Epimers from the leaves of Calophyllum inophyllum

The ethanolic extract of the fresh leaves of Calophyllum inophyllum afforded a pair of new epimers named as inophynone and isoinophynone. Their structures were elucidated with the aid of spectroscopic techniques. Some known constituents, cholesterol, friedelin, canophyllol and canophyllic acid, were also isolated from the same source.     

An insight into molecular taxonomy of bufonids,microhylids, and dicroglossid frogs: First genetic records from Pakistan

The current study was focused on documentation of amphibian assemblage in North Punjab and Islamabad Capital Territory, Pakistan, by using mitochondrial gene sequences of 16S rRNA. Our study entailed 37% of the known amphibian species of the country. We provided a phylogenetic analysis based on 74 newly generated mitochondrial 16S rRNAs from nine species of genus Microlyla, Duttaphrynus, Allopaa, Nanorana, Sphaerotheca, Minervarya, Hoplobatrachus, and Euphlyctis. We employed the maximum‐likelihood inference and Bayesian analysis to assess the taxonomic status of the samples obtained from Pakistan, with respect to other congeneric species from surrounding regions. Our findings confirmed the taxonomic status of South Asian anuran species Duttaphrynus stomaticus, Duttaphrynus melanostictus, Microhyla nilphamariensis, Allopaa hazarensis, Nanorana vicina, Sphaerotheca maskeyi (synonym: S. pashchima), Minervarya pierrei, Hoplobatrachus tigerinus, and Euphlyctis kalasgramensis in Pakistan. We have reported new country records of genus Minervarya ( M. pierrei). Minervarya pierrei was previously misidentified as Fejervarya limnocharis, due to dearth of genetic information. We provided the first genetic records of our endemic species N. vicina. The results revealed the taxonomic placement of N. vicina with respect to its congeners and validated the taxonomic status of N. vicina from its type locality (Murree) for the first time. The findings of the present study also indicated the paraphyletic relationship of A.‐ hazarensis with Nanorana species. So, based on our phylogenetic inferences, morphological characters, and habitat preferences, validity of generic status of A. hazarensis is undecided. As our data were not enough to resolve this issue, we suggest sequencing of additional mitochondrial and nuclear genes in the future studies to get a better resolution. We recommend carrying out extensive surveys throughout the country for proper scientific documentation of amphibians of Pakistan. Many new species, some of them might be endemic to Pakistan, are expected to be discovered, and taxonomic status of other species would be resolved.     

SARS-CoV-2 membrane protein causes the mitochondrial apoptosis and pulmonary edema via targeting BOK

Deaths caused by coronavirus disease 2019 (COVID-19) are largely due to the lungs edema resulting from the disruption of the lung alveolo-capillary barrier, induced by SARS-CoV-2-triggered pulmonary cell apoptosis. However, the molecular mechanism underlying the proapoptotic role of SARS-CoV-2 is still unclear. Here, we revealed that SARS-CoV-2 membrane (M) protein could induce lung epithelial cells mitochondrial apoptosis. Notably, M protein stabilized B-cell lymphoma 2 (BCL-2) ovarian killer (BOK) via inhibiting its ubiquitination and promoted BOK mitochondria translocation. The endodomain of M protein was required for its interaction with BOK. Knockout of BOK by CRISPR/Cas9 increased cellular resistance to M protein-induced apoptosis. BOK was rescued in the BOK-knockout cells, which led to apoptosis induced by M protein. M protein induced BOK to trigger apoptosis in the absence of BAX and BAK. Furthermore, the BH2 domain of BOK was required for interaction with M protein and proapoptosis. In vivo M protein recombinant lentivirus infection induced caspase-associated apoptosis and increased alveolar-capillary permeability in the mouse lungs. BOK knockdown improved the lung edema due to lentivirus-M protein infection. Overall, M protein activated the BOK-dependent apoptotic pathway and thus exacerbated SARS-CoV-2 associated lung injury in vivo. These findings proposed a proapoptotic role for M protein in SARS-CoV-2 pathogenesis, which may provide potential targets for COVID-19 treatments.Subject terms: Infectious diseases, Immunopathogenesis

In SARS-CoV-2-infected lung epithelial cells, endodomain of M protein binds to the BH2 domain of BOK and inhibits ubiquitination. BOK is stabilized and translocate to the mitochondrial outer membrane, promoting Cyt c release. Cyt c released outside the mitochondria activates CASP 9 mediated apoptosis, thereby inducing pulmonary edema.     

