Polypharmacological Cell-Penetrating Peptides from Venomous Marine Animals Based on Immunomodulating, Antimicrobial, and Anticancer Properties

Complex pathological diseases, such as cancer, infection, and Alzheimer's, need to be targeted by multipronged curative. Various omics technologies, with a high rate of data generation, demand artificial intelligence to translate these data into druggable targets. In this study, 82 marine venomous animal species were retrieved, and 3505 cryptic cell-penetrating peptides (CPPs) were identified in their toxins. A total of 279 safe peptides were further analyzed for antimicrobial, anticancer, and immunomodulatory characteristics. Protease-resistant CPPs with endosomal-escape ability in Hydrophis hardwickii, nuclear-localizing peptides in Scorpaena plumieri, and mitochondrial-targeting peptides from Synanceia horrida were suitable for compartmental drug delivery. A broad-spectrum S. horrida-derived antimicrobial peptide with a high binding-affinity to bacterial membranes was an antigen-presenting cell (APC) stimulator that primes cytokine release and naïve T-cell maturation simultaneously. While antibiofilm and wound-healing peptides were detected in Synanceia verrucosa, APC epitopes as universal adjuvants for antiviral vaccination were in Pterois volitans and Conus monile. Conus pennaceus-derived anticancer peptides showed antiangiogenic and IL-2-inducing properties with moderate BBB-permeation and were defined to be a tumor-homing peptide (THP) with the ability to inhibit programmed death ligand-1 (PDL-1). Isoforms of RGD-containing peptides with innate antiangiogenic characteristics were in Conus tessulatus for tumor targeting. Inhibitors of neuropilin-1 in C. pennaceus are proposed for imaging probes or therapeutic delivery. A Conus betulinus cryptic peptide, with BBB-permeation, mitochondrial-targeting, and antioxidant capacity, was a stimulator of anti-inflammatory cytokines and non-inducer of proinflammation proposed for Alzheimer's. Conclusively, we have considered the dynamic interaction of cells, their microenvironment, and proportional-orchestrating-host- immune pathways by multi-target-directed CPPs resembling single-molecule polypharmacology. This strategy might fill the therapeutic gap in complex resistant disorders and increase the candidates' clinical-translation chance.

Threatened, host-specific affiliates of a red-listed host: Three new species of Acanthobothrium van Beneden, 1849 (Cestoda: Onchoproteocephalidea) from the endangered white skate, Rostroraja alba (Lacépède)

The white skate, Rostroraja alba (Lacépède), is listed as an endangered species, the second-highest category before being declared extinct in the wild, in the International Union for Conservation of Nature's (IUCN) Red List of Threatened Species. This species is heavily affected by anthropogenic impacts such as capture induced stress by overfishing and by-catch, habitat degradation and pollution that caused a drastic decline in populations in recent years. As part of a larger study on elasmobranch affiliates in southern Africa, two specimens of R. alba were screened. Three species of the tapeworm genus Acanthobothrium van Beneden, 1849 (Cestoda: Onchoproteocephalidea) were discovered. Application of Ghoshroy and Caira's classification system facilitated the differentiation of congeners through a combination of specific morphological characteristics. As a consequence, three species new to science are described herein, namely Acanthobothrium umbungus n. sp., Acanthobothrium usengozinius n. sp., and Acanthobothrium ulondolozus n. sp. In light of these new discoveries from an endangered host, it is apparent to address the conservation status of its affiliate species, that co-evolved with their elasmobranch hosts for millions of years, thereby creating unique and intimate host-parasite interrelationships. Currently, altering environmental conditions caused by anthropogenic pressures have direct impacts on this host-parasite system with increasing risks of extinction. As merely 9% of elasmobranchs in South African waters have been examined for endohelminths and other affiliate taxa, extensive studies on these organisms and their hosts implementing multisource approaches are needed. This will provide a better understanding on the intimate nature of host-parasite systems that may lead to new prospects in conservation science and the preservation of threatened host species, such as R. alba, together with their unique fauna of affiliate species.

•

Three new species of Acanthobothrium were discovered in the endangered white skate, Rostroraja alba, off the coast of South Africa.

