mutation for wild type allele A, heterozygous mutation A/G against selected SNPs respectively. But homozygous polymorphic allele for allele G was only found against rs2397084. Mutation in rs2397084 resulted to change Lysine into Arginine, whereas mutation in rs763780 changed Histidine into Arginine. Maternal history was found as a stronger factor in transferring arthritis. The results of this study revealed an association of arthritis with IL17F among Pakistani population

Identification and Phylogenetic Analysis of Channa Species from Riverine System of Pakistan Using COI Gene as a DNA Barcoding Marker

Channa are the freshwater and important food fish species in Pakistan belonging to family Channidae. However, identification and phylogenetic analysis based on molecular tools of these species in Pakistan was not well known. Herein, the current investigation was conceptualized, which dealt with mitochondrial DNA sequences from three geographically distinct populations of this species from Pakistan’s water system. DNA from fin tissues was extracted. COI region of mtDNA was amplified using universal primers for fish. PCR products were sequenced. Phylogenetic analysis conducted in the present study, i.e. neighbor-joining (NJ) cladogram, maximum likelihood, K2P genetic divergence and histogram suggests that the studied species of family Channidae are genetically different. The K2P intraspecific divergences were lower than interspecific divergences. The clades in the evolutionary tree for three species were clearly separated

miR-4482 and miR-3912 aim for 3'UTR of ERG mRNA in prostate cancer.

Ets-related gene (ERG) is overexpressed as a fusion protein in prostate cancer. During metastasis, the pathological role of ERG is associated with cell proliferation, invasion, and angiogenesis. Here, we hypothesized that miRNAs regulate ERG expression through its 3'UTR. Several bioinformatics tools were used to identify miRNAs and their binding sites on 3'UTR of ERG. The selected miRNAs expression was analyzed in prostate cancer samples by qPCR. The miRNAs overexpression was induced in prostate cancer cells (VCaP) to analyze ERG expression. Reporter gene assay was performed to evaluate the ERG activity in response to selected miRNAs. The expression of ERG downstream target genes was also investigated through qPCR after miRNAs overexpression. To observe the effects of selected miRNAs on cell proliferation and migration, scratch assay was performed to calculate the cell migration rate. miR-4482 and miR-3912 were selected from bioinformatics databases. miR-4482 and -3912 expression were decreased in prostate cancer samples, as compared to controls (p<0.05 and p<0.001), respectively. Overexpression of miR-4482 and miR-3912 significantly reduced ERG mRNA (p<0.001 and p<0.01), respectively) and protein (p<0.01) in prostate cancer cells. The transcriptional activity of ERG was significantly reduced (p<0.01) in response to miR-4482 and-3912. ERG angiogenic targets and cell migration rate was also reduced significantly (p<0.001) after miR-4482 and -3912 over-expression. This study indicates that miR-4482 and -3912 can suppress the ERG expression and its target genes, thereby, halt prostate cancer progression. These miRNAs may be employed as a potential therapeutic target for the miRNA-based therapy against prostate cancer

In-silico prediction of TGF-β1 non-synonymous variants and their impact on binding affinity to Fresolimumab

TGF-β1 is a potent immunoregulatory cytokine that plays diverse roles in development, bone healing, fibrosis, and cancer. However, characterizing TGF-β1 gene variants is challenging because the structural and functional consequences of these variants are still undetermined. In this study, we aimed to perform an in-silico analysis of TGF-β1 non-synonymous variants and their pathogenic effects on the TGF-β1 protein. A total of 10,252 TGF-β1 SNPs were collected from the NCBI dbSNP database and in-silico tools (SIFT, PROVEAN, Mutation Taster, ClinVar, PolyPhen-2, CScape, MutPred, and ConSurf) were used. The in-silico predicted potential variants were further investigated for their binding to the TGF-β1 targeting drug “Fresolimumab”. Molecular docking was performed using HADDOCK and confirmed by PRODIGY and PDBsum. The in-silico analysis predicted four potential TGF-β1 nsSNPs: E47G in the LAP domain of the propeptide and I22T, L28F, and E35D in the mature TGF-β1 peptide. HADDOCK and molecular dynamics simulations revealed that the I22T and E35D variants have higher binding affinity for Fresolimumab as compared to the wild type and L28F variants. Molecular dynamics simulations (100 ns) and principal component analysis showed that TGF-β1 variants influenced the protein structure and caused variations in the internal dynamics of protein complexes with the antibody. Among them, the E35D variant significantly destabilized the TGF-β1 protein structure, resulting in rearrangement in the binding site and affecting the interactions with the Fresolimumab. This study identified four variants that can affect the TGF-β1 protein structure and result in functional consequences such as impaired response to Fresolimumab.: TGF-β1 is a potent immunoregulatory cytokine that plays diverse roles in development, bone healing, fibrosis, and cancer. However, characterizing TGF-β1 gene variants is challenging because the structural and functional consequences of these variants are still undetermined. In this study, we aimed to perform an in-silico analysis of TGF-β1 non-synonymous variants and their pathogenic effects on the TGF-β1 protein. A total of 10,252 TGF-β1 SNPs were collected from the NCBI dbSNP database and in-silico tools (SIFT, PROVEAN, Mutation Taster, ClinVar, PolyPhen-2, CScape, MutPred, and ConSurf) were used. The in-silico predicted potential variants were further investigated for their binding to the TGF-β1 targeting drug "Fresolimumab". Molecular docking was performed using HADDOCK and confirmed by PRODIGY and PDBsum. The in-silico analysis predicted four potential TGF-β1 nsSNPs: E47G in the LAP domain of the propeptide and I22T, L28F, and E35D in the mature TGF-β1 peptide. HADDOCK and molecular dynamics simulations revealed that the I22T and E35D variants have higher binding affinity for Fresolimumab as compared to the wild type and L28F variants. Molecular dynamics simulations (100 ns) and principal component analysis showed that TGF-β1 variants influenced the protein structure and caused variations in the internal dynamics of protein complexes with the antibody. Among them, the E35D variant significantly destabilized the TGF-β1 protein structure, resulting in rearrangement in the binding site and affecting the interactions with the Fresolimumab. This study identified four variants that can affect the TGF-β1 protein structure and result in functional consequences such as impaired response to Fresolimumab.Communicated by Ramaswamy H. Sarma

Mechanistic insights into PTS2-mediated peroxisomal protein import : the co-receptor PEX5L drastically increases the interaction strength between the cargo protein and the receptor PEX7

The destination of peroxisomal matrix proteins is encoded by short peptide sequences, which have been characterized as peroxisomal targeting signals (PTS) residing either at the C terminus (PTS1) or close to the N terminus (PTS2). PTS2-carrying proteins interact with their cognate receptor protein PEX7 that mediates their transport to peroxisomes by a concerted action with a co-receptor protein, which in mammals is the PTS1 receptor PEX5L. Using a modified version of the mammalian two-hybrid assay, we demonstrate that the interaction strength between cargo and PEX7 is drastically increased in the presence of the co-receptor PEX5L. In addition, cargo binding is a prerequisite for the interaction between PEX7 and PEX5L and ectopic overexpression of PTS2-carrying cargo protein drastically increases the formation of PEX7-PEX5L complexes in this assay. Consistently, we find that the peroxisomal transfer of PEX7 depends on cargo binding and that ectopic overexpression of cargo protein stimulates this process. Thus, the sequential formation of a highly stable trimeric complex involving cargo protein, PEX7 and PEX5L stabilizes cargo binding and is a prerequisite for PTS2-mediated peroxisomal import.Published versio