Genotypic variation for drought tolerance in cotton (Gossypium hirsutum L.): Leaf gas exchange and productivity

Although water-limited environments are detrimental to cotton growth and productivity worldwide, identification of cotton (Gossypium hirsutum L.) genotypes that are less sensitive to drought may improve productivity in drought prone areas. The objective of the study was to assess genotypic variation for drought tolerance in cotton varieties using physiological attributes as selection criteria, and to determine the relationship of physiological attributes with productivity traits. The association of target physiological traits for drought tolerance (photosynthetic rate (P_n), stomatal conductance (g_s), and transpiration rate (E)) with productivity traits under well-watered (W₁) and water-limited (W₂) regimes was analyzed using 32 public cotton cultivars/bred lines in two field experiments conducted during the normal cotton growing seasons 2003 and 2004. Seed cotton yield (SCY) and biological yield (BY) were markedly affected under W₂ regime in all cultivars except the outstanding performance of CIM-1100 and RH-510 proving their superiority to other cultivars in drought tolerance. Conversely, FH-901, FH-634, and FH-2000 were high yielding under W₁ regime; however, exhibited a sharp decline in yield under W₂ regime. A positive correlation between SCY and BY under water stress (r=0.44 in 2003; r=0.69 in 2004) indicates that BY is also a primary determinant of SCY under water stress and genetic improvement of BY under water-limited environment may also improve SCY. P_n, g_s, and E were significantly reduced by water stress. Substantial genotypic variation for gas exchange attributes existed among the cotton cultivars. A positive association (P<0.01) was observed between g_s and E under both regimes in both years indicating the prevalence of stomatal control of transpiration. The positive association (P<0.01) between P_n and g_s in both years in W₂ regime indicates also a major role of stomatal effects in regulating leaf photosynthesis under water-limited conditions. P_n was significantly correlated with SCY (P<0.01) and BY (P<0.05 in 2003; P<0.01 in 2004) in W₂ regime; however, the level of these associations was not significant in W₁ regime. These findings demonstrate that association of P_n with productivity is effective under water-limited environment and may be useful as a selection criterion in breeding programs with the objective of improving drought tolerance and SCY under water-limited environments. Moreover, association between SCY and BY under water stress suggests that genetic improvement of BY under water stress may also improve SCY.     

Prediction of Structure of Human WNT-CRD (FZD) Complex for Computational Drug Repurposing

The observed genetic alterations of various extracellular and intracellular WNT (Wingless, Int-1 proto-oncogene) signaling components can result in an increase or decrease in gene expression, and hence can be obstructed proficiently. These genetics target sites may include the prevention of WNT-FZD (Frizzled) binding, destruction of β-catenin and formation of Axin, APC and GSK-3β complex. Hence, the localized targeting of these interacting partners can help in devising novel inhibitors against WNT signaling. Our present study is an extension of our previous work, in which we proposed the co-regulated expression pattern of the WNT gene cluster (WNT-1, WNT-6, WNT-10A and WNT-10B) in human breast carcinoma. We present here the computationally modeled three dimensional structure of human WNT-1 in complex with the FZD-1 CRD (Cysteine Rich Domain) receptor. The dimeric cysteine-rich domain was found to fit into the evolutionarily conserved U-shaped groove of WNT protein. The two ends of the U- shaped cleft contain N-terminal and C-terminal hydrophobic residues, thus providing a strong hydrophobic moiety for the frizzled receptor and serving as the largest binding pocket for WNT-FZD interaction. Detailed structural analysis of this cleft revealed a maximum atomic distance of ∼28 Å at the surface, narrowing down to ∼17 Å and again increasing up to ∼27 Å at the bottom. Altogether, structural prediction analysis of WNT proteins was performed to reveal newer details about post-translational modification sites and to map the novel pharmacophore models for potent WNT inhibitors.     

The interplay between mitochondria and store-operated Ca2+ entry: Emerging insights into cardiac diseases

Store-operated Ca²⁺ entry (SOCE) machinery, including Orai channels, TRPCs, and STIM1, is key to cellular calcium homeostasis. The following characteristics of mitochondria are involved in the physiological and pathological regulation of cells: mitochondria mediate calcium uptake through calcium uniporters; mitochondria are regulated by mitochondrial dynamic related proteins (OPA1, MFN1/2, and DRP1) and form mitochondrial networks through continuous fission and fusion; mitochondria supply NADH to the electron transport chain through the Krebs cycle to produce ATP; under stress, mitochondria will produce excessive reactive oxygen species to regulate mitochondria-endoplasmic reticulum interactions and the related signalling pathways. Both SOCE and mitochondria play critical roles in mediating cardiac hypertrophy, diabetic cardiomyopathy, and cardiac ischaemia-reperfusion injury. All the mitochondrial characteristics mentioned above are determinants of SOCE activity, and vice versa. Ca²⁺ signalling dictates the reciprocal regulation between mitochondria and SOCE under the specific pathological conditions of cardiomyocytes. The coupling of mitochondria and SOCE is essential for various pathophysiological processes in the heart. Herein, we review the research focussing on the reciprocal regulation between mitochondria and SOCE and provide potential interplay patterns in cardiac diseases.