•

The three species described (A. umbungus n. sp., A. usengozinius n. sp., and A. ulondolozus n. sp.) display merely a single cestode genus among the hidden diversity of species from elasmobranchs.

•

The current increase in threatened free-living host species results in an even greater loss in affiliate species that remain unknown and scientifically underexplored.

•

Assessing the status and incorporating affiliate species (i.e. cestodes) into novel conservation schemes may contribute to the conservation of threatened host species and marine populations worldwide, which, in turn, will protect affiliate species as vital “key players” for host species and entire ecosystems.

A revision of the Rhoptrobothriidae (Cestoda: Tetraphyllidea)

The Rhoptrobothriidae are one of the more enigmatic families of cestodes of elasmobranchs. Opinions on the taxonomic status of the familys three original genera (i.e., Myzophyllobothrium, Rhoptrobothrium, and Myzocephalus) have varied over the 115 years since they were erected. Some authors have considered all three valid, others have considered Rhoptrobothrium to be a synonym of Myzopyllobothrium or a genus inquirendum, yet others have considered Myzocephalus to be a synonym of the phyllobothriid genus Thysanocephalum. All three genera were established for specimens collected from eagle rays off Sri Lanka. The erection of Mixophyllobothrium for two specimens from a cowtail stingray off India three decades ago added additional confusion to the situation, with some authors considering it valid and others a synonym of Myzocephalus. These disagreements stem largely from differences in interpretation of the complex morphology of the scolex of members of these genera. Furthermore, with the exception of Rhoptrobothrium comprising four species, each genus is monotypic. All but Rhoptrobothrium has not been considered in detail for nearly a century, largely because of a lack of available material. The taxonomic status of these genera is assessed here based on light and scanning electron microscopy, and molecular data generated from new material collected from eagle rays off Indonesian and Malaysian Borneo, Japan, Sri Lanka, and Viet Nam. Morphological work indicates that the genera differ largely only in the degree of folding of the four remi that extend from the cephalic peduncle. A molecular phylogeny based on sequence data for the D1D3 region of the 28S rRNA gene, which include new data for eight specimens of four species, indicates that Myzophyllobothrium, Myzocephalus, and Rhoptrobothrium are not mutually monophyletic. The latter two genera and Mixophyllobothrium are considered synonyms of Myzophyllobothrium and five species are transferred to that genus. Myzophyllobothrium okamuri n. comb. is considered a species inquirendum. Myzophyllobothrium nagasawai n. sp. is described from Aetobatus narutobiei off Japan. Myzophyllobothrium narinari n. comb. is re-described based on newly collected cestodes from the type host and locality (i.e., Aetobatus ocellatus off Sri Lanka). Despite consisting of only a single genus, the family status of the group is retained in recognition of the unusual configuration of the scolex, which bears four biloculate bothridia and four remi extending from the cephalic peduncle. The ordinal placement of the family remains uncertain, but affinities with the Phyllobothriidea, rather than Tetraphyllidea are considered.

Four new species of Acanthobothrium van Beneden, 1849 (Cestoda: Onchoproteocephalidea) from the spotted skate, Raja straeleni Poll, off the Western Cape, South Africa

The examination of eight spotted skates, Raja straeleni Poll, resulted in the discovery of four new species of Acanthobothrium van Beneden, 1849, namely A. microhabentes sp. n., A. microtenuis sp. n., A. crassus sp. n., and A. dolichocollum sp. n., located off the Western Cape of South Africa. With a total of over 200 valid species of Acanthobothrium recognised worldwide, the use of an integrative approach becomes imperative in the interest of simplifying interspecific comparisons between congeners. In accordance with this, the four new species were incorporated into the category classification system established by Ghoshroy and Caira in 2001, where they were identified as category 2 species, which, at present, includes 47 recognised species of Acanthobothrium. Nevertheless, each of the four new species exhibits postovarian testes, a most intriguing and highly unusual feature among Acanthobothrium, instantly differentiating them from most congeners. This feature has been reported in 12 congeners, which have previously been considered to be restricted to waters of the Indo-Pacific Ocean. Not only do the four new congeners represent the first species of Acanthobothrium reported from southern Africa, but they also represent the first reported species with postovarian testes from the southern Atlantic Ocean. Regarding the legitimacy of the four new species, only two other category 2 species are reported to exhibit this feature, namely A. popi Fyler, Caira et Jensen, 2009, and A. bobconniorum Fyler et Caira, 2010, to which the four congeners were compared to. Acanthobothrium microhabentes sp. n. is the smallest of the congeners and differs from A. popi and A. bobconniorum by having fewer testes and postovarian testes, a shorter body, fewer proglottids, a shorter scolex, and longer cephalic peduncle. Acanthobothrium microtenuis sp. n. differs from A. popi and A. bobconniorum by having fewer testes and postovarian testes, a shorter scolex, longer cephalic peduncle, and the possession of columnar spinitriches on the anterior region of the terminal proglottid. Acanthobothrium crassus sp.n. differs from A. popi and A. bobconniorum by having fewer postovarian testes, a narrower cirrus-sac, larger vitelline follicles, and a longer cephalic peduncle. Acanthobothrium dolichocollum sp. n. is the longest of the four new species and differs from A. popi and A. bobconniorum by having fewer postovarian testes, more postporal testes, a larger body, more proglottids, larger testes and vitelline follicles, and an exceptionally long cephalic peduncle. Apart from differences in overall size, the four new species differ in a combination of measurements for the scolex, vitelline follicles, muscular pad and cephalic peduncle, and the number of proglottids and testes. The four species were recovered from a previously unexplored host and locality, expanding the host associations and geographical distribution of the genus.

Host relationships and geographic distribution of species of Acanthobothrium Blanchard, 1848 (Onchoproteocephalidea, Onchobothriidae) in elasmobranchs: a metadata analysis

Species of Acanthobothrium have been documented as parasites of the spiral intestine of elasmobranchs. Results of a metadata analysis indicate that 114 species of elasmobranchs have been reported as hosts of 200 species of Acanthobothrium. The metadata analysis revealed that 3.7% of species of sharks and 14.9% of species of rays that have been reported as hosts to date; some species are parasitized by more than one species of Acanthobothrium. This work provides a Category designation, as proposed by Ghoshroy and Caira (2001), for each species of Acanthobothrium. These Category designations are a tool to facilitate comparisons among members of Acanthobothrium for descriptions of new species in the future.

A new species of Alexandercestus Ruhnke and Workman, 2013 (Cestoda: Phyllobothriidea) from the sicklefin lemon shark, Negaprion acutidens (Elasmobranchii: Carcharhinidae), in the Gulf of Oman

A new species, Alexandercestus masoumehae n. sp., is described from the sicklefin lemon shark, Negaprion acutidens (Rüppell), from the Iranian coast of the Gulf of Oman. The new species is the third in this genus, all parasitizing species of Negaprion Whitley. Based on morphological characters and scanning electron microscopy the new species is different from its congeners of in a combination of characters including total length, terminal proglottid length, cirrus sac length, and genital pore position. Compared to Alexandercestus gibsoni Ruhnke & Workman, 2013 and A. manteri Ruhnke & Workman, 2013 the specimens of the new species are smaller (7.08-8.5 mm), with a smaller terminal proglottid length to width ratio (1:0.7-1.3 vs. 1.4-3.2:1 and 1.2-3.1:1, respectively), and have a more anterior genital pore (70-73% of proglottid length vs. 42-66% and 41-65%, respectively). In addition, A. masoumehae possesses less foliose bothridia compared with A. gibsoni, and more densely packed vitelline follicles in comparison with A. manteri. The SEM examination of the scolex in the new species reveals a specific pattern of microtriches adding new details in our understanding of the surface morphology of members of Alexandercestus. Finally, the new species increases the total number of described tapeworm species from N. acutidens to five and the described tapeworms in the Persian Gulf and Gulf of Oman region to 65.

Two new species of Acanthobothrium Blanchard, 1848 (Onchobothriidae) in Narcineentemedor Jordan & Starks, 1895 (Narcinidae) from Acapulco, Guerrero, Mexico

Two species of Acanthobothrium (Onchoproteocephalidea: Onchobothriidae) are described from the spiral intestine of Narcineentemedor Jordan & Starks, 1895, in Bahía de Acapulco, Acapulco, Guerrero, Mexico. Based on the four criteria used for the identification of species of Acanthobothrium, A.soniae sp. nov. is a Category 2 species (less than 15 mm in total length with less than 50 proglottids, less than 80 testes, and with the ovary asymmetrical in shape). Acanthobothriumvidali sp. nov. is a Category 6 species (more than 15 mm in total length with more than 50 proglottids, fewer than 80 testes, and the ovary is asymmetrical). The new species differ from similar species from the Pacific Ocean by total length, the number of proglottids, diameter of the accessory sucker, the length of the cirrus sac, the number of testes per proglottid and the measurements of hooks. With the recognition of A.soniae sp. nov. and A.vidali sp. nov., 42 species of Acanthobothrium have been reported from the Pacific coast of the Americas. This is the first report of species of Acanthobothrium from a member of Narcine from Mexico and it brings the number of species reported from elasmobranchs from the Pacific Coast of Mexico to 13.

Two new species of Rhinebothrium (Cestoda: Rhinebothriidea) from granulated guitarfish Glaucostegusgranulatus in the Gulf of Oman

During a study of the rhinebothriideans of rays in the Gulf of Oman, two new species of Rhinebothrium Linton, 1890, Rhinebothrium kruppi sp. n. and R. persicum sp. n., were identified in Glaucostegus granulatus (Cuvier). Some significant features that distinguish R.kruppi sp. n. from R. persicum sp. n. include: scolex characteristics (hinged with 42–46 loculi vs. fusiform with 68–62 loculi), number of testes (4–5 vs. 20–27), genital pore position (61.1–76.9% of proglottid length vs. 47.2–63.3%), ovarian morphology (lobulated vs. follicular), cirrus-sac expansion (past midline of proglottid vs. limited to poral side of proglottid), vas deferens configuration (spanning posteriorly to near ovarian isthmus vs. to the level of ovarian anterior margins) and details of microthrix morphology. In addition, a combination of the aforementioned characteristics can be used to distinguish these two new species from other valid species of Rhinebothrium. These are the first species of rhinebothriidean cestodes to be described systematically from the Gulf of Oman, Iran. The two new species reported here increase the number of valid species of Rhinebothrium to 43.

Diphyllidean cestodes from the bigeye houndshark Iago omanensis (Norman) (Carcharhiniformes: Triakidae) in the Gulf of Oman, with the description of Coronocestus ehsanentezarii sp. nov. (Echinobothriidae)

A new species of Coronocestus Caira, Marques, Jensen, Kuchta and Ivanov, 2013 is described from Iago omanensis (Norman) from the Gulf of Oman. Coronocestus ehsanentezarii sp. nov. differs from C. musteli (Pintner, 1889) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 in that its ovary is H- rather than U-shape. The new species is easily distinguished from C. diamanti (Ivanov and Lipshitz, 2006) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 by the number of spines per column on the cephalic peduncle (24-36 vs 95-118). It differs from C. hormozganiense (Haseli, Malek, Palm and Ivanov, 2012) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 based on a greater number of spines per column on the cephalic peduncle (24-36 vs 18-21). The new species differs from C. notoguidoi (Ivanov 1997) Caira, Marques, Jensen, Kuchta and Ivanov, 2013 in that of its scolex is craspedote rather than acraspedote. Unlike C. coronatum (Robinson 1959) Caira, Marques, Jensen, Kuchta and Ivanov, 2013, C. ehsanentezarii sp. nov. possesses 29-35 rather than 20 apical hooks in each dorso-ventral group. The new species possesses lateral hooklets with two rows (a and b designations) in each cluster. This character had been presented earlier only for Andocadoncum Abbott and Caira, 2014. Furthermore, a new locality record is presented for C. diamanti from Iago omanensis in the Gulf of Oman. Thus, I. omanensis certainly hosts two diphyllidean species simultaneously in the Gulf of Oman. The generic diagnosis of Coronocestus is also revised to include new data.